Thursday, November 21, 2013

The Oldest Big Cat Fossils Found

The Fossil Record

Big Cat: The Panthera blytheae resembles a modern snow leopard shown here.
Credit: Mauricio Anton 
Source: Nature

An article, by Sid Perkins, in Nature News says that big cats that are in some ways similar to today's snow leopards have been moving around the Himalayas in Asia for six million years; so shows  the fossil evidence.

Perkins writes:
The remains of Panthera blytheae extend the known lineage of pantherine cats by at least 2 million years and bolster the notion that this group of carnivores originated in Asia. 
Researchers unearthed bones representing at least three individuals in southwestern Tibet. The most complete remnants include a partial adult skull with several teeth still embedded in the upper jaw, says Jack Tseng, a vertebrate palaeontologist at the American Museum of Natural History in New York. Those fragments were excavated from rocks about 4.42 million years old, but other fossils belonging to the same species came from nearby strata that were laid down about 5.95 million years ago, he and his colleagues report today in Proceedings of the Royal Society B1.
“These are beautiful fossils of great significance,” says Zhe-Xi Luo, a vertebrate palaeontologist at the University of Chicago in Illinois who was not involved in the study. “They add an evolutionary root to the pantherine family tree.”
Many features of the P. blytheae’s teeth are similar to those of the snow leopard, but some ridges and cusps are distinct, indicating that the fossils represent a new species. Judging from the size of the partial skull, the big cat was about the same size as the clouded leopard and about 10% smaller than the snow leopard, both of which live in the Himalayas today. A comparison of dozens of anatomical features for 12 living and extinct species of felines indicates that the snow leopard is P. blytheae’s “sister species”, says Tseng. Today’s tiger is also a very close relative, he adds.
This is interesting for two reasons, say the paleontologists: the first is that their original expectation was that the P. blytheae would show less development, or evolution, than current species of big cats like the snow leopard; and the second is that the fossil record is incomplete, missing intermediate forms, which go back to the progenitor. We’d need quite a lot of intermediate fossils to know how the lineage developed.” says Lars Werdelin, a vertebrate palaeontologist at the Swedish Museum of Natural History in Stockholm. 

These pieces form the larger puzzle of how a species developed over a period of millions of years. Without them, scientists have to rely on educated guesses and the current fossil record on how a species came about. So far, the results have been astonishingly good and accurate, if not fascinating.

For the rest of the article, go to [Nature].