October 29th, 2008 20:06 EST
Dinosaurs vs. Crocodiles?
DINOSAURS vs. CROCODILES?
In a recent article in Science Steven Brusatte and Mike Benton have electrified the paleontology community by suggesting that dinosaurs made their thunderous ascension via pure luck and was not a product of their inherent superiority. Researchers claim that dinosaurs were competing with crurotarsans (ancestors of crocodiles) during the late Triassic Period, about 230 million years ago. Crurotarsans fossils are widespread, more so than dinosaur fossils, and were more diverse than early dinosaurs. It was just cosmic luck that crurotarsans went extinct while dinosaurs survived, otherwise we would have an Age of Crurotarsans instead of the Age of Dinosaurs.
If we were standing in the Late Triassic, 210 million years ago or so, and had to bet on which group would eventually dominate ecosystems, all reasonable gamblers would go with the crurotarsans, says Brusatte. Dinosaurs and we share a common fate: if an asteroid would not have caused the extinction of the dinosaurs, we would not be here today, and, likewise, if the crurotarsans would not have gone extinct, the same would be true with the dinosaurs. So runs the argument.
But what caused the crurotarsans to go extinct? No one knows. It could not have been another asteroid because then would be hard pressed to explain why the dinosaurs did not go extinct also. The reason must lie elsewhere. But if the crurotarsans were so successful, then one must ponder the question of why did they go extinct. We do know that crurotarsans and dinosaurs evolved rapidly during the Triassic Period, but the diversity of the crurotarsans can be easily explained by the nature of fossils.
Animals that die in semi-aquatic environments fossilize easier than in drier places where bones become quickly scattered and dry out. Crurotarsan fossils should be more numerous than early dinosaurs because of this reason, much like the widespread dugong bones in Florida.
The issue could be easily decided if we could match a dinosaur with a cruotarsan in some eerie Darwinian battle for supremacy. We can only do that with computer models. Yet there is a way we can test it in real life if we match a tiger in mortal combat with a crocodile. Who would win? The tiger of course. On land the crocodile is no match as its morphology is designed for amphibious attacks where the crocodile is the master. But put him on dry land and he is very vulnerable.
So, what happened to these early crocodiles who ventured into dino-territory? Most were eaten for lunch while the rest had to make a hasty retreat back into the swamps and lakes where they have remained ever since. I know we like to root for underdogs, but in this case supremacy rules in favor of the dinosaurs!