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-----Original Message----- From: Christoph Kulmann <kulmann@zfn.uni-bremen.de> To: dinosaur@usc.edu <dinosaur@usc.edu>; thylacosmilus@hotmail.com <thylacosmilus@hotmail.com> Date: Monday, March 06, 2000 8:35 AM Subject: Brontornis >Most of these large ground birds have been describes as very fast, >running predators, with laterally compressed beaks ideal for cutting >through their victim's flesh. This would be true for the later members >of this stock, inluding Andalgalornis (from Pliocene Argentina) and the >more fearsome Titanis (Florida, early Pleistocene). They lived in a >savannah-like environment, dominated by grassland, where their superior >speed probably gave them an advantage against the marsupial carnivores >of South America. > What would be more advantageous against mamalian predators speed or size? Probably both, speed at a smaller size range, and sheer mass in the larger forms. Both would have their advantages in open areas where hiding was not an option. ...and both would be enabled by an avian type respiratory system that could get rid of excess heat. I was just previously contemplating on how and why dinosaurs (in general) were so huge compared to most mammals today, and came to this conclusion it was a more efficient respiratory system that accounts for it. Correct me if I`m wrong (and I`m sure somebody will!....8^). |