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Dino Talk Apr. 1-6, 2002: A Dinosaur Forum


"If Allosaurus hunted sauropods in packs I think it would be able to kill juvinile and sick adult sauropods."

Sauropods most likely traveled in groups, and therefore they probably would have protected the younger individuals. But the sick ones may have left behind. It would have taken 3 Allosaurs at minimum to take down even a sick one, in my opinion.
from Tim M., age ?, ?, ?; April 5, 2002


"Being an ectothermic homeotherm is very efficient so you should really consider my theory as valid.

Tunny is another fish that does that. It is an ectotherm, but is very fast.

And the multi-ton sauropods would take weeks to cool down, and they probably migrated, so they could well be ectotherms. Baby dinosaurs could be endotherms, and then become ectotherms! That's very possible.

And Tim, You said that other dinosaurs might not need that. But think about it. In such a competitive world being an animal as efficient as an ectothermic homeotherm could really give you the edge over competition.

Undoubedly, my theory flaws when it comes to animals that lived a very active lifestyle, involving a lot of running.

Pterosaurs, for instance, where NOT "flying reptiles," they just had to be endotherms. Consider it.

And I'm certainly not applying this theory to ornithomimids or dromaeosaurids"

Just to let you know, I generally agree with your theory. What I meant was that other animals weren't as big as Sauropods, and therefore wouldn't need as much fuel. But I guess the same thing could go for other dinosaurs too.
from Tim M., age ?, ?, ?; April 5, 2002


If Allosaurus hunted sauropods in packs I think it would be able to kill juvinile and sick adult sauropods.
from Tom G, age 13, Thames Coast, New Zealand; April 5, 2002


"On Sunday I went to the museum of natural history.At thier dino section,I asked one of thier people that work there,if T-Rex was a scavenger or not.And all of them said he was.So is he?
from Tom G., age ?, ?, ?, ?; March 28, 2002"

What the #$%*. This isn't me. I've just come back from an 8 day holiday in South Island. And whoever it is should know that there isn't a Natural History museum in the whole of NZ. So STOP IMPERSINATING ME!
from the real Tom G, age 13, Thames Coast, New Zealand, ?; April 5, 2002


"Well, there are MANY things that can not be completely ruled out in Paleontology."

Yes, and still many palaeontologists and dinosaur fans disregard points that can not be ruled out.
from da masta, age ?, ?, ?; April 5, 2002


"Those are very good points, but here's something one should consider.
Motion attracts attention. When you're walking along and you see something moving out of the corner of your eye, you turn to see what it is. If you don't see anytrhing movong, you probably won't be interested. Another example is when you're playing hide and seek: You'll be more likely to see the person if he/she's dancing around than if he/she's frozen solid, even if he/she isn't making any noise. I can't imagine an owl nor T-rex not attacking prey standing right in front of them, out in the open.
But there's also a profound difference between having vision that's based on movement and not attcking things that don't move."

OK. I can't think of a good response.
from da masta, age ?, ?, ?; April 5, 2002


"And it's I. bernissartensis."

That's the one I want. Thanks.
from da masta, age ?, ?, ?; April 5, 2002


"What do you suppose Allosaurus ate if it didn't eat sauropods? not Dryosaurus all the time! Not Stegosaurus all the time! But I don't think it could tackle Brachiosaurs, but maybe Diplodocids like Diplodocus."

Weeell... maybe young ones. Certainly not adults. And we have evidence that the young where protected by herds of adults. Ask if you're not sure what that evidence is, I'm presuming you know. You can guess easil... aw, I'll just say, just in case. Trackways. Prehistoric trackways. The adults on the outside, the young on the inside. And yes the experts think that they where made at the same time. Irrefutable evidence, huh?

Here's a list of what I think was included in Allosaurus' diet:

1) Drinker (hypsilophodontid.)
2) Othneilia (hypsilophodontid.)
3) Dryosaurus
4) Camptosaurus
5) Gargoyleosaurus (ankylosaurid.)
6) Mymooropelta (ankylosaurid.)
7) Stegosaurus
8) Koparion (maniraptoriformes.)
9) Ornitholestes (an Allosaurus vs. Ornitholestes "fight" wouldn't be like the one you described on DinoFiction. Although it was good reading, it wasn't accurate to real life. And I know that it doesn't matter, I don't mind, but here's what would happen in real life anyway: Allosaurus runs out of trees, grabs ornitholestes and eats. The end.)
10) Coelurus (Who said that carnivores can't eat carnivores?)
11) Baby sauropods, as Tim M said.
12) Anything else it could find, including sea life like turtles and washed up icthyosaurs.

from da masta, age ?, ?, ?; April 5, 2002


Being an ectothermic homeotherm is very efficient so you should really consider my theory as valid.

Tunny is another fish that does that. It is an ectotherm, but is very fast.

And the multi-ton sauropods would take weeks to cool down, and they probably migrated, so they could well be ectotherms. Baby dinosaurs could be endotherms, and then become ectotherms! That's very possible.

And Tim, You said that other dinosaurs might not need that. But think about it. In such a competitive world being an animal as efficient as an ectothermic homeotherm could really give you the edge over competition.

Undoubedly, my theory flaws when it comes to animals that lived a very active lifestyle, involving a lot of running.

Pterosaurs, for instance, where NOT "flying reptiles," they just had to be endotherms. Consider it.

And I'm certainly not applying this theory to ornithomimids or dromaeosaurids.
from da masta, age ?, ?, ?; April 5, 2002


"What do you suppose Allosaurus ate if it didn't eat sauropods? not Dryosaurus all the time! Not Stegosaurus all the time!"

I think Allosaurus could keep itself from going hungry with a diet of Dryosaurs, Camptosaurs, Stegosaurs, baby Sauropods, and carrion.
from Tim M., age ?, ?, ?; April 3, 2002


"Apatosaurus, Diplodocus, Camarasaurus, Amphicoelias, Brachiosaurs, Seismosaurus, Supersaurs, Ultrasauros. Multi - ton animals, some estimates for large brachiosaurids are up to 50 tonnes."

Even if Sauropods were Ectothermic, they would still need a lot of food. Take a modern day endothermic animal: the elephant. It's a 5 tonne animal that eats up to 350 kg of food a day. Take an animal like an Ultrasaur, over 10 times the size of an elphant. That would mean that these dinosaurs would have to shovel down well over 3 tonnes of food per day, and that food was most likely leaves and other vegetation, which isn't heavy at all. Imagine all the leaves you would have pile up to make a pile that weighed 3.5 tonnes. From this stand point, it would seem more advantageous for Sauropods to be Ectothermic so they wouldn't be condemned to eat as much food. The same doesn't really apply to many other dinosaurs, though.
from Tim M., age ?, ?, ?; April 3, 2002


What do you suppose Allosaurus ate if it didn't eat sauropods? not Dryosaurus all the time! Not Stegosaurus all the time! But I don't think it could tackle Brachiosaurs, but maybe Diplodocids like Diplodocus.
from Gianna, age ?, ?, ?, ?; April 3, 2002


"Well, that'll be only one question now!!!"

I don't know which one hasn't been eliminated, so I'll try and answer both.

"19) A cast of an adult Albertosaurus (is it gracilis?)"
It's A. sarcophagus.
And it's I. bernissartensis.

from Tim M., age ?, ?, ?; April 3, 2002


"I do not think that it should be completely ruled out that T - rex didn't attack things that didn't move. "

There are many things that can't be completely ruled out in paleontology.

"Firstly, we have no evidence that any dinosaurs froze when faced with danger.

Secondly, even if some did, it is unrealistic to assume that all of T - rexes' prey items did this. I just do not see ceratopsians and hadrosaurs freezing when faced with a bellowing, charging tyrannosaur.

Thirdly, some people, including me, argue that dinosaurs are closer to modern day birds than to any reptiles. Well, I yesterday went to the National Birds of Prey Centre, and included in the days program where numerous flight demonstrations of Harris Hawks, Golden Eagles, Eurasian Eagle Owls, Peregrine Falcons, and many others. (I even got a chance to participate!) Something curious I noticed then was during the Eagle Owl demonstration. When it was tossed two peices of meat, it immediately went after the first one, and caught it just as it touched the grass. But, despite it's peckishness, it did not touch the second one. When the handler flicked the piece of meat to make it suddenly move across the grass, the owl noticed and grabbed it in it's large, curved beak. The handler then explained that the owl only responded to movement, and did not go after still objects.

So it must be quite possible that T. rex only responded to movement. What's more, with T. rexes' great sense of hearing and smell, (and God knows what else!) it would not be as much of a handicap as we have so far assumed."

Those are very good points, but here's something one should consider.
Motion attracts attention. When you're walking along and you see something moving out of the corner of your eye, you turn to see what it is. If you don't see anytrhing movong, you probably won't be interested. Another example is when you're playing hide and seek: You'll be more likely to see the person if he/she's dancing around than if he/she's frozen solid, even if he/she isn't making any noise. I can't imagine an owl nor T-rex not attacking prey standing right in front of them, out in the open.
But there's also a profound difference between having vision that's based on movement and not attcking things that don't move.

from Tim M., age ?, ?, ?; April 3, 2002


Remember my post about endothermy and ectothermy in T - rex?

I may be wrong. I read this book that is also in the WWD series, "The Facts," and it explains something quite interesting which I think you should hear.

Remember I said that the predator - prey relationships in dinosaurs indicate endothermy in dinosaurs?

Well, that may be wrong. What I was looking at was the late jurassic, as was the book. The book's example was the Morrison Formation in the USA. A large part of the biomass in the Morrison Formation pyramid of biomass (a tree with the producers at the base, then the primary consumers, secondary consumers, etc. going up, it's width depending on how much biomass each stage of that tree has. In a normal, healthy ecosystem it is usually pyramid - shaped.) is taken up by the huge sauropods. Apatosaurus, Diplodocus, Camarasaurus, Amphicoelias, Brachiosaurs, Seismosaurus, Supersaurs, Ultrasauros. Multi - ton animals, some estimates for large brachiosaurids are up to 50 tonnes.

That is heavy.

But the main point is, what could eat them?

Sure allosaurus is the biggest and "meanest" predator at that time there, but it can't tackle these things. They're too big!

So, subtracting the huge sauropopds from the predator - prey ratio of the Morrison Formation, (the sauropods aren't prey really!) you get figures indicating an ectothermic community!

For there to be a constantly healthy population of stegosaurs, camptosaurs, and dryosaurs, the allosaurus could only eat these animals as often as a reptile eats.

So here is what I propose.

Some animals nowadays, which we would consider ectothermic, can generate heat. They are reptiles, and efficient at converting energy, and have a slower metabolic rate, but they can keep their muscles at surprisingly high temperatures. These animals include pythons, boas, and great white sharks.

So, most dinosaurs could have had the efficient energy converting mechanism and metabolic rate of reptiles, and yet still have a double circulatory system (so the sauropods could pump their blood up to their brains) and heat generating capacity of mammals.

Who agrees?

The dinosaurs which evolved into birds could have had full endothermy, though.

The question is, for them to evolve this feature, it would need to be advantageous over the other dinosaurs' ectothermic lifestyle.

And I'll think about that and try to include it in another post!

If you can think about it as well and maybe help me out I would be grateful!

What's more being ectothermic and generalting your own heat in muscles, like boas and pythons and great white sharks, is very efficient, and would have given dinosaurs that competitive edge in the late triassic.
Actually, that wouldn't really be ectothermic if they generate their own body heat? Well, I'll give a little description here of what I think:

1) Dinosaurs had all the anatomy and everything of a reptile. (remember I said that reptiles have a slow metabolism, and had a system more efficient at getting nutrients from their food than mammals.)
2) But they could generate their own body heat, and had a double circulatory system like alligators.

I'm not an expert though, so I can't get into all the details I'm afraid. In this country, and in most, actually, (so no offense England) everything that's taught in class is taught at the lowest level, of the most bored and uninterested pupil in the class, and progress through more advanced topics is slow. I don't learn as much as I like, even though the one I go to is a really good school. I shudder to think of what it's like in the worst schools. I can't wait until year ten, it gets much better then! But back to the subject.

Oh, and by the way, if T - rex was ectothermic but could still generate body heat, (I know it takes energy, but reptiles are more efficient at converting energy in their food if you remeber!) then T - rex could have scavenged more often! And remember the healed over hadrosaur tail? Tim mentioned it recently. If it healed over, then the pretty much defenseless (against T - rex, anyway) hadrosaur had gotten away from it. Maybe T - rex wasn't such a prefect hunter as some people would have it then! And I also read about the T - Rex coprolite with Triceratops frill in it. And the Triceratops pelvis with bite marks all over it. It does not neccesarily mean that T - rex killed it. The bones where systematically bitten off and swalled. The T - rex could have eaten them from a carcass. Obviously, it wanted the nutritious bone marrow, and had swallowed the bones so that it's stomach acids would do all the work and extract the marrow for it. I also remember that on the science forum som! eone said that it had been calculated that a Triceratops frill had been bitten from the front, as the animals was charging. I treated that sceptically from the very start. If T - rex had such a powerfull bite, it probably just tried to bite that bit of frill off and digest it after the triceratops had died. And the Triceratops did not have to be dead for the T - rex to start eating. It could just have been weak from blood loss and lying down or even unconcious. What does the T - rex care if the Triceratops dead or alive if it is not retaliating and is lying still?

But please do not think that I have changed my mind about T - rex, I still do firmly beleive that T - rex was an active hunter!

However, there is another point I would like to stress.

I remember Honkie Tong talking about healed over broken T - rex bones.
Honkie said that it could be explained that other Tyrannosaurs helped injured ones at kills. But I don't understand that.

1) If T - rex ate about 10 - 20 times a year, (remember my ectothermy theory, and that the animals which T - rex ate where about the same size as T - rex!) then I strongly doubt that T - rex would share it's hard won and important meal with a strange T - rex just like that. And even if T - rex was endothermic, that would mean that T - rex needs to eat comparatively very often, and so is also unlikely to share just like that.

2) If T - rexes always helped each other, wouldn't that be altruism?!?

My explanation for why the T - rexes survived bad wounds is simple, and is also part of my ectothermy theory.

Reptiles, and ectothermic animals in general can generally take bad wounds. Lizards shed their tails when attacked, crocodiles and alligators and snakes can take bad wounds and survive, and they are generally hard to kill.

The T - rex could have been badly injured, but being more or less ectothermic, having cooler blood, a different vascular system, and slow metabolism, would have survived. It could also have survived for a long time without food, being ectothermic, and this would have given it's injury time to heal. No other T - rex would attack it, remember, even if it's injured it still has bone - crushing jaws!

Well, what are everyone's opinions then?
from da masta, age ?, ?, ?; April 3, 2002


"I do not think that it should be completely ruled out that T - rex didn't attack things that didn't move."

Well, there are MANY things that can not be completely ruled out in Paleontology.
from Tim M., age ?, ?, ?; April 2, 2002


"BTW, I put two questions in the post which listed different specimens from the NH museum in London. Who can enlighten me?!?"

Well, that'll be only one question now!!!
from da masta, age 14, ?, ?; April 2, 2002


I do not think that it should be completely ruled out that T - rex didn't attack things that didn't move.

Firstly, we have no evidence that any dinosaurs froze when faced with danger.

Secondly, even if some did, it is unrealistic to assume that all of T - rexes' prey items did this. I just do not see ceratopsians and hadrosaurs freezing when faced with a bellowing, charging tyrannosaur.

Thirdly, some people, including me, argue that dinosaurs are closer to modern day birds than to any reptiles. Well, I yesterday went to the National Birds of Prey Centre, and included in the days program where numerous flight demonstrations of Harris Hawks, Golden Eagles, Eurasian Eagle Owls, Peregrine Falcons, and many others. (I even got a chance to participate!) Something curious I noticed then was during the Eagle Owl demonstration. When it was tossed two peices of meat, it immediately went after the first one, and caught it just as it touched the grass. But, despite it's peckishness, it did not touch the second one. When the handler flicked the piece of meat to make it suddenly move across the grass, the owl noticed and grabbed it in it's large, curved beak. The handler then explained that the owl only responded to movement, and did not go after still objects.

So it must be quite possible that T. rex only responded to movement. What's more, with T. rexes' great sense of hearing and smell, (and God knows what else!) it would not be as much of a handicap as we have so far assumed.

By the way guys, if this doesn't start a debate, I don't know what will!
from da masta, age 14, Birmingham, Selly Oak, West Midlands, GB; April 2, 2002


"So when was the last time you where there?"
Well, I've never really been to London itself, but the last time I was in the U.K. was back in early August 2000.

from Tim M., age ?, ?, ?; April 2, 2002


"Are you sure that it isn't "TYRANNOSAUROPUS"?"

90% sure. Names of ichnogenera can end with "opus" "ipus" and "apus" too.
from Tim M., age ?, ?, ?; April 1, 2002


"ichnites are fossil footprints,"

Hence the name!
from Tim M., age ?, ?, ?; April 1, 2002


Oh, sorry everyone, it isn't _Albertosaurus libratus_ in the Natural History museum in London, even though it says so, (outdated!) it should be _Gorgosaurus libratus_, shouldn't it?
from da masta, age ?, ?, ?; April 1, 2002


Whoops, I think that there's one more very significant fossil I ought to mention!

A fossil Edmontosaurus sp. lying on it's left side, with skin impressions too! (Yes, the actual specimen!)
from da masta, age ?, ?, ?; April 1, 2002


"Next time I'm in London(which undoubtledly will be a while from now) I'll check it out."

So when was the last time you where there?

I don't like it much, too crowded. But the suburbs are nice. I used to have relatives who lived there.
from da masta, age ?, ?, ?; April 1, 2002


"Yeah. It's called Ichnotaxonomy(and of course there are ichnogenera and such). I've heard about a certain Tyranosauripus from New Mexico."

Ichnotaxonomy? Oh yeah, ichnites are fossil footprints, so it makes sense.

"Tyranosauripus"? Are you sure that it isn't "TYRANNOSAUROPUS"?
from da masta, age ?, ?, ?; April 1, 2002


"29) Fifty or so marine reptiles, including 3 species of Icthyosaur, 3 species of Plesiosaur, several mosasaurs (Platycarpus sp.) and various marine crocodiles, notably Mystriosaurs sp."

Sorry, that's at least 5 SPECIES of icthyosaur, and at least 4 SPECIES of plesiosaur! I counted the genuses earlier!

What's more the collection includes:

-- Fossil Icthyosaurs with young inside their wombs!
-- The famous fossil Icthyosaur that died as it's baby was getting born!
-- Fossil Icthyosaurs with skin impressions!
-- Fossil Temnodontosaurus eucephalus with it's food between it's jaws!

BTW, I put two questions in the post which listed different specimens from the NH museum in London. Who can enlighten me?!?
from da masta, age ?, ?, ?; April 1, 2002


"Um, Tom, I don't think Tim is ignoring you because, well, he answered your question about T-rex being a scavenger.

I like your reasons, Tim, they are convincing."

Hmm, I think it isn't quite like you think Gianna.

Because the messages are put up by JC when she checks them, and not automatically, Tom G could have posted his message BEFORE JC had put up Tim's post, so Tom G did not know.

And yes, I beleive that there is unequivocal evidence for T - rex being a scavenger too.
from da masta, age ?, ?, ?; April 1, 2002


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