List of the prehistoric life of Missouri facts for kids

Missouri is a state with a rich history, not just of people, but of ancient life! Scientists have found many fossils here, showing us what kinds of plants and animals lived in Missouri millions of years ago. This article explores some of the amazing prehistoric creatures and plants whose remains have been discovered in the Show-Me State.

Paleozoic Era: Ancient Seas and Forests (541 to 252 Million Years Ago)

The Paleozoic Era was a time when life mostly lived in the oceans, but plants and animals also started to move onto land. Missouri was often covered by shallow seas during this time, which means many of the fossils found are from sea creatures. Later, vast forests grew, leaving behind plant fossils.

Sea Creatures of the Paleozoic

Many types of ancient sea animals have been found in Missouri. These include:

• †Achatella: A type of trilobite, which were ancient sea creatures with segmented bodies, a bit like modern horseshoe crabs or pill bugs.
• †Aphetoceras: A kind of nautiloid, related to modern-day squids and octopuses, but living inside a straight, cone-shaped shell.

Restoration of the Late Ordovician nautiloid cephalopod Aphetoceras being preyed upon by a Cameroceras

• †Bellerophon: An ancient snail with a coiled shell.
• †Composita: A common type of brachiopod, which are shelled marine animals that look a bit like clams but are different inside.

Fossilized shell of the Late Devonian-Permian brachiopod Composita

• †Ceraurus: Another type of trilobite, known for its spiky appearance.

Fossil of the Middle-Late Ordovician trilobite Ceraurus

• †Dinichthys: A huge, armored fish with powerful jaws. It was one of the top predators in the ancient seas.

Illustration of the jaws of Dinichthys

• †Favosites: A type of coral that formed honeycomb-like structures.
• †Halysites: Another colonial coral, often called "chain coral" because of its distinctive chain-like appearance.
• †Isotelus: A very large trilobite, some of the biggest trilobites ever found belong to this group.

Fossil of the Middle-Late Ordovician giant trilobite Isotelus

• †Naticopsis: An ancient sea snail.

Fossilized shell of the Early Devonian – Triassic sea snail Naticopsis

• †Orthoceras: A straight-shelled nautiloid, similar to Aphetoceras.
• †Orodus: An ancient cartilaginous fish, related to modern sharks.

Restoration of the Carboniferous-Permian cartilaginous fish Orodus

• †Ptyctodus: A type of armored fish (placoderm) with strong crushing plates instead of teeth.

Life restoration of the Late Devonian placoderm fish Ptyctodus

• †Spirifer: Another common type of brachiopod, known for its wing-like shape.

Fossilized shell of the Late Ordovician-Late Triassic brachiopod Spirifer

• †Tricrepicephalus: A type of trilobite from the Cambrian period, one of the earliest times in the Paleozoic.

Fossil of the Cambrian trilobite Tricrepicephalus

Paleozoic Plants of Missouri

Missouri's ancient forests were home to many unique plants, including:

• †Alethopteris: A type of seed fern, which were ancient plants that looked like ferns but reproduced using seeds.

Fossilized fronds of the Carboniferous-Early Cretaceous seed fern Alethopteris

• †Annularia: A plant related to modern horsetails, with rings of leaves around its stem.
• †Calamites: Another relative of horsetails, these plants grew very tall, like trees, and had segmented stems.

Fossilized stems from the Carboniferous-Permian horsetail relative Calamites

• †Cordaites: Tall, tree-like plants with long, strap-like leaves, thought to be early conifers.
• †Neuropteris: Another common type of seed fern.
• †Pecopteris: A genus of true ferns.
• †Sigillaria: Giant, tree-like clubmosses with distinctive patterns on their trunks where old leaves fell off.
• †Sphenophyllum: A small, vine-like plant with wedge-shaped leaves.

Mesozoic Era: The Age of Dinosaurs (252 to 66 Million Years Ago)

The Mesozoic Era is famous for dinosaurs, but it also saw the rise of many new types of plants and marine life. Missouri has some interesting finds from this period.

Mesozoic Marine Life

• †Baculites: A type of ammonite, which were shelled creatures related to modern squids. Unlike most ammonites, Baculites had a straight shell instead of a coiled one.

Fossilized shell of the Late Cretaceous ammonoid cephalopod Baculites

• †Corbula: A type of ancient clam.

Shell of a Corbula basket clam

• †Discoscaphites: Another type of ammonite with a coiled shell, common in the Late Cretaceous.

Fossilized shell of the Late Cretaceous ammonoid cephalopod Discoscaphites

• †Exogyra: A type of ancient oyster with a thick, coiled shell.

Interior of a fossilized shell of the Jurassic-Cretaceous foam oyster Exogyra

• †Pholadomya: A marine bivalve (like a clam) that lived in soft sediments.

Fossilized shell of the Early Triassic-Pliocene marine bivalve Pholadomya

• †Scaphites: An ammonite with a distinctive, partially uncoiled shell.

Fossilized shell of the Late Cretaceous ammonoid cephalopod Scaphites

• Turritella: A type of sea snail with a tall, spiral shell, still alive today.

Fossilized shells of the Late Jurassic-modern tower snail Turritella

Mesozoic Reptiles and Dinosaurs

• †Adocus: An ancient turtle.

Fossilized shell of the Early Cretaceous-Oligocene turtle Adocus

• †Albertosaurus: A large, meat-eating dinosaur, related to Tyrannosaurus rex.
• †Mosasaurus: A giant marine reptile that was a top predator in the oceans during the Late Cretaceous.

Life restoration of two of the Late Cretaceous Mosasaurus

• †Parrosaurus: This dinosaur is very special to Missouri! Parrosaurus missouriensis was a type of hadrosaur, or "duck-billed dinosaur." Its fossils were found in Missouri, making it the state's official dinosaur.

Cenozoic Era: The Age of Mammals (66 Million Years Ago to Today)

After the dinosaurs died out, mammals began to dominate the Earth. Missouri has many fossils from the Cenozoic Era, including large ice age animals.

Cenozoic Mammals

• Alligator: Modern alligators have ancient relatives that lived in Missouri.
• †Arctodus: Also known as the short-faced bear, this was a huge, powerful bear that lived during the Ice Age.
• Bison: Ancestors of today's bison roamed Missouri.
• †Camelops: An extinct type of camel that lived in North America.

Life restoration of the Pliocene-Holocene camel Camelops

• †Canis dirus: The famous dire wolf, a larger and more powerful relative of modern wolves.
• †Equus: Ancient horses lived in Missouri.
• †Mammut: The American mastodon, a large, elephant-like animal with shaggy fur and long tusks.

Restoration of a Mammut americanum, or American mastodon

• †Mammuthus: The mammoth, another elephant-like creature, known for its long, curved tusks.
• †Megalonyx: A giant ground sloth, as big as a modern elephant, that lived in North America.
• †Mylohyus: An extinct type of peccary, similar to a wild pig.
• Panthera onca: The jaguar, a large cat that once lived in Missouri.

A living Panthera onca, or jaguar

• †Platygonus: An extinct type of peccary, often called a "flat-headed peccary."
• Puma concolor: The cougar or mountain lion, which also lived in ancient Missouri.
• †Smilodon: The famous saber-toothed cat, known for its incredibly long canine teeth.

Life restoration of the Pleistocene-Holocene saber-tooth cat Smilodon

• Tapirus: The tapir, a pig-like animal with a short trunk, whose ancestors lived in Missouri.

A living Tapirus, or tapir

• †Tanupolama: An extinct type of llama.

Other Cenozoic Life

• Bufo: Ancient toads.
• Cnemidophorus: Whiptail lizards.
• Crotalus: Rattlesnakes.
• Dasypus: Armadillos.
• Elaphe: Rat snakes.
• Nerodia: Water snakes.
• Rana: Frogs.
• Sceloporus: Spiny lizards.