The world's least fresh fish

Ransom Riggs

Don't expect this guy to show up on your local fish market's list of daily specials -- he's over 380-million years old. That makes him the oldest fish ever discovered with morsels of fossilized muscle tissue intact. (Yeah, he'd be a little tough.) Unearthed in western Australia 20 years ago, the specimen belongs to a species of an extinct group of primitive, armored fish known as placoderms. Fossilized muscle is quite rare, and the new finds are even more exceptional, because they weren't flattened but rather preserved with their three-dimensional shape intact, Australian researchers say.

The remains shed light on the evolution of placoderms, which ruled the world's oceans, rivers, and lakes for 70 million years until they died out about 360 million years ago. "On the evolutionary tree, they're the first jawed animal, and we're the last. So they're our first jawed ancestors," said lead study author Kate Trinajstic, a paleontologist at the University of Western Australia.

But I think the researchers are overlooking the most exciting possibility here -- a little cloning and we could have our own Placoderm Park!