Small Curved Animals

©Nobu Tamura

During the Late Triassic and Early Jurassic therapsids called Cynodonts roamed the Earth and bridged gaps between what is a mammal and what is a reptile. One small animal (now classified as a reptile) that is of interest in this gap is Oligokyphus. Consisting of four species (Oligokyphus triserialis (Hennig E, 1922), Oligokyphus major (Kühne WG, 1956), Oligokyphus lufengensis (Luo Z & Sun A, 1993), and Oligokyphus sp.) this small detour from the mammalian topic of the month of September is well warranted. Originally named in 1922 by Hennig as a mammal, Oligokyphus has been redescribed many time as new species have been discovered and the remains of a vestigial joint in the jaw that retains the articulation of quadrate and squamosal has caused this small furry creature to be reclassified as a reptile. What can such a close association between reptile and mammal tell us about the small animals that lived with the dinosaurs and survived the extinction events at the end of the Mesozoic? How is a fossil representing a reptile genus included in the Cynodontia, a suborder that includes all living mammals? These are questions that we can hopefully answer this week, and that may cause the typical programming to be just a bit different from what we are used to here!