Tough Times in 

 the Tar Pits 



by Bloire Van Volkenburgh 



The camel had been a quick kill. Its 

 struggles at the stream's edge, where it had 

 been trapped in quicksand saturated with 

 asphalt, had attracted a pack of dire 

 wolves. They dispatched the huge beast 

 quickly with multiple, ripping bites to its 

 abdomen. 



Now the feeding wolves rapidly pull 

 muscle and viscera from the carcass, stop- 

 ping occasionally to scan their surround- 

 ings. Condors circle above and a coyote 

 paces nearby, eager to clean up any scraps. 

 At the sound of a warning growl, all the 

 wolves stop feeding and turn toward the 

 sound; the fur on the back of their necks 



stands erect, and their lips pull back to re- 

 veal their upper canines. Two saber- 

 toothed cats approach, each twice the 

 mass of a dire wolf. The cats display their 

 canines — long, slightly curved daggers 

 that extend well below their lower jaw. Al- 

 though only two sabertooths are challeng- 

 ing the pack of eight wolves, the wolves 

 are unwilhng to engage the big cats in bat- 

 tle. The sabertooths move closer, lunging 

 and swiping at the wolves, paws spread 

 wide and claws extended. All the wolves 

 move away from the camel and watch as 

 the sabertooths feed on the catch. 



After the big cats have left, the hungry 



wolves will return to eat what remains of 

 the carcass. By the following day, little ev- 

 idence will be left of the camel's death on 

 the sand's surface; all exposed bones will 

 have been carried off and chewed by scav- 

 engers such as the coyote. Those bones 

 mired in the sticky sand will be entombed 

 and preserved — and will emerge as fossils 

 from the tar pits of Rancho La Brea some 

 20,000 years later. 



The array of fossil mammals from this 

 Los Angeles site, which began to accumu- 

 late 36,000 years ago, reveals the diversity 

 of large animals that inhabited North 

 America until the late Pleistocene, only 

 about 10,000 years ago. Today only eleven 

 species of hoofed mammals the size of a 

 peccary or larger exist in North America; 

 in the past, fifty-six Mved on this continent. 

 They included giant camels, horses, bison, 

 mastodons, and mammoths. These herbi- 

 vores were preyed upon by a rich array of 

 carnivores: fifteen species the size of a 

 coyote or larger, as opposed to just seven 

 today. In addition to sabertooths, dire 

 wolves, and coyotes. North America was 

 home to black, grizzly, and short-faced 



84 Natural History 4/94 



