[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index][Subject Index][Author Index]

Re: Triassic protofeathers and fake-heads

Rob wrote:
What would you say to the presence of armour in late Triassic ornithischians then, if they were indeed found...
Rob, it would not surprised me if some late Triassic ornithischians had some armor. I'm just saying that they would generally have less armor than their Cretaceous descendants. We see a similar sort of arms race with trilobites in the Paleozoic. You don't find the most spiny trilobites in the Cambrian----they came later as the Paleozoic arms race escalated. I would expect something similar among non-theropod dinosaurs during the Mesozoic. And in the Cenozoic, armadillos armour didn't just suddenly appear. It gradually improved as its predators got bigger and smarter.
Jaime said that my hypothesis was "ecologically" unsound because predator on predator on attacks are rare. But I wasn't talking about predators on predators. I was talking about early theropods attacking early ornithischians and sauropodomorphs.
David's objections didn't make sense to me either. It's the predators that are doing most of the brain development. Gazelles concentrate on speed to escape, and their predators must compensate by a combination of some speed increase, but mostly on agility and the brainpower to harness that agility as the prey got faster and more agile.
There was a Mesozoic arms race just as surely as their was a Cenozoic arms race. And more and more tetrapods had bigger and more complicated brains than their Paleozoic ancestors. Sure brains are metabolically expensive, but the advantages must outweigh the costs, or we would all still have simple amphibian brains. Even if the mean hadn't gone up (and that is arguable), the upper end brains have clearly been increasing in size and mental ability.
The biggest doesn't necessarily have to be the smartest brain, but I certainly couldn't be communicating with you all if I had the brain of a therapsid, much less the brain of a Devonian amphibian. There are clearly general trends from Paleozoic to Mesozoic to Cenozoic that are so obvious, it puzzles me why people would want to argue against it. Is the word "progress" so politically incorrect that we have to ignore the obvious trends. This just seems like an overreaction to past mistakes, and the pendulum gets swung too far the other way. A Komodo dragon may be dumb compared to its mammalian or avian prey. But I bet it takes more brain power for them to ambush their prey than for a frog to stick out its tongue and catch an insect.
--------- Ken

Chat with friends online, try MSN Messenger: http://messenger.msn.com