Mammal

Ancient Egyptian Art Opens Window on Mammal Extinctions

Publication: NBC News   Date: September 8, 2014   View Article

Images of lions, giraffes, wildebeests and other creatures depicted on ancient Egyptian artifacts have helped scientists create a 6,000-year record of local mammal extinctions, according to a new study. Several of the extinction episodes correlate with known periods of drought and rapid human population growth.

While the correlations aren’t proof that drought and population pressures caused the animals to disappear, “it is an interesting pattern,” Justin Yeakel, a biologist at the Santa Fe Institute in New Mexico, told NBC News. What’s more, he added, “as the communities lost species, the system became more unstable and this was largely due to the loss of redundancy in the system.”

In other words, when an herbivore went locally extinct several thousand years ago, it wasn’t a big deal because there were plenty of other herbivores around for the carnivores to eat. Now, there are so few of any mammals left, that the loss of any one species has a larger impact on those that remain.

Oldest Antarctic Whale Found, Shows Fast Evolution

Publication: National Geographic News   Date: November 16, 2011   View Article

The oldest known whale to ply the Antarctic has been found, scientists say.

A 24-inch-long (60-centimeter-long) jawbone was recently discovered amid a rich deposit of fossils on the Antarctic Peninsula.

The creature, which may have reached lengths of up to 20 feet (6 meters), had a mouthful of teeth and likely feasted on giant penguins, sharks, and big bony fish, whose remains were also discovered with the jawbone.

Dino-era Mammal the “Jurassic Mother” of Us All?

Publication: National Geographic News   Date: August 24, 2011   View Article

A tiny, shrew-like creature of the dinosaur era might have been, in a sense, the mother of us all.

Named the “Jurassic mother from China” (Juramaia sinensis), the newfound fossil species is the earliest known ancestor of placental mammals—animals, such as humans, that give birth to relatively mature, live young—according to a new study.

The 160-million-year-old specimen pushes back fossil evidence for the evolutionary split between the placental and marsupial lineages by 35 million years. Although it’s unclear if the creature is a direct ancestor of modern placentals, it’s “either a great grand-aunt or a great grandmother,” the study authors say.

Dinosaur Extinction Spurred Rise of Modern Mammals, Study Says

Publication: National Geographic News   Date: June 20, 2007   View Article

The asteroid that finished off the dinosaurs 65 million years ago opened up niches for the majority of today’s living mammals, according to a new study.

The finding is the latest volley in a long-simmering debate over when and where the direct ancestors of everything from whales to rats to humans first arose.

Chimps Use “Spears” to Hunt Mammals, Study Says

Publication: National Geographic News   Date: February 22, 2007   View Article

For the first time, great apes have been observed making and using tools to hunt mammals, according to a new study. The discovery offers insight into the evolution of hunting behavior in early humans.

No fewer than 22 times, researchers documented wild chimpanzees on an African savanna fashioning sticks into “spears” to hunt small primates called lesser bush babies.

Extinct Mammal Had Venomous Bite, Fossils Suggest

Publication: National Geographic News   Date: June 22, 2005   View Article

About 60 million years ago, a small shrew-like mammal captured its prey by stabbing it with dagger-like teeth that delivered a nasty dose of venom, paleontologists reported today.

“Nothing like that has ever been described before,” said Richard Fox, a vertebrate paleontologist at the University of Alberta in Edmonton, Canada.

Scientists Recreate Genome of Ancient Human Ancestor

Publication: National Geographic News   Date: January 25, 2005   View Article

Scientists have recreated part of the genetic code of an extinct, shrewlike creature that is thought to have been the most recent common ancestor of most placental mammals, including humans.

Placental mammals give birth to live young, and they descended from a common ancestor scientists simply call the “boreoeutherian ancestor.” The creature scurried about the woodlands of Asia more than 70 million years ago.

© 2008-2010 Collected Writings By John Roach