So, the Obnoxious Kid in Jurassic Park

Forum Monk · Post by **Forum Monk** » Sat Sep 22, 2007 12:19 pm

I was thinking more deeply about T-Rex and in particular the copious numbers of kilo-calories it would take to move him; especially at any velocity greater than lumbering. It seems unlikley to me, such energy can be had from protein sources alone. One of the best energy sources for carnivores is fat.

Now, if T-Rex obtained the energy he required from fat, then his favorite food must have stored fat and what cold-blooded animal does that? Perhaps warm-blooded, fat storing, prey where necessary to support the evolution of such large predators/scavengers.

Digit · Post by **Digit** » Sat Sep 22, 2007 12:47 pm

Grrrrh! Monk, Dinos are cold blooded because the first modern find was a tooth that looked like a giant Iguana, therefore the tooth bearer was a giant lizard, and everybody knows lizards are cold blooded.
Any detective using that logic would have Jack the Ripper as a social worker!

Post by **Minimalist** » Sat Sep 22, 2007 12:54 pm

Yeah...birds are not cold-blooded.

Digit · Post by **Digit** » Sat Sep 22, 2007 1:01 pm

And though I am not suggesting this as proof Min, just how many modern terrestial, cold blooded animals, are herbivores?

Post by **Minimalist** » Sat Sep 22, 2007 1:46 pm

None that I know of.

Digit · Post by **Digit** » Sat Sep 22, 2007 2:00 pm

I can make it one Min. The marine Iguana, but it sure doesn't seem to be a common trait does it, and what holds good today may well have held good for the past.
T Rex types are strange types, if I were designing him I would describe the spine as a cable braced cantilever as there appears to be attachment points along the top of the spine for sinews, the cables.
This would infer that the tail was flexible in the horizontal but much less so in the vertical. Also the head seems to lack sufficiently large attachment points for muscles capable of lifting the head very far. If you stare at the skull from the front its vision only overlaps with the head in a predominantly vertical plane.
My conclusions are that the tail could swing left and right, which would have helped in the turns, and that the head could not be raised very high.
This infers that it could not have preyed on very large animals, unless it was an ankle biter!

This all goes by the board if it was a carrion eater or if it hunted in packs, and the vision plan suggests a predator.

Post by **Minimalist** » Sat Sep 22, 2007 2:29 pm

Part of being the biggest and the baddest means that you don't have to look up to anything, doesn't it?

Digit · Post by **Digit** » Sat Sep 22, 2007 2:31 pm

True.

Beagle · Post by **Beagle** » Sat Sep 22, 2007 3:26 pm

The reign of the dinosaurs lasted much longer than the mammals so far. Scientists now say that during that time, dinosaurs began to evolve into warm blooded animals. So at the end, when the comet hit, some were and some were not warm blooded.

The fossilized heart of a T. Rex was found and it was 4 chambered, like ours. This suggests that he was warm blooded. It takes a lot of energy to maintain a pump like that.

War Arrow · Post by **War Arrow** » Sat Sep 29, 2007 5:11 pm

I recommend The Dinosaur Heresies by Robert Bakker to anyone interested in the warm-blooded dinos hypothesis (which, by the way, I subscribe to). Although the fossil record can be unreliable, amongst his more convincing arguments (I thought) there was one which compares the distribution of skeletons - the ratio of predators to prey. A given population of prey animals can support a much larger number of cold-blooded predators than hot-blooded. The distribution of T-Rex (etc) fossils (Bakker claims) suggests a lot more in common with (for example) lions and tigers than with crocs and alligators.
A great book. I was punching the air with a fist roughly every six pages.

Digit · Post by **Digit** » Sun Sep 30, 2007 2:27 am

Haven't read it WA but have seen Baker in action, his arguments are logical, supportive of the evidence and concise. he, and others, though miss one additional point that I made to Min earlier. Just how many cold blooded herbivores exist today?
If they don't exist now I see no reason to suggest they existed in the past.

War Arrow · Post by **War Arrow** » Tue Oct 02, 2007 8:23 am

Forgive me if I've missed your point here, Digit (which I accept may well be the case) but I would say the point of Bakker's predator to prey ratio focusses entirely upon the predators as a measure of whether they would have been either endo or ectothermic. If cold-blooded, he suggests that there would have been more of them. Whether the prey animals were warm or cold blooded isn't the issue given that their numbers whether large or small serve as the yardstick by which the the (in relation) more modest predator group are measured.
Anyway, I still recommend the book. I think you'd enjoy it.

Digit · Post by **Digit** » Tue Oct 02, 2007 11:40 am

Basically WA I was just adding a bit more support to the warm blooded idea in as much that, currently, there are very few cold blooded herbivors, so I suggest that if the prey of warm blooded dinos were herbivorous I'll stake a pound to a pinch of snuff that the herbivors were warm blooded also.
T Rex was, along with many other predators a bird hip, and so were some of the herbivors, so it seems unlikely to me that the bird hipped predators would be warm blooded whilst the bird hipped herbivors were cold blooded.
Does that clarify it?

War Arrow · Post by **War Arrow** » Wed Oct 03, 2007 9:33 am

Ah. We were singing from the same hymn sheet then. Sorry. Thought process still a bit frazzled from fortnight's undiluted holiday exposure to my girlfriend's unique take on logic.

Digit · Post by **Digit** » Wed Oct 03, 2007 11:01 am

Womens' logic =?