Archaeopteryx, the first known bird

Archaeopteryx, the first known bird, had a hearing range similar to the modern-day emu's (pictured), according to a new study that boosts the avian claims of this descendant of the dinosaurs.

About the size and shape of a European magpie, Archaeopteryx lithographica appeared on the scene around 150 million years ago, in the Jurassic era.

komodo dragon

A komodo dragon roams around its enclosure at the Ragunan zoo in Jakarta. A Swedish diver who spent two nights marooned on an Indonesian island with four other Europeans told how she had to fight off an aggressive komodo dragon with her weight belt.

New sea crocodile fossil hints at transatlantic migration

A newly-discovered prehistoric marine crocodile, given the scientific name of Guarinisuchus munizi. The crocodile, estimated to have lived some 62 million years ago, is one of only two animal groups benefited from the massive extinction of dinosaurs to migrate from across the Atlantic some 65 million years ago .

Scientists find 'Devil Toad' fossil

A frog the size of a bowling ball, with heavy armor and teeth, lived among dinosaurs millions of years ago — intimidating enough that scientists who unearthed its fossils dubbed the beast Beelzebufo, or Devil Toad.

But its size — 10 pounds and 16 inches long — isn't the only curiosity. Researchers discovered the creature's bones in Madagascar. Yet it seems to be a close relative of normal-sized frogs who today live half a world away in South America, challenging assumptions about ancient geography.

The discovery, led by paleontologist David Krause at New York's Stony Brook University, was published Monday by the journal Proceedings of the National Academy of Sciences.

"This frog, if it has the same habits as its living relatives in South America, was quite voracious," Krause said. "It's even conceivable that it could have taken down some hatchling dinosaurs."

Butterfly

A butterfly rests on a leaf inside the new exhibition hall, 'Butterflies and Plants: Partners in Evolution', at the Smithsonian's National Museum of Natural History.

Bats could fly before they had 'radar'

A fruit bat in an abandonned quarry near the Cypriot village of Mammari. A nearly perfect bat fossil has proved that bats could fly before they developed sonar to track and trap their prey.

New mammal enters the book of life

A rare new species of mammal, a shrew-like creature called a grey-faced sengi, living in a small community in remote Tanzania. Sengis -- small, furry, insect-eating mammals that live on forest floors -- are also called elephant-shrews.

Until now, only 15 species of sengis were known, but this one is truly exceptional.

Whales have evolved from raccoon-sized creature

A Franca Austral whale, also known as the Southern Right whale, performs a tail slap by slapping its tail flukes on the surface of the water just off the shore of Puerto Piramides June 26, 2007. In the search for a missing evolutionary link to modern whales, scientists have come up with an unlikely land cousin -- a raccoon-sized creature with the body of a small deer.

Tiny mammal was ancestor of cetaceans

The skeleton of a whale hangs in a cetaceans museum in Puerto Calero, Spain. A tiny deer-like mammal was the forerunner of whales, dolphins and porpoises, according to a study released by Nature, the weekly British science journal.

This handout artist rendering shows The 48 million year old ungulate Indohyus from India. Indohyus is a close relative of whales, and the structure of its bones and chemistry of its teeth indicate that it spent much time in water. In this reconstruction, it is seen diving in a stream, much like the modern African Mousedeer does when in danger.

Ancient kangaroo didn't hop

A female Kangoroo and her baby near Brisbane. A 25-million-year-old fossil has revealed that a predecessor of Australia's iconic hopping kangaroo once galloped on all fours, had dog-like fangs and possibly climbed trees.

Panda fossils on tropical island

A giant panda in a file photo. Chinese archaeologists have found fossils that prove pandas once roamed what is now the southern Chinese island of Hainan