Creek Running North

This is a Knightia, a herring that lived in a large freshwater(ish) lake in North America during the Eocene period, about fifty million years ago.

The lake, called “Fossil Lake” for some reason, is gone, but its sediments live on in the Green River Formation in Colorado, Utah and Wyoming. The Green River Formation is the source of many of those gift shop fossil fish you’ve seen that look pretty much like this one. But there are a few less-common fossils that have been pulled out of the rock along with the herring, the oldest known bat fossil being an example.

What distinguishes the fish here from those gift shop fossils is this: I pulled it out of the rock myself, along with the about two dozen other fish that keep it company in my glass-topped coffee table. It was “pay to play” fossil hunting in a privately leased quarry, so there was no particular skill involved on my part. But I did get to sshove the metal blade into the cracks in the rock, twist to loosen the slab, and pick through the result to find the fish under the cold Wyoming sun. And I got to do so in the company of one of the most skillful fossil preparators in the country, Carl J. Ulrich, who is a hell of a cool guy.

Yes, that’s “preparator.” It’s inelegant jargon, but it’s the jargon nonetheless.

Ulrich has a number of examples of his work in the Smithsonian. I can’t imagine the patience involved in carefully freeing just one large fish from its rock matrix, and Ulrich has done thousands over the course of his long career. I know of the general disregard with which private fossil collectors are often held by paleontologists, but I have never heard anyone speak of Ulrich in anything but the most glowing tones. It was a privilege to shell out sixty bucks to stand next to him for three hours. Plus I have fish.

Breaking Eocene news update: Carl Dennis Buell sent along a couple of his fantastic paleontological paintings today after reading the first half of this post, and I’m sharing one with you with Carl’s permission. The two big rhinoey things in the water are Brontops, a big rhinoey member of the brontotheres, which were big rhinoey relatives of rhinos. The brontotheres were widespread in the northern hemisphere, with a fair number found in Mongolia and (literally) tons in Wyoming. The brontothere distantly related hyracodont Indricotherium, once called Baluchitherium, was the largest known land mammal of all time at around 18 feet tall and ten tons. (Indricotherium is often said to have been discovered by swashbuckling paleontologist Roy Chapman Andrews on one of his Central Asian expeditions, but the species was in fact first found and named by Sir Clive Foster Cooper in 1911. Andrews did find the first more or less complete Indricotherium skeleton.)

Brontops was far smaller, only about eight feet tall. When I was a kid looking through books on paleontology, I used to think it would be cool to have had a Brontops as a friend: I could have ridden on its back and shot at things with that slingshot on the beast’s snoot.

Running in front of the Brontopses is a Hyracodon, an early rhino (though not directly ancestral to modernday rhinos). North America was once a center of horse-rhino diversity, and both of those related groups of perissodactyls have pretty much died out. Oh, there are lots of Equus caballus still around, but conservationists eye the other seven extant horse species — from asses to zebras — with some concern, and three of the species teeter on the brink. There are five species of rhinos left, all threatened.

This is a really spectacular painting, of a scene that might well have been contemporary with the mortality of my Knightia near Fossil Butte National Monument outside Kemmerer Wyoming. I can’t imagine how Carl got all those perissodactyls to stand still for long enough to paint them.

Correction: Karl, in comments, points out a mistake I made, which I have both corrected and preserved above.