Dinosaurs May Have Been Neither Warm-blooded Nor Cold-Blooded 54
An anonymous reader writes An article published in Science (abstract) points to the possibility that dinosaurs were mesotherms more akin to modern Tuna. Their internal temperature would have been warmer than their surrounding environment, conferring on them the ability to move more quickly than any ectotherm ("cold blooded" animal), but wouldn't have been constant or as warm as any endoderm ("warm blooded" animal). Their energy use and thus their necessary food intake would have been greater than an ectotherm, but much less than an endotherm. In order to arrive at this possibility, bone growth rings in fossilized bone were used to establish growth rates and then compared to modern ectotherms and endotherms.
Re:New theory? (Score:5, Informative)
It's nice that they've come up with more evidence for it, but it would also be nice if every time someone tested an idea out they didn't feel compelled to pretend they were the first to have it.
I think this is a very unfair attack. The authors of this paper did not make the claim you've attributed to them. They start the actual article with this.
Over the past few decades, the original characterization of dinosaurs by early paleontologists as lumbering, slow-metabolizing ectotherms has been challenged.
There are 397 references given in this paper. I think they're clear about what previous science existed. Even the lay article doesn't pretend this is new research it talks about compiling existing research.
Re:Relation of birds to dinosaurs (Score:5, Informative)
Ichthyosaurs, Plesiosaurs and Mosasaurs are Lepidosaurs (the group containing lizards and snakes), which is a different branch off Diapsids from Archosaurs (the group containing dinosaurs and birds and crocodiles). Megalodon is a shark, which is a kind of fish and therefore not even a Diapsid.