Monkey-Lizard Update: Vallesaurus described!
11:38 pm
Little Vallesaurus cenensis, a 16cm long Triassic drepanosaur from Northern Italy, has finally been officially introduced to the scientific community. Its name and photograph have been appearing in technical and popular literature since 1991, but the formal description of the holotype was just published this month in Rivista Italiana di Paleontologia e Stratigrafia.
Drs. Silvio Renesto and Giorgio Binelli, of the Universitá degli Studi dell’Insubria, have described the only known specimen of Vallesaurus, a single tiny skeleton preserved in limestone deposited in a Late Triassic sea. Like most other drepanosaurs, Vallesaurus was arboreal, making its way through the Triassic treetops with an opposable big toe and prehensile tail. These adaptations have led one researcher to call the group Simiosaurs, or “Monkey-Lizards,” although Renesto and Binelli use the more traditional family name: Drepanosauridae, after Drepanosaurus, the first of its family described.
Above is a painting of Vallesaurus made last year for the “Monkey-Lizards of the Triassic” gallery here at the HMNH. With a better description now published, I can see that its forelimbs should be shorter while its fingers should be larger and longer, and its snout should be quite a bit sharper at the tip. Of interest for future restorations are the patches of skin preserved on the holotype, showing “granular” scales on its head and lizard-like, overlapping scales on its tail. This is the first example of fossilized drepanosaur skin I’ve heard of.
Renesto and Binelli reveal another surprise when they examine how Vallesaurus and the drepanosaurs fit into the reptile family tree. But that’s a topic I’ll save for a future post…until then, check out Silvio Renesto’s newly updated Vallesaurus pages for photographs and more details.
Renesto S. & Binelli G. 2006. “Vallesaurus cenensis Wild, 1991, a drepanosaurid from the Late Triassic of Northern Italy.” Rivista Italiana di Paleontologia e Stratigraphia. 112: 77-94.
[...] The fossil, described by Dr. Silvio Renesto (previously mentioned here for his work on Triassic “Monkey-Lizards”), preserves a partial skeleton of Tanystropheus that includes the first reported example of the animal’s soft tissue. A few traces of skin show that Tanystropheus had subrectangular, non-overlapping scales on at least part of its body. But even more intriguing are the “wide patches of black material” preserved around the base of its tail. [...]