Marine Snouters of the Triassic II: Gunakadeit Rising

Alaska's own Gunakadeit joseeae by the amazing Gabriel Ugueto, or @SerpenIllus on the Twitters.

A very long time ago, I posted an essay about one of my favorite groups of Triassic marine reptiles: thalattosaurs. These lizard-shaped swimmers, while generally similar in body form, differ from one another quite strongly in terms of feeding adaptations. While Anshunsaurus and Askeptosaurus may seem, to our modern eyes, rather vanilla in their clearly faunivorous dentition, others strain credulity. Xinpusaurus, for example, possesses a bizarre notched upper jaw and, in some specimens, an elongate premaxillary spear which overshoots the the lower jaw by an impressive degree, calling to mind swordfish and swordfish-snouted ichthyosaurs. Thalattosaurus and its “claraziid” brethren have reduced, shell-crushing dentition and snouts which curve downward—Hescheleria takes this trend to a puzzling extreme. Thalattosaurs also occupied a wide range of body lengths (1-5 meters). While some were more terrestrially capable than others, the group never seemed to stray far from the nearshore niche.

Marine Snouters of the Triassic

The holotype of Thalattosaurus

When I started this humble blog in (dear lord) late 2014, I did not intend for it to becomes a blog dedicated to Triassic hellasaurs, but here we are. The more I read about the Triassic, the weirder it gets. For example, it seems like half of the reptiles alive during the Late Triassic were marine or at least semi-aquatic. We’re already covered hupehsuchians (twice) and those wonderful but woefully obscure saurosphargids. There was that recent post about underappreciated vancleaveans. Placodonts will come later and will probably spread across several posts—it was a big group. Today we’ll be talking about a diverse, well-known family of Triassic marine reptiles that still aren't well-known outside the paleo community: thalattosaurs.