A NEW LOOK AT MEMBERS OF THE SUPERFAMILY BRACHYOPOIDEA (AMPHIBIA, TEMNOSPONDYLI) FROM THE EARLY TRIASSIC OF QUEENSLAND AND A PRELIMINARY-ANALYSIS OF BRACHYOPOID RELATIONSHIPS

Two further finds of Keratobrachyops australis Warren (Amphibia, Temno spondyli, Chigutisauridae) from the Early Triassic Arcadia Formation o f Queensland provide new information concerning skull characters not n oted in the holotype. The holotype of Xenobrachyops allos Howie (Amphi bia, Temnospondyli, Brachyopidae) from the same locality is redescribe d following the discovery of several features not previously noted. In addition, new but fragmentary brachyopoid material from the Arcadia a nd overlying Glenidal Formations provides information on derived chara cter states within the superfamily. Controversy surrounds the correct familial composition of the superfamily Brachyopoidea, with the family Brachyopidae being allied by various authors with a diversity of othe r Triassic and Permian families. A cladistic analysis of a number of t hese families has been performed in an attempt to determine interfamil ial relationships. Our results support a brachyopid-chigutisaurid dich otomy within the Brachyopoidea, but also suggest the families Tupilako sauridae, Dvinosauridae and Saurerpetontidae are plesiomorphous member s of the clade. Further analysis of genera within the superfamily show s that several brachyopid genera cannot be distinguished by cladistic means, indicating a need for revision of its members. Future analysis may support the erection of a new brachyopoid family for species of Si nobrachyops and Xenobrachyops.