Day 7 Prehistoric Animals that came after the Dinosaurs

Andrewsarchus

Andrewsarchus was a large mammal that lived in the Paleogene period. It was an early artiodactyl (hoofed animal), related to hippos and whales. Andrewsarchus was discovered in Mongolia by naturalist Roy Chapman Andrews, whom the genus was subsequently named after.

Andrewsarchus was a large-snouted predator, and, based on skull measurements, may have been the largest ever carnivorous mammal!

Basilosaurus

Although its name, which includes the word ‘saurus’, suggests that Basilosaurus was a reptile, it was later found to be a mammal. In fact, Basilosaurus was an early whale that lived in the Eocene epoch of the Paleogene period.

Basilosaurus was around 21 m (70 ft.) long and had a 1.5 m (5 ft.) skull. Its jaws were full of long, dagger-like teeth. Analysis of its skull suggests that it may have had the strongest bite force of any animal!

Brygmophyseter

Brygmophyseter was an early sperm whale that lived in the Miocene epoch. Its name means ‘biting sperm whale’, and for good reason; its teeth were up to 14 cm (5.5 in.) long, and it was an apex predator. Brygmophyseter grew to around 7 m (23 ft.) long,

Castoroides

Castoroides was a 2.5 m (8 ft.) long giant beaver that lived in North America during the Pleistocene epoch. It is the largest beaver ever to have lived, but it had a small brain in proportion to its body size and may not have been as smart as its modern day counterpart.

Coelodonta

Coelodonta is also known as the woolly rhinoceros. This huge animal was covered with thick fur and had two large horns on its nose. It was found in Europe, Africa and Asia, and several species have been identified. Coelodonta lived during the last ice age.

Entelodon

Entelodon was a hoofed animal that lived in the Paleogene period. Originally thought to be a type of prehistoric pig, it is now believed to be more closely related to whales and hippos. It lived in North America, Europe and Asia from the mid-Paleocene to the early Neogene period.

Glyptodon

Glyptodon was a giant armadillo of the Pliocene and Pleistocene epochs. With a shell that was around 1.5 m (5 ft.) in length, and a total body length of around 3.3 m (11 t.), it would have been an impressive sight walking through the South American forests and grasslands in which it lived.

Hyaenodon

Hyaenodon is a genus of large carnivorous mammals that lived from the Eocene to the mid Miocene epochs. The largest Hyaenodons were among the largest predators of their time. With a long skull, and powerful, doglike body, it would have had little to fear from most other animals.

Mastodon

The Mastodon was an ancestor of the elephant that walked the Earth in the Pleistocene epoch, around 10,000 to 11,000 years ago. It had long tusks and a trunk, and lived in the forests of North America.

Megalania

Megalania is the largest known lizard. It lived in Australia in the Pleistocene epoch. A carnivorous reptile, Megalania is related to modern-day goannas.

Megalodon

Megalodon, whose name means ‘mighty tooth’, was an early shark that lived during the Neogene period. Reaching 18 m (59 ft.) in length, it is not only the largest shark ever to have lived, but also one of the world’s largest ever predators.

Megatherium

Megatherium was a giant ground sloth that lived in South America from the Pliocene to the end of the Pleistocene. Thought to have weighed up to 4 tonnes, and being 6 m (20 ft.) in length, it was one of the biggest animals of its day. Megatherium had large claws, which may have been used for burrowing rather than for climbing.

Mesonychids / Mesonyx

Mesonyx was a prehistoric animal that resembled a wolf but had hoofed feet. It was a member of the Mesonychid group of carnivorous animals. It lived in America from the early to the mid Paleogene period.

Paraceratherium

This huge, hornless rhino lived during the Oligocene epoch. Paraceratherium had a long neck and thick, sturdy legs. It had tusk-like front teeth and fossils suggest that it may have had a short trunk. Weighing up to 20 tonnes, and standing up to 4.8 m (16 ft.) tall, it may even have been the largest land mammal ever to have lived.

Phorusrhacos Longissimus (Terror Bird)

Phorusrhacos Longissimus was a species in the Phorusrhacidae family, a group of animals which are also known as ‘terror birds’. These huge, flightless meat-eaters lived up to their name, being equipped with powerful hooked beaks and large claws.

Living in South American during the Miocene epoch, Phorusrhacos Longissimus was likely to have been an apex predator.

Procoptodon

The 2 m (6.5 ft.) tall Procoptodon is the largest kangaroo ever to have lived. It lived in Australia during the Pleistocene epoch, and was a member of the Sthenurinae, or short-faced kangaroo, subfamily.

Propalaeotherium

Propalaeotherium was a small, prehistoric relation of the horse. It lived in Europe and Asia during the Eocene epoch. Fossils discovered in Germany were so well preserved that scientists could see that the animals had been eating berries!

Smilodon (Saber-Toothed Tiger) (Sabre-Toothed Tiger in British English)

Several prehistoric cat-like animals with extended canine teeth have been discovered. Together, they have become known as ‘saber-toothed cats’. The best-known is the Smilodon, which is also known as the ‘saber-toothed tiger’.

Three species of Smilodon have been discovered. The biggest, Smilodon populator, was bigger than a tiger, and may have been the biggest cat species ever.

Smilodons lived during the Pleistocene epoch, and were found in both North and South America.

Titanoboa

Titanoboa is the largest snake that ever lived. It was over 13 m (43 ft.) long, and weighed around 1,135 kg. It lived in South America during the Paleocene epoch.

Uintatherium

Uintatherium was a large herbivore that lived during the Eocene epoch. Two species have been discovered, one in the USA and one in China. Uintatherium had extended tusk-like canine teeth, which may have been used as defensive weapons or as tools for manipulating food.

Woolly Mammoth

No list of prehistoric animals would be complete without the woolly mammoth! Mammoths were prehistoric members of the elephant family. They lived during the Pliocene and Pleistocene epochs.

The woolly mammoth, Mammuthus subplanifrons, is a species of mammoth that lived towards the end of this period. A similar size to African elephant, the woolly mammoth was covered in fur – an adaption for living during the ice age.