Saturday, 25 September 2010

La Brea: It’s the Pits

For decades now, I have been whizzing by the La Brea Tar Pits on Wilshire Boulevard to suck up to something interesting at the Los Angeles County Museum of Art a couple of blocks up the street.
To judge from a fascinating exhibition at our Academy of Natural Sciences (through May 14), I shoulda slowed down. “Treasures of the Tar Pits” is the finest bit of science explaining I have attended to in a mighty long time.
Rancho La Brea (to give the pits their full and proper name) is a geological depravity between the Santa Monica Mountains on the West and the Baldwin Hills on the East. Because of a peculiar fault, natural asphalt used to seep up to the surface here. And when it got hot and sticky in the summer, carnivores got their comeuppance, sticking in the muck until they died.
A fascinating bit of trivia about this greatest fossil find of the late ice age is that there are no nocturnal animals trapped (some poet ought to be able to make something neat out of that donnee), because at night—as during the winter—the sticky stuff hardened up.
And there are seven times as many carnivores trapped as herbivores—grasses were sparse there between 10,000 and 40,000 years ago. We have nothing older than that because the tar pits were under water until 50,000 years ago.
This natural trap did not generate fossils for future scientists at a very rapid clip. It is estimated that ten animals were trapped every decade for 30,000 years to yield the cache.
We’re not talking lemmings in droves. We are watching, with a kind of glacially slow time-lapse photography, an unlucky critter here and there piling up a heap of bones over 30 millennia. And some animals were unluckier than others—much unluckier. A thousand gold eagles’ feathers hit this sticky fan.
One display, in a kind of unintentional minimalist sculpture, deploys 500 tarsometatarsi (that’s the long heel bone from which the toes depend, for all you scientific ignoramuses who flunked anatomy—like me.)
Another, if you like, is a real Die-O-Rama—an American lion chasing a bison calf—each stuck unto death; a dead wild horse being scavenged by a passel of saber-toothed cats, stuck up for good; and a pack of “dire wolves” (how that soubriquet has its own howl built into it) attracted by the commotion, flat on their asses through no asphalt of their own.
It was a remorseless pit, this. And smaller scavengers such as cara-cara and carrion beetles add to the 3-D of this deadly dining out.
Forty percent of the La Brea fossils represent species now extinct, done in by something or other 8,000 to 10,000 years ago. There have been 500 species of flora and fauna identified, 151 of them plants. Ingenious archeologists study teeth crevices of herbivores to reconstruct plants. And defecation: What goes in must come out.
There are no dinosaurs stuck in the muck because their era (the Mesozoic, from 240 million years ago to a mere 63 millions) is many many coons’ ages away from the tiny blip of time during which the pits did their sticking. Sorry, Fred Flintstone—the probability of your having stoned those noble creatures is zilch.
I see by a recent Washington Post that accredited scientists are opening up a Truth Squad warfare against the toymakers who are gunging very ho on the Dino-Boom. Laser warfare against the DinDins.
It is shows like this—clear, intelligently placarded, with bones attractively cased—that make jihad now against bones of commercialized contentiousness. Take your kids to see the real things. And if you’re entering your second childhood, like me, you rue the day that your scientific education was so inadequate.
A fine traveling show, this one, from the Los Angeles Museum of Natural History: “Trapped in Time: Treasurers of the Tar Pits.” I’m promising myself a proper Pit stop this time on my way to the Los Angeles County Museum. It’s about time—trapped as I am in humanist ignorance—I started comprehending science.
Reprinted from Welcomat: After Dark, Hazard-at-Large, May 10, 1989

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