- Prehistoric Animal Facts (21)
- Prehistoric Mammals A to Z (259)
- Tetrapods and Amphibians A to Z (106)
- The Cenozoic Era (9)
- The Paleozoic Era (7)
Vertebrate Animal Evolution
Vertebrate animals have come a long way since their tiny, translucent ancestors swam the world's seas over 500 million years ago. Here's a detailed chronological list of the major vertebrate animal groups, ranging from fish and amphibians to reptiles and mammals (including human beings).
The First Mammals
It's not quite true that mammals succeeded the dinosaurs--they lived right alongside these lumbering beasts, in small, quivering, furry form, all through the Mesozoic Era. Here's a look at the evolution, anatomy and survival strategies of the earliest mammals.
Most people know only the end of the story of dog evolution--when wolves were domesticated by early humans. The fact is, though, that prehistoric dogs roamed the plains of North America for tens of millions of years before humans appeared on the scene.
The first vertebrate animals on the planet, prehistoric fish lay at the root of hundreds of millions of years of evolution. Here's everything you need to know about the evolution (and extinction) of prehistoric fish.
Sharks are among the most successful vertebrates on earth; the first species evolved about 420 million years ago and their descendants have survived down to the present day. Here's everything you need to know about the behavior and evolution of prehistoric sharks.
It seems that every type of animal on earth grew to giant sizes two, 20, or even 40 million years ago--witness the Giant Wombat, the Giant Beaver and the Giant Sloth, to name just three. Here's everything you need to know about the megafauna that prospered after the age of dinosaurs.
During the Carboniferous period, over 300 million years ago, the first tetrapods evolved features that allowed them to prosper on land as well as in water--and for tens of millions of years, these prehistoric amphibians were the dominant terrestrial animals on earth.
The first ancestral primates appeared on earth around the time the dinosaurs went extinct--and diversified, over the next 65 million years, into monkeys, lemurs, great apes and human beings. Here's everything you need to know about primate evolution.
The First Tetrapods
400 million years ago, give or take a few million years, a brave fish climbed out of the water and onto dry land, armed with primitive lungs and four stumpy limbs. Here's what we know about the first tetrapods that blazed the trail for the earth's land-dwelling animals.
The origin of snakes is shrouded in mystery: the first, fragmentary forms appeared about 150 million years ago, but it's unclear whether they evolved from land- or water-dwelling ancestors. Here's everything we currently know about snake evolution.
It may be hard to believe, but modern whales evolved from terrestrial, dog-sized mammals that roamed central Asia about 50 million years ago. Here's the story of cetacean evolution, along with profiles of a dozen prehistoric species.
Horses have come a long way since their tiny, ferret-sized ancestors prowled the woodlands of North America, 10 million years after the extinction of the dinosaurs. Here's a look at horse evolution, along with profiles of various important genera.
Modern elephants belong to a long and distinguished evolutionary line that dates back 60 million years, to shortly after the extinction of the dinosaurs. Here's a history of prehistoric pachyderms, along with profiles of various extinct species.
They weren't technically tigers, but saber-toothed cats were every bit as dangerous to the grazing mammals (and early hominids) of their day. Here's a look at saber-tooth evolution and lifestyles, as well as profiles of the most important genera.
Turtles and tortoises branched off from the mainstream of reptile evolution hundreds of millions of years ago, and have persisted down to the present day with the same basic body plan. Here's everything you need to know about testudine evolution.
How Big Were Prehistoric Animals?
It's one thing to know that a dinosaur was 40 feet long and weighed seven tons, and another to grasp just how enormous that was compared to the average full-grown human. This photo gallery will show you just how enormous some prehistoric animals were!