Wednesday, February 1, 2017

Ick! It’s an Ichthyosaur!

Ichthyosar means “fish reptile” in Greek. Fossils reveal that they appeared about 250 million years ago, and one branch lasted until 90 million years ago. Their ancestors were some unidentified land reptile that decided to return to the water and become fish-like, much like dolphins and whales.

Science became aware of ichthyosaurs in the early 1800s when the first complete skeleton fossil was discovered in England. Later that century, many more Ichy fossils were found in Germany, and some of them included soft tissue remains. (No longer soft, after being fossilized, of course.)

Ichys ranged from 1 meter to over 16. Some resembled modern fish, others looked more like dolphins. They had pointed heads and often pointed teeth. Some could and did attack large animals that wandered into reach. They had large eyes, probably so they could dive deep. Their legs had completely converted into flippers, although many species’ flippers had numerous digits and phalanges (bones of the digits). They were not really fish, because they breathed air, gave birth to live offspring (up to 11 at a time), and were warm-blooded.

Life as an ichy was not all hunting and reproducing. One fossil had bite marks on its snout, apparently from one of his own kind. The bites had started to heal, so it survived the attack, but was this common? Or had he/she really made someone angry? Another fossil was complete… except for its tail. The theory is that it was ambushed by another of the big ocean predators, which bit off its tail. That ichy – unable to swim – sank deeper, drowned, and eventually became a fossil.

At one of my jobs, they decided to install an aquarium. If you want a healthy aquarium, you need a bottom feeder, usually a catfish. The fish they got included a bottom feeder, probably some type of catfish, but I thought it was ugly; flat bottom, thick whiskers, brown with black spots on skin that looked slightly fuzzy. I wound up calling it ‘Ichy’. I was familiar with the name, but didn’t realize they had all died out long ago. And since this fish didn’t actually look anything like an Ichthyosar, the name really didn’t fit.

I feel sorry for that poor bottom-feeder, now. I grew to rather like him, but I still called him ‘Icky’ (my pronunciation). It really wasn’t fair. I’m sure others of his species – whichever one he belonged to – thought him quite acceptable.

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