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Permian period, early synapsid with a sail on its back

Cambrian period, peculiar creature known from the Burgess Shale

Mesozoic era, dolphin-like marine reptiles

Ordovician to present, ancient cephalopods with a hard shell

Pleistocene epoch, early human species

Carboniferous period, extensive coal-producing tropical wetlands

Mesozoic era, first vertebrates with powered flight

Late Jurassic period, known for plates on back and spiked tail

Precambrian to present, layered bio-chemical accretion structures

Mesozoic era, characteristic spiral shell

Paleozoic era, first major group of arthropods

Ordovician to Permian periods, extinct group of sea scorpions

Cenozoic era, iconic prehistoric predator with long upper canines

Late Jurassic period, transitional fossil between birds and dinosaurs

Pleistocene to Holocene epoch, large woolly tuskers

Devonian to present, thought to be extinct until found in 1938

Most common in Paleozoic and Mesozoic eras, lamp-shells

Late Jurassic period, extremely long-necked dinosaur

Jurassic to present, ancient seed plant

Mesozoic era, long-necked marine reptile

Late Cretaceous period, apex predator

Throughout geological time, fossilized remains of terrestrial vegetation

Paleozoic to present, tiny marine organisms with intricate shells

Late Cretaceous period, small but cunning dinosaur