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Re: Eodromaeus, new basal theropod from Triassic in Argentina

Wow, Eoraptor a Sauropodomorpha...


Roberto Takata

On Thu, Jan 13, 2011 at 9:02 AM,  <bh480@scn.org> wrote:
> From: Ben Creisler
> bh480@scn.org
> For anyone who was holding his/her breath, you can
> breathe again. The paper is officially out, so if someone
> else has not mentioned it yet:
> Ricardo N. Martinez, Paul C. Sereno, Oscar A. Alcober,
> Carina E. Colombi, Paul R. Renne, Isabel P. Montañez and
> Brian S. Currie (2011)
> A Basal Dinosaur from the Dawn of the Dinosaur Era in
> Southwestern Pangaea
> Science 331 (6014): 206-210 (14 January 2011)
> DOI: 10.1126/science.1198467
> http://www.sciencemag.org/content/331/6014/206.abstract
> Abstract
> Upper Triassic rocks in northwestern Argentina preserve
> the most complete record of dinosaurs before their rise
> to dominance in the Early Jurassic. Here, we describe a
> previously unidentified basal theropod, reassess its
> contemporary Eoraptor as a basal sauropodomorph, divide
> the faunal record of the Ischigualasto Formation with
> biozones, and bracket the formation with 40Ar/39Ar ages.
> Some 230 million years ago in the Late Triassic (mid
> Carnian), the earliest dinosaurs were the dominant
> terrestrial carnivores and small herbivores in
> southwestern Pangaea. The extinction of nondinosaurian
> herbivores is sequential and is not linked to an increase
> in dinosaurian diversity, which weakens the predominant
> scenario for dinosaurian ascendancy as opportunistic
> replacement.
> Also
> Michael Balter
> Pint-Sized Predator Rattles The Dinosaur Family Tree
> Science 331 (6014): 134 (14 January 2011)
> DOI: 10.1126/science.331.6014.134
> http://www.sciencemag.org/content/331/6014/134.short
> Summary
> On page 206 of this week's issue of Science, a team
> working in Argentina reports the discovery of a very
> early dinosaur—possibly a distant ancestor of
> Tyrannosaurus rex—that lived about 230 million years ago,
> during what paleontologists call the dawn of the
> dinosaurs. The researchers say the new finds—two
> specimens that together make up a nearly complete
> skeleton of a diminutive, 1-meter-long dinosaur—and
> neighboring fossils show that dinosaurs didn't outcompete
> other reptiles, but rather gradually replaced them as
> their predecessors died out for other reasons. More
> controversially, the team says the fossils show that one
> of the most well-known early dinosaurs, Eoraptor, long
> considered an ancestor of meat eaters like T. rex, was
> actually an ancestor of gigantic plant-eating dinosaurs
> like Apatosaurus.
> There's a cool video also at:
> http://news.discovery.com/videos/dinosaurs-dawn-runner-
> sheds-light-on-dino-evolution.html