Paleontology

A 47-million-year-old primate fossil that is so complete scientists can even tell what the animal's last meal was promises to shed new light on the earliest stages of evolution of the lineage that eventually led to humans, researchers said Tuesday. The unprecedented fossil of a lemur-like creature that probably weighed no more than 2 pounds when it was fully grown is remarkable because it is the most complete primate specimen ever obtained.

For months, maybe years, hikers trekking along the muddy creek bed stamped over it, mistaking it for a large rock. But Daryll Hansen knew differently. The amateur paleontologist could tell the flat gray hump protruding from the dusty sandstone was a rare prehistoric gem: a 5-foot-long baleen whale skull left from millions of years ago when Aliso Creek in Lake Forest was underwater.

A new study of one of the earliest feathered dinosaurs suggests it may have had upper and lower sets of wings, much like a biplane. The dinosaur, known as \o7Microraptor gui, \f7was originally described in 2003 by Chinese researchers as having aerodynamic feathers on both its arms and legs, arranged in flight one behind the other, like a dragonfly.

Human fossil remains from northern China, among the oldest found in Asia, show characteristics that throw into question the theory that modern people evolved directly from African ancestors, according to a study in Monday's Proceedings of the National Academy of Sciences. The 40,000-year-old Tianyuan Cave skeleton combines physical characteristics of modern humans and the earlier Neanderthal people, researchers said.

Foghorn Leghorn would be proud. The cantankerous Loony Tunes rooster and his brethren appear to be the closest living descendants of the ferocious \o7Tyrannosaurus rex\f7 that ruled the world of dinosaurs. That's the conclusion of a team of researchers who analyzed a remarkable 68-million-year-old sample of \o7T. rex\f7 tissue. It began two years ago when paleontologist Mary H.

Harley Garbani excused himself, ducked out of the room and returned with a savage set of 6-inch teeth and claws. "Take a look," he said, displaying the finer, if sharper, points of a \o7Tyrannosaurus rex\f7. "If he picks you up with these, you can kiss your butt goodbye." That fate seems unlikely these days even if Garbani's home is more appropriate to, say, Jurassic Park than the trailer park in Hemet where he lives.

The remains of a birdlike dinosaur as tall as the formidable \o7Tyrannosaurus rex \f7have been found in China, a discovery that indicates a more complicated evolutionary process for birds, scientists reported Thursday in the journal Nature.

Researchers reported Monday that they had unearthed two fossil penguins, one of which stood 5 feet tall, that lived in the warm climate of prehistoric Peru -- a discovery that promises to change the way scientists think about penguins and cold weather. Until now, scientists were comfortable with the notion that ancient penguins first appeared more than 60 million years ago in cold habitats and didn't move close to the equator until 8 million years ago.

Weighing in at 150 pounds or more and with a wingspan of 23 feet, the all-time biggest bird couldn't just hop into the air and fly away, researchers say. Researchers at Texas Tech University used computer programs originally designed for aircraft to analyze the probable flight characteristics of \o7Argentavis magnificens\f7, a giant bird that lived in South America 6 million years ago.

It was trapped under the Siberian permafrost for more than 12,000 years and discovered by fossil hunters who at first mistook it for a mammoth tusk. But on Sunday, the 4 1/2-foot-long fossilized walrus penis -- believed to be the world's largest specimen -- was the most talked-about piece of natural history up for bids at I.M. Chait in Beverly Hills. The prehistoric phallus sat on a metal display stand, curving to a narrow point. An attendant stood watch over it.