Report

A Basal Dinosaur from the Dawn of the Dinosaur Era in Southwestern Pangaea

Science  14 Jan 2011:
Vol. 331, Issue 6014, pp. 206-210
DOI: 10.1126/science.1198467

You are currently viewing the abstract.

View Full Text
As a service to the community, AAAS/Science has made this article free with registration.

This article has a correction. Please see:

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.

View Full Text

Cited By...