Tropidosuchus romeri (Arcucci 1990, holotype PVL 4601) Late Triassic was originally considered a lagosuchid like Marasuchus. Here this chanaresuchid is more gracile than Chanaresuchus, but had longer limbs like Lagerpeton. A second, more complete specimen (see below) has a pes more like that of Lagerpeton and a shorter forelimb, judging by the smaller humerus.
Distinct from Chanaresuchus, the skull of Tropidosuchus had a larger orbit and longer teeth. The antorbital fenestra was tiny.
The pes of Tropidosuchus was quite similar to that of Chanaresuchus in emphasizing digit II with a slender metatarsal IV. The tarsals did not have a calcaneal heel. The second specimen did not have a gracile metatarsal 4 and a longer metatarsal 1.
The PVL 4606 specimen attributed to Tropidosuchus (Bonaparte 1994) has a foot morphology is much closer to Lagerpeton. This specimen also has a smaller humerus than Tropidosuchus. The pelvis is distinct from both genera. Chevrons are missing from this specimen. Chevrons may be missing form this clade, which otherwise shares a relatively wide tail base according to the caudal transverse processes. |
