Giant Sea Reptiles Were Warm-Blooded?

nationalgeographic ^ | June 10, 2010 | Charles Q. Choi

[JoeProBono]

Giant reptiles that ruled dinosaur-era seas might have been warm-blooded, a new study says.

Researchers found that ancient ocean predators possibly regulated their body temperatures, which allowed for aggressive hunting, deep diving, and fast swimming over long distances.

(See "Giant 'Sea Monster' Fossil Discovered in Arctic.")

"These marine reptiles were able to maintain a high body temperature independently of the water temperature where they lived, from tropical to cold-temperate oceanic domains," said study co-author Christophe Lécuyer, a paleontologist at Université Claude Bernand Lyon 1 in France.

The prehistoric reptiles may have had body temperatures as high as 95 to 102 degrees Fahrenheit (35 to 39 degrees Celsius)—comparable to those of modern dolphins and whales, Lécuyer noted. (See whale pictures.)

Most modern reptiles and fish are cold-blooded, which means their internal temperatures vary along with those of the surrounding water.

Since the modern oceans' top predators—such as tuna and swordfish—are to some degree warm-blooded, this made the team wonder if ancient marine reptiles might have been, too, Lécuyer said.

Tuna and swordfish are homeothermic, or capable of keeping their body temperatures relatively constant, despite changing environmental temperatures. The predators are also partially endothermic, which means they can generate and retain enough heat to raise their body temperatures to high but stable levels.

Most animals thought of as warm-blooded, including mammals and birds, are also both homeothermic and endothermic

[ZULU]

Brooding pythons can raise their body temperature above ambient by shivering - making muscular contractions. Leatherback turtles also have body temperatures above ambient.

They are reptiles.

I think the problem in dealing with extinct forms is they don’t fit the same mold as contemporary reptiles do.

[null and void]

ok...you win

I disagree. Didn't stick to the topic of warm blooded.

[DollyCali]

sent you friend invite

[Scythian]

Love it, I miss those old movies. I think this coming winter (assuming we’re all still civilized) I’ll have a Godzilla weekend and the kids will love it.

[AdmSmith]

Warm-blooded creatures, like mammals and birds, try to keep the inside of their bodies at a constant temperature. They do this by generating their own heat when they are in a cooler environment, and by cooling themselves when they are in a hotter environment. To generate heat, warm-blooded animals convert the food that they eat into energy. They have to eat a lot of food, compared with cold-blooded animals, to maintain a constant body temperature. Only a small amount of the food that a warm-blooded animal eats is converted into body mass. The rest is used to fuel a constant body temperature.

http://coolcosmos.ipac.caltech.edu/image_galleries/ir_zoo/coldwarm.html

more infrared pictures via the link above.

[domeika]

I disagree. Didn't stick to the topic of warm blooded.

Hmmm....technically, Bawney Fwank is a cold-blooded reprobate reptile, but to go further, assigning him reptile status is probably way above his true classification of insect.

[SunkenCiv]

Thanks!