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Keywords:

  • Araripe Basin;
  • Brazil;
  • Early Cretaceous;
  • eusuchian evolution;
  • postcranial anatomy

A third specimen of Susisuchus anatoceps is described. The new material comprises postcranial remains, including an almost complete sequence of cervical vertebrae, prothoracic and posterior dorsal vertebrae, and osteoderms from dorsal and ventral shield, scapula, coracoid and the forelimb. The new specimen (MPSC-R1136) was recovered from the Crato Formation (Lower Cretaceous) of the Santana Group, near Nova Olinda municipality, Ceará State, Brazil. Some cervical vertebrae show slightly procoelous centra and at least one of these vertebrae is platycoelic, a feature reported for the first time in Susisuchus. Nevertheless, dorsals have amphicoelic centra. The sagittal segmented dorsal shield comprises two paravertebral rows of square osteoderms and two accessory rows of ellipsoidal osteoderms on each side of the trunk. Three diagnostic characters are present in the new Susisuchus specimen: the proximal and distal articulations of the ulna have about the same width and are thicker with respect to the shaft; the scapular blade has posterior concave and anterior straight margins; and the ungual phalanges are present only on first and second digits of the manus. A phylogenetic analysis of Susisuchus anatoceps based on new characters of MPSC-R1136 in addition to the holotype, and employing a previous data set of Jouve, placed this taxon as a basal member of the advanced neosuchian clade.

© 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163, S273–S288.