List of the prehistoric life of Montana facts for kids

This article is about the amazing ancient life found as fossils in the state of Montana. Scientists have discovered many different kinds of plants and animals that lived here millions of years ago. These fossils help us understand what Montana was like long before humans existed.

Ancient Life in Montana: The Paleozoic Era

The Paleozoic Era was a very long time ago, from about 541 to 252 million years ago. During this era, Montana was often covered by shallow seas. This means many of the fossils found from this time are sea creatures.

Fish and Sea Creatures of the Paleozoic

• †Allenypterus was a type of ancient lobe-finned fish. Its fossils were first found in Montana.
• †Belantsea was a strange-looking fish related to modern-day chimaeras, sometimes called "ghost sharks." It was also first discovered in Montana.
• †Caridosuctor was another ancient fish, a type of coelacanth, with its first fossils found here.
• †Delphyodontos was a unique fish, also related to chimaeras, first found in Montana.
• †Echinochimaera was a spiny, chimaera-like fish, with some of its first fossils found in Montana.
• †Harpagofututor was a fascinating "antlered" fish, another chimaera relative, first found in Montana.
• †Helicoprion was a shark-like fish famous for its spiral saw-like tooth whorl.
• †Stethacanthus was a shark relative with a strange, brush-like structure on its head, possibly used for mating or defense.

Shelled Animals of the Paleozoic

Many ancient shelled creatures called brachiopods lived in the seas covering Montana.

• †Composita was a common brachiopod with a rounded, ribbed shell.
• †Spirifer was another type of brachiopod known for its wing-like shell.
• †Pentremites were small, sea-bud shaped animals called blastoids, related to starfish and sea urchins.

Other Paleozoic Animals

• †Dikelocephalus and †Megistaspis were types of trilobites, ancient sea arthropods that looked a bit like modern horseshoe crabs.
• †Lingula was a very old type of brachiopod that has changed very little over millions of years.

Dinosaurs and More: The Mesozoic Era

The Mesozoic Era, often called the "Age of Dinosaurs," lasted from about 252 to 66 million years ago. Montana was home to many famous dinosaurs and other creatures during this time.

Horned Dinosaurs of Montana

Montana is famous for its horned dinosaurs, known as ceratopsians.

• †Achelousaurus was a horned dinosaur with bony bumps instead of a large nose horn. Its first fossils were found in Montana.
• †Albertaceratops was a large horned dinosaur with a long frill and two long brow horns.
• †Avaceratops was a smaller, early horned dinosaur, first discovered in Montana.
• †Brachyceratops was a small horned dinosaur, with its first fossils found in Montana.
• †Ceratops was one of the first horned dinosaurs ever found, and its first fossils were discovered in Montana.
• †Einiosaurus had a unique, forward-curving nose horn. Its first fossils were found in Montana.
• †Judiceratops was another horned dinosaur, first found in Montana.
• †Medusaceratops had a frill with wavy, snake-like horns, and its first fossils were found here.
• †Monoclonius was an early horned dinosaur, first found in Montana.
• †Montanoceratops was a more primitive horned dinosaur, first found in Montana.
• †Prenoceratops was a small, early horned dinosaur, also first found in Montana.
• †Rubeosaurus was a horned dinosaur with a rough, bumpy frill.
• †Spiclypeus was a horned dinosaur with a spiky frill, first found in Montana.
• †Triceratops was one of the most famous horned dinosaurs, with three horns and a large frill. Many Triceratops fossils have been found in Montana.

Duck-Billed Dinosaurs (Hadrosaurs)

Hadrosaurs were common plant-eating dinosaurs.

• †Acristavus was a duck-billed dinosaur without a crest, first found in Montana.
• †Anatotitan was a very large duck-billed dinosaur.
• †Brachylophosaurus was a duck-billed dinosaur with a flat, paddle-like crest. A famous fossil called "Leonardo," a mummified Brachylophosaurus, was found in Montana.
• †Corythosaurus was a duck-billed dinosaur with a tall, helmet-like crest.
• †Edmontosaurus was a large, crestless duck-billed dinosaur.
• †Glishades was a duck-billed dinosaur, first found in Montana.
• †Gryposaurus had a distinctive "Roman nose" bump on its snout.
• †Hadrosaurus was one of the first duck-billed dinosaurs discovered, with some fossils found in Montana.
• †Hypacrosaurus was a duck-billed dinosaur with a tall, hollow crest.
• †Maiasaura is famous for its nesting sites and caring for its young, with many fossils found in Montana. Its name means "good mother lizard."
• †Prosaurolophus was a duck-billed dinosaur with a small, solid crest.
• †Pteropelyx was a duck-billed dinosaur, first found in Montana.
• †Trachodon was an early name for some duck-billed dinosaur fossils found in Montana.

Armored Dinosaurs (Ankylosaurs)

Ankylosaurs were heavily armored plant-eaters.

• †Ankylosaurus was a large, heavily armored dinosaur with a club tail. Its first fossils were found in Montana.
• †Dyoplosaurus was another armored dinosaur.
• †Edmontonia was an armored dinosaur with spikes on its shoulders.
• †Euoplocephalus was a large armored dinosaur with a wide, bony club tail.
• †Oohkotokia was an armored dinosaur, first found in Montana.
• †Panoplosaurus was an armored dinosaur without a tail club.
• †Sauropelta was an early armored dinosaur with long shoulder spikes, first found in Montana.
• †Scolosaurus was an armored dinosaur with a tail club.
• †Tatankacephalus was an armored dinosaur, first found in Montana.

Meat-Eating Dinosaurs (Theropods)

Montana was home to many fierce predators.

• †Acheroraptor was a small, bird-like raptor dinosaur, first found in Montana.
• †Allosaurus was a large, powerful meat-eater from the Jurassic period.
• †Aublysodon was a tyrannosaur-like dinosaur.
• †Bambiraptor was a small, agile raptor, first found in Montana.
• †Daspletosaurus was a large tyrannosaur, a close relative of Tyrannosaurus rex.
• †Deinodon was an early tyrannosaur, first found in Montana.
• †Deinonychus was a famous raptor with a large, sickle-shaped claw on each foot. Its first fossils were found in Montana.
• †Dromaeosaurus was a smaller raptor.
• †Gorgosaurus was a large tyrannosaur, with its first fossils found in Montana.
• †Microvenator was a small, bird-like dinosaur, first found in Montana.
• †Nanotyrannus was a smaller tyrannosaur, first found in Montana.
• †Ornithomimus was a fast, ostrich-like dinosaur.
• †Pectinodon was a small, bird-like dinosaur.
• †Richardoestesia was a small, slender dinosaur.
• †Saurornitholestes was a small raptor.
• †Troodon was a small, intelligent dinosaur with large eyes, first found in Montana.
• †Tyrannosaurus was the most famous meat-eating dinosaur, and its first fossils were found in Montana.

Long-Necked Dinosaurs (Sauropods)

• †Amphicoelias was a very large long-necked dinosaur.
• †Camarasaurus was a common long-necked dinosaur.
• †Diplodocus was a very long, slender long-necked dinosaur.
• †Rugocaudia was a long-necked dinosaur, first found in Montana.
• †Suuwassea was a long-necked dinosaur, first found in Montana.

Other Mesozoic Reptiles

• †Champsosaurus was a crocodile-like reptile that lived in water.
• †Deinosuchus was a giant crocodile, much larger than modern crocodiles. Its first fossils were found in Montana.
• †Mosasaurus and †Tylosaurus were huge marine reptiles that swam in the ancient seas.
• †Thalassomedon was a large plesiosaur, a long-necked marine reptile, first found in Montana.
• †Montanazhdarcho was a large flying reptile (pterosaur), first found in Montana.
• †Quetzalcoatlus was one of the largest flying animals ever, a giant pterosaur.

Mesozoic Mammals and Birds

• †Alphadon and †Cimolomys were early mammals that lived alongside dinosaurs.
• †Avisaurus and †Hesperornis were types of ancient birds.

Mesozoic Plants and Other Life

• Aralia, Ginkgo, Nelumbo (lotus), and Sequoia (redwood) are examples of plants whose ancient relatives grew in Montana.
• †Inoceramus was a very large clam-like mollusk that lived in the seas.

Mammals and Modern Life: The Cenozoic Era

The Cenozoic Era began about 66 million years ago and continues to today. After the dinosaurs died out, mammals became the dominant large animals.

Cenozoic Mammals

Montana was home to many different kinds of mammals.

• †Acritohippus, †Archaeohippus, †Dinohippus, †Epihippus, †Hypohippus, †Merychippus, †Mesohippus, †Miohippus, †Neohipparion, †Pliohippus, and †Protohippus were all types of ancient horses that lived in Montana.
• †Aepycamelus, †Camelops, †Oxydactylus, and †Stenomylus were ancient camels.
• †Mammut (mastodon) and †Mammuthus (mammoth) were large elephant relatives that lived in Montana.
• †Arctodus was a giant short-faced bear.
• †Homotherium and †Dinictis were types of saber-toothed cats.
• †Megalonyx and †Paramylodon were giant ground sloths.
• †Megacerops and †Menodus were large, rhino-like animals called brontotheres.
• †Hyaenodon was a large, wolf-like predator.
• †Leptauchenia and †Merycochoerus were types of oreodonts, ancient pig-like mammals.
• †Plesiadapis and †Purgatorius were very early primate relatives.
• †Titanoides was a large, early mammal called a pantodont.
• Bison (bison), Canis (wolves and coyotes), Lynx (bobcats), Odocoileus (deer), and Rangifer (caribou) are examples of modern mammals whose ancestors lived in Montana.

Other Cenozoic Animals

• †Borealosuchus and †Champsosaurus were crocodile-like reptiles that continued to live in Montana.
• †Helodermoides was an ancient lizard, first found in Montana.
• Acipenser (sturgeon) and Amia (bowfin) are types of fish whose ancestors lived in Montana.
• Azolla (water fern) and Sassafras are examples of plants found as fossils from this era.

Images for kids

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  Life restoration of the Carboniferous lobe-finned fish Allenypterus

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  Restoration of the Carboniferous Chimaera relative Belantsea

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  Fossilized skeleton of the Carboniferous coelacanth Caridosuctor

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  Fossilized shell of the Late Devonian-Permian brachiopod Composita

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  Life restoration of the Carboniferous Chimaera relative Delphyodontos

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  †Echinochimaera meltoni Lund 1977 from the Mississippian of Bear Gulch

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  Restoration (bottom) of the Carboniferous "antlered" Chimaera relative Harpagofututor

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  Fossil of the Cambrian-Silurian trilobite Megistaspis

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  Fossilized theca of the Carboniferous blastoid echinoderm ("sea bud") Pentremites

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  Fossilized shell of the Late Ordovician-Late Triassic brachiopod Spirifer

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  Life restorations of a male (foreground) and female (background) of the Late Devonian-Carboniferous Chimaera relative Stethacanthus

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  Life restoration of the Late Cretaceous horned dinosaur Achelousaurus

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  Life restoration of the Late Jurassic theropod dinosaur Allosaurus

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  Life restoration of the Late Cretaceous armored dinosaur Ankylosaurus

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  Life restoration of the Late Cretaceous toothed bird Avisaurus perched on a crocodilian

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  Mounted fossilized skeleton of the Cretaceous turtle Basilemys

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  Fossilized natural mummy of the Late Cretaceous duck-billed dinosaur Brachylophosaurus

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  Life restoration of the Late Cretaceous-Eocene choristoderan reptile Champsosaurus

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  Life restoration of the face of the Late Cretaceous multituberculate mammal Cimolomys

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  Mounted fossilized skeleton of the Late Cretaceous duck-billed dinosaur Corythosaurus

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  Life restoration of the Early Cretaceous dromaeosaur ("raptor") Deinonychus

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  Life restoration of the Late Jurassic long-necked dinosaur Diplodocus

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  Life restoration of the Late Cretaceous duck-billed dinosaur Edmontosaurus annectens

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  Restoration of the Late Cretaceous armored dinosaur Euoplocephalus

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  Mounted fossilized skeleton of the Middle Jurassic-Late Cretaceous mammal Gobiconodon

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  Restoration (bottom) of the Carboniferous "antlered" Chimaera relative Harpagofututor

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  Life restoration of the Late Cretaceous toothed bird Hesperornis

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  Fossilized shell of the Early Jurassic-Late Cretaceous marine bivalve Inoceramus with a human indicating its size

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  Life restoration of the Late Cretaceous horned dinosaur Judiceratops

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  Life restoration of the Late Cretaceous primitive horned dinosaur Leptoceratops

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  Mounted fossilized skeletons of the Late Cretaceous pterosaur Montanazhdarcho

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  A living Nelumbo lotus

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  A living Odontaspis sand shark

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  Life restoration of the Late Cretaceous herbivorous dinosaur Oryctodromeus in a burrow

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  Illustration of a fossilized skull of the Late Cretaceous armored dinosaur Panoplosaurus

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  Fossilized shell of the Late Cretaceous ammonoid cephalopod Parapuzosia with a human indicating its size

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  Mounted fossilized skeleton of the Late Cretaceous duck-billed dinosaur Prosaurolophus

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  Life restoration of a flock of the Late Cretaceous pterosaur Quetzalcoatlus feeding on the ground

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  Life restoration of the Early Cretaceous armored dinosaurs Sauropelta

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  Base of the trunk of a living Sequoia tree with a human to scale

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  Restoration of the Late Cretaceous horned dinosaur Spiclypeus

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  Life restoration of the Early Cretaceous Iguanodon relative Tenontosaurus

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  Mounted fossilized skeleton of the Late Cretaceous horned dinosaur Triceratops

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  Fossilized skeleton of the Late Cretaceous tyrannosaur Tyrannosaurus

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  Fossil of the Early Triassic-Eocene cycad-like frond Zamites

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  Mounted fossilized skeleton of the Miocene horse Acritohippus

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  Life restoration of the Miocene elephant relative Amebelodon. Margret Flinsch (1932).

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  Living Azolla water ferns

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  Mounted fossilized skeleton of the Pleistocene Bison latifrons, also known as the giant bison or long-horned bison

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  Life restoration of the Paleocene primate relative Carpolestes

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  Life restoration of the Late Cretaceous-Eocene choristoderan reptile Champsosaurus

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  A living Cinnamomum, or cinnamon tree

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  Fossilized leaf from a Credneria tree

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  Life restoration of the Eocene-Miocene false saber-toothed cat Dinictis. Robert Bruce Horsfall (1913).

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  Fossilized horns, jaws, and limb bones of the Miocene deer relative Dromomeryx

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  Fossilized fruit of the Eocene Eucommia montana plant

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  Fossilized skull of the Oligocene lizard Helodermoides

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  Restoration of Pliocene-Pleistocene Homotherium, or scimitar cat

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  Life restoration of the Miocene horse Hypohippus. Heinrich Harder (1920).

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  Restoration of the Oligocene-Miocene oreodont mammal Leptauchenia

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  A living Lynx rufus, or bobcat

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  Life restoration of battling males of the Eocene brontothere mammal Megacerops

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  Restorative portrait of the Oligocene-Miocene oreodont mammal Merycochoerus

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  Life restoration of the Paleocene-Eocene mammal Miacis

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  Life restoration of a herd of Neohipparion. Robert Bruce Horsfall (1913).

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  A living Odocoileus deer

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  Life restoration of a pair of the Oligocene-Miocene camel Oxydactylus. Robert Bruce Horsfall (1913).

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  Fossilized skeleton of the Pliocene-Pleistocene ground sloth Paramylodon

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  Life restoration of the Paleocene-Eocene ungulate Phenacodus. Charles R. Knight (1898).

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  Illustration of a fossilized skull of the Oligocene false faber-toothed cat Pogonodon

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  Fossil of the Oligocene ant Protazteca

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  Restoration of the Paleocene taeniodont mammal Psittacotherium multifragum

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  Life restoration of the Late Cretaceous-Paleocene primate relative Purgatorius

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  Fossilized leaf of the Eocene sassafras Sassafras hesperia

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  Life restoration of the Oligocene-Miocene camel Stenomylus

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  Life restoration of the Eocene carnivoran relative Tapocyon

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  Life restoration of the Paleocene pantodonts mammal Titanoides