科学美国人60秒 SSS 古代海洋爬行动物拥有熟悉的装备

（单词翻译）

This is Scientific American — 60-Second Science. I'm Christopher Intagliata.

Long before dolphins swam the seas, their near look-alike ichthyosaurs inhabited the earth's oceans. Now scientists say these ancient seafaring reptiles¹ may have ha?????d more in common with modern-day sea turtles and marine² mammals than we knew.

Over time, a dead animal's bones can be slowly replaced by minerals, leaving behind a rocky fossil. The researchers demineralized the 180-million-year-old fossil of an ichthyosaur...leaving them with soft, flexible tissues.

"Which is kind of amazing."

Johan Lindgren, a paleontologist at Lund University in Sweden. "It turns out that the skin, is still there, with cells and cellular³ organelles. And even traces of the original biomolecular makeup⁴."

Those remains⁵ revealed that the ichthyosaur sported camouflage⁶ appropriate for its underwater environment—light on the bottom, darker on top—like many marine animals have today.

The researchers also found a black, glossy⁷ substance that was harder to identify. So they collected dead sea turtles and porpoises⁸ and mimicked⁹ fossilization by heating and squashing the creatures' skin. Which led them to realize that that the darker substance in the ichthyosaur fossil must be blubber.

"So from having blubber we can say that, to some extent the ichthyosaurs must have been warm blooded, so to say. At least to the same degree as the modern leatherback turtle."

The write-up and photos of the fossil are in the journal Nature.

There's one more intriguing¹⁰ secret contained in the remains: proteinaceous material. Which makes you wonder if you sequenced it, could you go backwards¹¹, and reconstruct the DNA¹² that coded for the proteins?

In other words: (Jurassic Park clip: "Bingo... Dino DNA!)

Of course, ichthyosaurs were not dinosaurs¹³, but the Jurassic Park methodology is what's important. So, could we resurrect one starting from their protein sequences?

"Yeah well, perhaps. You should never say never!"

Thanks for listening for Scientific American — 60-Second Science. I'm Christopher Intagliata.