In the geologic timescale the Bathonian is an age and stage of the Middle Jurassic. It lasted from approximately 168.3 Ma to around 166.1 Ma. The Bathonian Age succeeds the Bajocian Age and precedes the Callovian Age.
In the geologic timescale, the Callovian is an age and stage in the Middle Jurassic, lasting between 166.1 ± 4.0 Ma and 163.5 ± 4.0 Ma. It is the last stage of the Middle Jurassic, following the Bathonian and preceding the Oxfordian.
The Oxfordian is, in the ICS' geologic timescale, the earliest age of the Late Jurassic Epoch, or the lowest stage of the Upper Jurassic Series. It spans the time between 163.5 ± 4 Ma and 157.3 ± 4 Ma. The Oxfordian is preceded by the Callovian and is followed by the Kimmeridgian.
Kosmoceras is a moderately evolute ammonite genus from the upper Callovian of Europe with a simple apterure and irregular ribbing interrupted by an irregular row of lateral tubercles. Strong ventral tubercles are separated by a smooth depression running along the rim.
Simolestes is an extinct pliosaurid genus that lived in the Middle to Late Jurassic. The type specimen, BMNH R. 3319 is an almost complete but crushed skeleton diagnostic to Simolestes vorax, dating back to the Callovian of the Oxford Clay formation, England. The genus is also known from the Callovian and Bajocian of France (S.keileni), and the Tithonian of India (S.indicus). The referral of these two species to Simolestes is dubious, however.
Cadomites is an extinct ammonite genus from the superfamily Stephanoceratoidea that lived during the Middle Jurassic.
Guliemina is a species of extinct ammonite from the Jurassic period in England. It lived during the Callovian period of the Jurassic, and its fossils are often found in the Kellaways rock strata of Chippenham, Wiltshire.
The Chari Formation is a Jurassic geologic formation in Gujarat, western India. Dinosaur remains are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.
The Vanguard Formation is a stratigraphical unit of Callovian to Oxfordian age in the Western Canadian Sedimentary Basin.
Kepplerites is a moderately evolute ammonite from the lower Callovian included in the Stephanoceratoidea.
Hecticoceras is an ammonite genus belonging to the haploceratoid family Oppeliidae, that lived during the Middle and Late Jurassic, from the Callovian. Hecticoceras may be seen as a series of some nine subgenera, beginning with the lower Callovian H. (Hecticoceras) and H. (Hecticoceratoides) and ending with the lower Oxfordian H. (Pseudobrightia) and H. (Eochetoceras). Hecticocerassensu lato and Prohecticoceras from the underlying Bathonian form the oppeliid subfamily, Hecticoceratinae.
Pachyceras is a genus of perisphinctoid ammonites from the Middle Jurassic, upper Callovian stage, and is the type genus for the family Pachyceratidae. The shell is involute, subglobular, with a deep umbilicus and flattened flanks that slope toward a more narrowly rounded venter, and covered by low, widely spaced ribs.
Reineckeia is an extinct genus of ammonoid cephalopods belonging to the family Reineckeiidae.
Reineckeiidae is an extinct ammonoid cephalopod family belonging to the superfamily Perisphinctoidea.
Pseudopeltoceras is a genus of perisphinctoid ammonites belonging to the family Perisphinctidae.
Cadoceras is an extinct ammonite genus belonging to the Cardioceratidae that lived during the Jurassic period from the late Bajocian to the early Callovian.
Oppeliinae is a subfamily within the Oppeliidae, a family of Jurassic ammonites characterized by forms that are mainly oxyconic, compressed with sharp venters, in the adult and with keeled inner whorls. Sutures are complex, consisting of a long series of evenly graded lobes and saddles with finely frilled endings.
The Ornatenton Formation is a Jurassic marine formation in Germany that is middle Callovian in age. The formation represents a shallow marine environment.
Funiferites is genus of ammonite that lived during end of middle and in upper Callovian stage of middle Jurassic.
Cobbanites is a genus of extinct ammonoid cephalopods from the Family Perisphinctidae. Species of the genus date from the Jurassic period and have been found in the US.
