Fig. 1

In the conventional practice of quadrupedal trackmaker size estimation, a line segment is constructed between two pes tracks (LP1 and RP1, above) and another between two manus tracks (LM2 and RM2). The separation GA between the centers of these two line segments is often used as the basis for estimating the trackmaker’s gleno-acetabular distance D_GA, subject to a correction to account for the presumed gait (see text), and having selected the correct pair of manus tracks to associate with the given pair of pes tracks. Perhaps contrary to intuition, an exquisitely preserved and regular trackway such as BEB-500-S4 (lower), one of the trackways used in this study, could have been created by a quadruped of many possible sizes and many possible gaits