Natural History Trivia, II
Some people seem to appreciate this, so I'll keep doing this on a weekly basis unless I'm told to knock it off. I won't run out of trivia.
1. Lamnid sharks (great whites, makos, etc.) are warm-blooded. So are xiphiids (swordfish, marlin, etc.) and tunas. Indeed, so are leatherback sea turtles, uniquely among turtles.
Lamnid endothermy (warm-bloodedness) doesn't work like ours. Mammals and birds have more mitochondria in their cells than related ectotherms. Mitochondria convert sugar into energy, releasing heat as they do so. But lamnids have specialized muscles in their body cores that repeatedly flex, generating heat the same way we do when we walk around in cold weather.
This, by the way, is why white sharks are infamous for attacks off the coasts of South Africa, California, New England, and southern Australia, but shark attacks in Polynesia, or the Atlantic coast south of Long Island are likelier to come from tiger or bull sharks. White sharks like cold water, where their preferred prey (seals and sea lions) can be found in abundance.
2. Crocodylians cannot stick out their tongues. Their tongues are completely fastened to the lower jaw. (Don’t believe me? Show me an alligator or crocodile sticking its tongue out. Using a scalpel to loosen it is cheating.)
3. Botany helped win the Second World War. Geoffrey Tandy, a marine biologist and expert on seaweed, worked at Bletchley Park, where the British were working to break Axis codes. As it happens, the techniques used to preserve delicate water plants are also highly effective at preserving water-logged paper with writing on it, such as the code books being fished out of wrecked German ships. There's a legend that Tandy ended up at Bletchley Park because someone confused the word “cryptogam” (a commonly-used term at the time for seaweeds and related forms) with “cryptogram," but although I think the world is a cooler place if this is true, it might not be.
4. The beak of a sword-billed hummingbird is longer than the rest of the bird.
5. The fastest land mammal today is the cheetah. The second-fastest, however, is the pronghorn antelope of North America. Nothing today in North America can catch a pronghorn at full run without a motorized vehicle. But until about 16,000 years ago, there was a cat closely related to the mountain lion that had independently evolved the proportions and adaptations for speed seen in cheetahs. The pronghorn evolved great speed to escape a predator that no longer exists.
(Actual cheetahs are also related to mountain lions. Cheetahs are big, and they’re cats, but they’re not big cats in the evolutionary sense. Big cats like lions, tigers, leopards, and jaguars are pantherines. They roar. Cheetahs are felines, and they don’t roar.)
6. The earliest camels appeared around 45 million years ago. For the first 40 million of that, camels were found in North America and nowhere else. There were antelope-like camels and giraffe-like camels. About 5 million years ago, one camel lineage crossed the Bering Land Bridge to Asia, giving rise to modern dromedaries and Bactrian camels. 3 million years ago, a second lineage moved down into South America and became the ancestors of today’s guanacos and vicunas, which were domesticated to become llamas and alpacas. And then, they died out in North America.
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Thanks for posting!
Scientists crossed a cheetah with a crab; I don't know what they got, but things went sideways real fast! 
I love stuff like this.
