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Caltech Scientists Measure Dinosaur Body Temp

Soulskill posted about 3 years ago | from the clever-girl dept.

Earth 51

damn_registrars writes "Using rare isotope ratios, a geology team at CalTech has determined body temperatures of sauropod dinosaurs. Their work finds temperatures that are roughly in line with modern mammals for body temperature. However, as the authors point out, this does not on its own confirm dinosaurs to be entirely warm-blooded, as they may have kept these temperatures by sheer mass. The peer-reviewed paper is available online in PNAS. You can also get the article free through pubmed."

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51 comments

Jeez (-1)

Anonymous Coward | about 3 years ago | (#36558432)

Tried to click the links to get to the comments and kept getting a 503 error and no page. I finally get here, and there are 0 comments. Boooo!

Good work, guys (5, Funny)

eln (21727) | about 3 years ago | (#36558472)

You'd think the reason this took so long was because they had to fabricate a thermometer large enough, but in fact the real hold up was convincing a grad student to stick that thermometer up the dinosaur's ass.

Re:Good work, guys (0)

Anonymous Coward | about 3 years ago | (#36558520)

You'd think the reason this took so long was because they had to fabricate a thermometer large enough, but in fact the real hold up was convincing a grad student to stick that thermometer up the dinosaur's ass.

LOL!

Re:Good work, guys (1)

MooseDontBounce (989375) | about 3 years ago | (#36560030)

You'd think the reason this took so long was because they had to fabricate a thermometer large enough, but in fact the real hold up was convincing a grad student to stick that thermometer up the dinosaur's ass.

After Professor Waxman was killed, it was hard to find anyone willing to do this. - Very Old 'Far Side' reference

Re:Good work, guys (3, Funny)

milkmage (795746) | about 3 years ago | (#36560544)

http://www.pulse.org.za/pulse/farside.html [pulse.org.za]

An instant later, both Professor Waxman, and his time machine are obliterated, leaving the cold-blooded / warm-blooded dinosaur debate still unresolved.

Re:Good work, guys (1)

drainbramage (588291) | about 3 years ago | (#36560354)

Do you know the difference between an oral and a rectal thermometer?
.
.
The taste.

Re:Good work, guys (1)

damn_registrars (1103043) | about 3 years ago | (#36562492)

in fact the real hold up was convincing a grad student to stick that thermometer up the dinosaur's ass.

Are you kidding?

The grad student was probably happy to do it, since it meant the adviser was finally off of their ass!

Where did they get . . . (2)

hduff (570443) | about 3 years ago | (#36558484)

. . . that big a rectal thermometer?

Re:Where did they get . . . (0)

Anonymous Coward | about 3 years ago | (#36558552)

And it still wouldn't be large enough for that cold hearted bitch working in HR!

Re:Where did they get . . . (0)

Anonymous Coward | about 3 years ago | (#36563342)

Goatse link in 3...2...1...

It's Caltech (2, Informative)

Anonymous Coward | about 3 years ago | (#36558574)

That is all.

Re:It's Caltech (1)

grcumb (781340) | about 3 years ago | (#36562802)

That is all.

WALLOWITZ: It was him or me, ma! HIM OR ME!!!

Birds Are Warm Blooded (1)

Normal Dan (1053064) | about 3 years ago | (#36558586)

So I suppose it would make sense that their supposed ancestors have some warm blood in them too.

Re:Birds Are Warm Blooded (1)

Arlet (29997) | about 3 years ago | (#36558688)

It could have evolved somewhere half way between dinosaurs and birds.

Re:Birds Are Warm Blooded (1)

Anonymous Coward | about 3 years ago | (#36559138)

There is nothing half-way between dinosaurs and birds. One of Jesus' miracles was turning all those gigantic, roving eating machines into birds to the delight of all involved (but mostly just for the lulz.)

Didn't you pay attention in history class?

Re:Birds Are Warm Blooded (1)

John Saffran (1763678) | about 3 years ago | (#36562444)

There is nothing half-way between dinosaurs and birds. One of Jesus' miracles was turning all those gigantic, roving eating machines into birds to the delight of all involved (but mostly just for the lulz.)

Didn't you pay attention in history class?

For the lulz? I didn't know that Jesus was a terrorist!

PNAS? (0, Funny)

Anonymous Coward | about 3 years ago | (#36558626)

Seriously? PNAS??? Who thought that that would be a good name?

Re:PNAS? (1)

interkin3tic (1469267) | about 3 years ago | (#36560144)

The Veterinary And Geriatric Investigator National Association (VAGINA) suggested it actually, why?

Re:PNAS? (0)

Anonymous Coward | about 3 years ago | (#36565394)

Wow, what an idiot you are.

Large Size = Warm Blooded (1)

Normal Dan (1053064) | about 3 years ago | (#36558652)

I wonder if large land animals have to be warm blooded to function. One would think if a large dinosaur was cold blooded it would take a full day of sun to warm up all that mass, then when it was finally warm enough, it would be too dark to do anything useful.

Re:Large Size = Warm Blooded (1)

Arlet (29997) | about 3 years ago | (#36558762)

Not necessarily, the metabolism inside the dinosaur could have kept it warm enough, even when it was resting. The energy produced goes up by the cube of the size, while the surface area to lose that heat only goes up by the square.

Re:Large Size = Warm Blooded (1)

bkaul01 (619795) | about 3 years ago | (#36558960)

"Metabolism keeping it warm enough" is pretty much the definition of warm-blooded, right? ...

Re:Large Size = Warm Blooded (1)

Arlet (29997) | about 3 years ago | (#36559094)

Warm blooded also implies that the temperature stays relatively constant within a narrow range. Dinosaurs could have been warmer than their environment, but still with a wide range in operating temperatures, depending on their activity, sunshine and other factors.

That's how warm-bloodedness would have evolved. Starting with a crude mechanism to keep temperature within a wide band, and slowly refining it to narrower and narrower bands.

Re:Large Size = Warm Blooded (1)

WastedMeat (1103369) | about 3 years ago | (#36565156)

I remember reading as a child that this was the suspected point of the sail structures found on many dinosaurs.

Re:Large Size = Warm Blooded (1)

marcosdumay (620877) | about 3 years ago | (#36558982)

If its metabolism was enough to keep it warm, and it has some mechanism to reduce the metabolism or get ride of the extra heat when it gets too warm, we have a warm blooded creature!!! Now it its metabolism was enough to keep it warm, it does not have some mechanism to slow that metabolism or get ride of the extra heat when it gets too warm, we have a dead creature!!! So, I guess stating that its metabolism can keep it warm is enough here.

Please compare a cold blooded creature (like a snake, for example) that often pass through months without eating and is ok with that, and a warm blooded creature that must eat every week (or even more often). Metabolism seems to be the biggest difference here, altough, IAMN a biologist...

Re:Large Size = Warm Blooded (1)

MozeeToby (1163751) | about 3 years ago | (#36558780)

Even cold blooded animals generate some body heat. I would think that if you were to balloon a monitor lizard up to surapod size it's body temperature would probably be significantly higher than the environment. An Apatosaurus is 330 times more massive than a komodo dragon but has only 50 times the surface area. Quite frankly, I'd be surprised if they didn't have to go looking for shade on warm days to avoid overheating, even if they were relatively cold blooded (komodos often need to burrow through the warmest parts of the day for just that reason).

Re:Large Size = Warm Blooded (1)

marcosdumay (620877) | about 3 years ago | (#36559004)

I'd be quite surprized if sauropodes did need to look for shade in hot days. Finding some could be quite a challenge.

Re:Large Size = Warm Blooded (1)

tompaulco (629533) | about 3 years ago | (#36559050)

That may be the case for Apatosaurus, but most dinosaur species were less than two feet tall, so they probably did not generate much body heat. The environment itself was significantly warmer back then, though.

FTFA (0, Informative)

Anonymous Coward | about 3 years ago | (#36558662)

Were dinosaurs slow and lumbering, or quick and agile? It depends largely on whether they were cold or warm blooded. When dinosaurs were first discovered in the mid-19th century, paleontologists thought they were plodding beasts that had to rely on their environments to keep warm, like modern-day reptiles.

The writer is a moron.

No those paleontologists didn't fucking think that. The only damn reason the T. Rex in the American Museum of Natural History was mounted upright like that was because it was too damn heavy to mount with the backbone horizontal using the technology of the day.

Why the hell is there this general belief that people today are SOOO much smarter than people in the past?

Re:FTFA (3, Informative)

hawguy (1600213) | about 3 years ago | (#36559110)

Were dinosaurs slow and lumbering, or quick and agile? It depends largely on whether they were cold or warm blooded. When dinosaurs were first discovered in the mid-19th century, paleontologists thought they were plodding beasts that had to rely on their environments to keep warm, like modern-day reptiles.

The writer is a moron.

No those paleontologists didn't fucking think that. The only damn reason the T. Rex in the American Museum of Natural History was mounted upright like that was because it was too damn heavy to mount with the backbone horizontal using the technology of the day.

Why the hell is there this general belief that people today are SOOO much smarter than people in the past?

I don't see the connection between the mounting position of a T.Rex and the speed or agileness of dinosaurs in general? The erect T-Rex doesn't look any more lumbering than a prone T-Rex to my untrained eye.

And is it really true that it takes modern structural materials to mount a t-rex horizontally? It seems like even in the early 1900's, they could have used a steel beam and cables to hang it if they really wanted to show it in a more horizontal position.

This reference says that scientists didn't discover until the 1970's that the upright position was not accurate, but it was because of biomechanics, not speed or agility.

http://landbeforetime.wikia.com/wiki/Tyrannosaurus [wikia.com]

Henry Fairfield Osborn, former president of the American Museum of Natural History (AMNH) in New York City, who believed the creature stood upright, further reinforced the notion after unveiling the first complete T. rex skeleton in 1915. It stood in this upright pose for nearly a century, until it was dismantled in 1992.[48] By 1970, scientists realized this pose was incorrect and could not have been maintained by a living animal, as it would have resulted in the dislocation or weakening of several joints, including the hips and the articulation between the head and the spinal column.[49]

Dear Caltech: (0)

Anonymous Coward | about 3 years ago | (#36558680)

If in doubt, clone [youtube.com] one.

Thanks in advance.

Yours In Science.

Yours In Novosibirsk,
Kilgore Trout, Ph. D.

PNAS = Penis? lol (-1)

Anonymous Coward | about 3 years ago | (#36558686)

So how do you pronounced PNAS? Why would you write for something whose name is pronounced like penis?

Yo momma (1)

Halo1 (136547) | about 3 years ago | (#36558764)

Yo momma is so fat she heats the whole city by sheer mass.

Re:Yo momma (0)

Anonymous Coward | about 3 years ago | (#36558972)

Yo momma's so fat she's been extinct for 150 million years and is still warm!

Re:Yo momma (0)

Anonymous Coward | about 3 years ago | (#36563958)

Damn, well if that's true then yo mamma must've been so fat that she was her own species!

Troll post (0)

Anonymous Coward | about 3 years ago | (#36558958)

I'm *pretty* sure that the time constant for post-mortem dinosaur temperature decay is less than a million years, but then again, I'm no paleontologist (aka biologist who failed organic and just went in the field because they like animals).

Ahhhh, that felt better.

metabolic vs. thermoregulated heat (4, Interesting)

smellsofbikes (890263) | about 3 years ago | (#36558996)

The point about body mass, if it's not clear, is that metabolism produces huge amounts of heat. When we digest food, about 50% of the energy that's released in converting complex molecules to carbon dioxide and water is released as heat. A huge animal can keep warm just from that. Mammals and birds maintain their temperature in a very narrow range. However, it's more complicated than just that would indicate: hibernating mammals (and one species of bird that hibernates) allow their temperature to fluctuate with the outside temperature. Likewise, there are reptiles that do some things to reduce their temperature variation, by seeking sunlight or shade, which is a type of active regulation. One current theory about dinosaurs and the evolution of feathers is that they showed up primarily as a thermoregulation system, providing insulation (particularly in rain) but allowing the animals to fluff their feathers to increase temperature losses to again actively thermoregulate.

Re:metabolic vs. thermoregulated heat (0)

Anonymous Coward | about 3 years ago | (#36559816)

When we digest food, about 50% of the energy that's released in converting complex molecules to carbon dioxide and water

When we digest food

digest

*ahem!* I think you mean "respire nutrients".

Re:metabolic vs. thermoregulated heat (0)

Anonymous Coward | about 3 years ago | (#36559980)

Given the whole square/cube thing about heat-producing volume vs heat-radiating surface area, it wouldn't surprise me if feathers developed as a way to keep juvenile dinos warm until they grew large enough that they didn't need them. Smaller dinos might have needed them all the time, but T. Rex "chicks" would have shed when they got larger.

Re:metabolic vs. thermoregulated heat (1)

smellsofbikes (890263) | about 3 years ago | (#36560712)

Given the whole square/cube thing about heat-producing volume vs heat-radiating surface area, it wouldn't surprise me if feathers developed as a way to keep juvenile dinos warm until they grew large enough that they didn't need them. Smaller dinos might have needed them all the time, but T. Rex "chicks" would have shed when they got larger.

You could be right. Many mammals -- cats and dogs, certainly -- are born essentially cold-blooded and will freeze to death if taken away from their mother and siblings, and don't start self-regulating their temperature for a day or so.

The thing with feathers being evolved to deal with rain was based on the observation by biologists studying hypothermia and different hibernation strategies, that it's pretty easy to stay warm if you're dry, and fairly easy to stay warm if it's snowing, but cold rain is extremely difficult to deal with. Huge feather-like structures can act like a raincoat. Look at the primary flight feathers on geese: massive close-knit waterproof feathers that when folded cover almost their whole backs, with little insulation value but great rain-shedding value. Likewise, their fine feathers on the rest of their bodies provide good insulation, with only some water resistance. When the bird is hot, it can stretch out its wings and expose its nearly unfeathered armpits to dump heat to the environment. Development of scales into insulating and water-shedding feathers could be an entire thermoregulation strategy, and flight an unexpected but very welcome by-product.

When I was poking around reading about this I was surprised to find out that there are thermoregulating plants: the sacred lotus maintains 85F even when the air temperature is close to freezing [goodacres.org] . Nature never fails to come up with something weirder than I could have imagined.

Do yt the GW way (0)

Anonymous Coward | about 3 years ago | (#36559026)

We need to handle this with all the scientific methodology used in the Global Warming controversy.

1. State that dinosaurs are cold blooded, and were killed by man,
2. Ban all funding to schools that teach otherwise.
3. Ridicule all opposing views, especially if they have testable theories.
4. Take a vote of those remaining, especially the phone sanitizers.
5. You now have a consensus! Win!

Re:Do yt the GW way (1)

TapeCutter (624760) | about 3 years ago | (#36562920)

I see you have already started on step 3.

Looks like the researchers forgot... (0)

Anonymous Coward | about 3 years ago | (#36559136)

Looks like the researchers forgot that in the time of the dinosaurs, the temprature of the planet was significantly warmer.

Re:Looks like the researchers forgot... (1)

RockDoctor (15477) | about 3 years ago | (#36579468)

While the mean temperature of the planet was (probably, on average) hotter in the mid-Cretaceous compared to today, there is also substantial evidence of dinosaurs over-wintering in the polar regions and having to struggle behaviourally to succeed in doing it. Burrowing (for small dinosaurs, where the thermoregulation problems would have been most severe) is fairly well established ; communal nesting (as per the modern Antarctic dinosaurs (footnote)) is fiarly well supported ; migration is a near certainty.

The polar regions of the Cretaceous would have been challenging for the humanoids of a million years ago to survive. Which is probably why humanoids didn't appear to settle and navigate in the modern Arctic until around 11-15 kyr ago.

What next? (2)

pjbgravely (751384) | about 3 years ago | (#36559268)

Warm blooded? The next thing they are going to tell us is that dinosaurs had feathers.

Why hasn't? (0)

Anonymous Coward | about 3 years ago | (#36560082)

Why hasn't anyone mentioned PNAS yet? Right on par with the thermometer jokes.

Not a hard problem (1)

slapout (93640) | about 3 years ago | (#36560192)

After all those years, I'd think they'd be room temperature by now.

I'll lift ... (1)

PPH (736903) | about 3 years ago | (#36563294)

... T-rex's tail. You shove the thermometer in.

Teeth are Outside (0)

Anonymous Coward | about 3 years ago | (#36563578)

Even if they could somehow measure ambient temperature for the teeth... I don't know about you, but my teeth spend much of their live with cold drinks.

Teeth are outside of the thermoregulation zone, just like your skin, hair, nails... Also, if their metabolism effectively turns on and off between hot and cold, it's easy to surmise that the teeth would only grow in the daytime.

Temp? (0)

Anonymous Coward | about 3 years ago | (#36563800)

Room Temperature Perhaps?

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