URUGUAYSUCHIDAE GASPARINI, 1971

Soto, Matías, Pol, Diego & Perea, Daniel, 2011, A new specimen of Uruguaysuchus aznarezi (Crocodyliformes: Notosuchia) from the middle Cretaceous of Uruguay and its phylogenetic relationships, Zoological Journal of the Linnean Society 163 (5), pp. 644-645 : 644-645

URUGUAYSUCHIDAE GASPARINI, 1971

Type genus: Uruguaysuchus Rusconi, 1933 .

Diagnosis: The family Uruguaysuchidae is supported by two unambiguous synapomorphies: surangular forming approximately one-third of the glenoid fossa and dorsal surface of mandibular symphysis strongly concave and narrow, trough shaped. See discussion in the section on ‘Phylogenetic relationships’ below.

Comments: Although it is still premature to give a phylogenetic definition of the family Uruguaysuchidae (as the clade is only weakly supported), it should be noted that the only existing phylogenetic definition (that of Carvalho, Ribeiro & Avilla, 2004) is incomplete. A node-based (employing both Uruguaysuchus aznarezi and Araripesuchus gomesii as internal specifiers) or stem-based (using also Notosuchus terrestris as the external specifier) phylogenetic definition is equally possible. However, it should also be noted that if eventually Uruguaysuchus turns out to be closer to Ziphosuchia (instead of being the sister taxon of Araripesuchus ), a node-based Uruguaysuchidae would be redundant with Notosuchia , and a stem-based Uruguaysuchidae would include a paraphyletic array of basal notosuchians.