Oldest Big Cat Fossils Discovered in Tibet
Panthera blytheae is an ancient species of cat that was discovered in Tibet. At right is a three-dimensional reconstruction of the cat's cranium from different views.
These three Canada lynx (Lynx canadensis) kittens live in the Great North Woods region of Maine. In June of 2010, the kittens were studied by a team of biologists from the U.S. Fish and Wildlife Service (USFWS) and the State of Maine Department of Inland Fisheries and Wildlife.
Studies of the Canada lynx has been conducted by the USFWS and the State of Maine Department of Inland Fisheries and Wildlife since 1999. Here, a wildlife biologist sets an ear tag in place.
The shadow of climate change hangs over these young lynx. As New England warms, the cats are losing their habitat.
Lynx strut on long legs with big feet perfect for walking on snow. The wild felines depend on heavy snow to maintain their advantage over other predators as they stalk snowshoe hare, their primary prey.
Reductions in snowfall in the Great North Woods region of Maine (shown here) where the lynx research took place may cause the cats to suffer.
“Lynx are uniquely sensitive to climate change based on their physical attributes,” said Chris Hoving, of the Michigan Department of Natural Resources and Environment in a press release. “Their preferred habitat requires at least 2.7 meters of average annual snowfall. If snowfall decreases, there may be almost no suitable habitat in Maine where the only verifiable lynx population on the East Coast exists.”
Hoving published a study of lynx habitat needs in the Journal of Wildlife Management.
Canada lynx thrive in the wilderness of Canada and as well as Alaska, Montana, Idaho, Washington, Oregon and Wyoming in the United States. Other states support smaller populations. In 2000, the USFWS officially listed Canada lynx as a threatened species in 13 states.
Canada lynx kittens grow up to look like this adult in approximately two years. Adult Canada lynx differ from bobcats (Lynx rufus) in that they sport long ear tufts that aid in hearing, have longer legs and bigger feet, and tend to be more gray compared to the spotted bobcat.
Lynx kittens spend their first five weeks in their den. Between seven to nine months of age they begin to hunt. By the beginning of the breeding season on the next year, the kittens are ready to leave mom's side, though they might not breed themselves for another year.
The earliest known big cat lived in what is now China between 5.9 million and 4.1 million years ago, newfound fossils of the ancient prowler suggest.
The fossils, which were discovered on the Tibetan plateau, belong to a sister species of the snow leopard that prowls the Himalayan region today, said study co-author Zhijie Jack Tseng, a paleontologist at the American Museum of Natural History in New York.
The new study also reveals that all cats diverged about 16 million years ago, about 5 million years earlier than was previously thought. [See Images of the Oldest Big Cat Fossils]
The group of felines known as "big cats" includes tigers, leopards, lions and jaguars, as well as snow leopards and clouded leopards. But exactly where and when they evolved hasn't been clear.
Tseng and his colleagues were excavating a rocky region of badlands in the Tibetan plateau in 2010 when they uncovered a fossil skull and one other bone that seemed to belong to a big cat. On return trips, they excavated five more specimens of the cat. [See Images of the Big Cat Fossils]
The team didn't know how old the fossils were, so the researchers looked at the orientation of magnetic minerals in the rock layers around the fossils. Because the Earth's magnetic poles have flipped at known points in geologic time, counting the number of times magnetic particles switch orientation in nearby rocks can reveal the approximate age of a fossil.
The team concluded the big cat was at least 4 million years old — a few million years older than some other ancient tiger fossils.
A detailed look at the anatomy in comparison with other living and extinct cats revealed the primeval cat didn't look too different from a modern snow leopard.
But this cat is by no means the first feline from which all other cats evolved. After combining an analysis of the fossil cat's physical features with genetic data — including some from a fossil cave lion — the team puts the origin of all cats (including housecats) somewhere around 16 million years ago.
"These fossils are the oldest, but they're by no means the most primitive," Tseng told LiveScience. "There is some big cat out there that has yet to be described."
The findings are exciting because they corroborate genetic estimates of when cats first emerged, and because the fossils were found near Central Asia, the area where most scientists believe cats first evolved, said Julie Meachen, a paleontologist at Des Moines University in Iowa, who was not involved in the study.
In addition, the cat skull came from a region where other fossils of mega-creatures have been found, suggesting perhaps this is the region where Pleistocene megafauna, including "big furry guys" such as wooly mammoths and rhinos, evolved, Meachen said. (Megafauna are large or giant animals.)
It's also fascinating how little cats have changed over the past several million years, she said.
"The reason they don't change is that they are so good at what they do that they don't need to change," Meachen told LiveScience. "They're just really effective killers of prey right from the get-go."
The cat fossil was described today (Nov. 12) in the journal Proceedings of the Royal Society B.
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