Fossil taxa described in 1875

Mesohippus (Greek: / meaning "middle" and / meaning "horse") is an extinct genus of early horse. It lived 37 to 32 million years ago in the Early Oligocene. Like many fossil horses, Mesohippus was common in North America. Its shoulder height is estimated at 60 cm.

Bothriospondylus (from Ancient Greek βοθρίον (bothríon), meaning "trench", and σπόνδυλος (spóndulos), meaning "vertebra") is a dubious genus of possibly neosauropodan sauropod dinosaur. It lived during the Late Jurassic in England and the type (and only) species is B. suffossus.

Diceratherium (meaning "two horned beast") is an extinct genus of rhinocerotid native to North America during the Oligocene through Miocene living from 33.9 to 11.6 mya, existing for approximately . Mass estimates for the type species, D. armatum average around

Arctosaurus is an extinct genus of archosauromorph, possibly an allokotosaurian, but was often classified as a sauropodomorph dinosaur between 1900 and 1976. Although it has also been classified as a theropod, recent review finds that the similarities it shares with theropods are spread throughout several groups of Late Triassic reptiles, and so it cannot be assigned any more specifically than to Archosauriformes. Other authors have suggested trilophosaurian affinities. Based on the size of the vertebra, a size of about in length is extrapolated.

genus of molluscs (fossil)

Microbrachis is an extinct genus of microsaurian tetrapod from the Carboniferous Kladno Formation of the Czech Republic.

Clepsydrops is an extinct genus of primitive synapsids from the early Late Carboniferous that was related to Archaeothyris. The name means 'hour-glass appearance' (Greek klepsydra = "hourglass" + Greek ops = "eye, face, appearance").

Priodontognathus (meaning "saw tooth jaw") is a genus of ankylosaurian dinosaur possibly from the Late Jurassic (Oxfordian-aged) Lower Calcareous Grit of Yorkshire, England. It is a dubious genus based on a maxilla, and has been erroneously mixed up with iguanodonts and stegosaurs.

Marmarospondylus ("marble [reference to the Forest Marble Formation] vertebra") is a dubious genus of sauropod dinosaur from Middle Jurassic deposits in the English Midlands.

Pampatherium (from the Pampas Plain, and Ancient Greek θηρίον (theríon), meaning "beast") is an extinct genus of xenarthran cingulates that lived in the Americas during the Pleistocene. Some species went extinct right at the Pleistocene-Holocene border.

Doratorhynchus is a generic replacement name for Pterodactylus validus, in 1875 suggested by Harry Govier Seeley. Today it is considered a nomen vanum.

Thrinacodus is an extinct genus of basal elasmobranch, found worldwide from the Late Devonian-Lower Carboniferous. The type species is Thrinacodus nanus. Most species are only known from their tricuspid teeth. T. gracia, originally placed in the separate genus Thrinacoselache from the Serpukhovian-aged Bear Gulch Limestone, of what is now Montana, is known from full body impressions, showing a long, slender eel-like body up to a metre in length, with an elongate rostrum. Stomach contents of T. gracia include remains of crustaceans and small chondrichthyan fish (Harpagofututor and Falcatus). It

Pelycodus (from Ancient Greek πέλυξ (pélux), “bowl” + ὀδούς (odoús), “tooth”) is an extinct genus of adapiform primate that lived during the early Eocene (Wasatchian) period in Europe and North America, particularly Wyoming and New Mexico. It is very closely related to Cantius and may even be its subgenus. It may also have given rise to the Middle Eocene Uintan primate Hesperolemur, although this is controversial. From mass estimates based on the first molar, the two species, P. jarrovii and P. danielsae, weighed 4.5 kg and 6.3 kg respectively and were frugivores with an arboreal, qu

Phoebodus is an extinct genus of phoebodontiform total group elasmobranch, known from over a dozen species found worldwide spanning the middle to late Devonian, making it one of the oldest known total group elasmobranchs. Most species are only known from their isolated tricuspid teeth, but one species, Phoebodus saidselachus from the Late Devonian of Morocco, is known from a complete skeleton, estimated to have been in total length in life, which shows that it had a slender body superficially similar to that of the living frilled shark. The teeth of Phoebodus and frilled sharks are also morpho

Olcostephanus is an extinct ammonoid cephalopod genus belonging to the family Olcostephanidae. These fast-moving nektonic carnivores lived during the Cretaceous, from the upper Valanginian to the lower Hauterivian age.

Diplacodon ("double-pointed tooth") is an extinct genus of brontothere. Diplacodon fossils have been found in North America and date to the Middle Eocene, during the Uintan land mammal age. Two Diplacodon species are recognized, the type species D. elatus from the Uinta Formation and the larger D. gigan from the Wiggins Formation.