Procompsognathus triassicus Fraas, 1913

Rauhut, Oliver W. M., 2003, The interrelationships and evolution of basal theropod dinosaurs, Special papers in palaeontology 69, pp. 1-213 : 16-17

Procompsognathus triassicus Fraas, 1913 ; metataxon

Age . Norian.

Occurrence. Weisser Steinbruch, Pfaffenhofen, Baden-WÜrttemberg, Germany; Middle Stubensandstein of the middle Keuper.

Diagnosis. Small theropod; differs from the contemporaneous Lilienstemus liliensterni in the overall size and the greater elongation of the posterior dorsal vertebral centra. Differences from the contemporaneous taxon Coelophysis are difficult to establish due to the inadequate preservation of the type specimen and the probable close relationships of these two taxa. However, the distal hindlimb elements are slightly more elongated in Procompsognathus triassicus than in any specimen of Coelophysis measured by Colbert (1989), although this might be size-related (Holtz 1 995b), and the scapular blade seems to be wider in the latter taxon. Furthermore, even if the holotype is a juvenile individual, adult P. triassicus probably were of slightly smaller average size than Coelophysis . Procompsognathus differs from herrerasaurids in the presence of pleurocoels in the cervical vertebrae, the much more elongated posterior dorsal vertebrae, the elongated distal hindlimb elements, and attachment of Mt I to the shaft of Mt II and not reaching the ankle joint proximally. The genus differs from Alwalkeria maleriensis in the more elongated dorsal vertebrae and the shorter femoral neck. Differences from Liliensternus airelensis are again found in the more elongated posterior dorsal vertebrae of P. triassicus and the significantly larger size of the former taxon.

Remarks. Procompsognathus triassicus was named by Fraas (1913) on the basis of ‘... the major part of an extremely delicate dinosaur skeleton, including the skull, the middle part of the body with the legs and the anterior part of the tail ’ (p. 1099; my translation). In 1992, Sereno and Wild reviewed the type material and argued that the skull and the postcranial skeleton represent different animals. Thus, the name Procompsognathus is used here only for the partial postcranial skeleton (see Rauhut and HungerbÜhler 2000).