Mosasaurus was among the largest and last of the sea-dwelling mosasaurs.

Giant Sea Lizards Ruled the Waves While T. Rex Roamed on Land

A new fossil discovery shows marine reptiles called mosasaurs lived up until the asteroid impact that killed non-avian dinosaurs

A gharial has the same skull shape as some extinct crocodiles. This skull shape has likely evolved three different times during the history of crocodiles.

Modern Crocodiles Are Evolving at a Rapid Rate

Despite their reputation as "living fossils," crocodiles have changed dramatically in the last two million years

The apex predator Ulughbegsaurus was much larger than the contemporaneous tyrannosaur Timurlengia.

New, Giant Carnivorous Dinosaur Was a Terror to Smaller Tyrannosaurs

A fossil jaw reveals the large predator lived 90 million years ago

An adult male woolly mammoth navigates a mountain pass 17,100 years ago.

Woolly Mammoths Roamed Far and Wide Just Like Living Elephants

A new analysis of a mammoth tusk tracks the movements of an Ice Age icon

Paleontologist François Therrien measures the jaws of a Gorgosaurus.

Tyrannosaurs Dominated Their Cretaceous Ecosystems

Studies of body size and bite force show that the predators, from babies to adults, filled many niches in their environment

The ancient mammal Gobioconodon (right) squabbles with a therian mammal over a meal in the Late Cretaceous.

Other Mammals, Not Dinosaurs, Kept Our Ancestors Down

The asteroid impact that ended the Cretaceous gave our mammalian ancestors, the therians, an edge over their mammalian competitors

The tyrannosaur Nanuqsaurus with its young

Dinosaurs Nested in the High Arctic

Tiny fossils of polar dinosaurs suggest that the reptiles stayed year-round

An artist’s rendering of Oculudentavis naga

World's 'Smallest Dinosaur' Revealed to Be a Mystery Reptile

Paleontologists analyzed two skulls and made the call, but aren't sure about the exact type of animal they've discovered

A Microraptor, a small four-winged dinosaur that could fly, eats a fish.

Dinosaurs Evolved Flight at Least Three Times

A new study finds that many feathered dinosaurs were more aerodynamic than previously thought

Illustration of Smilodon fatalis cubs playing
together.

The Softer Side of Sabercats

The iconic fanged predators may have raised their young for years—dragging baby mastodon bones home for them and slowly teaching them how to hunt

Edmontasaurus, a duckbilled creature weighing around 7,000 pounds that could walk on two or four legs, was an average-sized dinosaur.

An Ode to the World's Most Average Dinosaurs

They lacked the gargantuan size and spikes of the species museums often celebrate, but these species are how paleontologists learn about the Mesozoic

The new species of toadlet, Brachycephalus rotenbergae, opens its mouth in a defensive posture.

Biologists Discover New Species of Glowing Pumpkin Toadlet

The bright orange amphibian, which shines green under UV light, is different from other pumpkin toadlets due to its appearance and call

An illustration of the ancient shark Edestus heinrichi preying on a fish. Many ancient sharks had different jaws than modern sharks.

These Prehistoric Sharks Had Jaws Shaped Like Circular Saws and Sawtoothed Scissors

CT scans and visualization tools are now allowing scientists to recreate the weird cartilaginous structures of ancient predators

A fulgurite made of fused quartz found in Florida

Ancient Lightning May Have Sparked Life on Earth

More than a billion strikes a year likely provided an essential element for organisms

A piece of bone labeled PP-00128 was thought to belong to a bear until DNA analysis revealed it came from a dog.

Ancient DNA Reveals the Oldest Domesticated Dog in the Americas

A 10,000-year-old dog bone was found in an Alaskan cave near a site with human remains

Steppe mammoths evolved shaggy coats over a million years ago, a trait inherited by woolly mammoths.

Oldest DNA Sequenced Yet Comes From Million-Year-Old Mammoths

Genetic material from three ancient molars reveals secrets of about how the Ice Age elephants evolved

Published in Scientific Reports, the new study by astronomers Amir Siraj and Avi Loeb of the Harvard-Smithsonian Center for Astrophysics, propose that a series of break-ups and chance events sent the huge chunk of space rock our way.

Astrophysicists Chart Source of Asteroid That Killed Dinosaurs

A new model explains a possible route for the extraterrestrial rock before it blasted Earth

Zebrafish are classic study animals for understanding genetics and development.

A Single Altered Gene Can Make Fish Fins More Like Limbs

Researchers find a mutation that offers clues to the ancient sea-to-land transition of vertebrates

The fossil of Aphelicophontes danjuddi, a new genus and species of assassin bug, accompanied by the fossil of a small beetle

Ancient Insect Genitals Found in 50-Million-Year-Old Fossil

A newly discovered assassin bug features a well-preserved phallus the size of a grain of rice

Centrosaurus had the first well-documented case of malignant bone cancer in a non-avian dinosaur.

The Top Ten Dinosaur Discoveries of 2020

Paleontologists uncovered a great deal about the “terrible lizards” this year

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