Grooves to tubes: evolution of the venom delivery system in a Late Triassic “reptile”

Venom delivery systems occur in a wide range of extant and fossil vertebrates and are primarily based on oral adaptations. Teeth range from unmodified (Komodo dragons) to highly specialized fangs similar to hypodermic needles (protero- and solenoglyphous snakes). Developmental biologists have documented evidence for an infolding pathway of fang evolution, where the groove folds over to create the more derived condition. However, the oldest known members of venomous clades retain the same condition as their extant relatives, resulting in no fossil evidence for the transition. Based on a comparison of previously known specimens with newly discovered teeth from North Carolina, we describe a new species of the Late Triassic archosauriform Uatchitodon and provide detailed analyses that provide evidence for both venom conduction and document a complete structural series from shallow grooves to fully enclosed tubular canals. While known only from teeth, Uatchitodon is highly diagnostic in possessing compound serrations and for having two venom canals on each tooth in the dentition. Further, although not a snake, Uatchitodon sheds light on the evolutionary trajectory of venom delivery systems in amniotes and provide solid evidence for venom conduction in archosaur-line diapsids.     

Turanoceratops tardabilis—the first ceratopsid dinosaur from Asia

Turanoceratops tardabilis from the Upper Cretaceous (Turonian) Bissekty Formation of Dzharakuduk, Uzbekistan, represents the first definite ceratopsid dinosaur recorded from Asia. Reexamination of the original and study of newly collected material indicate that Turanoceratops has well-developed supraorbital horns and apparently lacks a nasal horn. Turanoceratops is more derived than the more or less coeval Zuniceratops from the Moreno Hill Formation of New Mexico in the presence of double-rooted teeth and of two or three teeth in each vertical dental file.