Primeros datos descriptivos sobre nuevos reptiles arcosaurios del Triásico de Ischigualasto (San Juan, Argentina)

Abstract

Tn this article the first diagnostic and descriptivo data of two new genera and apecios of Archosaurian Reptils from the Mesotriassio ot Argentine are given. The mew fossil Reptils come from Ischigualasto, in the North of the Province of San
Juan and were discovered by the Instituto « Miguel Lillo» Expedition, in April-May, 1959. The author álso discusses the sistematio relationschips and phylogenetical significance of the described new genera, but ouly preliminarly. One of the new
reptils is named Saurosuchas galileí, n. gen., u. sp. and is represented by a nearly complete skull and much of the skeleton of another specimen. It obvionsly belongs to the suborder Pseudorachia of the order Zkccodontía, and to superfamily Ornitosuchoidea. Ut is possibly a representive of the fiumily Ornitosuchidae, but a giant form, witb a skull of abont 65 em of total length avd an estimated length of tho entire animal of abont live meters and a half, The other new reptil is only represented by skull material, among which is an excellently preserved and nearly complete skull with mandibles. lt is typically a erocodiloid reptil, and the name Prolerochampsa barrionuecol, N, gen., n. sp, is proposed for it, Tentatively itis assigned to the
asuborder Protosuchia ol the order Crocodilia, bmt it does not seem to belong to the family Notochampeidare, in which the three previonslg known protosuchian genera are grouped, The significance of Saurosachus for the problem of the origin ofsaurischian dinosanrs and, more closely, of the origin of carnosanrians ls obvioús, in the mame manner as is obvios the significanes ol Proterochampsa Perm stadies in erocodilian origins, The author promises more detailed acconvtís on these problema in mture work.