Fossil taxa described in 1883

Entelodontidae is an extinct family of pig-like artiodactyls (even-toed ungulates) that inhabited the Northern Hemisphere (Asia, Europe, and North America) from the late Eocene to the early Miocene epochs, about 38 to 15 million years ago. Their large heads, low snouts, narrow gait, and proposed omnivorous diet inspires comparisons to suids (true pigs) and tayassuids (peccaries), and historically they have been considered closely related to these families purely on a morphological basis. However, studies which combine morphological and molecular (genetic) data on artiodactyls instead suggest t

Chriacus is an extinct genus of placental mammals that lived in what is now North America from the Paleocene and early Eocene epochs. In life, members of the genus may have looked something like a kinkajou or binturong, though they were not closely related to any living mammal. Like many early Cenozoic mammals, its relationships are uncertain, with possible affinities to ungulates or Ferae (carnivorans and their relatives).

Craspedodon (meaning 'edge tooth') is an extinct genus of ornithischian dinosaur from the Late Cretaceous Lonzée Member of Belgium. Only a single species, C. lonzeensis, is known.

Actiosaurus (meaning "coast lizard") is an extinct genus of reptile first described by Henri Sauvage in 1883 from Antully bonebed, Autun (Triassic of France). The type species is A. gaudryi (commonly misspelled A. gaudrii after Boulenger). Little is known of it, and it is considered a nomen dubium. Actiosaurus was originally described as a dinosaur in 1883 and was reinterpreted as an ichthyosaur in 1908. Actiosaurus may instead represent the remains of a choristodere. Fischer et al. (2014) considered A. gaudryi to be a species inquirenda, and noted the similarity of its bones to the limb bones

Bernissartia ('of Bernissart') is an extinct genus of neosuchian crocodyliform that lived in the Early Cretaceous, around 130 million years ago.

species of mammal

Orthomerus (meaning "straight femur") is a genus of dubious hadrosaurid dinosaur from the Late Cretaceous of the Netherlands. It is today an obscure genus, but in the past was conflated with the much better known Telmatosaurus.

Dioplotherium is an extinct genus of sirenian related to the dugongs, known from Neogene-aged deposits from southern North America.

Mixodectidae, from Ancient Greek μιξο (mixo) "mixed", and δεκτες (dektes) "biter", is an extinct family of insectivorous placental mammals in the order Dermoptera. The mixodectids originated in the late Cretaceous and survived into the Paleocene in Europe and North America.

Acanthostomatops is an extinct genus of zatracheidid temnospondyl from the Lower Permian Döhlen Basin of Saxony.

Luetkesaurus is an extinct genus of plesiosaur from the Late Cretaceous of what is now the Kursk area of western Russia. Luetkesaurus was first named by V. Kiprijanoff in 1883, in honor of paleontologist and zoologist Christian Frederich Luetken; no type species has ever been designated. The genus is considered dubious, based on isolated teeth and vertebrae.

Promegatherium ("before Megatherium") is a genus of prehistoric xenarthrans that lived in Argentina, during the Late Miocene. This genus is regarded as closely related to the later, and more famous genus, Megatherium, hence the reference in the name. The first specimens of Promegatherium were originally described by the biologist Florentino Ameghino in 1883.

Sthenomerus is an extinct genus of Diprotodontia.

Brachalletes was an early marsupial from the Pliocene deposits of Australia. Its relationship with other marsupial species is under debate. The genus is extinct. The species was assigned to the order Diprotodontia by McKenna and Bell in 1997, though it is placed in its own order by other authorities. The species is described as an omnivore.

Ribodon is an extinct genus of manatee that lived around South America (Ituzaingó Formation, then described as Entrerriana Formation, Argentina, Solimões Formation, Brazil and Urumaco Formation, Urumaco, Venezuela) during the Tortonian (Mayoan to Huayquerian in the South American land mammal ages). The type species is R. limbatus.

Palaehoplophorus (also spelled, historically, Palaeohoplophorus) is an extinct genus of glyptodont. It lived from the Middle to the Late Miocene, and its fossilized remains were discovered in South America.

Mixodectes is an extinct genus of mixodectid mammal that lived in North America during the Palaeocene epoch.

Rachitrema is a poorly known genus of ichthyosaur from the Triassic of France. Its remains were found in France by two independent collectors, towards the end of the nineteenth century. They were only isolated bone fragments.

Crossopholis is an extinct paddlefish known from the early Eocene (Ypresian) of North America, approximately 52 million years ago. It is a close relative of the contemporary American paddlefish, though it is thought to have been a fish-eater like the Chinese paddlefish rather than a filter feeder.

Plegiocidaris is an extinct genus of echinoids that lived from the Triassic to the Early Cretaceous. Its remains have been found in Asia and Europe. It was named by the paleontologist Auguste Pomel.