Dinosaurs and Prehistoric Life

Velociraptor was a theropod — the group of mostly two-legged, often meat-eating dinosaurs that also includes T. rex, and from which modern birds are descended.

The Mesozoic Era began with the Triassic period about 252 million years ago, followed by the Jurassic and finally the Cretaceous, which ended about 66 million years ago.

The Chicxulub impactor struck what is now Mexico's Yucatan Peninsula roughly 66 million years ago, creating a crater about 110 miles wide and triggering the mass extinction that wiped out most of the world's species.

Geologist William Buckland formally described and named Megalosaurus bucklandii in 1824, making it the first dinosaur ever given a scientific name — 18 years before the word 'dinosaur' was even coined.

Mary Anning, a self-taught fossil hunter who began collecting fossils as a child in the early 1800s, made some of the 19th century's greatest paleontological discoveries — though as a woman of her era she rarely received formal credit.

Triceratops was a ceratopsian, or 'horned-face' dinosaur — a group of plant-eaters distinguished by bony neck frills and horns that lived primarily during the Cretaceous period.

The Bone Wars was a decades-long feud between Edward Drinker Cope and Othniel Charles Marsh, who raced to discover and name new dinosaur species — together naming more than 130 new species, though their rivalry often led to sloppy science and sabotage.

Unlike most sauropods where the hind legs are the longest, Brachiosaurus had notably longer front limbs — the name itself means 'arm lizard' — so its back sloped downward from shoulders to hips, much like a modern giraffe.

Spinosaurus aegyptiacus, from what is now Morocco and Egypt, is estimated to have reached 46 to 59 feet in length, making it longer than T. rex — though the two never met, having lived on different continents in different time periods.

Andrews led a series of Central Asiatic Expeditions for the American Museum of Natural History to Mongolia's Gobi Desert, where his team unearthed dinosaur eggs, Velociraptor fossils, and dozens of previously unknown species.

Stegosaurus, which lived about 155 to 150 million years ago during the Late Jurassic, carried two rows of upright bony plates along its back and four sharp tail spikes — a cluster paleontologists have cheerfully nicknamed the 'thagomizer.'

Parasaurolophus was a hadrosaur known for the long, hollow, curved crest on its head — scientists believe the crest may have worked like a resonating tube, letting the animal produce deep, carrying calls to communicate across distances.

The Cretaceous-Paleogene (K-Pg) extinction event occurred about 66 million years ago when the Chicxulub asteroid struck Earth, ending the roughly 165-million-year reign of the non-bird dinosaurs.

Ankylosaurus carried a large, solid knob of fused bone at the tip of its tail that it could swing like a wrecking ball — powerful enough to shatter the leg bones of even a large predator.

The real Velociraptor mongoliensis weighed about 33 pounds and stood only 1.5 to 2 feet tall at the hip — closer to a large turkey than a person — and fossil arm bones confirm it was covered in feathers.