[Andrew K Fletcher]

Gpan
There are many examples of plants and trees, so why not internal organs? Maybe we have not even scratched the surface "pun intended"

Death is natures way of telling us to slow down.

[Exodus]

Andrew, remember that when we are looking at plants, they are made up of cellulose which is in fact quite a hardy material. Its longevity in the ground before it is eventually broken down by bacteria has allowed fossil imprints of structure. As i'm sure you are aware, animal cells are more easily broken down and hence are less likely to remain within the fossil record. You must also remember that plants were also significantly more copious than animals so there are likely to be a greater number of plant fossils than animal. Bones of animals are our only real record as they often undergo mineralisation within the ground.

[Andrew K Fletcher]

Fair point Exodus

But we really aught to take a look at the mummified remains in South America and China, before we presume that the internal organs cannot be preserved. Maybe they became desiccated by the deserts, as did the discovered mummified remains.

Or maybe the dinosaurs ate a lot of food with artificial preservatives in it


Death is natures way of telling us to slow down.

[daveshorts]

Soft tissues in animals do fossilise very rarely, or at least their imprints do, but I  would have thought that they would end up very squashed and hard to interpret. Add this to how increadibly rare they are and you have big problems making general conclusions.

[Isambard]

Dinosaurs belonged to the Saurischia (Sauropoda and Theropoda) or Ornithischia. Theropoda were without a doubt warm blooded, at least the more advanced forms.
What about the Ornithischia? There is very good reasons to believe some of them, like Leaellynasaura, were warm blooded too.

[Exodus]

True Isambard... and to add another cog to it.... Birds are true desecendants of the Ornithischian Dinosaurs... and they are warm blooded. I think this is an important aspect to address.

[rahonavis]

I'm afraid that's not true. Birds are dsscended from Saurischian (lizard-hipped) dinosaurs, not Ornithischian (bird-hipped)dinosaurs; confusing I know! Ornithischians' hips only superficially resemble birds' hips.

But I agree that Ornithischians may well have been warm-blooded too. Another possibility is that dinosaurs were heterotherms; a sort of halfway house between 'warmbloodedness' and 'coldbloodednes'.

[Monox D. I-Fly]

Dinosaur morphology was wrong to have been mammals. To my knowledge, no one thinks dinosaurs were mammals.

I still can't get over the fact that the rhinoceros-like Ceratopsians are reptiles/birds instead of mammals.

[evan_au]

It is now thought that many dinosaurs had feathers or filaments on their surface - although in the larger dinosaurs (bigger than a turkey) they may have been for warmth or signaling rather than flight.

Since the original Jurassic Park, thinking has changed, to the extent that some of the scaly dinosaurs in the original movie would now be portrayed with feathers. But as an ongoing franchise, it's now too late to change the "horrible lizard" icon!

See: https://en.wikipedia.org/wiki/Feathered_dinosaur

[RD]

Since this thread was active (2005) a mummified dinosaur has been found (in 2011)...
https://www.nationalgeographic.co.uk/history-and-civilisation/2017/11/amazing-dinosaur-found-accidentally-miners-canada

[Professor Mega-Mind]

...............dino mysteries .
Recent T-Rex skin impressions have been found which show that it did not have feathers on it's body .  This is explained by giganto-thermy ; animals over 3k.lbs. don't need insulation , except in extreme environments .  They have less surface area per pound of mass , thus it takes longer for them to shed body heat . 
On a related note: Therizinasaurus. Why were it's claws that way ? I already know , anybody else ? 
P.M. 

[Monox D. I-Fly]

On a related note: Therizinasaurus. Why were it's claws that way ? I already know , anybody else ? 
P.M. 

Googled that dinosaur, and its anatomy reminds me to Mech Mole Zombie from Yu-Gi-Oh! (probably just the big claws). Also, I tried so hard to recall an animal with similar arms until I remembered that it was a sloth.

[Professor Mega-Mind]

Therizinasaurus...
Pot-bellied bark-eater , with a stomach full of grinding-stones .  The claws were highly specialized for stripping bark from trees , whereas Gigantoraptor (and Megatherium) had more general-purpose , tree-killing claws .
Also , for the most similar arms , try Deinocheirus + Spinosaurus .  Although both hooked fish with them , Deino. caught smaller fish and vegetation .   Witness the difference in claws , resulting  from the difference in diets .
*Happy hunting !
P.M.

[Professor Mega-Mind]

In response to Replies # 25 , 26 :
Birds are highly atypical dinosaurs , with many major modifications in order to optimize their bodies for the extreme regimen of flight . The least appreciated of these traits is their extreme warm-bloodedness .
The normal bird body-temperature is 105°F. , across the spectrum of the many bird species . This is far above the normal body-temps. for most modern mammal species . Humans , for instance , live with a normal body-temp. of 98.6°F . The bird high B-T , goes hand-in-hand with an extremely high metabolism . This temperature setting , basic and fundamental to the essential bio-chemical functions of their hi-energy cellular machinery , is in-built to bird genetics , and the unimaginably complex molecular interelations/actions which determine both metabolism level , and the concurrent body-temps. that go with it .
This feature of birds , combined with less-robust bones , and other in-built flight adaptations , is likely the main reason that birds were not able to reconstitute the dinosaurs' ecological dynasty , when the Earth recovered from the End-Cretaceous-Extinction . The "meso-thermic" dinosaurs were gone , never to return . The "hyper-endothermic" birds were a poor substitute , and were quickly sidelined , as mammals became the dominant life-forms on Earth .
P.M.
Addendum : The ornithischian lineages represent a dead-end divergence from the typical  archosaur/dinosaur architecture.  They moved away from the normal "power" (lizard) hip , to the more gracile "carry" (bird) hip . Birds did this also , as they are relatively lightweight creatures , with no heavyweight tail to use for pursuit and combat .
The similarity in structure is a clear example of convergent  (parallel) evolution ; nature tends to trim down that which is not needed , this in service of functional efficiency . Obviously , this has a very high survival value , and explains why many creatures are given just enough to survive , in their natural environment .
P.M.
Ref : commons.m.wikimedia.org/wiki/File:PSM_V10_D233_Bird_dinosaur_crocodile_leg_bone_structures.jpg

/File:PSM_V10_D233_Bird_dinosaur_crocodile_leg_bone_structures.jpg 

[Professor Mega-Mind]

Is there any evidence of dinosaurs possibly being warm blooded or even being mammals?

*Updated discussion : Reply.27 .

[Professor Mega-Mind]

*For updated analysis and discussion , go to Reply # 27 .

[chris]

On this week's Naked Scientists Podcast we ran an interview with Yale's Robin Dawson who has developed a technique to measure a mother dinosaur's body temperature using the isotopes present in the fossilised shell of the eggs she laid.

Very neat.

[Border]

Science is everywhere.

[Sporteganmen]

Dinosaurs most likely had four-chamber hearts. They could provide dinosaurs with high blood pressure so that blood entered the head, which was far from the body. In addition, the presence of a four-chambered heart means that the creature is most likely warm-blooded, while all reptiles (including dinosaurs) also have a three-chambered heart. Such hearts allow a mixture of venous and arterial blood. In this regard, the organs of the body are supplied with mixed blood, and the level of metabolism decreases - which causes cold-bloodedness.In 2000, the skeleton of the Tescelosaurus dinosaur was discovered (I can talk about it in one of the following articles). It found something that scientists described as the fossilized remains of a four-chamber heart and aorta. This was the reason to believe that the dinosaur had a fast metabolism and warm-bloodedness.

[Professor Mega-Mind]

I take you meant -... all 
reptiles , excluding dinosaurs...
P.