Aalenian to Cenomanian Radiolaria of the Bermeja Complex (Puerto Rico) and Pacific origin of radiolarites on the Caribbean Plate

Abstract

The study of the radiolarian ribbon chert is a key in determining the origins of associated Mesozoic oceanic terranes and may help to achieve a general agreement regarding the basic principles on the evolution of the Caribbean Plate. The Bermeja Complex of Puerto Rico, which contains serpentinized peridotite, altered basalt, amphibolite, and chert (Mariquita Chert Formation), is one of these crucial oceanic terranes. The radiolarian biochronology presented in this work is mainly based by correlation on the biozonations of Baumgartner et al. (1995) and O’Dogherty (1994) and indicates an early Middle Jurassic to early Late Cretaceous (late Bajocian–early Callovian to late early Albian–early middle Cenomanian) age. The illustrated assemblages contain about 120 species, of which one is new (Pantanellium karinae), and belonging to about 50 genera. A review of the previous radiolarian published works on the Mariquita Chert Formation and the results of this study suggest that this formation ranges in age from Middle Jurassic to early Late Cretaceous (late Aalenian to early–middle Cenomanian) and also reveal a possible feature of the Bermeja Complex, which is the younging of radiolarian cherts from north to south, evoking a polarity of accretion. On the basis of a currently exhaustive inventory of the radiolarite facies s.s. on the Caribbean Plate, a re-examination of the regional distribution of Middle Jurassic sediments associated with oceanic crust, and a paleoceanographic argumentation on the water currents, we come to the conclusion that the radiolarite and associated Mesozoic oceanic terranes of the Caribbean Plate are of Pacific origin. Eventually, a discussion on the origin of the cherts of the Mariquita Formation illustrated by Middle Jurassic to middle Cretaceous geodynamic models of the Pacific and Caribbean realms bring up the possibility that the rocks of the Bermeja Complex are remnants of two different oceans.

Résumé

L’étude des radiolarites rubanées est capitale pour la détermination de l’origine des terrains océaniques allochtones mésozoïques et peut être utile pour parvenir à un compromis général concernant les principes basiques de l’évolution de la Plaque Caraïbes. Le complexe de Bermeja à Puerto Rico qui est constitué de péridotites serpentinisées, de basaltes altérés, d’amphibolites et de cherts (Formation des Cherts de Mariquita), est l’un de ces terrains océaniques déterminants. La biochronologie des radiolaires présentée dans ce travail est basée par correlation essentiellement sur les biozonations de Baumgartner et al. (1995) et d’O’Dogherty (1994) et indique un âge Jurassique Moyen inférieur à Crétacé Supérieur inférieur (Bajocien supérieur-Callovien inférieur à Albien inférieur supérieur-Cénomanien moyen inférieur). Les assemblages illustrés contiennent environ 120 espèces, parmis lesquelles une est nouvelle (Pantanellium karinae), et appartenant à environ 50 genres différents. Une révision des travaux publiés précédemment sur les radiolaires de la Formation des Cherts de Mariquita, ainsi que les résultats de cette étude suggèrent que cette formation a un âge allant du Jurassique moyen au Crétacé Supérieur inférieur (Aalénien supérieur à Cénomanien moyen inférieur) et révèle aussi une caractéristique éventuelle du Complexe de Bermeja qui est le rajeunissement des radiolarites du nord au sud, évoquant une polarité d’accrétion. Sur la base d’un inventaire actuellement exhaustif du facies radiolaritique rubané s.s. sur la Plaque Caraïbes, d’un nouvel examen de la distribution régionale des sédiments du Jurassique Moyen associés à de la croûte océanique et d’une argumentation paléocéanographique, nous arrivons à la conclusion que les radiolarites et les unités tectoniques océaniques du Mésozoïque associées de la Plaque Caraïbes sont d’origine pacifique. Finalement, une discussion sur l’origine des cherts de la Formation de Mariquita illustrée par des modèles géodynamiques du Jurassique Moyen au Crétacé moyen des régions pacifique et caraïbes, fait poindre la possibilité que les roches du Complexe de Bermeja proviennent de deux océans différents.

1 Introduction

Geodynamic models describing the Mesozoic history of the Caribbean realm (Fig. 1) can be divided into two main categories. The simplest model consists of an in situ origin of the actual Caribbean plate or Inter-American Origin Model (e.g., James 2009). In opposition, a “non-fixist” hypothesis proposes an eastward transport relative to the Americas of oceanic fragments from the Pacific s.l., the Pacific Origin Model (e.g., Pindell and Kennan 2009). In this debate, the study of the paleoceanography of radiolarites is a key in determining the origins of Mesozoic oceanic terranes of the Caribbean plate.

Fig. 1

Circum-Caribbean region map modified from Baumgartner et al. (2008), and Pindell and Kennan (2009) with plate-boundaries and bathymetry, showing important tectonic features

The advances in radiolarian biochronology of the last 20 years has allowed to date radiolarites throughout the world which has greatly enhanced our understanding of ancient remnants of ocean floor found in many orogenic settings on land. The Bermeja Complex in south-western Puerto Rico is one of these enigmatic terrane, where elements of oceanic upper mantle, crust and oceanic sediments—mainly radiolarian ribbon chert—are jumbled together in a heavily tectonized mélange.

In this study, we present new radiolarian biochronological data form 16 samples of the Mariquita Chert Formation collected in the Sierra Bermeja. Our data and a review of the previous radiolarian published works (Mattson and Pessagno 1979; Montgomery et al. 1994b) tend to show an early Middle Jurassic (late Aalenian, ca.172 Ma according to Gradstein et al. 2004) maximum age for the Mariquita Formation and the Bermeja Complex, which a priori would be compatible with a Proto-Caribbean or central Atlantic origin of these sediments.

The previous argument for a Pacific origin of the Bermeja Complex presented by Montgomery et al. (1994b), based on their radiolarian age and their estimation of the oldest Proto-Caribbean oceanic crust, is nowadays seriously questionable, owing to the recent progresses in radiolarian biostratigraphy and new discoveries on the age of the first oceanic crust spreading between the Americas. Furthermore, we reassess the meaning of the radiolarian Parvicingulidae-rich assemblages in the low-latitude Caribbean context as potential indicators of upwelling or land nutrients inputs, instead of indicators of paleolatitudes, as firstly stated by Pessagno and Blome (1986).

Finally, we discuss the emplacement of the cherts of the Bermeja Complex from their supposed Pacific origin to their late Early Cretaceous position based on Middle Jurassic to middle Cretaceous geodynamic models of the Pacific and the Caribbean realms.

2 Geological setting

The Bermeja Complex (Fig. 2) of the Sierra Bermeja in the southwestern part of Puerto Rico was first described by Mattson (1960). It forms a tectonized chaotic mélange, which contains serpentinized peridotite, altered basalt (Cajul Basalt), amphibolite (Las Palmas Amphibolite) and chert (Mariquita Chert). This mélange could clearly be separated from other geological units of the island because of its lithology, tectonic history and age. As noted by Montgomery et al. (1994b), the extensive deformation in the Sierra Bermeja has destroyed most primary textures and bedding. Moreover, stratigraphic relationships between rock types or even between adjacent boulders are difficult to reconstruct in the jumble of floating blocks that comprise the serpentinite mélange. The lack of continuity of stratigraphic contacts and the inclusion of blocks of diverse size, lithology, and age (ranging through 80 Ma) with many adjacent to or floating in serpentinite have suggested to previous workers an ophiolitic mélange (e.g., Mattson 1973; Mattson and Pessagno 1979) forming part of an accretionary complex (Burke 1988).

Fig. 2

Geological map of the Sierra Bermeja Complex, which forms a tectonized chaotic mélange containing serpentinized peridotite, altered basalt (Cajul Basalt), amphibolite (Las Palmas Amphibolite) and chert (Mariquita Chert) (modified from Jolly et al. 1998). Numbers indicate location of radiolarite samples. The topographical informations are based on the Puerto Real, San German, Cabo Rojo, and La Parguera USGS 1:20,000 quadrangles

2.1 The serpentinized peridotite

The serpentinized peridotite is an intensely sheared green, greenish-white, blue-green, or brownish-black rock, in some cases with visible green pyroxene crystals (Mattson 1960). The depleted rare earth patterns of these ultramafic rocks are typical of upper mantle peridotite (Jolly et al. 1998).

2.2 The Cajul Basalt

The Cajul Basalt (Mattson 1960) in the central part of Sierra Bermeja complex and at the type section along Arroyo Cajul exhibits MORB-like Sr, Nd and Pb isotope ratios and depleted normalized REE patterns (Jolly et al. 1998). In the central Sierra Bermeja, the Cajul Basalt is interlayered with the Mariquita Chert suggesting this suite represents the upper part of the transition zone from oceanic basalt to pelagic sediment within the original oceanic crust (Jolly et al. 1998). If this interpretation is correct, the Cajul Basalt could be similar in age to the associated radiolarites.

2.3 The Las Palmas Amphibolite

The Las Palmas Amphibolite (Mattson 1973) has a medium-grade metamorphic paragenesis of green hornblende and calcic plagioclase, sometimes with relics of clinopyroxene, brown hornblende, and plagioclase (Schellekens et al. 1990). Two varieties of amphibolite can be distinguished based on the texture: foliated and non-foliated, there is, however, no difference in mineralogy between the two varieties (Schellekens et al. 1990). In several locations, the presence of chlorite could be an evidence of retrograde metamorphism (Schellekens et al. 1990). The Amphibolite has yielded whole-rock K–Ar ages of hornblende that range from 126 ± 3 and 110 ± 3.3 Ma to 86.3 ± 8.6 and 84.9 ± 8.5 Ma (Mattson 1964, 1973; Tobisch 1968; Cox et al. 1977). These ages are much younger than the ages of associated radiolarian chert and the variations probably reflect multiple periods of metamorphism rather than the actual time of MORB volcanism (Jolly et al. 1998).

2.4 The Mariquita Chert

The Mariquita Chert (Mattson 1973) was named after Cerro Mariquita, the highest peak of the Sierra Bermeja. It is a faulted formation, which overlies the peridotite, volcanic rocks and amphibolite. Lenses of sheared serpentinite mark a somewhat brecciated subhorizontal contact at the base of the chert (Mattson and Pessagno 1979). The chert is a fine-grained greenish-gray, greenish-white, red or dark grey radiolarian ribbon chert rock that generally weathers reddish, and greenish-black chert interlayered with tuffs. Previous radiolarian studies have given ages of chert from the Bermeja Complex that range from Early Jurassic (Montgomery et al. 1994b) and Late Jurassic to Early Cretaceous (Mattson and Pessagno 1979).

3 Radiolarian biochronology

We collected 32 samples in the Sierra Bermeja, of which 16 yielded identifiable radiolarians. In total, about 120 species, of which 1 is new (Pantanellium karinae, see systematic paleontology in Appendix A), belonging to about 50 genera, were present in these samples, ranging in age from the early Middle Jurassic to the early Late Cretaceous (late Bajocian–early Callovian to late early Albian–early middle Cenomanian). Apart from radiolarians, no other biogenic constituents were found in the residues. This part includes a brief lithological description and biochronological ages of each localities, which are sorted alphanumerically. Faunal contents are listed in Tables 1, 2, 3, 4, 5, 6, 7, 8, 9, and could also be found with description of the localities in Appendix B.

Table 1 List of Late Jurassic to Early Cretaceous radiolarian species of samples PR-SB01 and PR-SB02 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 2 List of Middle Jurassic radiolarian species of sample PR-SB05 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 3 List of Middle-Late Jurassic and Early–Late Cretaceous radiolarian species of samples PR-SB07 and PR-SB08 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 4 List of Early Cretaceous radiolarian species of samples PR-SB11 and PR-SB12 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 5 List of Middle to Late Jurassic radiolarian species of samples PR-SB14 and PR-SB17 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 6 List of Middle Jurassic radiolarian species of samples PR-SB21 and PR-SB23 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 7 List of Middle Jurassic radiolarian species of sample PR-SB24 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 8 List of Early to Late Cretaceous radiolarian species of samples PR-SB26, PR-SB27 and PR-SB28 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

Table 9 List of Early Cretaceous radiolarian species of sample PR-SB30 from the Mariquita Chert Formation of the Bermeja Complex with ranges for the species considered important for the biostratigraphy (see Sect. 3 for detailed discussion)

The dominant radiolarian-bearing lithology of the studied samples is chert. The procedure described by Bandini et al. (2008, p. 6) was used for the extraction of siliceous radiolarians. The remaining material and SEM stubs are stored in the collection of the Musée de Géologie de Lausanne, Université de Lausanne, Switzerland (MGL no. 97008–97023).

The supraspecies taxonomy used in this work follows De Wever et al. (2001) and O’Dogherty et al. (2009a, b). The radiolarian biostratigraphy is mainly based on the Middle Jurassic–Early Cretaceous radiolarian zonation of the InterRad Jurassic-Cretaceous Working Group (Baumgartner et al. 1995) and the middle Cretaceous zonation of O’Dogherty (1994). Both zonations have been established using the Unitary Association method (Guex 1991). Moreover, in order to better constrain age ranges, several assemblages have been compared with radiolarian faunas illustrated by previous authors.

3.1 Samples PR-SB01 and PR-SB02

The decimeter bedded radiolarite is a 6 m thick greenish-white chert sequence that weathers dark grey to black (Fig. 3a, b). This radiolarite is embedded in a massive and intensely brecciated greenish-gray siliceous rock that weathers reddish and composes most of the Sierra Bermeja (Fig. 4). Two of 4 processed samples give radiolarian ages.

Fig. 3

a Sketch and b photograph of latest Jurassic–Early Cretaceous radiolarite outcrop showing the position of sample PR-SB01 and PR-SB02

Fig. 4

Photograph of the massive and intensely brecciated red or greenish-gray siliceous rock that weathers reddish and composes most of the Sierra Bermeja

3.1.1 PR-SB01 (Table 1; Plate 1)

The species Emiluvia chica Foreman, Svinitzium depressum (Baumgartner), and Obesacapsula bullata Steiger are present in the Tethys zonation of Baumgartner et al. (1995) and this assemblage corresponds to UAZ 13–18 of latest Tithonian–earliest Berriasian to latest Valanginian–earliest Hauterivian age. This fauna is comparable with the Berriasian assemblages PF28.80 to PF41.75 described by Dumitrica-Jud (1995), Préalpes médianes plastiques, Switzerland). In the same publication, the early Valanginian assemblage PI95.50 from the Umbria-Marche Apenines (Italy) is comparable with our fauna. Our assemblage also bears some resemblance with sample 565 presented by Dumitrica et al. (1997, Maghilah Unit, Oman), which is correlative with the zones E1a and E1b of Jud (1994) of late Berriasian–early Valanginian. A comparable late Berriasian–early Valanginian assemblage from Svinita (Romania) has been observed by Dumitrica (1995, samples Mo17 and Mo22).

3.1.2 PR-SB02 (Table 1; Plate 1)

The occurrence of Pantanellium squinaboli (Tan) also present in the zonation of Baumgartner et al. (1995) indicates a late Kimmeridgian–early Tithonian to late Barremian–early Apian (UAZ 11–22) age without further precision. However, it seems to be restricted to the latest Tithonian to late Barremian–early Aptian interval by stratigraphic superposition with sample PR-SB01 (see above).

3.2 Sample PR-SB05 (Table 2; Plate 2)

In this assemblage 4 species included in the zonation of Baumgartner et al. (1995) were found. The species Williriedellum tetragona (Matsuoka) allows to assign the assemblage to the UAZ 5, latest Bajocian to early Bathonian.

3.3 Samples PR-SB07 and PR-SB08

Both radiolarite samples come from two blocks of chert of about 2 m long and 1 m high.

3.3.1 PR-SB07 (Table 3; Plate 2)

The species Archaeodictyomitra montisserei (Squinabol) is present in the Mid-Cretaceous zonation of O’Dogherty (1994) and corresponds to UA 8 to 20 of early late Aptian to early Turonian age. However, Danelian (2008) have also observed this species in the late Aptian–early Albian sequence of the Sopoti section (southern Albania). This poorly constrained age is also the youngest radiolarian age of the Bermeja Complex, but since this age is mainly based on the occurrence of only one species, which range is not very well constrained, it remains clearly disputable.

3.3.2 PR-SB08 (Table 3; Plate 3)

According to Baumgartner et al. (1995), the presence of Loopus primitivus (Matsuoka & Yao) corresponds to UAZ 7–12 of late Bathonian–early Callovian to early Tithonian–early late Tithonian. Moreover, the presence of genus Cryptamphorella, which according to O’Dogherty et al. (2009a) has a range that extended between the early Tithonian and the late Maastrichtian, restricts this interval from early Tithonian to early late Tithonian.

3.4 Samples PR-SB11 and PR-SB12

We sampled 3 metric greenish-white radiolarite blocks that weather dark grey and crop out on the slope of the hill, of which two yielded identifiable radiolarians. These blocks are embedded in a massive and brecciated greenish-grey siliceous rock that weathers reddish.

3.4.1 PR-SB11 (Table 4; Plate 4)

The occurrence of Pantanellium squinaboli (Tan) also present in the zonation of Baumgartner et al. (1995) indicates a late Kimmeridgian–early Tithonian to late Barremian–early Aptian (UAZ 11–22) age without further precision. This fauna is comparable with the late Tithonian–Berriasian assemblage 657 described by Dumitrica et al. (1997, Maghilah Unit, Oman). Moreover, the absence of Ristola altissima altissima (Rüst) and the presence of Archaeodictyomitra immenhauseri Dumitrica in our fauna both suggest a Berriasian age for sample PR-SB11.

3.4.2 PR-SB12 (Table 4; Plate 4)

Despite the low diversity of this assemblage, a Berriasian age can be stated based on the presence of Archaeodictyomitra immenhauseri Dumitrica, which has not been cited neither from earlier nor later than Berriasian. Moreover, this age is consistent with the age of sample PR-SB11 (see above), which was collected near PR-SB12.

3.5 Samples PR-SB14 and PR-SB17

Four samples were collected from a very tectonized metric greenish-brown radiolarite block, which lies in an area adjacent to basalts. The location of this outcrop seems to correspond to this of the Early Jurassic sample PR92.1B from Montgomery et al. (1994b). Two out of 4 samples from this block yielded relatively well-preserved radiolarians.

3.5.1 PR-SB14 (Table 5; Plate 4)

Both species Eucyrtidiellum unumaense s.l. (Yao) and E. unumaense pustulatum Baumgartner are present in the zonation proposed by Baumgartner et al. (1995) and give a latest Bajocian–early Bathonian to middle Callovian–early Oxfordian age (UAZ 5–8).

3.5.2 PR-SB17 (Table 5; Plate 5)

According to the zonation of Baumgartner et al. (1995), the occurrence of Praewilliriedellum convexum (Yao), Eucyrtidiellum ptyctum (Riedel & Sanfilippo), Williriedellum carpathicum Dumitrica, Emiluvia ordinaria Ozvoldova, and Deviatus diamphidius hipposidericus (Foreman) corresponds to UAZ 9–11 of middle–late Oxfordian to early Tithonian. Moreover, the presence of genus Vallupus, which according to O’Dogherty et al. (2009a) has a range that extended between the early Kimmeridgian and early Berriasian, restricts this interval from early Kimmeridgian to early Tithonian. Two characteristic species of Middle Jurassic are also present in the studied assemblage: Striatojaponocapsa plicarum (Yao) and Williriedellum formosum (Chiari, Marcucci & Prela) that may most probably be reworked into the younger material.

3.6 Samples PR-SB21 and PR-SB23

The radiolarite sequence is 1 m high and 3 m wide and appears as centimeter bedded greenish-orange radiolarian chert alternating with millimeter shale beds (Fig. 5).

Fig. 5

Photograph of the Middle Jurassic 1 m high and 3 m wide radiolarite sequence appearing as centimeter bedded greenish-orange radiolarian chert alternating with millimeter shale beds (sample PR-SB21 and PR-SB23)

3.6.1 PR-SB21 (Table 6; Plate 6)

According to Baumgartner et al. (1995), the presence of Ristola turpicula Pessagno & Whalen corresponds to UAZ 5–6 of latest Bajocian–early Bathonian to middle Bathonian age.

3.6.2 PR-SB23 (Table 6; Plate 6)

This assemblage contain morphotypes present in the Tethys zonation of Baumgartner et al. (1995) and corresponds to UAZ 5–7 of latest Bajocian–early Bathonian to late Bathonian–early Callovian age.

3.7 Sample PR-SB24 (Table 7; Plate 6)

The radiolarite crops out in a 2 m sequence of centimeter bedded red radiolarian cherts alternating with millimeter shale beds (Fig. 6).

Fig. 6

Photograph of the Middle Jurassic 2 m sequence of centimeter bedded red radiolarian cherts alternating with millimeter shale beds (sample PR-SB24)

In this assemblage five species included in the zonation of Baumgartner et al. (1995) were found. The species Triactoma parablakei Yang & Wang allow to assign the assemblage to the UAZ 4–7. The corresponding time interval ranges from late Bajocian to late Bathonian–early Callovian.

3.8 Samples PR-SB26, PR-SB27 and PR-SB28

The radiolarite crops out in 2–15 cm boudinaged layers of dark green to black radiolarian cherts rich in organic matter that weather orange and interlayered with volcanic tuffs and may correspond to outcrop 7919-5B from Mattson and Pessagno (1979). The three samples PR-SB26, PR-SB27 and PR-SB28 come from the same section, respectively, 0, 40 and 240 cm from its base (Fig. 7).

Fig. 7

Photograph of the Early Cretaceous radiolarite, which crops out in 2–15 cm boudinaged layers of dark green to black radiolarian cherts rich in organic matter that weather orange (samples PR-SB26, PR-SB27, and PR-SB28)

3.8.1 PR-SB26 (Table 8; Plate 7)

The rare species Pseudoeucyrtis corpulentus Dumitrica has been recorded from the early–early late Barremian and late Aptian from Masirah Ophiolite in the Sultanate of Oman (Dumitrica et al. 1997). The species Pseudoeucyrtis hanni (Tan) is present in the zonation of O’Dogherty (1994) and corresponds to UA 1 to 9 of latest Barremian to latest Aptian age. The age of this assemblage could be constrained to latest Barremian to latest Aptian.

3.8.2 PR-SB27 (Table 8; Plate 8)

The species Archaeodictyomitra montisserei (Squinabol), Quadrigastrum lapideum O’Dogherty and Thanarla brouweri (Tan) are present in the middle Cretaceous zonation proposed by O’Dogherty (1994) The co-occurrence of Archaeodictyomitra montisserei (Squinabol) and Thanarla brouweri (Tan) allow to assign this assemblage to the late Aptian to early middle Albian (UA 8 to 11 of O’Dogherty 1994). Moreover, the genus Pantanellium Pessagno ranges from middle Carnian to late Aptian (O’Dogherty et al. 2009a, b), and indicates a late Aptian age for this assemblage. The first appearance of the species Quadrigastrum lapideum O’Dogherty, which is also present in the zonation proposed by O’Dogherty (1994), could therefore be at least in the latest Aptian (probably UA 9 instead of UA 12).

3.8.3 PR-SB28 (Table 8; Plate 9)

The species Archaeodictyomitra gracilis (Squinabol) gr. is present in the middle Cretaceous zonation proposed by O’Dogherty (1994, =Dictyomitra gracilis) and ranges from UA 10 (late early Albian) to 17 (middle Cenomanian).

3.9 PR-SB30 (Table 9; Plate 9)

The radiolarite crops out in 2–15 cm boudinaged layers of dark green to black radiolarian cherts that weather orange and interlayered with volcanic tuffs.

In this assemblage four species included in the zonation of Baumgartner et al. (1995) were found. The species Syringocapsa (?) limatum Foreman is present in UAZ 21 (early Barremian) but is absent in UAZ 22 (late Barremian–early Aptian). Pseudodictyomitra leptoconica (Foreman) is the only characteristic species in UAZ 22 but is absent in UAZ 21. The illustrated assemblage could correspond to an interval between UAZ 21 and 22 of middle Barremian age.

4 Age of the Bermeja Complex

The age of the Bermeja Complex is based on both radiolarian biostratigraphy and radiometric determinations. The oldest K–Ar age is of 126 ± 3 Ma on hornblende in the amphibolites of the northeastern Sierra Bermeja (Cox et al. 1977). This age could be interpreted as a metamorphic age (Schellekens et al. 1990). Another K–Ar age of 110 ± 3.3 Ma was determined by Mattson (1964). This age and two others K–Ar ages for the amphibolites of 86.3 ± 8.6 Ma and 84.9 ± 8.5 Ma (Tobisch 1968) were all considered to be reset, possibly by intrusions (Schellekens et al. 1990). Schellekens et al. (1990) interpreted the 112 ± 15 Ma K–Ar age of Cox et al. (1977) as a magmatic age.

The two previous radiolarian studies have given ages that range from Early Jurassic (Montgomery et al. 1994b) and Late Jurassic to Early Cretaceous (Mattson and Pessagno 1979) for the Mariquita Chert Formation of the Bermeja Complex. However, the Early Jurassic interpretation by Montgomery et al. (1994b) of their faunal assemblage is nowadays somewhat misleading owing to the fact that the bibliography on radiolarian biostratigraphy has been enriched since 1994. Indeed, the assemblage illustrated by Montgomery et al. (1994b) as diagnostic of an Early Jurassic age is now known to range into the Middle Jurassic as discussed herein. Moreover, our revision of several samples from the same locality indicates a late Bajocian–early Callovian maximum age.

The figured taxa for the Puertorican oldest sample PR92.1B described as late Pliensbachian in age by Montgomery et al. (1994b) include Parasaturnalis (?) sp. (Montgomery et al. 1994b, Fig. 5, no. 1 and 2), which the authors considered comparable with the Early Jurassic form Parasaturnalis (?) n. sp. from the Maude Formation of the Queen Charlotte Islands, British Columbia (Montgomery et al. 1994b, Fig. 5, no. 3). In our opinion, Parasaturnalis (?) n. sp. differs clearly from Parasaturnalis (?) sp. by having all the secondary spines aligned with primary spines rather than in staggered arrangement. We interpret the Figured specimens named Parasaturnalis (?) sp. by Montgomery et al. (1994b) as being Parasaturnalis diplocyclis (Yao), which is present in the zonation proposed by Baumgartner et al. (1995) and give an early–middle Aalenian to early–middle Bajocian age (UAZ 1–3). After Carter et al. (2010) the first appearance datum of Parasaturnalis diplocyclis (Yao) occurs in the early Pliensbachian. This assemblage illustrated by Montgomery et al. (1994b) also contains the species Laxtorum (?) jurassicum (Montgomery et al. 1994b, Fig. 5, no. 4), which presence corresponds to UAZ 2–3 of late Aalenian to early–middle Bajocian according to Baumgartner et al. (1995). The other figured species comprise Acanthocircus hexagonus, which is present in Baumgartner et al. (1995) zonation as Hexasaturnalis hexagonus (Yao) and correspond to UAZ 1–4 of early–middle Aalenian to late Bajocian. After Carter et al. (2010) the first appearance datum of Hexasaturnalis hexagonus (Yao) occurs in the middle–late Toarcian. This radiolarian assemblage also comprises the following genera Ares, Bernoullius, Lupherium and Pantanellium, which all have intervals of existence that include the Middle Jurassic (O’Dogherty et al. 2009a, b).

We conclude that the radiolarian age of sample PR92.1B described by Montgomery et al. (1994b) is restricted to Middle Jurassic (and not Early Jurassic) and ranges in age from late Aalenian to early–middle Bajocian by the presence of Laxtorum (?) jurassicum Isozaki & Matsuda. Moreover, the locality and description of the outcrop where Samples PR-SB14 and PR-SB17 of Middle Jurassic maximum age were collected, both correspond very closely to the locality and description of the outcrop PR92.1B of Montgomery et al. (1994b) (Fig. 8). However, this assemblage still establishes the Bermeja Complex as the oldest known island terrane on the Caribbean plate.

Fig. 8

Radiolarite outcrop map of Sierra Bermeja Complex showing the younging of radiolarian cherts from north to south, evoking a polarity of accretion. Outcrops 7919-5B, 7919-21, and PE-5 were sampled by Mattson and Pessagno (1979). Outcrops PR89.4, PR91.7, and PR92.1B were sampled by Montgomery et al. (1994a)

To summarize, the two previous radiolarian published works (Mattson and Pessagno 1979; Montgomery et al. 1994b) and our study on the blocks of Mariquita Chert Formation show that the Bermeja Complex ranges in age from Middle Jurassic to early Late Cretaceous (late Aalenian to early middle Cenomanian, Table 10). These studies also reveal a possible feature, which is the younging of radiolarian cherts from north to south (Fig. 8), suggesting an accretionary polarity. Five of the sixteen studied samples (Table 10) have biostratigraphic ranges comprising the Middle Jurassic, faunas of this age have never been illustrated by previous studies of the Bermeja Complex. This brings new and important information on the origin of the remnants of oceanic crust of the Bermeja Complex, more generally on the paleogeography of the Caribbean plate.

Table 10 Synopsis of the biochronologic ages determined from outcrops of the Mariquita Chert Formation of the Bermeja Complex

At first view, Montgomery et al. (1994b) presented a convincing argument for a Pacific origin of the radiolarites from the Bermeja Complex. They supposed the first Proto-Caribbean oceanic crust to have formed in Callovian times, and therefore, their Pliensbachian radiolarites (see Discussion above) could not have originated from the oceanic seaway between the Americas. At present, the oldest Proto-Caribbean crust is thought to have formed around 190 Ma (latest Sinemurian, according to Gradstein et al. 2004) based on ⁴⁰Ar/³⁹Ar ages on hornblende in the pegmatite and amphibole dikes of the oceanic Tinaquillo Complex from Venezuela (Sisson et al. 2005). Therefore, the age of the radiolarian faunas, either Pliensbachian or Aalenian is no longer an evidence for a Pacific origin of the radiolarite (Fig. 9).

Fig. 9

Comparison of the age of the Mariquita Formation and the ages of the oldest known post-rift sediments of the Proto-Caribbean and the Central Atlantic. The age of the radiolarian faunas is no longer an evidence for a Pacific origin of the Bermeja Complex. Whereas, the presence of the radiolarite facies in Mesozoic oceanic terranes of the Caribbean plate is a good indication for a Pacific origin, because this facies has never been observed in neither the sediments of the Proto-Caribbean and the Central Atlantic. Initiation of the sea-floor spreading for the Proto-Caribbean after Sisson et al. (Tinaquillo Complex, 2005) and for the central Atlantic (Fuerteventura, Canary Islands) after Huon et al. (1993) and Steiner et al. (1998). Geological time scale after Gradstein et al. (2004)

Our argumentation for a Pacific origin of the oceanic remnants on the Caribbean plate (see list above) is based on the presence of the radiolarite facies s.s. in these units. Indeed, Middle Triassic to Early Cretaceous radiolarian ribbon cherts are widespread in Tethyan and circumpacific orogenic belts, but they are unknown from the Atlantic, the Gulf of Mexico, and the Venezuelan Mesozoic passive margin. Moreover, no radiolarites have been drilled in the Atlantic Ocean, Gulf of Mexico, and Caribbean sea.

5 Origins of radiolarites on the Caribbean plate

Paleogeographic models attempting to describe the Jurassic and Cretaceous history of the Caribbean tectonic plate can be divided into two main categories, an autochthonous (e.g., James 2009) and an allochthonous (e.g., Pindell and Kennan 2009) model. On the Caribbean plate, the radiolarites are often associated with remnants of Mesozoic oceanic crust and thus, is of great importance for paleogeographic reconstructions, like already suggested by previous authors (e.g., Cordey and Cornée 2009). In this debate, we think that the study of this facies is a key in seeking the origins of Mesozoic oceanic terranes of the Caribbean plate.

In this chapter, we define what we call radiolarites s.s. and give an actual exhaustive inventory of localities and ages of this facies on the Caribbean plate. Then we discuss the Pacific origin of this facies based on paleoceanographic parameters that have influenced their deposition during the Mesozoic. This two-stage discussion focuses firstly on the paleoceanography of the radiolarite facies s.s. and its depositional settings, and secondly on the paleobiogeography of the radiolarian faunas to explain the presence of Northern (or Southern) Tethyan Province assemblages (22° to 30°N or S sensu Pessagno et al. 1987) in a low-latitude context.

5.1 Definition

Radiolarite s.l. is typically described as hard fine-grained chert of biogenic origin rich in radiolarian skeletons. The term radiolarite s.s. is herein restricted to the facies of centimeter ribbon-bedded radiolarian chert usually alternating with millimeter shale beds (Jenkyns and Winterer 1982, De Wever et al. 1994) and does not comprise other radiolarian-rich rocks (e.g. black shale and siliceous volcaniclastic limestone). Usually radiolarites are red—but also include a wide range of colors depending on inclusions and oxydes—and thus, could erroneously be compared to deep oceanic red clays.

5.2 Localities and ages

On the Caribbean plate, Late Triassic to early Late Cretaceous oceanic fragments associated with radiolarites s.s. (according to the definition above) are recognized along the western (Central America) and northeastern (Antilles) margin of the plate (Fig. 10). These are elements of the Nicoya Complex (Bajocian to late Coniacian–Santonian, Gursky 1994; Baumgartner and Denyer 2006) and the Santa Rosa Accretionary Complex of Costa Rica (Pliensbachian–Toarcian to Cenomanian, De Wever et al. 1985; Denyer and Baumgartner 2006), the El Castillo and Siuna Serpentinite Mélanges of Nicaragua (respectively, late Rhaetian and Bajocian–middle Bathonian to late Kimmeridgian–early Tithonian, Baumgartner et al. 2008), El Tambor Group Ophiolites of Guatemala (Oxfordian–Kimmeridgian, Chiari et al. 2006), the Duarte Complex of Hispaniola (Oxfordian–Tithonian, Montgomery et al. 1994a), the Bermeja Complex of Puerto Rico (late Aalenian to middle Cenomanian, Mattson and Pessagno 1979; Montgomery et al. 1994b; and this study) and the La Désirade Basement Complex of Guadeloupe, in the Lesser Antilles (Kimmeridgian–early late Tithonian, Montgomery et al. 1992; Mattinson et al. 2008; Cordey and Cornée 2009; Montgomery and Kerr 2009).

Fig. 10

Circum-Caribbean region map modified from Baumgartner et al. (2008), and Pindell and Kennan (2009) with plate-boundaries and bathymetry, showing important tectonic features and radiolarite localities discussed in the text. From west to east, ETGO El Tambor Group Ophiolites, SRAC Santa Rosa Accretionary Complex, NC Nicoya Complex, SSM Siuna Serpentinite Mélange, ECM El Castillo Mélange, DC Duarte Complex, BC Bermeja Complex, and LDBC La Désirade Basement Complex of Guadeloupe

5.3 Paleoceanography of radiolarites

Our hypothesis presented herein for the radiolarian cherts deposition is an attempt to explain the absence of radiolarites s.s. in the Central Atlantic and Proto-Caribbean basins. It is mainly based on actualistic paradigms, which could be disputable (see Racki and Cordey 2000).

In the circum-Pacific regions, radiolarites s.s. are commonly found in Devonian to Cretaceous ophiolitic or suture belts (Racki and Cordey 2000). The Tethyan and Pacific realms were characterized by a number of internal subduction zones (Johnston and Borel 2007). These relatively large oceanic basins covering wide paleolatitude and paleolongitude ranges were most of the time fully connected with each other (Fig. 11). This oceanic connexion allowed the dispersal of pelagic faunas and the presence of sub-surface and deep-water circulation belts partly directed by the landmasses they encountered. The existence of a deep cold water circulation during this period may be hypothesized based on a relatively steep pole-to-equator temperature gradient, warm or warmer than today low-latitude regions, and glacial or cold polar conditions (Price 1999). The presence of deep cold water circulations, winds, and a combination of topographic features may have induced upwelling currents, and other phenomenons (e.g., mesoscale eddies, circulation of the equatorial surface ocean, river inputs) resulting in the occurrence of high plankton productivity zones, which have produced paleoceanographic conditions for the sedimentation of the radiolarite facies s.s. (Baumgartner 1987). This change to siliceous sedimentation occurred for instance during the continental breakup and oceanic spreading of the Alpine Tethys between the continents of Laurasia and Gondwana, which caused a deep-water connection with the Central Tethys and extended this water circulation system to the west at least since the Bathonian (Bill et al. 2001), forming a Gulf of California-like restricted sea connected to the world ocean.

Fig. 11

Paleogeographic map for 165 Ma (Bathonian, according to Gradstein et al. 2004) showing the oceanic basins discussed in the text, with continental crust in grey and oceanic crust in white. The Neotethys and the Pacific oceans were covering wide paleolatitude and paleolongitude ranges and were most of the time fully connected with each other. Whereas, the Central Atlantic and the Proto-Caribbean oceanic basins formed a low-latitude restricted Mediterranean-like sea with indirect surface-water connections with the world ocean

During the Middle Jurassic, two natural barriers bound the Pacific-Tethyan deep-water circulation system: to the west by the thin seaway between Iberia and Gondwana, and to the east by the western border of the American plates. The Central Atlantic and Proto-Caribbean oceanic basins formed a low-latitude restricted Mediterranean-like sea not connected to this deep-water circulation system. However, these two basins shared indirect surface-water connections with the world ocean (Iturralde-Vinent 2006). For the radiolarians, this is attested for example, by the faunal affinities of the Bathonian radiolarian assemblages from the Central Atlantic and the Alpine Tethys (Bill et al. 2001).

Lithologically, the Central Atlantic and Proto-Caribbean oceanic basins were rich in detritals along their margins, but of low surface productivity, resulting in clay-rich (below the CCD) and/or calcareous pelagic facies throughout (Baumgartner 1987). In the Central Atlantic and Caribbean area, Middle Jurassic sediments associated with oceanic crust remnants have been reported from several localities. These series do not contain any radiolarite s.s. (Fig. 9):

• 1. In the southern Caribbean region, the Siquisique Ophiolite Complex located in west-central Venezuela is interpreted as a remnant of an early Proto-Caribbean rift (Bartok et al. 1985). It exhibits Bajocian to possibly early Bathonian ammonite-bearing shale enveloped by mid oceanic ridge pillow basalts (MORB, Bartok et al. 1985).

• 2. In western Cuba, the Guaniguanico Terrane shows a passive margin sedimentary sequence of the Proto-Caribbean ocean (Pszczolkowski 1999; Pszczolkowski and Myczynski 2003). Belonging to this terrane, normal oceanic crust (N-MORB) has been reported from the Oxfordian–early Kimmeridgian El Sábalo Formation (Pszczolkowski 1999). The oldest sediment of this sequence is a black shale of the Early(?)-Middle to Late Jurassic San Cayetano Formation (Pszczolkowski 1978, 1999).

• 3. The oldest known sediments resting on basalts from the western-central Atlantic ocean, which are middle Bathonian in age, are found at the Blake Bahama Basin (Baumgartner and Matsuoka 1995). This sedimentary sequence includes claystone/shale, calcareous claystone, carbonate turbidites, and pelagic limestone with secondary silicifications.

• 4. In the eastern-central Atlantic, the oldest sediments lying on normal-mid oceanic ridge basalt (N-MORB) are found in the Mesozoic sequence of Fuerteventura (Canary Islands, Favre et al. 1991; Favre and Stampfli 1992). The age of the initiation of the uplift of the rift shoulders is based on the radiometric age of 184 ± 4 Ma (Huon et al. 1993, Pliensbachian according to the time scale of Gradstein et al. 2004). The overlaying sedimentary sequence, of which the oldest sediments are of at least late Toarcian–early Aalenian age (late Early Jurassic–early Middle Jurassic), includes dark, green and red claystone, and black shale (Steiner et al. 1998). According to the Middle Jurassic distribution of sediments associated with oceanic crust and associated paleoceanographic conditions, we believe the radiolarite facies s.s. was common in the Pacific-Tethys world ocean, but was absent in the restricted Central Atlantic-Proto-Caribbean sea. This is consistent with a Pacific origin of the radiolarite of the Caribbean plate and thus, of the associated Mesozoic oceanic terranes (see also Baumgartner et al. 2008).

5.4 Paleobiogeography of radiolarians

Montgomery et al. (1994a) presented an argument based on faunal observations for a Pacific origin of the radiolarites from the Bermeja Complex. They interpreted the radiolarian faunas associated with some of the Caribbean radiolarites (Bermeja Complex of Puerto Rico, Duarte Complex of Hispaniola and La Désirade Basement Complex of Guadeloupe) like having Pacific faunal affinities based on the paleolatitudinal model for the radiolarian assemblages developed by Pessagno and Blome (1986) and modified later on by Pessagno et al. (1986, 1987, 1993). This model is based on Gordon’s hypothesis (1974) that one of the most important factors of biogeographic distribution of the marine plankton is the decline of the mean ocean water temperature from the equator to the poles. Provinces and realms of this model were defined using multiple criteria (ammonites, Buchia spp., calpionellids and other well-studied fossil groups) and is mainly based on the relative abundance of Parvicingula and Praeparvicingula radiolarian genera versus Pantanelliidae radiolarian family (Pessagno et al. 1987). With the help of this model, it should be possible to determine the relative paleolatitudinal position of any given terrane from the study of the radiolarian assemblage. The inductive reasoning resulting from this model applied to the above-cited Caribbean terranes stated that no high latitudes fauna of Late Jurassic age would have been endemic in a low paleolatitude constrained Proto-Caribbean ocean between North and South America (Fig. 12). Therefore, all these radiolarites were originated from either the eastern Pacific or the “Mediterranean” region. The Pacific faunal affinities sensu Montgomery et al. (1994a) based on this paleolatitudinal argument was included in the literature in many occasions in order to consolidate certain paleogeographic hypotheses (e.g., Hoernle et al. 2002; Bosch et al. 2002; Bortolotti and Principi 2005).

Fig. 12

Paleogeographic map for 165 Ma (Bathonian, according to Gradstein et al. 2004) showing the oceanic basins discussed in the text, with continental crust in white, the different provinces of the paleolatitudinal model of Pessagno et al. (1993) in grey, and active margins in dark grey. The model of Pessagno et al. (1993) does not take in account the paleogeography and the oceanic currents

Montgomery et al. (1994a) applied this model to the Jurassic radiolarian assemblages from the Bermeja Complex of Puerto Rico. Though, it is difficult to reproduce their results as the paleolatitudinal model presented above is based on planktonic relative abundances and no quantified data or complete faunal list from these assemblages have been made available to the readers. Their conclusions were a Central Tethyan (22°S–22°N) origin for most of the assemblages, with two exceptions, both of Late Jurassic age and from Northern (or Southern) Tethyan Province (22°–30°N or S) origin. We do not bring into question the paleolatitudinal endemism of certain characteristic faunas as presented by several previous authors (e.g., Empson-Morin 1984; Matsuoka 1995; Kiessling 1999), but is it really possible to make the difference among a radiolarian assemblage originating from a Central Tethyan Province (22°S–22°N) and another one originating from a Northern (or Southern) Tethyan Province (22°–30°N or S)?

We believe these faunal changes could not only be a consequence of paleolatitude, but could result more generally from a significant switch of the paleoenvironmental conditions (Boltovskoy et al. 1996). A drop in water temperature, higher nutrients availability, and higher productivity levels, could represent an alternative hypothesis to explain these distinct radiolarian assemblages (e.g., Abelmann and Gowing 1997). Similar substitutions of paleoenvironmental conditions could be encountered near large landmasses as continents (Americas) or volcanic arcs associated with intra-oceanic subduction zones resulting in coastal upwelling (Molina-Cruz et al. 1999) or river inputs (Fig. 13). Moreover, the presence of Late Jurassic tuffaceous cherts reported by Montgomery et al. (1994a) would be consistent with this hypothesis.

Fig. 13

Paleogeographic map for 165 Ma (Bathonian, according to Gradstein et al. 2004) showing the oceanic basins discussed in the text, with continental crust in white and active margins in dark grey. This map represents an attempt to show the distribution of radiolarian assemblages taking in account the paleogeography and potential water currents. In the generally low-latitude context of the Proto-Caribbean and Central Pacific, “high-latitude-faunas” can be associated with intraoceanic subduction zones or active continental margins of the Americas, both acting as upwelling margins or providers of land nutrients inputs

Despite the work started by Pessagno et al. 1986, which underlined how radiolarian assemblages could be a powerful tool to solve complex paleogeographic problems, it seems that faunal compositions are linked to variation of paleoceanographic variables, rather than only paleolatitude. In the generally low-latitude context of the Proto-Caribbean and Central Pacific, we interpret “high-latitude” assemblages as “margin-related”—even though none assemblage of this kind have been illustrated from the Caribbean plate. They can be associated with intraoceanic subduction zones or active continental margins of the Americas, both acting as upwelling margins or providers of land nutrients inputs (Fig. 13).

6 Geodynamic models

Our plate tectonic model for the Middle Jurassic to Early Cretaceous western Pacific and Caribbean region, constrained by dynamic plate boundaries, plate buoyancy factors, oceanic spreading rates, subsidence patterns, stratigraphy and paleobiogeographic data, as well as the major tectonic and magmatic events, is an alternative explanation for the genesis and accretion of Pacific radiolarites (Fig. 14a–c). The reconstructions presented herein are part of a study developed at the Université de Lausanne (Stampfli and Borel 2002, Ferrari et al. 2008; Hochard 2008; Stampfli and Hochard 2009; Flores 2009), which describes the geodynamic history of several regions of the world.

Fig. 14

Paleogeographic map for a 165 Ma (Bathonian, according to Gradstein et al. 2004), b 142 Ma (Berriasian, according to Gradstein et al. 2004), and c 112 Ma (Aptian–Albian, according to Gradstein et al. 2004) showing the main geodynamic units discussed in the text, potential position of the rocks composing the Bermeja Complex of Puerto Rico (BC) and position of the Taino Arc (TAI), the Guaniguanico Terrane of Cuba (GT), the Tinaquillo Complex (TC) and the Siquisique Ophiolite Complex (SOC) of Venezuela, the Blake Bahama Basin (BBB) in the western central Atlantic, and the Mesozoic sequence of Fuerteventura (MSF) in the eastern central Atlantic

6.1 165 Ma (Bathonian)

Several internal subduction zones characterized the Panthalassa (or Pacific) superocean as shown by Johnston and Borel (2007). One of these intra-oceanic subduction zones did develop immediately adjacent to the western margin of North America (Fig. 14a). The herein called Mezcalera ocean subducted northwest beneath the Mackinley ocean and leaded to the formation of the Guerrero-Phoenix island arcs system and the opening of the Guerrero back-arc ocean. The Triassic to Jurassic magmatic belt from British Columbia to Peru testify to a west-facing arc system on the western margin of the American plates (e.g., Pindell et al. 2005). This arc system resulted from the east-dipping subduction of the Mezcalera ocean. The Proto-Caribbean ocean opening, separating the North American plate from the South American plate, is weakly constrained. However, ⁴⁰Ar/³⁹Ar ages of 190 to 154 Ma on hornblende in both the pegmatite and amphibole dikes of the oceanic Tinaquillo Complex from Venezuela (Sisson et al. 2005) attest to the presence of a pre-Pliensbachian active oceanic ridge between the Americas. Whereas, the oldest sea-floor magnetic anomaly in the Central Atlantic is of Toarcian age (175–183 Ma, Steiner et al. 1998).

During the Middle Jurassic, the oldest radiolarites of the Bermeja Complex (sample PR92.1B of Montgomery et al. 1994b, and samples PR-SB05, PR-SB14, PR-SB21, PR-SB23, and PR-SB24 of this study, see Table 10) could have been deposited in the southeastern Mackinley ocean or in the young Guerrero back-arc ocean, close to their spreading ridge, but a Mezcalera origin seems more probable. This oceanic complex comprises a very tectonized Late Jurassic radiolarite (sample PR-SB17), which yielded reworked radiolarian specimens of Middle Jurassic age. Moreover, this Late Jurassic outcrop is surrounded by scattered Middle Jurassic cherts. This could be a convincing indication for a Late Jurassic deposition of this sediment near an accretionary prism enclosing Middle Jurassic accreted material. Furthermore, Montgomery et al. (1994a) reported the presence of Late Jurassic (Kimmeridgian–Tithonian) tuffaceous cherts, which deposition would be consistent with a subduction context. These observations may indicate that these rocks would have undergone a Kimmeridgian–Tithonian accretionary event. This tectonic situation could have been encountered south of the Guerrero-Phoenix arc. In the case of this hypothesis is accepted, most probably all the Middle Jurassic sediments of the Bermeja Complex would have been deposited in the Mezcalera ocean.

6.2 142 Ma (Berriasian)

During the Late Jurassic, the Mesquito Terrane collided with and accreted to the North American plate (Fig. 14b). The old oceanic crust of the Mezcalera ocean continued its north-west-dipping subduction beneath the Guerrero ocean displacing the Guerrero-Phoenix Island arc southward. Rifting of the Gulf of Mexico began during the late Middle Jurassic (Pindell and Kennan 2007) and was synchronous with the opening of the Arpero oceanic basin. This basin was extended to the south with the opening of the Quebrada Grande oceanic basin during the early Early Cretaceous.

The Late Jurassic radiolarian cherts of the Bermeja Complex (samples PR-SB08 and PR-SB17, see also discussion above concerning sample PR-SB17) could have been deposited in the Mezcalera ocean.

6.3 112 Ma (Aptian–Albian)

The Mezcalera ocean was completely consumed in subduction zones during the Early Cretaceous and was replaced by the Guerrero ocean in its former equatorial position dragging the Farallon oceanic plate eastward (Fig. 14c). During the Early Cretaceous, the Farallon plate was subducting beneath the North American plate. Closure of the Arpero oceanic basin and the collision of the Chortis block with the North American plate also occurred during this period.

The Early Cretaceous radiolarites of the Bermeja Complex (samples PR-SB01, PR-SB02, PR-SB11, and PR-SB12, see Table 10) were probably deposited in the Mezcalera ocean out of range from any continental or volcanic arc influence (Fig. 14b). Whereas, the late Early Cretaceous cherts rich in organic matter and interbedded with tuffs (samples PR-SB26, PR-SB27, PR-SB28, and PR-SB30, see Table 10) were probably sedimented in the Guerrero ocean closer to the Taino arc formed by the east-dipping subduction of this ocean beneath the Proto-Caribbean realm (Fig. 14c).

7 Conclusions

Sixteen radiolarian samples directly date the Mariquita Chert Formation, ranging in age from early Middle Jurassic to early Late Cretaceous (late Bajocian–early Callovian to late early Albian–early middle Cenomanian). The radiolarian ages presented in this study, the review of previous radiolarian studies, and published radiometric ages show that the Bermeja Complex ranges in age from Middle Jurassic to early Late Cretaceous (late Aalenian to middle Cenomanian). Moreover, the study of radiolarian ages of the Bermeja Complex reveals a possible feature, which is the younging of the cherts to the south. This could suggest an accretionary mechanism along an active margin. However, this hypothesis still remains debatable, as it needs a more systematic study to be validated.

We think that the deep oceanic water currents, have played a major role in the deposition of radiolarian cherts. During the Jurassic, these currents, driven by density and temperature gradients, could not be normally generated in the low-latitude restricted Proto-Caribbean and Central Atlantic basins. Based on this paleoceanographic argument and on the global distribution of Middle Jurassic sediments associated with oceanic crust, we come to the conclusion that the radiolarite facies s.s. and the associated Mesozoic oceanic terranes of the Caribbean plate, i.e. the Nicoya Complex and the Santa Rosa Accretionary Complex of Costa Rica, the El Castillo and Siuna Serpentinite Mélanges of Nicaragua, the El Tambor Group Ophiolites of Guatemala, the Duarte Complex of Hispaniola, the Bermeja Complex of Puerto Rico, and the La Désirade Basement Complex of Guadeloupe are of Pacific origin. The previous argument for a Pacific origin of the Bermeja Complex presented by Montgomery et al. (1994b), based on their radiolarian age and their estimation of the oldest Proto-Caribbean oceanic crust, is nowadays seriously questionable, owing to the recent progresses in radiolarian biostratigraphy and new discoveries on the age of the first oceanic crust spreading between the Americas.

The observed changes in radiolarian faunal composition suggest a variation of the paleoceanographic conditions, rather than an indication on the paleolatitude of deposition, as firstly stated by Pessagno and Blome (1986). In the low-latitudinal Caribbean context, Parvicingulidae-rich assemblages could indicate the proximity of important landmasses acting as upwelling margins or land nutrients inputs, instead of higher paleolatitudinal deposition.

According to this radiolarian study and our plate tectonic model, the Middle Jurassic to Early Cretaceous radiolarian ribbon chert of the Bermeja Complex are remnants of the Mezcalera ocean and may have undergone at least one accretionary and one collisional events. The first one during the northwest dipping intra-oceanic subduction of the Mescalera ocean beneath the Mackinley ocean (and later the Guerrero ocean). The second one during the late Early Cretaceous collision of the Guerrero-Phoenix arc with the Chortis block. Finally, we interpret the middle Cretaceous radiolarites as remnants of the Guerrero ocean sedimented close to the Taino Arc.

Appendices

Appendix A: Systematic paleontology

Three new radiolarian taxa are described herein. Although these new species have been described on the basis of three or even of a single specimen, they present well-individualized morphological characters.

Holotypes and paratypes are stored in the collection of the Musée de Géologie de Lausanne, Université de Lausanne, Switzerland (MGL no. 97012 and 97016).

Subclass RADIOLARIA

Order POLYCYSTINA

Suborder SPUMELLARIA

Family PANTANELLIIDAE Pessagno

Genus Pantanellium Pessagno

Type species Pantanellium riedeli Pessagno

Pantanellium karinae Bandini, n. sp.

Plate 5, Figs. 38–40

Description Cortical shell small, subspherical to ellipsoid and relatively thick-walled with four to five massive hexagonal and pentagonal pore frames on half the circumference with relatively high nodes at vertices. In the equatorial zone, nodes with short and conical secondary spines circular in cross-section. Cortical shell with triradiate bipolar primary spines, massive, relatively long, and subequal having three wide ridges alternating with three wide grooves. Diameter of cortical shell about half-length of primary spines. Diameter of primary spines at their base about two-third that of cortical shell.

Dimensions (based on one complete and two partial specimens) Diameter of the cortical shell 60–80 μm, length of primary spines 110–130 μm.

Holotype Plate 5, Fig. 38, MGL no. 97016, Musée de Géologie de Lausanne, Université de Lausanne, Switzerland.

Remarks Pantanellium karinae n. sp. differs from P. riedeli Pessagno by having secondary spines in the equatorial zone, wider bipolar primary spines, and a more elongated cortical shell. P. karinae n. sp. differs from P. coronense Cheng by having a subspherical to ellipsoid cortical shell with maximum width along the bipolar primary spines axis, and primary spines subequal in length. P. karinae n. sp. differs from P. philippinense Cheng by having bipolar primary spines subequal in length and width.

Etymology This species is named for the London-based architect and contemporary art curator Karine Teyssier.

Occurrence and possible range Rare in the early Kimmeridgian to early Tithonian sample PR-SB17 (however, some reworked characteristic species of Middle Jurassic are also present in this sample). This species was also found in the late Kimmeridgian–Tithonian of Romania (Dumitrica unpublished data).

Appendix B: Locality description

1.1 Samples PR-SB01 and PR-SB02

This outcrop is approximately located 1 km north of the small village of Las Palmas (Fig. 2). To reach this outcrop (Fig. 3) from Las Palmas leave road 303 and follow the track called “Camino El Zapato” going northward and crossing the Bermeja mountain range. About 1.5 km further, take a small road going westward and up the hill to an antenna (coordinates N17°59′33.10″ W067°08′05.70″). Following this small road, one crosses two small valleys (approximately 150 and 300 m after the crossing), the outcrop is located in the second valley a few meters above the road (coordinates N17°59′28.40″ W067°08′03.00″).

1.1.1 PR-SB01 (Table 1; Plate 1)

This sample yielded a radiolarian association comprising: Amuria sp., Archaeodictyomitra cf. tumandae Dumitrica, Archaeodictyomitra pseudomulticostata (Tan), Archaeodictyomitra spp., Caneta (?) sp., Cinguloturris cf. cylindra Kemkin & Rudenko, Cryptamphorella sp., Emiluvia cf. ordinaria Ozvoldova, Emiluvia chica Foreman, Hiscocapsa cf. kitoi (Jud), Hiscocapsa cf. kaminogoensis (Aita), Obesacapsula bullata Steiger, Pantanellium squinaboli (Tan), Pseudodictyomitra carpatica (Lozyniak), Svinitzium depressum (Baumgartner), Tethysetta boesii (Parona).

Plate 1

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB01 (latest Tithonian–Late Valaginian). Fig. 1 Caneta (?) sp. Fig. 2 Archaeodictyomitra pseudomulticostata (Tan). Fig. 3 Archaeodictyomitra cf. tumandae Dumitrica. Figs. 4, 5 Archaeodictyomitra spp. Fig. 6 Cinguloturris cf. cylindra Kemkin & Rudenko. Fig. 7 Tethysetta boesii (Parona). Fig. 8 Svinitzium depressum (Baumgartner). Fig. 9 Pseudodictyomitra carpatica (Lozyniak). Fig. 10 Hiscocapsa cf. kaminogoensis (Aita). Fig. 11 Hiscocapsa cf. kitoi (Jud). Fig. 12 Cryptamphorella sp. Fig. 13 Emiluvia chica Foreman. Fig. 14 Emiluvia cf. ordinaria Ozvoldova. Fig. 15 Obesacapsula bullata Steiger. Fig. 16 Amuria sp. Fig. 17 Pantanellium squinaboli (Tan). Sample PR-SB02 (latest Tithonian–early Aptian). Fig. 18 Archaeodictyomitra cf. chalilovi (Aliev). Fig. 19 Archaeodictyomitra cf. tumandae Dumitrica. Fig. 20 Archaeodictyomitra mitra gr. Dumitrica. Fig. 21 Archaeodictyomitra sp. Fig. 22 Pseudodictyomitra cf. suyarii Dumitrica. Figs. 23–25 Cryptamphorella spp. Figs. 26, 27 Acanthocircus sp. Figs. 28–30 Pantanellium squinaboli (Tan). Fig. 31 Homoeoparonaella cf. irregularis (Squinabol)

1.1.2 PR-SB02 (Table 1; Plate 1)

This sample yielded a radiolarian association comprising: Acanthocircus sp., Archaeodictyomitra cf. chalilovi (Aliev), Archaeodictyomitra cf. tumandae Dumitrica, Archaeodictyomitra mitra gr. Dumitrica, Archaeodictyomitra sp., Cryptamphorella spp., Homoeoparonaella cf. irregularis (Squinabol), Pantanellium squinaboli (Tan), Pseudodictyomitra cf. suyarii Dumitrica.

1.2 Sample PR-SB05 (Table 2; Plate 2)

The outcrop is located approximately 20 m in elevation above outcrop PR-SB01 in the same valley (Fig. 2). The radiolarite crops out in a block of about 2 m long and 1 m high. The greenish-grey radiolarite block is embedded in a massive and brecciated greenish-grey siliceous rock that weathers reddish and compose most of the Sierra Bermeja (Fig. 4).

Plate 2

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB05 (latest Bajocian–early Bathonian). Fig. 1 Svinitzium cf. kamoense (Mizutani & Kido). Fig. 2 Triversus (?) sp. Fig. 3 Parahsuum sp. Fig. 4 Hiscocapsa lugeoni O’Dogherty, Goričan & Dumitrica. Figs. 5, 7 Praewilliriedellum convexum (Yao). Fig. 6 Praewilliriedellum japonicum (Yao). Figs. 8, 9 Striatojaponocapsa synconexa O’Dogherty, Goričan & Dumitrica. Fig. 10 Williriedellum tetragona (Matsuoka). Fig. 11 Hexasaturnalis nakasekoi Dumitrica & Dumitrica-Jud. Fig. 12 Tetraditryma sp. Sample PR-SB07 (late early Albian–early early Turonian). Fig. 13 Archaeodictyomitra cf. chalilovi (Aliev). Fig. 14 Archaeodictyomitra sp. Fig. 15 Archaeodictyomitra montisserei (Squinabol) Figs. 16–18 Theocampe (?) sp. Fig. 19 gen. et sp. indet. Figs. 20–23 Cryptamphorella spp. Figs. 24–26, 29 Hiscocapsa pseudouterculus (Aita & Okada). Fig. 27 Hiscocapsa cf. uterculus (Parona) Figs. 28, 30 and 31 Hiscocapsa cf. asseni (Tan). Figs. 32, 33 Obeliscoites (?) sp. Figs. 34, 35 Napora sp.

This sample yielded a radiolarian association comprising: Hexasaturnalis nakasekoi Dumitrica & Dumitrica-Jud, Hiscocapsa lugeoni O’Dogherty, Goričan & Dumitrica, Parahsuum sp., Praewilliriedellum convexum (Yao), Praewilliriedellum japonicum (Yao), Striatojaponocapsa synconexa O’Dogherty, Goričan & Dumitrica, Tetraditryma sp., Svinitzium cf. kamoense (Mizutani & Kido), Triversus (?) sp., Williriedellum tetragona (Matsuoka).

1.3 Samples PR-SB07 and PR-SB08

This outcrop (coordinates N17°59′27.60″ W067°08′12.3″) situated on top of a crest is located 300 m southwest of the antenna (coordinates N17°59′33.10″ W067°08′05.70″, see above PR-SB01 and PR-SB02 for the pathway to reach the antenna, see also Fig. 2).

1.3.1 PR-SB07 (Table 3; Plate 2)

This sample yielded a radiolarian association comprising: Archaeodictyomitra cf. chalilovi (Aliev), Archaeodictyomitra montisserei (Squinabol), Archaeodictyomitra sp., Cryptamphorella spp., gen. et sp. indet., Hiscocapsa cf. asseni (Tan), Napora sp., Obeliscoites (?) sp., Hiscocapsa pseudouterculus (Aita & Okada), Hiscocapsa cf. uterculus (Parona), Theocampe (?) sp.

1.3.2 PR-SB08 (Table 3; Plate 3)

This sample includes the following radiolarian association: Archaeodictyomitra spp., Cryptamphorella spp., gen. et sp. indet., Hiscocapsa cf. campana (Kiessling), Hiscocapsa cf. subcrassitestata Aita, Loopus aff. primitivus (Matsuoka & Yao), Loopus sp., Loopus primitivus (Matsuoka & Yao), Napora spp., Praeconocaryomma sp., Spinosicapsa (?) sp., Triactoma sp.

Plate 3

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB08 (late Bathonian–early late Tithonian). Figs. 1–5 Archaeodictyomitra spp. Figs. 6, 7 Loopus primitivus (Matsuoka & Yao). Figs. 8, 9 Loopus aff. primitivus (Matsuoka & Yao). Fig. 10 Loopus sp. Figs. 11, 12 Spinosicapsa (?) sp. Figs. 13–17 Cryptamphorella spp. Figs. 18, 19 Napora spp. Fig. 20 gen. et sp. indet. Fig. 21 Hiscocapsa cf. campana (Kiessling). Fig. 22 Hiscocapsa cf. subcrassitestata (Aita). Fig. 23 Triactoma sp. Fig. 24 Praeconocaryomma sp.

1.3.3 Samples PR-SB11 and PR-SB12

The outcrops (coordinates N17°59′05.7″ W67°07′24.3″) are located approximately 1.5 km east of the small town of Las Palmas (Fig. 2). To reach these outcrops follow road 303 to the east for 2 km from Las Palmas. The outcrops are situated on the hill to the north of the road.

1.3.4 PR-SB11 (Table 4; Plate 4)

This sample yielded a radiolarian association comprising: Acanthocircus sp., Archaeodictyomitra cf. vulgaris Pessagno, Archaeodictyomitra immenhauseri Dumitrica, Archaeodictyomitra cf. tumandae Dumitrica, Archaeodictyomitra sp., Archaeospongoprunum sp., Cryptamphorella sp., Mictyoditra sp., Pantanellium squinaboli (Tan), Pantanellium sp., Pseudodictyomitra aff. leptoconica (Foreman), Pseudodictyomitra sp., Svinitzium (?) mizutanii Dumitrica, Thanarla cf. conica (Aliev), Stichomitra (?) sp.

Plate 4

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB11 (Berriasian). Fig. 1 Archaeodictyomitra cf. vulgaris Pessagno. Fig. 2 Archaeodictyomitra sp. Fig. 3 Archaeodictyomitra cf. tumandae Dumitrica. Fig. 4 Archaeodictyomitra immenhauseri Dumitrica. Figs. 5, 6 Mictyoditra sp. Fig. 7 Stichomitra (?) sp. Fig. 8 Thanarla cf. conica (Aliev). Fig. 9 Pseudodictyomitra aff. leptoconica (Foreman). Fig. 10 Pseudodictyomitra sp. Fig. 11 Svinitzium (?) mizutanii Dumitrica. Fig. 12 Cryptamphorella sp. Fig. 13 Archaeospongoprunum sp. Fig. 14 Acanthocircus sp. Fig. 15 Pantanellium squinaboli (Tan) Fig. 16 Pantanellium sp. Sample PR-SB12 (Berriasian). Fig. 17 Archaeodictyomitra cf. pseudomulticostata (Tan). Figs. 18, 19 Archaeodictyomitra mitra gr. Dumitrica. Fig. 20 Archaeodictyomitra immenhauseri Dumitrica. Figs. 21, 22, 24 C ryptamphorella sp. Fig. 23 Obesacapsula (?) cf. cetia (Foreman). Fig. 25 Hiscocapsa (?) sp. Sample PR-SB14 (latest Bajocian–early Oxfordian). Fig. 26 Archaeodictyomitra sp. Fig. 27 Archaeodictyomitra prisca Kozur & Mostler. Fig. 28 Transhsuum sp. Fig. 29 gen. et sp. indet. Figs. 30, 31 Eucyrtidiellum unumaense s.l. (Yao). Fig. 32 Eucyrtidiellum unumaense pustulatum Baumgartner. Fig. 33 Spinosicapsa (?) sp. Fig. 34 Striatojaponocapsa (?) sp. Figs. 35, 36 Homeoparonaella sp. Fig. 37 Alievium cf. longispineum Yang & Wang

1.3.5 PR-SB12 (Table 4; Plate 4)

This sample includes the following radiolarian association: Archaeodictyomitra cf. pseudomulticostata (Tan), Archaeodictyomitra immenhauseri Dumitrica, Archaeodictyomitra mitra gr. Dumitrica, Hiscocapsa (?) sp., Obesacapsula (?) cf. cetia (Foreman), Cryptamphorella sp.

1.4 Samples PR-SB14 and PR-SB17

The outcrop (coordinates N18°00′18.6″ W67°07′42.1″) is located along the northwestern margin of Sierra Bermeja (Fig. 2). To reach this outcrops from Las Palmas leave road 303 and follows the track called “Camino El Zapato” going north–north-east and crossing the Bermeja mountain range. About 3 km further, a very tectonized metric green–brown radiolarite block crops out where the path crosses a stream gully in an area adjacent to basalts. The location of this outcrop seems to correspond to this of the Early Jurassic sample PR92.1B from Montgomery et al. (1994b).

1.4.1 PR-SB14 (Table 5; Plate 4)

This sample includes the following radiolarian association: Alievium cf. longispineum Yang & Wang, Archaeodictyomitra prisca Kozur & Mostler, Archaeodictyomitra sp., Eucyrtidiellum unumaense s.l. (Yao), Eucyrtidiellum unumaense pustulatum Baumgartner, gen et sp. indet., Homeoparonaella sp., Spinosicapsa (?) sp., Striatojaponocapsa (?) sp., Transhsuum sp.

1.4.2 PR-SB17 (Table 5; Plate 5)

This sample contains by far the richest radiolarian assemblage of this study: Archaeodictyomitra patricki Kocher, Archaeodictyomitra spp., Archaeospongoprunum elegans Wu, Cryptamphorella sp., Deviatus diamphidius hipposidericus (Foreman), Emiluvia ordinaria Ozvoldova, Emiluvia (?) sp., Eucyrtidiellum ptyctum (Riedel & Sanfilippo), Hiscocapsa (?) sp., Napora sp., Nassellaria gen. et sp. indet., Pantanellium karinae Bandini n. sp., Pantanellium ranchitoense Pessagno & Macleod, Pantanellium sp., Parvicingula vera Pessagno & Whalen, Parvicingulidae gen. et sp. indet., Praeconocaryomma sp., Praewilliriedellum convexum (Yao), Praewilliriellum sp. aff. robustum (Matsuoka), Pseudodictyomitra (?) sp., Pseudodictyomitra sp., Pseudodictyomitrella (?) sp., Spumellaria gen. et sp. indet., Stichomitra (?) doliolum Aita gr., Stichomitra (?) spp., Striatojaponocapsa plicarum (Yao), Vallupus hopsoni Pessagno & Blome, Williriedellum carpathicum Dumitrica, Williriedellum formosum (Chiari, Marcucci & Prela), Williriedellum sp..

Plate 5

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB17 (early Kimmeridgian–early Tithonian). Fig. 1 Archaeodictyomitra patricki Kocher. Figs. 2, 3 Archaeodictyomitra spp. Fig. 4 Pseudodictyomitrella (?) sp. Figs. 5–7 Stichomitra (?) spp. Figs. 8, 9, 11 Parvicingulidae gen. et sp. indet. Fig. 10 Parvicingula vera Pessagno & Whalen. Fig. 12 Pseudodictyomitra (?) sp. Fig. 13 Pseudodictyomitra sp. Figs. 14, 15 Stichomitra (?) doliolum Aita gr. Fig. 16 Eucyrtidiellum ptyctum (Riedel & Sanfilippo). Fig. 17 Vallupus hopsoni Pessagno & Blome. Figs. 18, 19 Napora sp. Fig. 20 Striatojaponocapsa plicarum (Yao). Fig. 21 Praewilliriedellum sp. aff. robustum (Matsuoka). Fig. 22 Praewilliriedellum convexum (Yao). Fig. 23 Hiscocapsa (?) sp. Figs. 24, 25 Williriedellum carpathicum Dumitrica. Fig. 26 Williriedellum sp. Figs. 27, 28 Williriedellum formosum (Chiari, Marcucci & Prela). Fig. 29 Cryptamphorella sp. Figs. 30, 31 Nassellaria gen. et sp. indet. Fig. 32 Emiluvia ordinaria Ozvoldova. Fig. 33 Emiluvia (?) sp. Fig. 34 Praeconocaryomma sp. Fig. 35 Deviatus diamphidius hipposidericus (Foreman). Fig. 36 Pantanellium ranchitoense Pessagno & Macleod. Fig. 37 Pantanellium sp. Figs. 38–40 Pantanellium karinae Bandini, n. sp. Fig. 41 Archaeospongoprunum elegans Wu. Fig. 42 Spumellaria gen. et sp. indet

1.5 Samples PR-SB21 and PR-SB23

This outcrop (no coordinates, because GPS signal was too weak) is located 20 m upstream from outcrop PR-SB14 and PR-SB17 (Fig. 2). The radiolarite sequence is 1 m high and 3 m wide and appears as centimeter bedded green-orange radiolarian chert alternating with millimeter shale beds (Figs. 5, 6). Sample PR-SB21 comes from the east side of the stream gully and sample PR-SB23 from the west side of the stream gully.

1.5.1 PR-SB21 (Table 6; Plate 6)

This sample yielded a radiolarian association comprising: Archaeodictyomitra aff. rigida Pessagno, Canoptum (?) sp., Praewilliriedellum convexum (Yao), Ristola turpicula Pessagno & Whalen, Striatojaponocapsa synconexa O’Dogherty, Goričan & Dumitrica, Transhsuum sp., Williriedellum yaoi (Kozur).

Plate 6

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB21 (latest Bajocian–middle Bathonian). Fig. 1 Archaeodictyomitra aff. rigida Pessagno. Fig. 2 Transhsuum sp. Fig. 3 Canoptum (?) sp. Fig. 4 Ristola turpicula Pessagno & Whalen. Fig. 5 Praewilliriedellum convexum (Yao). Figs. 6, 7 Striatojaponocapsa synconexa O’Dogherty, Goričan & Dumitrica. Fig. 8 Williriedellum yaoi (Kozur). Sample PR-SB23 (latest Bajocian–early Callovian). Fig. 9 Archaeodictyomitra aff. rigida Pessagno. Fig. 10 Archaeodictyomitra patricki Kocher. Figs. 11, 12 Transhsuum maxwelli gr. (Pessagno). Fig. 13 Stichomitra (?) sp. Fig. 14 Triversus (?) sp. Fig. 15 Svinitzium kamoense (Mizutani & Kido). Fig. 16 Parahsuum (?) sp. Fig. 17 Xitus sp. Figs. 18, 19 Praewilliriedellum convexum (Yao). Fig. 20 Praewilliriedellum robustum (Matsuoka). Figs. 21, 22 Williriedellum yaoi (Kozur). Figs. 23, 24 Striatojaponocapsa synconexa O’Dogherty, Goričan & Dumitrica. Fig. 25 Eucyrtidiellum unumaense s.l. (Yao). Fig. 26 Nassellaria gen. et sp. indet. Figs. 27, 28 gen. et sp. indet. Fig. 29 Levileugeo ordinarius Yang & Wang. Fig. 30 Angulobracchia sp. Sample PR-SB24 (late Bajocian-early Callovian). Fig. 31 Archaeodictyomitra aff. rigida Pessagno. Fig. 32 Archaeodictyomitra sp. Fig. 33 Parahsuum sp. Fig. 34 Transhsuum cf. hisuikyoense (Isozaki & Matsuda). Fig. 35 Transhsuum cf. maxwelli gr. (Pessagno). Fig. 36 Praewilliriedellum japonicum (Yao). Fig. 37 Praewilliriedellum convexum (Yao). Fig. 38 Canoptum (?) sp. Fig. 39 Triactoma parablakei Yang & Wang. Fig. 40 Emiluvia sp. Figs. 41, 42 Eucyrtidiellum unumaense s.l. (Yao)

1.5.2 PR-SB23 (Table 6; Plate 6)

This sample includes the following radiolarian association: Angulobracchia sp., Archaeodictyomitra aff. rigida Pessagno, Archaeodictyomitra patricki Kocher, Eucyrtidiellum unumaense s.l. (Yao), gen. et sp. indet., Levileugeo ordinarius Yang & Wang, Nassellaria gen. et sp. indet., Parahsuum (?) sp., Praewilliriedellum convexum (Yao), Praewilliriedellum robustum (Matsuoka), Stichomitra (?) sp., Striatojaponocapsa synconexa O’Dogherty, Goričan & Dumitrica, Svinitzium kamoense (Mizutani & Kido), Transhsuum maxwelli gr. (Pessagno), Triversus (?) sp., Williriedellum yaoi (Kozur), Xitus sp.

1.6 Sample PR-SB24 (Table 7; Plate 6)

This outcrop (coordinates N18°00′13.5″ W067°07′41.2″) is located 100 m upstream from outcrop PR-SB14 (Fig. 2), and 80 m upstream from outcrop PR-SB21 and may correspond to outcrop 7919-21 from Mattson and Pessagno (1979).

This sample yielded a radiolarian association comprising: Archaeodictyomitra aff. rigida Pessagno, Archaeodictyomitra sp., Canoptum (?) sp., Emiluvia sp., Eucyrtidiellum unumaense s.l. (Yao), Parahsuum sp., Praewilliriedellum convexum (Yao), Praewilliriedellum japonicum (Yao), Transhsuum cf. hisuikyoense (Isozaki & Matsuda), Transhsuum cf. maxwelli gr. (Pessagno), Triactoma parablakei Yang & Wang.

1.7 Samples PR-SB26, PR-SB27 and PR-SB28

The outcrop (coordinates N17°59′31.2″ W67°07′50.6″) is located about 1.2 km north–north-east from the village of Las Palmas along the track called “Camino El Zapato” (Fig. 2).

1.7.1 PR-SB26 (Table 8; Plate 7)

This sample includes the following radiolarian association: Acaeniotyle cf. umbilicata (Rüst), Acanthocircus sp., Archaeodictyomitra spp., Crucella sp., Crucella sp. (with five rays), Emiluvia sp., Napora sp., Nassellaria gen. et sp. indet., Obeliscoites cf. vinassai (Squinabol), Obesacapsula sp., Pantanelliidae gen. et sp. indet., Parvicingula sp., Praeconocaryomma sp., Pseudoeucyrtis corpulentus Dumitrica, Pseudoeucyrtis hanni (Tan), Thanarla sp.

Plate 7

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB26 (latest Barremian–late Aptian) Figs. 1, 2 Archaeodictyomitra spp. Fig. 3 Thanarla sp. Fig. 4 Parvicingula sp. Fig. 5 Pseudoeucyrtis corpulentus Dumitrica. Fig. 6 Obesacapsula sp. Fig. 7 Pseudoeucyrtis hanni (Tan). Fig. 8 Obeliscoites cf. vinassai (Squinabol). Fig. 9 Nassellaria gen. et sp. indet. Fig. 10 Napora sp. Fig. 11 Nassellaria gen. et sp. indet. Fig. 12 Acaeniotyle cf. umbilicata (Rüst). Fig. 13 Emiluvia sp. Fig. 14 Acanthocircus sp. Fig. 15 Crucella sp. Fig. 16 Pantanelliidae gen. et sp. indet. Fig. 17 Crucella sp. (with five rays). Fig. 18 Praeconocaryomma sp.

1.7.2 PR-SB27 (Table 8; Plate 8)

This sample yielded a radiolarian association comprising: Archaeodictyomitra cf. gracilis (Squinabol), Archaeodictyomitra cf. immenhauseri Dumitrica, Archaeodictyomitra montisserei (Squinabol), Archaeodictyomitra spp., Archaeospongoprunum sp., Halesium (?) cf. palmatum Dumitrica, Pantanellium sp., Quadrigastrum lapideum O’Dogherty, Spumellaria gen. et sp. indet., Stichomitra (?) spp., Thanarla aff. veneta (Squinabol), Thanarla brouweri (Tan), Thanarla sp., Stylosphaera spp.

Plate 8

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB27 (late Aptian–middle Cenomanian). Figs. 1, 2 Archaeodictyomitra cf. immenhauseri Dumitrica. Fig. 3 Archaeodictyomitra cf. gracilis (Squinabol). Figs. 4, 5 Archaeodictyomitra montisserei (Squinabol). Figs. 6, 7 Archaeodictyomitra spp. Figs. 8, 9 Stichomitra (?) spp. Fig. 10 Thanarla aff. veneta (Squinabol). Fig. 11 Thanarla brouweri (Tan). Fig. 12 Thanarla sp. Figs. 13–15 Archaeospongoprunum sp. Figs. 16, 17 Stylosphaera spp. Fig. 18 Halesium (?) cf. palmatum Dumitrica. Figs. 19, 20 Pantanellium sp. Fig. 21 Quadrigastrum lapideum O’Dogherty. Fig. 22 Spumellaria gen. et sp. indet

1.7.3 PR-SB28 (Table 8; Plate 9)

This sample includes the following radiolarian association: Archaeodictyomitra gracilis (Squinabol) gr., Archaeodictyomitra sp., Neosciadiocapsidae Pessagno gen. et sp. indet., Squinabollum aff. fossile (Squinabol), Stichomitra (?) sp.

Plate 9

Scanning electron microscope pictures of radiolarians from the Bermeja Complex, western Puerto Rico. Marker = 100 μm. Sample PR-SB28 (late early Albian–middle Cenomanian). Figs 1, 2 Archaeodictyomitra gracilis (Squinabol) gr. Fig. 3 Archaeodictyomitra sp. Fig. 4 Stichomitra (?) sp. Fig. 5 Squinabollum aff. fossile (Squinabol). Fig. 6 Neosciadiocapsidae Pessagno gen. et sp. indet. Sample PR-SB30 (Barremian). Fig. 7 Pseudodictyomitra leptoconica (Foreman). Fig. 8 Pseudodictyomitra sp. Fig. 9 Archaeodictyomitra sp. Fig. 10 Tuguriella sp. Figs. 11, 15 Hiscocapsa (?) spp. Fig. 12 Hiscocapsa aff. asseni (Tan). Fig. 13 Hiscocapsa uterculus (Parona). Fig. 14 Zhamoidellum cf. testatum Jud. Fig. 16 Syringocapsa (?) limatum Foreman. Fig. 17 Pseudocrucella (?) elisabethae (Rüst). Fig. 18 Praeconocaryomma sp.

1.8 PR-SB30 (Table 9; Plate 9)

The outcrop (coordinates N17°59′32.5″ W67°07′50.2″) is located approximately 50 m north of outcrop PR-SB26 on the track called “Camino El Zapato” (Fig. 2).

This sample yielded a radiolarian association comprising: Archaeodictyomitra sp., Hiscocapsa aff. asseni (Tan), Hiscocapsa (?) spp., Hiscocapsa uterculus (Parona), Praeconocaryomma sp., Pseudocrucella (?) elisabethae (Rüst), Pseudodictyomitra leptoconica (Foreman), Pseudodictyomitra sp., Syringocapsa (?) limatum Foreman, Tuguriella sp., Zhamoidellum cf. testatum Jud.

Appendix C: Species list

Acaeniotyle cf. umbilicata (Rüst): PR-SB26 (Plate 7, Fig. 12)

Acanthocircus spp.: PR-SB02 (Plate 1, Figs. 26, 27), PR-SB11 (Plate 4, Fig. 14), PR-SB26 (Plate 7, Fig. 14)

Alievium cf. longispineum Yang & Wang: PR-SB14 (Plate 4, Fig. 37)

Amuria sp.: PR-SB01 (Plate 1, Fig. 16)

Angulobracchia sp.: PR-SB23 (Plate 6, Fig. 30)

Archaeodictyomitra aff. rigida Pessagno: PR-SB21 (Plate 6, Fig. 1), PR-SB23 (Plate 6, Fig. 9), PR-SB24 (Plate 6, Fig. 31)

Archaeodictyomitra cf. chalilovi (Aliev): PR-SB02 (Plate 1, Fig. 18), PR-SB07 (Plate 2, Fig. 13)

Archaeodictyomitra cf. gracilis (Squinabol): PR-SB27 (Plate 8, Fig. 3)

Archaeodictyomitra cf. immenhauseri Dumitrica: PR-SB27 (Plate 8, Figs. 1, 2.)

Archaeodictyomitra cf. pseudomulticostata (Tan): PR-SB12 (Plate 4, Fig. 17)

Archaeodictyomitra cf. tumandae Dumitrica: PR-SB01 (Plate 1, Fig. 3), PR-SB02 (Plate 1, Fig. 19), PR-SB11 (Plate 4, Fig. 3)

Archaeodictyomitra cf. vulgaris Pessagno: PR-SB11 (Plate 4, Fig. 1)

Archaeodictyomitra gracilis (Squinabol) gr.: PR-SB28 (Plate 9, Figs. 1, 2)

Archaeodictyomitra immenhauseri Dumitrica: PR-SB11 (Plate 4, Fig. 4), PR-SB12 (Plate 4, Fig. 20)

Archaeodictyomitra mitra gr. Dumitrica: PR-SB02 (Plate 1, Fig. 20), PR-SB12 (Plate 4, Figs. 18, 19)

Archaeodictyomitra montisserei (Squinabol): PR-SB07 (Plate 2, Fig. 15), PR-SB27 (Plate 8, Figs. 4, 5)

Archaeodictyomitra patricki Kocher: PR-SB17 (Plate 5, Fig. 1), PR-SB23 (Plate 6, Fig. 10)

Archaeodictyomitra prisca Kozur & Mostler: PR-SB14 (Plate 4, Fig. 27)

Archaeodictyomitra pseudomulticostata (Tan): PR-SB01 (Plate 1, Fig. 2)

Archaeodictyomitra spp.: PR-SB01 (Plate 1, Figs. 4, 5), PR-SB02 (Plate 1, Fig. 21), PR-SB07 (Plate 2, Fig. 14), PR-SB08 (Plate 3, Figs. 1–5), PR-SB11 (Plate 4, Fig. 2), PR-SB14 (Plate 4, Fig. 26), PR-SB17 (Plate 5, Figs. 2, 3), PR-SB24 (Plate 6, Fig. 32), PR-SB26 (Plate 7, Figs. 1, 2), PR-SB27 (Plate 8, Figs. 6, 7), PR-SB28 (Plate 9, Fig. 3), PR-SB30 (Plate 9, Fig. 9)

Archaeospongoprunum elegans Wu: PR-SB17 (Plate 5, Fig. 41)

Archaeospongoprunum spp.: PR-SB11 (Plate 4, Fig. 13), PR-SB27 (Plate 8, Figs. 13–15)

Caneta (?) sp.: PR-SB01 (Plate 1, Fig. 1)

Canoptum (?) spp.: PR-SB21 (Plate 6, Fig. 3), PR-SB24 (Plate 6, Fig. 38)

Cinguloturris cf. cylindra Kemkin & Rudenko: PR-SB01 (Plate 1, Fig. 6)

Crucella sp. (with five rays): PR-SB26 (Plate 7, Fig. 17)

Crucella sp.: PR-SB26 (Plate 7, Fig. 15)

Cryptamphorella spp.: PR-SB01 (Plate 1, Fig. 12), PR-SB02 (Plate 1, Figs. 23–25), PR-SB07 (Plate 2, Figs. 20–23), PR-SB08 (Plate 3, Figs. 13–17), PR-SB11 (Plate 4, Fig. 12), PR-SB12 (Plate 4, Figs. 21, 22, 24), PR-SB17 (Plate 5, Fig. 29)

Deviatus diamphidius hipposidericus (Foreman): PR-SB17 (Plate 5, Fig. 35)

Emiluvia (?) sp.: PR-SB17 (Plate 5, Fig. 33)

Emiluvia cf. ordinaria Ozvoldova: PR-SB01 (Plate 1, Fig. 14)

Emiluvia chica Foreman: PR-SB01 (Plate 1, Fig. 13)

Emiluvia ordinaria Ozvoldova: PR-SB17 (Plate 5, Fig. 32)

Emiluvia spp.: PR-SB24 (Plate 6, Fig. 40), PR-SB26 (Plate 7, Fig. 13)

Eucyrtidiellum ptyctum (Riedel & Sanfilippo): PR-SB17 (Plate 5, Fig. 16)

Eucyrtidiellum unumaense s.l. (Yao): PR-SB14 (Plate 4, Figs. 30 and 31), PR-SB23 (Plate 6, Fig. 25), PR-SB24 (Plate 6, Figs. 41, 42)

Eucyrtidiellum unumaense pustulatum Baumgartner: PR-SB14 (Plate 4, Fig. 32)

gen. et sp. indet.: PR-SB14 (Plate 4, Fig. 29), PR-SB07 (Plate 2, Fig. 19), PR-SB08 (Plate 3, Fig. 20), PR-SB23 (Plate 6, Fig. 27), PR-SB23 (Plate 6, Fig. 28)

Halesium (?) cf. palmatum Dumitrica: PR-SB27 (Plate 8, Fig. 18)

Hexasaturnalis nakasekoi Dumitrica & Dumitrica-Jud: PR-SB05 (Plate 2, Fig. 11)

Hiscocapsa cf. asseni (Tan): PR-SB07 (Plate 2, Figs. 28, 30, 31)

Hiscocapsa pseudouterculus (Aita & Okada): PR-SB07 (Plate 2, Figs. 24–26, 29)

Hiscocapsa (?) spp.: PR-SB12 (Plate 4, Fig. 25), PR-SB17 (Plate 5, Fig. 23), PR-SB30 (Plate 9, Figs. 11, 15)

Hiscocapsa aff. asseni (Tan): PR-SB30 (Plate 9, Fig. 12)

Hiscocapsa cf. campana (Kiessling): PR-SB08 (Plate 3, Fig. 21)

Hiscocapsa cf. kitoi (Jud): PR-SB01 (Plate 1, Fig. 11)

Hiscocapsa cf. kaminogoensis (Aita): PR-SB01 (Plate 1, Fig. 10)

Hiscocapsa lugeoni O’Dogherty, Goričan & Dumitrica: PR-SB05 (Plate 2, Fig. 4)

Hiscocapsa cf. subcrassitestata Aita: PR-SB08 (Plate 3, Fig. 22)

Hiscocapsa cf. uterculus (Parona): PR-SB07 (Plate 2, Fig. 27)

Hiscocapsa uterculus (Parona): PR-SB30 (Plate 9, Fig. 13)

Homeoparonaella sp.: PR-SB14 (Plate 4, Figs. 35, 36)

Homoeoparonaella cf. irregularis (Squinabol): PR-SB02 (Plate 1, Fig. 31)

Levileugeo ordinarius Yang & Wang: PR-SB23 (Plate 6, Fig. 29)

Loopus aff. primitivus (Matsuoka & Yao): PR-SB08 (Plate 3, Figs. 8, 9)

Loopus sp.: PR-SB08 (Plate 3, Fig. 10)

Loopus primitivus (Matsuoka & Yao): PR-SB08 (Plate 3, Figs. 6, 7)

Mictyoditra sp.: PR-SB11 (Plate 4, Figs. 5, 6)

Napora spp.: PR-SB07 (Plate 2, Figs. 34, 35), PR-SB08 (Plate 3, Figs. 18, 19), PR-SB17 (Plate 5, Figs. 18, 19), PR-SB26 (Plate 7, Fig. 10)

Nassellaria gen. et sp. indet.: PR-SB17 (Plate 5, Figs. 30, 31), PR-SB23 (Plate 6, Fig. 26), PR-SB26 (Plate 7, Fig. 11), PR-SB26 (Plate 7, Fig. 9)

Neosciadiocapsidae Pessagno gen. et sp. indet.: PR-SB28 (Plate 9, Fig. 6)

Obeliscoites (?) sp.: PR-SB07 (Plate 2, Figs. 32, 33)

Obeliscoites cf. vinassai (Squinabol): PR-SB26 (Plate 7, Fig. 8)

Obesacapsula (?) cf. cetia (Foreman): PR-SB12 (Plate 4, Fig. 23)

Obesacapsula bullata Steiger: PR-SB01 (Plate 1, Fig. 15)

Obesacapsula sp.: PR-SB26 (Plate 7, Fig. 6)

Pantanelliidae gen. et sp. indet.: PR-SB26 (Plate 7, Fig. 16)

Pantanellium karinae Bandini, n. sp.: PR-SB17 (Plate 5, Figs. 38–40)

Pantanellium ranchitoense Pessagno & Macleod: PR-SB17 (Plate 5, Fig. 36)

Pantanellium spp.: PR-SB11 (Plate 4, Fig. 16), PR-SB17 (Plate 5, Fig. 37), PR-SB27 (Plate 8, Figs. 19, 20)

Pantanellium squinaboli (Tan): PR-SB01 (Plate 1, Fig. 17), PR-SB02 (Plate 1, Figs. 28–30), PR-SB11 (Plate 4, Fig. 15)

Parahsuum (?) sp.: PR-SB23 (Plate 6, Fig. 16)

Parahsuum spp.: PR-SB05 (Plate 2, Fig. 3), PR-SB24 (Plate 6, Fig. 33)

Parvicingula sp.: PR-SB26 (Plate 7, Fig. 4)

Parvicingula vera Pessagno & Whalen: PR-SB17 (Plate 5, Fig. 10)

Parvicingulidae gen. et sp. indet.: PR-SB17 (Plate 5, Figs. 8, 9, 11)

Praeconocaryomma spp.: PR-SB17 (Plate 5, Fig. 34), PR-SB26 (Plate 7, Fig. 18), PR-SB30 (Plate 9, Fig. 18), PR-SB08 (Plate 3, Fig. 24)

Praewilliriedellum convexum (Yao): PR-SB05 (Plate 2, Figs. 5, 7), PR-SB17 (Plate 5, Fig. 22), PR-SB21 (Plate 6, Fig. 5), PR-SB23 (Plate 6, Figs. 18, 19), PR-SB24 (Plate 6, Fig. 37)

Praewilliriedellum japonicum (Yao): PR-SB05 (Plate 2, Fig. 6), PR-SB24 (Plate 6, Fig. 36)

Praewilliriedellum robustum (Matsuoka): PR-SB23 (Plate 6, Fig. 20)

Praewilliriedellum sp. aff. robustum (Matsuoka): PR-SB17 (Plate 5, Fig. 21)

Pseudocrucella (?) elisabethae (Rüst): PR-SB30 (Plate 9, Fig. 17)

Pseudodictyomitra (?) sp.: PR-SB17 (Plate 5, Fig. 12)

Pseudodictyomitra aff. leptoconica (Foreman): PR-SB11 (Plate 4, Fig. 9)

Pseudodictyomitra carpatica (Lozyniak): PR-SB01 (Plate 1, Fig. 9)

Pseudodictyomitra cf. suyarii Dumitrica: PR-SB02 (Plate 1, Fig. 22)

Pseudodictyomitra leptoconica (Foreman): PR-SB30 (Plate 9, Fig. 7)

Pseudodictyomitra spp.: PR-SB11 (Plate 4, Fig. 10), PR-SB17 (Plate 5, Fig. 13), PR-SB30 (Plate 9, Fig. 8)

Pseudodictyomitrella (?) sp.: PR-SB17 (Plate 5, Fig. 4)

Pseudoeucyrtis corpulentus Dumitrica: PR-SB26 (Plate 7, Fig. 5)

Pseudoeucyrtis hanni (Tan): PR-SB26 (Plate 7, Fig. 7)

Quadrigastrum lapideum O’Dogherty: PR-SB27 (Plate 8, Fig. 21)

Ristola turpicula Pessagno & Whalen: PR-SB21 (Plate 6, Fig. 4)

Spinosicapsa (?) sp.: PR-SB08 (Plate 3, Figs. 11, 12), PR-SB14 (Plate 4, Fig. 33)

Spumellaria gen. et sp. indet.: PR-SB17 (Plate 5, Fig. 42), PR-SB27 (Plate 8, Fig. 22)

Squinabollum aff. fossile (Squinabol): PR-SB28 (Plate 9, Fig. 5)

Stichomitra (?) doliolum Aita gr.: PR-SB17 (Plate 5, Figs. 14, 15)

Stichomitra (?) spp.: PR-SB11 (Plate 4, Fig. 7), PR-SB23 (Plate 6, Fig. 13), PR-SB28 (Plate 9, Fig. 4), PR-SB17 (Plate 5, Figs. 5–7), PR-SB27 (Plate 8, Figs. 8, 9)

Stylosphaera spp.: PR-SB27 (Plate 8, Fig. 16)

Striatojaponocapsa (?) sp.: PR-SB14 (Plate 4, Fig. 34)

Striatojaponocapsa plicarum (Yao): PR-SB17 (Plate 5, Fig. 20)

Striatojaponocapsa synconexa O’Dogherty, Goričan & Dumitrica: PR-SB05 (Plate 2, Figs. 8, 9), PR-SB21 (Plate 6, Figs. 6, 7), PR-SB23 (Plate 6, Figs. 23, 24)

Svinitzium (?) mizutanii Dumitrica: PR-SB11 (Plate 4, Fig. 11)

Svinitzium depressum (Baumgartner): PR-SB01 (Plate 1, Fig. 8)

Svinitzium kamoense (Mizutani & Kido): PR-SB05 (Plate 2, Fig. 1), PR-SB23 (Plate 6, Fig. 15)

Syringocapsa (?) limatum Foreman: PR-SB30 (Plate 9, Fig. 16)

Tethysetta boesii (Parona): PR-SB01 (Plate 1, Fig. 7)

Tetraditryma sp.: PR-SB05 (Plate 2, Fig. 12)

Thanarla aff. veneta (Squinabol): PR-SB27 (Plate 8, Fig. 10)

Thanarla brouweri (Tan): PR-SB27 (Plate 8, Fig. 11)

Thanarla cf. conica (Aliev): PR-SB11 (Plate 4, Fig. 8)

Thanarla sp.: PR-SB26 (Plate 7, Fig. 3), PR-SB27 (Plate 8, Fig. 12)

Theocampe (?) sp.: PR-SB07 (Plate 2, Figs. 16–18)

Transhsuum cf. hisuikyoense (Isozaki & Matsuda): PR-SB24 (Plate 6, Fig. 34)

Transhsuum cf. maxwelli gr. (Pessagno): PR-SB24 (Plate 6, Fig. 35)

Transhsuum maxwelli gr. (Pessagno): PR-SB23 (Plate 6, Figs. 11, 12)

Transhsuum spp.: PR-SB14 (Plate 4, Fig. 28), PR-SB21 (Plate 6, Fig. 2)

Triactoma parablakei Yang & Wang: PR-SB24 (Plate 6, Fig. 39)

Triactoma spp.: PR-SB08 (Plate 3, Fig. 23)

Triversus (?) sp.: PR-SB05 (Plate 2, Fig. 2), PR-SB23 (Plate 6, Fig. 14)

Tuguriella sp.: PR-SB30 (Plate 9, Fig. 10)

Vallupus hopsoni Pessagno & Blome: PR-SB17 (Plate 5, Fig. 17)

Williriedellum carpathicum Dumitrica: PR-SB17 (Plate 5, Figs. 24, 25)

Williriedellum formosum (Chiari, Marcucci & Prela): PR-SB17 (Plate 5, Figs. 27, 28)

Williriedellum sp.: PR-SB17 (Plate 5, Fig. 26)

Williriedellum tetragona (Matsuoka): PR-SB05 (Plate 2, Fig. 10)

Williriedellum yaoi (Kozur): PR-SB21 (Plate 6, Fig. 8), PR-SB23 (Plate 6, Figs. 21, 22)

Xitus sp.: PR-SB23 (Plate 6, Fig. 17)

Zhamoidellum cf. testatum Jud: PR-SB30 (Plate 9, Fig. 14)