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Mammals

An artist’s rendering of ancient Arctic hyenas belonging to the genus Chasmaporthetes. A new study reports that two enigmatic fossil teeth found in Yukon Territory in Canada belonged to Chasmaporthetes, making the teeth the first known fossils of hyenas found in the Arctic.

Beyond Dinosaurs: The Secrets of Earth's Past

Prehistoric Hyena’s Teeth Show Bone-Crushing Carnivore Roamed the Arctic

The only hyena to live in North America, Chasmaporthetes, had the stature of a wolf and the powerful jaws of its modern relatives

Unlike modern beavers, which use their sharp-edged teeth to chop up trees and build dams, mega-sized ones were unable to alter their environment to fit their needs

Why Did These Human-Sized Beavers Go Extinct During the Last Ice Age?

A new study suggests the giant beavers disappeared after their wetland habitats dried up, depriving the species of its aquatic plant-based diet

If listed under the Endangered Species Act, giraffes would become eligible for federal funding aimed at conservation, and limits would be placed on the import of the animal's body parts

The United States May List Giraffes as an Endangered Species

Last week, the U.S. Fish and Wildlife Service announced plans to conduct in-depth review of the popular animal’s threat status

Argali are the largest wild sheep in the world, weighing up to 400 pounds.

The Decades-Long Effort to Protect the World’s Largest Sheep

In the Gobi Desert, where argali roam, a group of Mongolian researchers work to conserve the wild sheep populations

An artist's rendering of the extinct hypercarnivore

This Toothy Carnivore Was Bigger Than a Polar Bear

Some 22 million years ago, the apex predator ruled the forests of Africa and dined on the ancestors of hippopotamuses and elephants

Researcher Jack Ashby initially suspected a crow was responsible for the toad's skinning, but after examining the photo, he concluded that an otter was the more likely culprit

Why Otters Disembowel Toads Before Eating Them

The unfortunate amphibian likely fell victim to an otter, which skinned it to avoid ingesting the deadly toxins found in its glands

The lowland streaked tenrec (Hemicentetes semispinosus) in Andasibe-Mantadia National Park, Madagascar.

Defensive Spines on Tenrecs Could Come at a Cost to Brain Size

The little mammals of Madagascar appear to have undergone an evolutionary tradeoff between brain size and defensive armor

A rare, blue-eyed coyote

Rare Blue-Eyed Coyotes Spotted in California

Coyotes’ eyes are consistently golden-brown, so researchers have been surprised to learn of five California coyotes with piercing baby blues

New Research

Scientists Use AI to Decode the Ultrasonic Language of Rodents

The DeepSqueak software translates the high-pitched communication into sonograms, which can be analyzed to determine what mice and rats are saying

A newly collared mule deer is released onto its winter range.

New Tracking Technology Reveals Hidden Animal Migration Routes

Using improved GPS collars, scientists are mapping more herd migration routes than ever before, a key to conservation efforts in the western United States

Magnet, one of the endangered North Atlantic right whales returning to their wintering grounds in Georgia and Florida.

Cool Finds

First Right Whale Calf in Two Years Spotted Off Florida Coast

A mother and calf were recently sighted along with several possibly pregnant endangered North Atlantic right whales

The Best Places to See Reindeer Around the World

From Norway to Alaska, here’s where to see members of Santa’s herd in person

The jumping spider bears a distinct resemblance to ants

Jumping Spiders Are the Only Arachnids Known to Provide ‘Milk’ For Their Young

The milk-like nutritious fluid contains four times the protein of cow’s milk

Baleen is the soft, hair-like structure on the upper mouth of whales, such as the humpback whale in this photo, which allows them to trap prey in their mouth.

Prehistoric Whale Jaw Bone Sheds Light on the Evolution of Baleen

Hidden in a museums’ collections for years, a fossil provides a link between past and present feeding mechanisms

Cool Finds

Early Mammals Were Thought to Be Small and Unseen in the Age of Dinosaurs. An Elephant-Sized Fossil Complicates That Story

At a time when proto-mammals and other creatures were getting smaller, this dicynodont bulked up with the thunder lizards

A figure representing the Kayentatherium babies found with an adult specimen. They are the only known fossils of babies from an extinct mammal relative that lived during the Early Jurassic.

Weasel-Like Fossils Reveal Evolutionary Clues of the First Mammals

A protomammal known as Kayentatherium was discovered with 38 babies in 185-million-year-old rock

Princepajaro, a male California sea lion, swims in a pool during treatment for leptospirosis at The Marine Mammal Center in Sausalito, CA. When a leptospirosis outbreak occurs, the Center’s scientists study the disease to learn more about what causes an outbreak and how we can improve treatment for infected animals.

Major Disease Outbreak Strikes California Sea Lions

Leptospirosis afflicts sea lions on a semi-regular cycle, but warming waters and migrating fish could make the marine mammals more susceptible

Buffaloes at Rest recalls a time when bison were plentiful. When the print was created in 1911, only about 1,350 remained.

The Bison Returns to the Great American Plains

After years of fierce debate, the West’s greatest symbol will again roam the countryside

Hormone signals help ready worker mole-rats to treat pups as their own.

Eating the Queen’s Poop Makes Naked Mole-Rats Better Parents

Hive-minded naked mole-rats work together to care for the queen’s offspring, and eating her poop gives them hormones to boost nurturing instincts

Asian elephants have less than a 33 percent chance of lasting beyond the 21st century

Earth Lost 2.5 Billion Years’ Worth of Evolutionary History in Just 130,000 Years

Even if humans curbed destructive actions within next 50 years, it would take between five to seven million years for mammal biodiversity to fully recover

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