Evolution Diary

The split between primates and humans may have its roots in some common ancestors’ simple shuffle, a new study says.

Living between four and seven million years ago, these ancestors are believed to have walked on four limbs.

But the ancestors likely began lifting up their torsos and shuffling about on two feet for short distances when foraging for high-hanging food, according to new research.

Moving on two legs for short distances—between 9 and 16 meters (30 to 53 feet)—required less energy than returning to all fours to move to the next foraging spot, said study co-author Patricia Kramer, an anthropologist at the University of Washington.
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Crowded with dinosaurs, petrified trees, and other prehistoric treasures, an ancient riverbed in Utah is surprising scientists.

The discovery sheds new light on a Jurassic landscape dominated by dinosaur giants that lived 145 to 150 million years ago (prehistoric time line).

In just three weeks of work on federal land near Hanksville, Utah, paleontologists say they unearthed at least two meat-eating dinosaurs, a probable Stegosaurus, and four sauropods—long necked, long-tailed plant-eaters that could reach 130 feet (40 meters) long, making them the largest animals ever to have walked the Earth.
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Yes, they had wings, but the largest flying creatures ever to have lived preferred to hunt baby dinosaurs and similar-size snacks on foot, scientists say.

A new study of a group of pterosaurs called azhdarchids suggests that, even though they had wingspans of more than 10 meters (33 feet), they stalked their prey on the ground like modern-day storks.

Mark Witton and Darren Naish of England’s University of Portsmouth based their findings on a detailed review of the reptiles’ fossils and habitats.
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A new fossil find may be an evolutionary missing link in the amphibian family tree, scientists say.

The 290-million-year-old fossil was first collected in Texas by a paleontologist with the Smithsonian Institution in the mid-1990s. It was rediscovered in the collections of the National Museum of Natural History in Washington, D.C., in 2004.

“It had an overall amphibian gestalt. … You know, kind of a froggy slamander-y sort of look,” said Jason Anderson, a comparative biologist at the University of Calgary, Canada, who led a new analysis of the fossil.

“But also I recognized some of the archaic features too, and I thought that this would be a critical piece of evidence in trying to work out the origins of modern amphibians.”

Dubbed Gerobatrachus hottoni, the animal looked somewhat like a salamander with a stubby tail and froglike ears.
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A fossil fish uncovered in Australia is the oldest-known example of a mother giving birth to live young, scientists have reported in the journal Nature.

The 380 million-year-old specimen has been preserved with an embryo still attached by its umbilical cord.

The find, reported in Nature, pushes back the emergence of this reproductive strategy by some 200 million years.

Until now, scientists thought creatures from these times were only able to develop their young inside eggs. Keep reading →