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Basal dinosaur I
A big Thank you to Bruno for reporting about a Middle Triassic (?Ladinian)
ceratosaur found in Brazil. So after 2 years of W4TP (1) we've finally got
> The presence of large size "thecodonts" (?Prestosuchus)
> the traversodontid (?Massetognathus) and medium size dicynodnts
> (? Dinodontosaurus), as well the absence of Upper Triassic
> vertebrates, permit to infer a Middle Triassic (?Ladinian) age
> for stratigraphic levels of ceratosaur material.
It would be nice to have a radiometric dating. Same problem here as with the two
unnamed dinosaurs from Madagascar (2); Is it a late surviving fauna or not?
But this dating would nicely match with the late Ladinian-early Carnian
heterodontosaurian maxillary mentionened in (3) by Mickey Mortimer.
BTW: Does anybody knows how this dating was determined?
> These findings partially corroborate the hypothesis that the divergence
> between Ceratosauria and Tetanurae occurred before Upper Triassic.
> However the presence of a typical Ceratosauria in the Middle Triassic
> (?Ladinian) permit to suppose that such divergence could be have occurred
> at the Anisian or even before.
I would bet on it.
Heinz Peter Bredow
Oldest Dinosaur Discovery
early dino news from Madagascar
Flynn, J.J. et al. (1999). A Triassic fauna from Madagascar, including
early dinosaurs. Science 286 (5440): 763-765.
(3) http://www.cmnh.org/dinoarch/2001Jun/msg00407.html Re: ORNITISCHIANS :-)
BAEZ, A.M. and MARSICANO, C.A., 1998. A heterodontosaurian
ornithischian in the Upper Triassic of southern Patagonia? Gondwana 10:
Event Stratigraphy of Gondwana, Journal of African Earth Sciences