Speaking of evolution;

Labrador Retriever-Sized Herbivore Shakes up Theories of Dino Evolution

According to the Nature editor’s summary, Asilisaurus is an early member of the Ornithodira line, the “avian” group that broke off from the crocodile group during the time before dinosaur emergence. What does that mean for the dinosaur ancestry? The balance of opinion has alternated between more reptilian ancestors, which walked on all fours, and two-legged animals that had bird-shaped bodies but couldn’t fly. Recently, the idea of two-legged dino ancestors had been winning out, but the new find yanks the trend back toward quadrupeds [ScienceNOW].

Paul Barrett of London’s Natural History Museum says: “The creatures share a lot of features with dinosaurs,” he said. “They show us an intermediate step between more primitive reptiles and the more specialised dinosaurs” [BBC News]. While dinos hung around for 165 million years or so, the silesaurs like Asilisaurus lived only 45 million years before extinction. However, since silesaurs and true dinosaurs diverged from a common ancestor, the two groups should have existed during the same time frame [National Geographic]. Thus, the earliest emerging dinos might stretch back even to the time frame of this Asilisaurus, more than 240 million years ago.

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