Table 1 Studied specimens of Grammatodon inaequivalvis (Goldfuss) from Northern Switzerland (PIMUZ numbers) and Southern Germany (SMNS numbers)

PIMUZ 6008

Schinznach

22

13

1.69

Double-valved, butterflied, slightly deformed, cast with periostracum

PIMUZ 6009

Schinznach

26

14.5

1.79

Right valve, undeformed, cast with periostracum

PIMUZ 6246

Schinznach

17

10

1.70

Double-valved, butterflied, cast with periostracum

PIMUZ 6247

Schinznach

17.5

11

1.59

Left valve, undeformed, cast

PIMUZ 6248

Schinznach

18

11.5

1.57

Right valve, undeformed, cast with periostracum

PIMUZ 6249

Schinznach

16.5

10

1.65

Left valve, undeformed, cast

PIMUZ 6253

Schinznach

13.5

8

1.69

Double-valved, butterflied, cast with periostracum

SMNS 67137/1

Hohenstaufen

25

16

1.56

Left valve, undeformed, calcite

SMNS 67138/1

Weilerstoffel

33

18

1.83

Double-valved, right valve displaced dorsally, aragonite

SMNS 67138/2

Weilerstoffel

23

12.5

1.84

Double-valved, left valve displaced dorsally, aragonite

SMNS 67139/1

Balingen

27

17

1.59

Double-valved, right valve displaced dorsally, aragonite

SMNS 67139/2

Balingen

25

15

1.67

Double-valved, left valve displaced dorsally, aragonite

SMNS 67139/3

Balingen

23

16

1.44

Double-valved, left valve displaced dorsally, aragonite

SMNS 67139/4

Balingen

N/A

N/A

N/A

Double-valved, strongly deformed, aragonite

SMNS 67140/1

Frickenhausen

25

16

1.56

Double-valved, right valve displaced dorsally, calcite

SMNS 67140/2

Frickenhausen

24

14

1.71

Right valve, undeformed, calcite

SMNS 67140/3

Frickenhausen

23

13.5

1.70

Left valve, undeformed, calcite

SMNS 67140/4

Frickenhausen

18.5

12

1.54

Double-valved, right valve displaced dorsally, calcite