Reconstructing the hand of the basal croc SMNS 12352

Figure 1. SMNS 12532 manus. Left: as originally interpreted. Middle: as reinterpreted to match sister taxa. Right: reconstructed using PILs.

Figure 1. SMNS 12532 manus. Left: as interpreted by Sereno and Wild 1992. Middle: as reinterpreted to match sister taxa, reversing the digit numbers. Right: reconstructed using PILs. A thick metacarpal 4 is odd. More derived taxa have a more gracile mt4 and digit 4.

Earlier here and here we looked at the rare and typically incomplete manus of several basal crocs. With the manus pattern established another look at the manus of SMNS 12352 (Fig. 1) is needed. Sereno and Wild (1992) interpreted the identity of the metacarpals 5-3 aligned. In the new interpretation matching other basal crocs, metacarpals 1-3 were aligned in the basic pattern with metacarpal 5 shorter than the others by half. I’m assuming here that there’s not much else of metacarpal 5 missing behind metacarpal 4.

That also changes the identification of the wrist elements, the ulnare and radiale.

References
Knoll F and Rohrberg K 2012. CT scanning, rapid prototyping and re-examination of a partial skull of a basal crocodylomorph from the Late Triassic of Germany. Swiss Journal of Geosciences. DOI 10.1007/s00015-012-0094-4.
von Huene F 1921. Neue Pseudosuchier und Coelurosaurier aus dem württembergischen Keuper. Acta Zoologica, 2, 329–403.
Sereno PC and Wild R 1992. Procompsognathus: theropod, ‘‘thecodont’’ or both? Journal of Vertebrate Paleontology, 12, 435–458.

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