List of the prehistoric life of Alaska facts for kids

The prehistoric life of Alaska includes all the ancient plants and animals whose fossil remains have been found in the US state of Alaska. These fossils tell us about the amazing creatures that lived in Alaska millions of years ago, from tiny sea creatures to giant woolly mammoths and dinosaurs!

Ancient Life in the Paleozoic Era

The Paleozoic Era was a very long time ago, from about 541 to 252 million years ago. During this time, life on Earth became much more complex. In Alaska, scientists haven't found any fossils from the very oldest part of the Paleozoic Era, called the Precambrian. But they have found many fossils from later parts of this era.

Cool Paleozoic Creatures of Alaska

Here are some of the interesting prehistoric animals and plants found in Alaska from the Paleozoic Era:

• †Acanthopyge – This was a type of trilobite, an ancient sea creature with a hard, segmented shell, like a modern-day crab or shrimp.

Fossil of the Silurian-Middle Devonian trilobite Acanthopyge

• †Agoniatites – A type of ammonite, which were ancient sea creatures related to modern squids and octopuses, but with coiled shells.
• †Athyris – A kind of brachiopod, which are shelled marine animals that look a bit like clams but are different inside.
• †Atrypa – Another common brachiopod from this time.
• †Aviculopecten – This was an ancient bivalve, similar to a scallop or clam.

Mold fossil of a shell of the Early Devonian-Late Triassic bivalve Aviculopecten

• †Bellerophon – A type of ancient sea snail.
• †Calymene – Another kind of trilobite, known for its distinct head shape.

Fossil of the Silurian trilobite Calymene blumenbachii

• †Catenipora – A type of ancient coral that grew in chain-like patterns.
• †Chonetes – A small, ribbed brachiopod.
• †Climacograptus – These were graptolites, tiny colonial animals that lived in the ocean and floated or were attached to the seafloor.

Assemblage of fossils of the Cambrian graptolite Climacograptus

• †Composita – A common brachiopod with a rounded, often smooth shell.

Fossilized shell of the Late Devonian-Permian brachiopod Composita

• †Cyrtoceras – A type of nautiloid, a shelled creature related to modern nautiluses.

Restoration of the Cambrian-Middle Devonian nautiloid cephalopod Cyrtoceras

• †Dalmanites – A large trilobite.
• †Didymograptus – Another type of graptolite, often found in V-shapes.

Fossil of the Middle Ordovician graptolite Didymograptus

• †Euomphalus – A type of sea snail with a flat, coiled shell.

Fossilized shell of the Silurian-Permian sea snail Euomphalus

• †Favosites – A common type of coral, often called "honeycomb coral" because of its many small, hexagonal tubes.
• †Geragnostus – A small, blind trilobite.

Fossil of the Early-Late Ordovician trilobite Geragnostus

• †Hexagonaria – A colonial coral, sometimes called "Petoskey stone" when fossilized.

Fossil of the Devonian colonial rugose coral Hexagonaria, also known as a Petoskey stone

• †Kionoceras – A straight-shelled nautiloid.

Fossilized shells of the Middle Ordovician-Permian nautiloid cephalopod Kionoceras

• †Lithostrotion – Another type of colonial coral.
• †Meristella – A brachiopod with a smooth, oval shell.

Illustration (lower right, entry 15) of a fossilized shell in front and side views of the Silurian-Late Devonian brachiopod Meristella

• †Monograptus – A common type of graptolite, often found as single-branching forms.

Fossils of the Early Devonian graptolite Monograptus

• †Mucrospirifer – A brachiopod with wide, wing-like extensions on its shell.

Fossilized shell of the Devonian brachiopod Mucrospirifer

• Nucula – A small, modern-looking clam that has been around since ancient times.

Interior of a fossilized shell of the Early Ordovician-modern marine bivalve Nucula

• †Paradoxides – A very large trilobite from the Cambrian period.

Fossil of the Cambrian trilobite Paradoxides

• †Pecopteris – An ancient fern.
• †Polygnathus – A type of conodont, which were tiny, eel-like animals with tooth-like structures.

Various conodont elements of Polygnathus

• †Pseudobornia – An early tree-like plant.
• †Psilophyton – A very early vascular plant, meaning it had tissues to transport water and nutrients.

Fossil of the primitive Devonian vascular plant Psilophyton

• †Spirifer – A common brachiopod with a distinctive spiral internal structure.

Fossilized shell of the Late Ordovician-Late Triassic brachiopod Spirifer

• †Tentaculites – Small, cone-shaped fossils from a group of animals whose exact identity is still a mystery.

Assemblage of fossilized shells of the Early Ordovician-Late Devonian probable mollusc Tentaculites

• †Wodnika – An ancient shark.

Restoration of the Permian shark Wodnika

Life in the Mesozoic Era

The Mesozoic Era, often called the "Age of Dinosaurs," lasted from about 252 to 66 million years ago. This era saw the rise of dinosaurs, flying reptiles, and marine reptiles. Many new types of plants also appeared.

Amazing Mesozoic Animals of Alaska

Here are some of the fascinating creatures from the Mesozoic Era found in Alaska:

• †Alaskacephale – This was a type of pachycephalosaur, a dome-headed dinosaur that lived in Alaska during the Late Cretaceous period. It's special because its fossils were first found here!

Life restoration of the Late Cretaceous dome-headed dinosaur Alaskacephale and inset diagram depicting it with an anachronistic human to scale

• †Amaltheus – A type of ammonite, a coiled-shell sea creature.
• †Anagaudryceras – Another kind of ammonite.
• †Arcticoceras – An ammonite found in the Arctic regions.

Fossilized shells of the Middle Jurassic ammonoid cephalopod Arcticoceras

• †Cadoceras – A common ammonite from the Middle Jurassic.

Fossilized shell of the Middle Jurassic ammonoid cephalopod Cadoceras

• †Calliphylloceras – An ammonite with a smooth, elegant shell.

Fossilized shell of the Early Jurassic-Early Cretaceous ammonoid cephalopod Calliphylloceras

• Cladophlebis – A fern that lived from the Permian to the Late Cretaceous.

Fossilized foliage of the Permian-Late Cretaceous fern Cladophlebis

• †Claraia – A small, thin-shelled bivalve that was very common right after the biggest mass extinction in Earth's history.
• †Dactylioceras – A ribbed ammonite from the Early Jurassic.

Restoration of the Early Jurassic ammonoid cephalopod Dactylioceras

• †Didymoceras – An ammonite with an unusual, uncoiled shell shape.
• †Dromaeosaurus – A small, meat-eating dinosaur, related to Velociraptor.
• †Edmontosaurus – A large, duck-billed dinosaur. Fossils of these plant-eaters are common in Alaska.

Restoration of the Late Cretaceous duck-billed dinosaur Edmontosaurus annectens

• Ginkgo – The ginkgo tree is a "living fossil," meaning it has changed very little over millions of years. Its ancient relatives lived in Alaska.

Restored foliage of the Late Cretaceous-Miocene ginkgo tree Ginkgo adiantoides

• †Gryphaea – A type of oyster with a very curved, thick shell.
• †Hesperornis – A large, flightless diving bird with teeth, that lived in the Late Cretaceous seas.

Life restoration of the Late Cretaceous toothed bird Hesperornis

• †Inoceramus – A very large, common bivalve from the Mesozoic Era.
• †Lytoceras – An ammonite with a distinctive, ribbed shell.

Fossilized shell of the Early Jurassic-Late Cretaceous ammonoid cephalopod Lytoceras

• †Myophorella – A type of bivalve with strong ribs and bumps on its shell.
• †Nanuqsaurus – This was a tyrannosaur, a meat-eating dinosaur related to T. rex, that lived in Alaska. Its name means "polar bear lizard"!

Life restoration of the Late Cretaceous tyrannosaur Nanuqsaurus

• Nucula – A small, modern-looking clam that has been around since ancient times.

Exterior of the shell of a modern specimen of the Early Ordovician-modern marine bivalve Nucula

• †Pachydiscus – A large, thick-shelled ammonite.
• †Pachyrhinosaurus – A horned dinosaur, similar to Triceratops, but with a large, rough boss on its nose instead of a horn. Pachyrhinosaurus perotorum was first found in Alaska.

Life restoration of two of the Late Cretaceous horned dinosaur Pachyrhinosaurus perotorum

• Platanus – The plane tree, a type of tree whose ancient relatives grew in Alaska.

Leaves and fruit of a living Platanus, or plane tree

• †Saurornitholestes – A small, agile, meat-eating dinosaur, part of the dromaeosaurid family (like Velociraptor).

Life restoration of the Late Cretaceous dromaeosaurid Saurornitholestes preying upon a multituberculate mammal

• Spondylus – A spiny oyster.

Shell of a Spondylus, or spiny oyster

• †Troodon – A small, bird-like dinosaur known for its large brain and sharp teeth.
• †Ugrunaaluk – Another type of duck-billed dinosaur, similar to Edmontosaurus, found in Alaska. Its name means "ancient grazer" in the Iñupiaq language.

Fossilized skeleton found in Alaska of the Late Cretaceous duck-billed dinosaur Ugrunaaluk

Life in the Cenozoic Era

The Cenozoic Era, from 66 million years ago to today, is often called the "Age of Mammals." After the dinosaurs died out, mammals grew larger and spread across the world. Alaska was home to many familiar and extinct mammals during this time.

Cenozoic Animals of Alaska

Here are some of the interesting prehistoric animals and plants found in Alaska from the Cenozoic Era:

• Alces – The moose, a large deer that still lives in Alaska today.

A living Alces, or moose

• Alopex – The Arctic fox, a small fox adapted to cold climates.
• †Arctodus – The giant short-faced bear, one of the largest bears that ever lived.
• †Arktocara – An ancient river dolphin that lived in Alaska during the Oligocene epoch.

Life restoration of the Oligocene river dolphin Arktocara

• Astarte – A type of clam.
• Balanus – Barnacles, which are small crustaceans that attach themselves to surfaces.
• Bison – Ancient bison, including the steppe bison. A famous mummified specimen called "Blue Babe" was found in Alaska!

Mummified specimen found in Alaska of the Pleistocene-Holocene Bison priscus, or steppe bison. This specimen, known as "Blue Babe" after the blue ox of Paul Bunyan folklore, derives its unusual coloration from a chemical reaction between the phosphorus in its skin and iron in the surrounding soil to produce a coating of vivianite.

• †Bootherium – The woodland musk ox, an extinct relative of today's musk ox.
• Callorhinus – The northern fur seal, which still lives in Alaskan waters.

A living Callorhinus ursinus, or northern fur seal

• Canis – Wolves, including the gray wolf, have lived in Alaska for a long time.
• †Cervalces – The stag moose, an extinct type of deer with large, complex antlers.

Fossilized skeleton of the Pliocene-Pleistocene cervid Cervalces, or the stag moose

• Cervus – Elk, another type of deer.
• Chlamys – A type of scallop.
• Clinocardium – A type of cockle, a marine bivalve.

Shell of a Clinocardium cockle

• †Desmatophoca – An ancient seal.

Fossilized cranium of the Miocene seal Desmatophoca

• Equus – Ancient horses, which roamed Alaska during the Ice Age.
• Erignathus – The bearded seal, a large seal found in Arctic waters.
• †Flabellaria – An ancient flowering plant.

Fossilized foliage of the Cretaceous-Oligocene flowering plant Flabellaria

• Hiatella – A type of clam that can attach itself to rocks.
• Histriophoca – The ribbon seal, known for its unique striped pattern.
• †Hydrodamalis – Steller's sea cow, a giant, gentle marine mammal related to manatees, which went extinct recently.

Restorative model of the Pleistocene-Holocene manatee relative Hydrodamalis gigas, or Steller's sea cow

• Lemmus – Lemmings, small rodents found in Arctic regions.
• Liocyma – A type of clam.
• Littorina – Periwinkles, small sea snails.

Shells in differing orientation of a Littorina sea snail, or periwinkle

• †Mammuthus – Woolly mammoths, giant hairy elephants that lived during the Ice Age. Their fossils are often found in Alaska's permafrost.

Restoration of a herd of Mammuthus primigenius, or wooly mammoths

• Myrica – The firetree, a type of shrub or small tree.

Fruit of a living Myrica, or firetree

• †Mya – A type of clam, including the soft-shell clam.
• Mytilus – Mussels, a common type of bivalve.
• Neptunea – A type of sea snail, or whelk.
• Nucula – A small, modern-looking clam that has been around since ancient times.
• Ochotona – Pikas, small, rabbit-like mammals.
• Odobenus – Walruses, large marine mammals with long tusks.

A living Odobenus rosmarus, or walrus

• Ovibos – Musk oxen, large, shaggy mammals adapted to cold environments.
• Ovis – Sheep, including Dall sheep.
• Phoca – Seals, including harbor seals.

A living Phoca vitulina, or harbor seal

• Picea – Spruce trees, common in Alaska's forests.
• Pinus – Pine trees.
• Populus – Poplar trees, including aspens and cottonwoods.

Montage of photographs in spring (top left), summer (top right), autumn (bottom left), and winter (bottom right) of Populus, or poplar tree

• Rangifer – Reindeer or caribou, a type of deer found in Arctic regions.

A living Rangifer tarandus, or reindeer

• Serripes – A type of cockle.
• Siphonalia – A type of whelk sea snail.

Shell of the whelk sea snail Siphonalia

• Spermophilus – Ground squirrels.
• Strongylocentrotus – Sea urchins.
• Taxodium – Bald cypresses, a type of conifer tree.

Living Taxodium distichum, or bald cypresses

• Trichotropis – A type of sea snail.
• Tsuga – Hemlock trees.
• Ursus – Bears, including brown bears and polar bears.
• Vulpes – Foxes, including the red fox.

A living Vulpes vulpes, or red fox