Duck and heron fossils found at the site suggest water was close by, and ancient horse and llama remains indicate a plains environment existed not too far away.
(Related: "Ice Age Horses May Have Been Killed Off by Humans, Study Finds" [May 1, 2006].)
After finding two sabertooth teeth on separate digs in western Venezuela, Rincon guessed that there had to be a scimitar cat fossil in the country.
The scimitar, about the size of a modern lion, is a lesser known type of saber-toothed cat that roamed North America during the Ice Age. The hunter used its serrated teeth—shorter than the sabertooth's—to take down mammoths and other prey.
The rare scimitar skull suggests the cats had shorter faces than was previously thought, Rincon said.
The points where the cat's neck muscles connected to the head also suggested the animal had a more robust neck and a more mobile head, Rincon said.
And instead of four holes for the nerves, the newfound scimitar skull has only three. The missing nerve hole perhaps broke off or remains covered up by asphalt, Rincon said, but he is nevertheless excited by the uncertainty.
Rincon plans to determine the diet and mobility of these animals to reconstruct their communities. Analyzing the isotopes—or different types of an element—in the fossilized bones will indicate roughly what those animals ate.
For instance, he can determine which cats were hunters and which couldn't hunt because of some physical handicap. One intriguing, heavily eroded tooth suggests its owner could not hunt and thus depended on its kin for assistance, Rincon said.
Comparing diet and clues such as the eroded tooth with modern tiger communities may also offer insights into ancient scimitar cat populations.
(Related: "Saber-Toothed Cat Had Weak Bite, Digital Model Says" [October 1, 2007].)
Though Rincon said he's only scratched the surface, he has already collected 5,000 specimens.
These include horses, llamas, crocodiles, ducks, herons, a rhino-like animal called a mixotoxodon, giant ground sloths, and other glyptodons.
"It's one of the most important paleontological finds in 20 years," said Chris Bell, a Pleistocene-mammals expert at the University of Texas at Austin who has visited the site.
The discoveries suggest more treasures may lie in the tar pit.
"The little hint is so exciting," Bell said.
"It's a very different story here from North America and Argentina. Its a different assemblage of mammal species."
Millions of specimens that may be buried in this tar pit, and there may be hundreds more such pits in oil-rich Venezuela.
"The asphalt-preserved animals could rival those of Rancho La Brea," said Christopher Shaw, collections manager at Los Angeles's George C. Page Museum, which handles the La Brea collection.
Rancho La Brea, in the heart of Los Angeles, has the largest and most diverse assemblage of extinct Ice Age plants and animals in the world—including sabertooths, mammoths, and giant ground sloths.
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