SilesianTriassic

Reptilia indet.

Dating uncertain – Upper Roeth or Lower Muschelkalk (Olenekian or Anisian)

Upper Silesia, Poland

The specimen is an incomplete, fragmentary medial gastralium (“abdominal rib”) of an unidentified reptile. As mentioned in another post, the gastralia are non-diagnostic and do not support taxonomic identification.

The specimen, although incomplete, clearly illustrates the morphology of these dermal bones. The bone is symmetrical, V-shaped, with the central part (visible short anterior process) located along the body’s axis of symmetry. The distal parts (in this case, not preserved) did not form the head but were pointed. These ends were flexibly connected to the lateral gastralia, creating a flexible structure. In turn, a set of these bones formed a gastral basket, protecting the organs and stiffening the ventral side of the animal.

Such finds are often associated with Nothosauridae, but as mentioned above, the lack of diagnostic features makes such a designation an oversimplification, if not an error.