Chroniosuchus paradoxus (Vjuschkov 1957) Early Permian ~1.5m in length, was considered an aberrant pre-reptile by all prior workers, but here it nests within the Archosauromorpha. Derived from a sister to Solenodonsaurus, Chroniosuchus was a sister to Chroniosaurus.

Distinct from Chroniosaurus, the skull of Chroniosuchus was taller with a taller naris and antorbital fenestra and a higher orbit. The teeth were not oriented posteroventrally, but slightly anteroventrally. The quadratojugal and postorbital were deeper.

Madygenerpeton pustulatus (Schoch, Voigt & Buchwitz, 2010 ) middle to late Triassic ~10 cm skull length, was derived from a sister to Chroniosuchus and converged with the large eryopids of its time. Here the naris was smaller, the orbit was higher on the skull (like a hippopotamus) and more teeth lined the upwardly curved jawline. The solid palate was peppered with tiny teeth.

The highly derived dorsal dermal plates enabled lateral undulation by sliding past one another like plates in an airport baggage conveyor system.

Buchwitz M and Voigt S 2010. Peculiar carapace structure of a Triassic chroniosuchian implies evolutionary shift in trunk flexibility. Journal of Vertebrate Paleontology 30 (6): 1697–1708. doi:10.1080/02724634.2010.521685

Novikov IV and Shishkin MA 2000. Triassic Chroniosuchians (Amphibia, Anthracosauromorpha) and the evolution of trunk dermal scutes in bystrowianids. Paleontological Journal 34 (Suppl. 2): 165-178.

Schoch RR, Voig S and Buchwitz M 2010. A chroniosuchid from the Triassic of Kyrgyzstan and analysis of chroniosuchian relationships. Zoological Journal of the Linnean Society 160: 515–530. doi:10.1111/j.1096-3642.2009.00613.x

Vjuschkov BP 1957. New Unusual Animals from the Tatarian Deposits of the European part of the USSR, Dokl. Akad. Nauk SSSR 113: 183–186.

wiki/Chroniosuchus

wiki/Madygenerpeton