LATE TRIASSIC TETRAPOD BIOCHRONOLOGY OF PANGAEA

	LUCAS, Spencer G., New Mexico Museum of Natural History 
		and Science,  1801 Mountain Rd. NW, Albuquerque, 
		NM  87104
	HUNT, Adrian P., Mesalands Dinosaur Museum, Mesa 	
		Technical College,  Tucumcari, NM 88401
	HUBER, Philip, Dept. of Education, University of Bridgeport, 
		Bridgeport, CT 06601

	Tetrapods provide a concise means by which Late Triassic 
nonmarine strata across much of Pangaea can be correlated.  Early 
Carnian (Julian) faunas are poorly represented, and include Laurasian 
assemblages dominated by labyrinthodonts with relatively few 
thecodonts (Schilfsandstein, T-4 Morocco) and a Gondwanan 
assemblage (Caturrita Fm.) marked by an abundance of 
rhynchosaurids. Late Carnian (early Tuvalian) faunas are widespread, 
and defined by a diverse association that includes numerous 
labyrinthodonts, the last rhynchosaurs, the first definite phytosaurs, 
aetosaurs and dinosaurs, dicynodonts and sphenodontids.  Of 
importance are the near-cosmopolitan distribution of Paleorhinus on 
four continents, and it's occurrance in marine (dilleri  zone) strata, 
thus providing a critical tiepoint to the standard Alpine stage 
chronology.  Well-documented early Tuvalian faunas include those 
from the basal Chinle Group, Pekin and Wolfville Fms. (Newark), 
Lossiemouth Fm. (Scotland), interval T-5 (Morocco), Maleri (India) 
and Ischigualasto (Argentina) Fms. and Blasensandstein. Late 
Tuvalian faunas are largely restricted to North America and are 
dominated by an association of metoposaurids, rutiodontid phytosaurs 
and aetosaurs from the lower Chinle Group and type Pekin, Cumnock, 
New Oxford, upper Stockton Fms of the Newark.  Other Newark 
faunas of this age include aquatic lepidosaur-dominated assemblages 
from the Cow Branch and Lockatong Fms. and a terrestrial therapsid 
assemblage from the Turkey Branch Fm.  Late Tuvalian faunas from 
other regions of Pangaea may occur in the Tiki (India) and basal Los 
Colorados (Argentina) Fms., but these have not been described. 
	Early to middle Norian faunas are well-represented in the 
middle Chinle Group, Newark Supergroup, Fleming Fjord Fm. 
(Greenland), German Keuper and lower Elliot Fm. (S. Africa).  
Laurasian faunas show a certain degree of provinciality, as illustrated 
by the abundance of prosauropods and turtles in the Stubensandstein-
Knollenmergel and Fleming Fjord Fm. compared to the metoposaur-
phytosaur-aetosaur fauna from the middle Chinle Group.  
Nonetheless, the middle Keuper and middle Chinle share a number of 
taxa (pseudopalatine phytosaurs, Paratypothorax) that support their 
correlation, while the Newark contains a transitional fauna that 
includes indet. metoposaurs, phytosaurs and the aetosaur Aetosaurus, 
a taxon common to the Stubenstandstein, Fleming Fjord Fms. and 
marine (columbianus zone) strata in Italy.  Laurasian late Norian-
Rhaetain faunas are characterized by a high relative abundance of 
theropod dinosaurs and/or their footprints in the upper Chinle and 
Newark, while coeval European faunas include a variety of 
sphenodontids and mammals, in addition to dinosaurs, 
crocodilomorphs and a depauperate record of largely indet. 
labyrinthodonts and thecodonts.  The upper Elliott and Los Colorados 
faunas are marginally similar to European assemblages in terms of 
composition, but lack independent age control and are tentatively 
assigned a Rhaetian age.  

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