Monday, July 2, 2012

Sciurumimus albersdoerferi: Is it a girl? Is it a boy? No, it’s a Megalosauroid…


Remember the perfectly preserved complete articulated skeleton of a young dinosaur that was presented to the press last year? Well, the paper describing it has finally been published in the Proceedings of the National Academy of Science. ‘Otto’, also known as the Kelheim theropod,  has now a proper scientific name, Sciurumimus albersdoerferi, the generic name meaning “Squirrel mimic” (in reference to its bushy tail) and the specific name honors Raimund Albersdörfer, who made the specimen available for study.  The fossil was found near Painten, Bavaria (Germany) and dates from the upper Kimmeridgian. Besides the exquisite state of preservation of the fossil that shows evidence of proto-feathers covering at least part of the body, the importance of Sciurumimus stems from its phylogenetic position on the dinosaur evolutionary tree.  It is a megalosauroid, sister taxon to the likes of Megalosaurus, Torvosaurus and Eustreptospondylus, therefore representing the most basal theropod showing direct evidence of feathers, and the most complete megalosauroid remain yet discovered. This raises the interesting possibility that feathers might be a common inherited trait to all theropods and even to all dinosaurs if indeed the feather-like structures found on Tianyulong (an heterodontosaur) and quills on the tail of Psittacosaurus (a Ceratopsian) are analogous structures.

References:

Oliver W. M. Rauhut, Christian Foth, Helmut Tischlinger, and Mark A. Norell (2012) Exceptionally preserved juvenile megalosauroid theropod dinosaur with filamentous integument from the Late Jurassic of Germany, PNAS, Advanced online publication.