A DROMAEOSAURIDAE CLAW FROM THE GRÈS À REPTILES FORMATION (UPPER CRETACEOUS, CAMPANIAN-MAASTRICHTIAN), FRANCE

Vol. 2, 2019. - 118562
Oral
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Abstract

The specimen D-25 was collected at the Grès à Reptiles Formation (Upper Cretaceous, between the Campanian and the Maastrichtian), France (Fox-Amphoux - Var), in the 1980s and has since been housed in the collection of the _Musée_ _des Dinosaures_ (Espéraza - Aude). This formation presents many vertebrate fossils and already has records of other dinosaurs, including specimens associated with the Dromaeosauridae (Theropoda, Maniraptora). However, only the taxon _Variraptor mechinorum_ is known for the region based on few post-cranial elements, but no claws present. The referred material is a very curved and hyperextensible ungual phalanx of the digit II of the foot, which is a typical feature in Deinonychosauria being accentuated in Dromaeosauridae. The ungual is partially preserved missing a small portion of the distal curvature. The method proposed by Senter (2007) to evaluate to which limb belongs isolated Dromaeosauridae claws was applied. This resulted in the detection of a shallow flexor tubercle that does not extend far ventral to the articular facet, absence of a proximodorsal lip and, if the articular facet is oriented vertically, the dorsal margin arches below the degree of the articular facet (pedal ungual above the articular facet extends less distally). These features suggest that it is a possible pedal claw of Dromaeosauridae. Currently, the specimen is being described in further detail and we will use a geometric morphometric approach to compare and detect quantitatively and qualitatively the morphospace variation present in this specimen in relation to the other dromaeosaurids. Thus, giving greater attention to undisclosed materials may further broaden knowledge about the broad morphology of this clade.

Institutions
  • 1 Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ.
  • 2 Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, RJ e Instituto de Geociências, Universidade Estadual de Campinas, Campinas, SP.
Track
  • Forma: Morfologia e Descrições