The Jurassic is a geologic period and stratigraphic system that spanned from the end of the Triassic Period 201.4 million years ago (Mya) to the beginning of the Cretaceous Period, approximately 145 Mya. The Jurassic constitutes the middle period of the Mesozoic Era and is named after the Jura Mountains, where limestone strata from the period were first identified.
Ammonoids are extinct spiral shelled cephalopods comprising the subclass Ammonoidea. They are more closely related to living coleoids than they are to shelled nautiloids. The earliest ammonoids appeared during the Devonian, with the last species vanishing during or soon after the Cretaceous–Paleogene extinction event. They are often called ammonites, which is most frequently used for members of the order Ammonitida, which represented the only living group of ammonoids from the Jurassic onwards.
Sunnyodon is a genus of tiny, extinct mammal, probably of the Lower Cretaceous. Found in what is now southern England and Denmark, it was a relatively early member of the extinct order of Multituberculata. It is part of the suborder Plagiaulacida and family Paulchoffatiidae.
Chimaeras are cartilaginous fish in the order Chimaeriformes, known informally as ghost sharks, rat fish, spookfish, or rabbit fish; the last three names are not to be confused with rattails, Opisthoproctidae, or Siganidae, respectively.
Derodontidae is a family of beetles, in its own superfamily, Derodontoidea, sometimes known as the tooth-necked fungus beetles. Beetles of this family are small, between 2 and 6 mm in length, typically with spiny margins on their pronotum that give them their name, though the genus Laricobius lacks these spines. Unusual among beetles, they have two ocelli on the top of their heads.
Proceratosaurus is a genus of carnivorous theropod dinosaur from the Middle Jurassic (Bathonian) of England. It contains a single species. P. bradleyi, known from a mostly complete skull and lower jaws. Proceratosaurus was a small dinosaur, estimated to measure around 3 m (9.8 ft) in length. Its name refers to how it was originally thought to be an ancestor of Ceratosaurus, due to the partially preserved portion of the crest of Proceratosaurus superficially resembling the small crest of Ceratosaurus. Now, however, it is considered a coelurosaur, specifically a member of the family Proceratosauridae, and amongst the earliest known members of the clade Tyrannosauroidea.
Saurophaganax, also known as Allosaurus maximus or Saurophagus maximus, is a genus of large allosaurid dinosaur from the Morrison Formation of Late Jurassic Oklahoma, United States. Some paleontologists consider it to be a junior synonym and species of Allosaurus. Saurophaganax represents a very large Morrison allosaurid characterized by horizontal laminae at the bases of the dorsal neural spines above the transverse processes, and "meat-chopper" chevrons. It was the largest terrestrial carnivore of North America during the Late Jurassic, reaching 10.5 metres (34 ft) in length and 2.7–3.8 metric tons in body mass.
Dromaeosauroides is a genus of dromaeosaurid theropod dinosaur from the Early Cretaceous of what is now Denmark and possibly also England. It was discovered in the Jydegaard Formation in the Robbedale valley, on the island of Bornholm in the Baltic Sea. This is the only likely place for dinosaur remains to be discovered on Danish territory, since the Mesozoic deposits exposed in the rest of the country are marine. Dromaeosauroides is the first known dinosaur from Denmark, and the only one which has been scientifically named. It is one of the oldest known dromaeosaurs in the world, and the first known uncontested dromaeosaur from the Early Cretaceous of Europe.
Trionychia is a superfamily of turtles which encompasses the species that are commonly referred to as softshelled turtles as well as some others. The group contains two families, Carettochelyidae, which has only one living species, the pig-nosed turtle native to New Guinea and Northern Australia, and Trionychidae, the softshelled turtles, containing numerous species native to Asia, North America and Africa. These families likely diverged during the late Jurassic. The oldest known stem-trionychian is Sinaspideretes from the Late Jurassic of China.
Docodon is an extinct docodont mammaliaform from the Late Jurassic of western North America. It was the first docodont to be named.
Sinaspideretes is an extinct genus of turtle from the Late Jurassic of China, probably from the Shaximiao Formation. It is considered the earliest and most basal representative of the Trionychia, and is possibly the oldest known member of Cryptodira. In 2013, it was proposed that this animal and the genus Yehguia are in fact one and the same.
Eurycleidus is an extinct genus of large-bodied rhomaleosaurid known from the Early Jurassic period of the United Kingdom. It contains a single species, E. arcuatus. Like other plesiosaurs, Eurycleidus probably lived on a diet of fish, using its sharp needle-like teeth to catch prey. Its shoulder bones were fairly large, indicating a powerful forward stroke for fast swimming.
Cteniogenys is a genus of choristodere, a morphologically diverse group of aquatic reptiles. It is part of the monotypic family Cteniogenidae. The type and only named species, C. antiquus, was named in 1928 by Charles W. Gilmore. The holotype, VP.001088, was collected in the Morrison Formation, Wyoming in 1881 by William H. Reed. More specimens have been discovered since then, including specimens from the Late Jurassic of Portugal and Middle Jurassic of Britain, which have not been assigned to species.
Parviraptor is a genus of squamate containing one species, Parviraptor estesi, from the Late Jurassic (Tithonian) or Early Cretaceous (Berriasian) Purbeck Limestone Formation of Dorset, England. A second species, Parviraptor gilmorei, was described from the Late Jurassic Morrison Formation of Western North America; it was present in stratigraphic zone 4. However, the second species was subsequently transferred to a separate genus Diablophis. An indeterminate species is known from the Bathonian aged Kirtlington Mammal Bed.
Marmornectes is a genus of pliosaurid known from the Middle Jurassic of Bedfordshire, United Kingdom.
The Allgäu Formation is a geologic formation in Austria, Germany and Slovakia. It preserves fossils dating back to the Hettangian to Sinemurian stages of the Early Jurassic period, or Raricostatum to Obtusum in the regional stratigraphy. Initially and formally defined by Jacobshagen (1965). The Allgäu Formation is formerly known as spotted marls (Lias-Fleckenmergel) and spotted marly limestones (Fleckenkalk). The formation is represented by dark-grey bioturbated limestones and marlstone interbeds. It represents basinal hemipelagic facies common in Alpine Tethys regions of Alps, Carpathians and other mountain ranges. Several horizons of the formation are particularly rich in ammonite fauna.
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
Antiquaobatis is an extinct genus of ray from the Early Jurassic of Europe, containing the single species A. grimmenensis. It is the oldest known described member of the Rajiformes, and is based on a single tooth from Pliensbachian of Northern Germany. It was recovered from the Grimmen Clay Pit, on Spinatum strata that belongs in the region to the Komorowo Formation. The holotype is a single antero-lateral tooth, very small and slightly asymmetrical, measuring 0.25 mm in maximum height and 0.26 mm in maximum width, that has an overall morphology, that suggests a consistent referral to Batoidea, encompassing all skates and rays. The tooth has an overall rather gracile crown morphology, different from any other know jurassic batomorphs, indicating closest affinities to the monotypic genus Engaibatis schultzei from the Kimmeridgian-Tithonian of Tanzania.
Agaleus is an extinct genus of stem-galeomorph shark from the Early Jurassic Epoch. The genus Agaleus is monotypic, consisting solely of the species Agaleus dorsetensis. This species is currently only known from isolated teeth.
Alethodontus is an extinct genus of chimaera from the Hettangian stage of the Jurassic period. It is known from a single species, A. bavariensis, known from Germany.
