Callovian life

Cryptoclidus ( ) is a genus of plesiosaur reptile from the Middle Jurassic period of England, France, and Cuba.

Peloneustes (meaning ) is a genus of pliosaurid plesiosaur from the Middle Jurassic of England. Its remains are known from the Peterborough Member of the Oxford Clay Formation, which is Callovian in age. It was originally described as a species of Plesiosaurus by palaeontologist Harry Govier Seeley in 1869, before being given its own genus by naturalist Richard Lydekker in 1889. While many species have been assigned to this genus, P. philarchus is currently the only one still considered valid, with the others moved to different genera, considered nomina dubia, or synonymised with P. philarchus

Steneosaurus (from , 'narrow' and , 'lizard') is a dubious genus of teleosaurid crocodyliform from the Middle or Late Jurassic (Callovian or early Oxfordian) of France and possibly also India. The genus has been used as a wastebasket taxon for thalattosuchian fossils for over two centuries, and almost all known historical species of teleosauroid have been included within it at one point. The genus has remained a wastebasket, with numerous species still included under the label '''Steneosaurus''', many of which are unrelated to each other (either paraphyletic or polyphyletic with respect to eac

Tyrannoneustes is an extinct genus of geosaurine metriorhynchid crocodyliform from the Callovian stage Oxford Clay Formation of England and the Marnes de Dives of France. It contains a single species, Tyrannoneustes lythrodectikos, meaning "blood-biting tyrant swimmer".

Proexochokefalos (meaning "big head with big tuberosities") is an extinct genus of machimosaurid teleosauroid from the Middle to Late Jurassic of France and Switzerland. In life, it was a large marine reptile that would have fed on other large animals.

left|thumb|CGI reconstruction of a gliding M. furculiferum Maiopatagium is an extinct genus of gliding euharamiyids which existed in Asia during the Jurassic period. It possessed a patagium between its limbs and presumably had similar lifestyle to living flying squirrels and colugos. The type species is Maiopatagium furculiferum, which was described from the Tiaojishan Formation by Zhe-Xi Luo in 2017; it lived in what is now the Liaoning region of China during the late Jurassic (Oxfordian age). Maiopatagium and Vilevolodon, described concurrently, offer clues to the ways various synapsids have

Megaconus is an extinct genus of allotherian mammal from the Middle Jurassic Tiaojishan Formation of Inner Mongolia, China. The type and only species, Megaconus mammaliaformis was first described in the journal Nature in 2013. Megaconus is thought to have been a herbivore that lived on the ground, having a similar posture to modern-day armadillos and rock hyraxes. Megaconus was in its initial description found to be member of a group called Haramiyida. A phylogenetic analysis published along its description suggested that haramiyidans originated before the appearance of true mammals, but in co

Eardasaurus is a genus of thalassophonean pliosaurid from the middle Jurassic Oxford Clay Formation. The animal would have measured over long (the tail was not fully preserved) and possessed a high amount of teeth relative to other pliosaurs. Its teeth show distinct ridges formed by the tooth enamel, some of which are very pronounced and similar to carinae, giving the teeth a cutting edge.

Simpsonodon is an extinct genus of docodontan mammaliaform known from the Middle Jurassic of England, Kyrgyzstan and Russia. The type species S. oxfordensis was described from the Kirtlington Mammal Bed and Watton Cliff in the Forest Marble Formation of England. It was named after George Gaylord Simpson, a pioneering mammalologist and contributor to the Modern Evolutionary Synthesis. A second species S. sibiricus is known from the Itat Formation of Russia, and indeterminate species of the genus are also known from the Balabansai Formation in Kyrgyzstan

Peltoceras is an extinct ammonite genus from the aspidoceratid subfamily Peltoceratinae that lived during the later part of the Middle Jurassic (U Callovian).

Neosteneosaurus is a genus of machimosaurid, known from the Middle Jurassic Oxford Clay of the UK, and Marnes de Dives, France.