List of the Mesozoic life of South Dakota

This list of the Mesozoic life of South Dakota contains the various prehistoric life-forms whose fossilized remains have been reported from within the US state of South Dakota and are between 252.17 and 66 million years of age.

Restorative model of the Late Cretaceous mammal Alphadon
Mounted fossilized skeleton of the Late Cretaceous sea turtle Archelon
Fossilized shell of the Late Cretaceous ammonoid cephalopod Baculites
Restoration of the Late Jurassic sauropod dinosaur Barosaurus rearing to defend itself against a pair of the theropod Allosaurus
Life restoration of the Late Cretaceous Alligator relative Brachychampsa
Life restoration of a herd of the Late Jurassic sauropod dinosaur Camarasaurus
Life restoration of the Late Cretaceous-Eocene choristoderan reptile Champsosaurus
Life restoration of the Late Cretaceous mosasaurid Clidastes
Fossil of the Early Cretaceous-Eocene shark Cretolamna
Fossil of the Jurassic-Cretaceous cycad relative Cycadeoidea
Restoration of the Late Cretaceous dromaeosaurid ("raptor") Dakotaraptor preying upon an ostrich dinosaur
Life restoration of the Late Cretaceous duck-billed dinosaur Edmontosaurus annectens
Life restoration of the Late Cretaceous mosasaur Globidens
Life restoration of the Late Cretaceous tyrannosaur Gorgosaurus
Life restoration of the Late Cretaceous toothed bird Hesperornis
Fossilized shell of the Early Jurassic-Late Cretaceous marine bivalve Inoceramus with a human indicating its size
Fossilized shell of the Late Cretaceous ammonoid cephalopod Jeletzkytes
Fossilized skull of the Late Cretaceous alligator relative Leidyosuchus
Life restoration of two of the Late Cretaceous Mosasaurus
A living Nelumbo lotus
Life restoration of the Late Cretaceous ostrich dinosaur Ornithomimus
Fossilized skeleton of the Late Cretaceous dome-headed dinosaur Pachycephalosaurus
Life restoration of the Late Cretaceous mosasaur Platecarpus
Fossilized skull of the Late Cretaceous mosasaur Prognathodon
Life restoration of the Late Cretaceous pterosaur Pteranodon
Micrograph with magnified inset of a fossilized tooth of the Late Cretaceous theropod dinosaur Richardoestesia
Base of the trunk of a living Sequoia tree with a human to scale
Animated life restoration of the Late Cretaceous plesiosaur Styxosaurus
Life restoration of the Late Cretaceous herbivorous dinosaur Thescelosaurus
Fossilized skeleton of the Late Cretaceous tyrannosaur Tyrannosaurus
Shell of a Viviparus freshwater snail