Dakosaurus is an extinct genus of crocodylomorph within the family Metriorhynchidae that lived during the Late Jurassic and Early Cretaceous. It was large, with teeth that were serrated and compressed lateromedially. The genus was established by Friedrich August von Quenstedt in 1856 for an isolated tooth named Geosaurus maximus by Theodor Plieninger in 1846. Dakosaurus was a carnivore that spent much, if not all, its life out at sea. The extent of its adaptation to a marine lifestyle means that it is most likely that it mated at sea, but since no eggs or nests have been discovered that have been referred to Dakosaurus, whether it gave birth to live young at sea like dolphins and ichthyosaurs or came ashore like turtles is not known. The name Dakosaurus means "biter lizard", and is derived from the Greek dakos ("biter") and σαῦρος -sauros ("lizard").
Machimosaurus is an extinct genus of machimosaurid crocodyliform from the Late Jurassic and Early Cretaceous. The type species, Machimosaurus hugii, was found in Switzerland. Other fossils have been found in England, France, Germany, Portugal, Switzerland and Tunisia. Machimosaurus rex is the largest named teleosauroid and thalattosuchian, with an estimated length of up to 7.15 m (23.5 ft). Machimosaurus is the largest known crocodyliform of the Jurassic.
"Mesosuchia" is an obsolete name for a group of terrestrial, semi-aquatic, or fully aquatic crocodylomorph reptiles. The marine crocodile Metriorhynchus had paddle-like forelimbs, Dakosaurus andiniensis had a skull that was adapted to eat large sea reptiles, and Shamosuchus was adapted for eating molluscs and gastropods. Shamosuchus also looked like modern crocodiles and was very closely related to their direct ancestor.
Metriorhynchus is an extinct genus of marine crocodyliform that lived in the oceans during the Late Jurassic. The type species, M. brevirostris was named in 1829 as a species of Steneosaurus before being named as a separate genus by the German palaeontologist Christian von Meyer in 1832. The name Metriorhynchus means "Moderate snout", and is derived from the Greek Metrio- ("moderate") and -rhynchos ("snout").
Metriorhynchidae is an extinct family of specialized, aquatic metriorhynchoid crocodyliforms from the Middle Jurassic to the Early Cretaceous period of Europe, North America and South America. The name Metriorhynchidae was coined by the Austrian zoologist Leopold Fitzinger in 1843. The group contains two subfamilies, the Metriorhynchinae and the Geosaurinae. They represent the most marine adapted of all archosaurs.
Geosaurus is an extinct genus of marine crocodyliform within the family Metriorhynchidae, that lived during the Late Jurassic and the Early Cretaceous. Geosaurus was a carnivore that spent much, if not all, its life out at sea. No Geosaurus eggs or nests have been discovered, so little is known of the reptile's lifecycle, unlike other large marine reptiles of the Mesozoic, such as plesiosaurs or ichthyosaurs which are known to give birth to live young out at sea. Where Geosaurus mated, whether on land or at sea, is currently unknown. The name Geosaurus means "Mother of Giants lizard", and is derived from the Greek Ge- and σαῦρος -sauros ("lizard"). The name Geosaurus was established by the French naturalist Georges Cuvier in 1824.
Teleidosaurus is an extinct genus of carnivorous metriorhynchoid crocodyliform from Middle Jurassic deposits of Normandy, France. The name Teleidosaurus means "Complete lizard", and is derived from the Greek Teleidos- ("complete") and σαῦρος -sauros ("lizard").
Thalattosuchia is a clade of marine crocodylomorphs from the Early Jurassic to the Early Cretaceous that had a cosmopolitan distribution. They are colloquially referred to as marine crocodiles or sea crocodiles, though they are not members of Crocodilia and records from Thailand and China suggest that some members lived in freshwater. The clade contains two major subgroupings, the Teleosauroidea and Metriorhynchoidea. Teleosauroids are not greatly specialised for oceanic life, with back osteoderms similar to other crocodyliformes. Within Metriorhynchoidea, the Metriorhynchidae displayed extreme adaptions for life in the open ocean, including the transformation of limbs into flippers, the development of a tail fluke, and smooth, scaleless skin, and probably gave live birth, seemingly uniquely among archosaurs.
Teleosaurus is an extinct genus of teleosaurid crocodyliform found in the Middle Jurassic Calcaire de Caen Formation of France. It was approximately 3 metres (10 ft) in length and weighed 60 kg (130 lb). The holotype is MNHN AC 8746, a quarter of a skull and other associated postcranial remains, while other fragmentary specimens are known. The type species is T. cadomensis, but a second species, T. geoffroyi may also exist. It was previously considered a wastebasket taxon, with many other remains assigned to the genus.
Purranisaurus is an extinct genus of marine crocodyliform from the Middle to Late Jurassic period of Chile and Vaca Muerta of Argentina. Rusconi originally regarded Purranisaurus potens to be a plesiosaur; however, Gasparini demonstrated that it was in fact a metriorhynchid crocodyliform, and that may be a junior synonym of Metriorhynchus. It was about 3.3 m (11 ft) long.
Cricosaurus is an extinct genus of marine crocodyliforms of the Late Jurassic. belonging to the family Metriorhynchidae. The genus was established by Johann Andreas Wagner in 1858 for three skulls from the Tithonian of Germany. The name Cricosaurus means "Ring lizard", and is derived from the Greek Krikos- ("ring") and σαῦρος -sauros ("lizard"). It was a relatively small reptile, with C. suevicus and C. araucanensis measuring 2 m (6.6 ft) and 3.2 m (10 ft) in total body length, respectively.
Steneosaurus is a dubious genus of teleosaurid crocodyliform from the Middle or Late Jurassic of France. 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.
Platysuchus is an extinct genus of teleosaurid crocodyliform from the Early Jurassic (Toarcian) of southern Germany and Luxembourg.
Aeolodon is an extinct genus of teleosaurid crocodyliform reptile from the Late Jurassic (Tithonian) of Germany and France that was initially named as a species of Crocodylus in 1814. Although previously synonymized with Steneosaurus, recent cladistic analysis considers it distantly related to the Steneosaurus type species and the type species is A. priscus, named in 1830 and described in 2020.
Sericodon is an extinct genus of teleosaurid crocodyliform from the Late Jurassic (Tithonian) of Germany and Switzerland. The genus contains a single species, S. jugleri. Sericodon was placed in 'Clade T' (Aeolodontinae) and was found to be the sister taxon to Bathysuchus, another teleosaurid.
Metriorhynchoidea is an extinct superfamily of thalattosuchian crocodyliforms from the Early Jurassic to the Early Cretaceous of Europe, North America and South America. Metriorhynchids are fully aquatic crocodyliforms. Named by Fitzinger, in 1843, it contains the basal taxa like Teleidosaurus, Zoneait and Eoneustes and the family Metriorhynchidae. An unnamed taxon is known from Chile.
Torvoneustes is an extinct genus of metriorhynchid thalattosuchian. It is known from skull and postcranial remains found in the Kimmeridge Clay Formation of Dorset and Wiltshire, England, the Virgula Marls of Switzerland and also from Oaxaca, Mexico . The holotype skull of the type species was initially assigned to the species Metriorhynchus superciliosus. Postcranial remains were later discovered from the same quarry as the skull, and then these specimens were recognised as belonging to a new species of Dakosaurus, as D. carpenteri. The species was named to honour Simon Carpenter, an amateur geologist from Frome in Somerset, who discovered the fossils.
Macrospondylus is an extinct genus of machimosaurid teleosauroid crocodyliform from the Early Jurassic (Toarcian) of Europe. Fossils are known from the Posidonia Shale of Germany, the Whitby Mudstone of the United Kingdom, and the "schistes bitumineux" of Luxembourg.
Bathysuchus is an extinct genus of teleosaurid thalattosuchian from Late Jurassic (Kimmeridgian) deep water marine deposits in England and France. Bathysuchus displays features that suggest it was more pelagic than other teleosaurids, including smoother skull bones and reduced armour plating, similar to the fully marine metriorhynchids. This was possibly an adaptation to rising sea levels during the Kimmeridgian, as its earlier relatives such as Teleosaurus were suited for shallow coasts and lagoon environments.
Turnersuchus is an extinct genus of thalattosuchian, a group of marine crocodylomorphs, from the Pliensbachian of the United Kingdom. It is the oldest diagnostic member of Thalattosuchia and was also found to be the group's most basal member, being situated outside the two major groups Metriorhynchoidea and Teleosauroidea. Subsequently, this genus is considered to be of great importance to understanding the relationship between thalattosuchians and other crocodylomorphs as well as their rapid diversification during the early Jurassic. Turnersuchus is a monotypic genus, meaning it includes only a single species, Turnersuchus hingleyae.
