HUNT, Adrian P., Mesalands Dinosaur Museum, Mesa 	
		Technical College,  Tucumcari, NM 88401
	LUCAS, Spencer G., NM Museum of Natural History and 	
		Science, Albuquerque, NM 87104
	HUBER, Phillip,  Dept. of Education, University of 	
		Bridgeport,  Bridgeport, CT 06601
	LOCKLEY, Martin G., Dept. of Geology, University of 	
		Colorado at Denver,  Denver. CO 80227

The Late Triassic encompasses one of the greatest faunal turnovers 
among nonmarine tetrapods. During this time interval several 
significant groups originated (e. g., mammals, dinosaurs and 
pterosaurs), others became extinct (primitive crurotarsans = 
"thecodonts") and others suffered a significant decline (non-
lissamphibian temnospondyls and non-mammalian therapsids).
	Late Carnian (early Tuvalian) faunas are the most 
cosmopolitan as evidenced by the distribution of the parasuchian 
Paleorhinus and the metoposaurid Buettneria. Late Tuvalian and 
Norian faunas exhibit increased provinciality (e.g., distribution of 
aetosaur Paratypothorax). By the late Norian-Rhaetian there are no 
cosmopolitan body-fossil taxa although ichnotaxa, which probably 
represent Linnaean families, such as "Pseudotetrasauropus" have 
broad ranges. Early Jurassic faunas are again cosmopolitan.
	Three broad biogeographic provinces existed in the Carnian-
Norian: northern Laurasia (Europe, Greenland, ?northeastern North 
America), southern Laurasia and northern Gondwana (Western North 
America, Morocco) and southern Gondwana (India, South Africa, 
Argentina, Brazil).
	Dinosaurs are rare in late Carnian faunas and become more 
numerous and speciose in the Norian and Rhaetian. Taphonomic data 
indicates that dinosaurs were ecologically separated from "typical" 
semi-aquatic, crurotarsan-dominated faunas and lived in drier 
environments. There is a prosauropod acme zone in the late Norian-
	There is no evidence for a major end-Carnian extinction. 
Extinction, or near extinction, of several groups (dicynodonts, 
rhynchosaurs, trilophosaurs) was insignificant in comparison to the 
diversity of those that were unaffected. The end-Rhaetian event is 
essentially the extinction of primitive crurotarsans, many of which 
were associated with semi-aquatic communities.