Naked Science Forum
Non Life Sciences => Geology, Palaeontology & Archaeology => Topic started by: Scarlet King Snake on 31/05/2004 23:23:47
-
Is there any evidence of dinosaurs possibly being warm blooded or even being mammals?
-
Dinosaur morphology was wrong to have been mammals. To my knowledge, no one thinks dinosaurs were mammals. The warm-blooded question remains a topic of debate, however. All the evidence is circumstantial. Birds are warm-blooded, and reptiles are cold-blooded. Dinosaurs resembled both, and seemed to act like both. Maybe the answer is somewhere in the middle, with some being cold, and some having some temperature control. Also, dinosaurs ruled the animal kingdom for ~100 million years, and evolved considerably during that time, so cold or warm may have changed both by species, and timewise.
-
Actually I brought this up because there is still a large debate as to whether they'e warm or cold blooded.
Science is everywhere.
-
Its hard to imagine warm blooded reptiles - but maybe some/all dinosaurs were and thats why they became extinct (would probably be highly specialised and successful in their respective environments, but useless when environment changes).
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
-
Its quite possible due to information received from the preserved heart of a Thescelosaurus since it resembles more of a mammals heart or a birds not a reptile.
Science is everywhere.
-
In what way was it preserved? Would have had to survive at least 65 million years! Thats one hellava preservative!
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
-
It was actually fossilized heres the site.
http://www.enchantedlearning.com/subjects/dinosaurs/news/Heart.shtml
Science is everywhere.
-
Cool-but how exactly does tissue become fossilised (as usually its the bones)? I suppose in rare cases (such as if the dinosaur falls into a bog) and the tissue is preserved, then the tissue might last long enough to be fossilised, but it must be some strange method of fossilisation to be able to preserve the structure of the tissue (especially the internal detail too).
"I have great faith in fools; self-confidence my friends call it."
-Edgar Allan Poe
-
This is very interesting. There's more information and images here:
http://www.dinoheart.org/insideout/index.html
I don't know what I'm looking for, but some of those images seem a real stretch to me. Very interesting though.
----
John - The Eternal Pessimist.
-
Dinosaurs are close relatives of birds and reptiles. The closest living reptile ancestor is the crocodile. But significantly, whilst birds have a 4 chambered heart like our own, reptiles have a 3 chambered heart (2 atria with a single ventricle), and crocodiles have a 4 chambered heart (like ours) but with an extra-pulmonary branch (the so-called right systemic artery) which allows blood to bypass the lungs under low-oxygen conditions.
Where dinosaurs fit into this jigsaw is a matter of considerable debate. I spoke with a palaeontologist about this today who told me that the fossilised heart discovered recently is now not believed to demonstrate a 4 chambered architecture as claimed previously. Instead the identified morphology is thought to be artefactual. The jury is therefore still out.
Similarly, we still do not know whether dinosaurs were hot of cold blooded. It is likely that many of the large meat-eaters were warm-blooded; indeed when they emerged from the egg many dinosaurs like Tyrannosaurus were probably feathered to preserve heat. However, as they grew, the need for heat conservation became less of a problem and in fact heat-loss became more of a priority. So-called 'gigantothermy' takes over whereby an animal is so big that it literally cannot lose heat fast enough. This is thought to have driven the development of heat-loss mechanisms like long necks and skin plates doubling as heat-sinks. The evidence that this is the case comes from modern-day big crocodiles. Large specimens maintain an even body temperature continuously, despite (in theory) being cold blooded.
Chris
"I never forget a face, but in your case I'll make an exception"
- Groucho Marx
-
Very helpful thank you Chris.
Science is everywhere.
-
A fossil of a T-Rex was found in S. Dakota.(named Samson) It is touted as the most complete T-Rex skeleton ever found. The article I read also talks about the fact that the orbits are found further back on the side of the head lending us to believe that it was NOT the horrid meat eating preditor that we have long thought. I don't think this article convinced me that the T-Rex was a warm fuzzy kind of guy, but it was interesting.
http://www.carnegiemuseums.org/cmnh/exhibits/carnegiesdinosaurs/paleolab.htm
-
quote:
Originally posted by Broca
A fossil of a T-Rex was found in S. Dakota.(named Samson) It is touted as the most complete T-Rex skeleton ever found. The article I read also talks about the fact that the orbits are found further back on the side of the head lending us to believe that it was NOT the horrid meat eating preditor that we have long thought. I don't think this article convinced me that the T-Rex was a warm fuzzy kind of guy, but it was interesting.
http://www.carnegiemuseums.org/cmnh/exhibits/carnegiesdinosaurs/paleolab.htm
hmmm, nah. You don't evolve an animal with such powerful jaws and teeth for it to ***** foot around and scavenge. Most scavengers are fairly small, just think how much T Rex would have to scavenge to stay alive? intersting all the same.
-
ok, you know, i used to believe that T.rex was a powerful predator, but you know, actually jack horner's evidence is pretty good, if you dont know about it, i'm gonna try to explain it
1. the t.rex femur is shorter than the tibia and perone, so, this makes it slow. this is why ostriches are faster than humans, even when human legs are almost as long as the ones in ostriches. this made t.rex a slow runner, in fact, its possible than t.rex couldnt even run, instead, the fastest locomotion for a t.rex would be something like a fast walk.
2. not all the scarvangers are small... and in fact, they have to be big and more powerfull than predators. here in mexico, when a hawk kills its prey, it has to eat fast, because the bigger and stronger vulture is always there. the vulture is stronger, and bigger cause it has to scare the hawk, not because it has to kill the pray. this also happens with the hyena, which is bigger than the cheetah only because it has to scare the cheetah to succesfully scarvange.
3. guess who has the most powerfull jaws in africa today? a scavanger, the hyena. the scarvangers have to have a powerfull bite, to be able to esat the left overs, such as bones.
i hope this was useful, and excuse my english... by the way, dinosaurs were warm blooded
to cry is to know that you're alive
-
I wonder if they tasted like Chicken or Turkey [8D]
(https://www.thenakedscientists.com/forum/proxy.php?request=http%3A%2F%2Fhome.comcast.net%2F%7Em.hefner%2Fgarage%2Fsigpicture.jpg&hash=10710076d432e3d84b9dd0a12f8fbc8b)
It is good to be alive! It's impossible I'm here but here I am.. and I rock!
-
Are t rexes warm blooded? Did they amniotic eggs? Did they sing to their young? Please help me answer theses questions, it's for school!
johanna
-
scientists think mammals came from a dog sive dino looking thing. it produced milk, layed eggs, partnared 4 life, protective parents, and had hair!!!
http://www.abc.net.au/dinosaurs/tv_series/default.htm this should help
scientist think t rex had amniotic eggs, communitated(sang) to their young and were a mix between cold n warm blooded.
i think trex ran down its pray, suprised its pray, and hurased its pray. i also think dinos r MORE related to birds then reptiles(atleast the carnivourse) the way their hips n backs r structsured they r similer to an ostrige also the way they balance is like a bird.
-
If this is the same walking with dinosaurs that came out on the BBC a few years ago, you may well want to take it with a pinch of salt. It was dreadful for mixing good science with stuff that is just wild speculation, it is possible there is evidence for amniotic eggs, the cold vs warm blooded thing is still a bit contraversial, but noone has any way of finding out whether they sang to their young or not!
Saying scientists think something is rather weak as all you need is one scientist to speculate slightly wildly, and an unscrupulous TV producer to run with it, and you suddenly find that scientists thing that black is white and up is down.
-
wat ever!
i think dinos had niether warm or cold but possible a mix it needs to warm up but it can also control the temputer and pressure.
Drew Rody
-
Actually I posted it first :)
For many years dinosaurs were thought to be cold blooded. The general concensus now is that they were in fact warm blooded. There was after all a 50% chance of getting it either right or wrong :)Still even the brightest light will cast a shadow and a stopped clock can be correct twice a day.
But this adds some serious considerations with relatively un-elevated reptiles today. Is there a connection between the heat generated in warm blooded creatures and their more upright posture than the relatively un-elevated reptiles today? For example, does a giant monitor lizard generate more heat than say a gator or a crock?
Andrew
Actually I brought this up because there is still a large debate as to whether they'e warm or cold blooded.
Science is everywhere.
-
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.
-
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.
-
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 :P
Death is natures way of telling us to slow down.
-
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.
-
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.
-
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.
-
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'.
-
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.
-
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
-
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
-
...............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.
-
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.
-
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.
-
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
-
Is there any evidence of dinosaurs possibly being warm blooded or even being mammals?
*Updated discussion : Reply.27 . 8)
-
*For updated analysis and discussion , go to Reply # 27 . 8)
-
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 (https://www.thenakedscientists.com/articles/interviews/dinosaur-eggs-reveal-most-were-warm-blooded).
Very neat.
-
Science is everywhere.
-
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.
-
I take you meant -... all
reptiles , excluding dinosaurs...
P.