Since this initial work, additional studies have been conducted on the vertebrate faunas of the Woodbine Formation, most notably on the Woodbine archosaurs
(Lee 1997; Head 1998; Winkler & Jacobs 2002; Main 2005).
evolved along two different paths, one of which gave rise to the crocodilian ancestors of crocodiles and alligators.
vary tremendously, from marine crocodiles to bipedal, flying birds.
Phylogenetic relationships of the crocodylomorph archosaurs
, whose living relatives are birds and crocodilians, are of interest to scientists because it's thought that they led to animals like Asilisaurus, a dinosaur-like animal, and Nyasasaurus parringtoni, a dog-sized creature with a five-foot-long tail that could be the earliest dinosaur.
Dinosaurs are just part of this archosaur
diversification, an explosion of new forms soon after the Permian extinction," Nesbitt said.
We looked back approximately 250 million years, to the Archosaurs
, the group which gave rise to crocodiles and alligators as well as modern birds.
Dinosaur heresy--dinosaur renaissance: why we need endothermic archosaurs
for a comprehensive theory of bioenergetic evolution.
It's) a simple hinge and not a more complex rotary joint like the ankles of crocodile-line archosaurs
, lizards and even humans," he said.
Even though early archosaurs
were commonly thought to be primarily carnivorous, A.
It further implies that one-way airflow evolved in archosaurs
earlier than once thought, and may explain why those animals came to dominance in the Early Triassic Period, after the extinction and when the recovering ecosystem was warm and dry, with oxygen levels perhaps as low as 12 percent of the air compared with 21 percent today.
Crocodilians are the sole surviving reptilian archosaurs
, a group of ancient reptiles that includes dinosaurs and gave rise to birds.
A major part of the problem is that most descriptions presenting these newly discovered fossils of Cretaceous archosaurs
were done without thorough systematic studies but simply assuming that they were dinosaurs if they lacked definite avian features whatever these may be.
Archosaurian reptiles from the Evangeline Member comprise various taxa of crocodile-line archosaurs
But Farmer cautions that because lizard lungs have a different structure than bird and alligator lungs, it is also possible that one-way airflow evolved independently about 30 million years ago in the ancestors of monitor lizards and about 250 million years ago in the archosaurs
, the group that gave rise to alligators, dinosaurs and birds.