Mosasaurus (/ˌmoʊzəˈsɔːrəs/; "lizard of the Meuse River") is a genus of mosasaurs, extinct carnivorous aquatic squamates. It existed during the Maastrichtian age of the late Cretaceous period, between about 70 and 66 million years ago, in western Europe, North America, and possibly Japan and New Zealand. The name means "Meuse lizard", as the first specimen was found near the Meuse River (Latin Mosa + Greek sauros lizard).
|Mounted skeleton cast of M. hoffmanni, Maastricht Natural History Museum|
†M. beaugei Arambourg, 1952
Batrachiosaurus Harlan, 1839
Mosasaurus was among the last of the mosasaurids, and among the largest. As with most mosasaurids, the legs and feet of Mosasaurus were modified into flippers, and the front flippers were larger than the hind flippers. The largest known species, M. hoffmanni reached lengths up to 17 m (56 ft), slightly longer than its relatives Tylosaurus and Hainosaurus. Mosasaurus was also more robust than related mosasaurids. The skull was more robust than in other mosasaurids, and the lower jaws (mandibles) attached very tightly to the skull. They had deep, barrel-shaped bodies, and with their fairly large eyes, poor binocular vision, and poorly developed olfactory bulbs. Experts believe that Mosasaurus lived near the ocean surface, where they preyed on fish, turtles, ammonites, smaller mosasaurs, birds, pterosaurs, and plesiosaurs. Although they were able to dive, they evidently did not venture into deeper waters.
The skull of Mosasaurus tapered off into a short, conical tip. The jaws were armed with massive conical teeth. Their paddle-like limbs had five digits in front and four in back. The body ended in a strong tail, which other mosasaurid fossils suggest had a fluke similar to those of sharks and some ichthyosaurs. The body probably remained stiff to reduce drag through the water, while the end of the tail provided strong propulsion.
Mosasaurus was the first genus of mosasaurs to be named. The first remains known to science were a fragmentary skull from a chalk quarry in the St Pietersberg, a hill near Maastricht, the Netherlands, found in 1764 and collected by lieutenant Jean Baptiste Drouin in 1766. It was procured for the Teylers Museum at Haarlem in 1784 by Martinus van Marum, the first director of the museum, who published its description only in 1790. He considered it to be a species of "big breathing fish" (Pisces cetacei, in other words: a whale). It is still part of the collection as TM 7424.
At some time between 1770 and 1774 ("1770" according to Faujas de Saint-Fond, "about the year 1770" according to Camper and "en 1780" according to Cuvier in 1808) a second partial skull was discovered and procured. It was found in the ground owned by canon Theodorus Joannes Godding, who displayed it in his country house on the slope of the hill. A local retired German/Dutch army physician, Johann Leonard Hoffmann (1710–1782), also collected some fragments and corresponded about the skull with the Dutch Professor Petrus Camper. Hoffmann presumed the animal was a crocodile. In 1786 however, Camper disagreed and concluded the remains were those of "an unknown toothed whale".
Maastricht, an important fortress city, was captured by the French revolutionary armies by the end of 1794. Accompanying the French troops, although arriving in Maastricht two months after the city had been taken, was geologist Barthélemy Faujas de Saint-Fond on a mission to secure the piece, together with représentant du peuple (political commissar) Augustin-Lucie de Frécine (1751–1804), who during the campaign tried to transport anything of artistic or scientific value he could lay his hands on to France. Finding that it had been removed from the cottage and hidden within the fortress, Frécine supposedly offered "six hundred bottles of excellent wine" to those being the first to locate the skull and bring it to him in one piece. Soon, a dozen grenadiers claimed their reward, carrying the piece with them. December 1794 it was moved to Paris as war booty, by decree declared a national heritage and added to the collection of the new Muséum national d'Histoire naturelle.
In 1798 Faujas de Saint-Fond published his Histoire naturelle de la montagne de Saint-Pierre de Maestricht [Tome 1], which also contained an account of the circumstances of the find. According to him, Dr. Hoffmann paid the quarrymen to inform him of any fossil finds. When the skull was found in 1770 Hoffmann was notified by the quarrymen and he is said to have led the excavation from then on. Afterwards, Godding would have claimed his rights as landowner and forced Hoffmann to relinquish his ownership through a lawsuit, won by influencing the court. De Saint-Fond, after all, in 1795, saved the specimen for science, promising a considerable indemnity to Godding to compensate for his loss. However, as Dutch historian Peggy Rompen has illustrated, very little of this famous story can be substantiated by other sources. Godding was the original owner, Hoffmann clearly never possessed the fossil, there is no trace of any lawsuit, Faujas de Saint-Fond probably never paid anything, and the entire account seems to have been fabricated by him to justify the dispossession by military force.
De Saint-Fond still assumed the specimen represented a crocodile. In 1798 the son of Petrus Camper, Adriaan Gilles Camper, again studied the fossil indirectly by reconsidering the description by his father. He was the first to reach the conclusion that the remains were those of a giant monitor, which result in 1799 he corresponded to Georges Cuvier.
In 1808 Cuvier confirmed Camper's result. The fossil had already become part of Cuvier's first speculations on the possibility of animal species going extinct. The idea of extinction paved the way for his theory of catastrophism or "consecutive creations", one of the predecessors of the evolution theory. Prior to this, almost all fossil reptile specimens, when recognized as having come from once-living animals, were interpreted as forms similar to those of the modern day: crocodiles, fish, whales, or large land mammals. Cuvier's idea that the Maastricht specimen was a gigantic version of a modern animal unlike any species alive today seemed strange, even to him. He justified this by trusting his techniques in the then-developing field of comparative anatomy, which he had already used to identify giant, extinct members of other modern groups known only from fossils, including giant tapir and ground sloth specimens.
A scientific name had not yet been given to the new species, the specimen usually being referred to as the Grand Animal fossile des Carrières de Maëstricht or "Great Fossil Animal of the Maastricht quarries". In 1822 William Daniel Conybeare named it Mosasaurus after the Latin name (Mosa) of the Maas (Meuse) River passing along Mount Saint Peter, the second skull being the holotype, MNHNP AC9648. The specific name (epithet) hoffmanni was added by Gideon Mantell in 1829, honouring Hoffmann, on the presumption he was the discoverer of the type specimen. As the spelling hoffmanni is in prevailing usage over the alternative spelling hoffmannii, it must be preserved under Article 33.3.1 of the ICZN.
In 1854 German biologist Hermann Schlegel was the first to conjecture Mosasaurus had flippers instead of normal feet.
On Saturday, April 18, 2015, a fourteen-year-old amateur paleontologist, Lars Barten, from Rijkevoort village in Noord-Brabant province in the Netherlands, together with his father Jos Barten, discovered a Mosasaurus hoffmani fossil near ENCI-Maastricht. The fossil has been named Lars, after its finder and now resides in the Natuurhistorisch Museum Maastricht (Maastricht Natural History Museum).
The family Mosasauridae is split into several subfamilies, with Mosasaurus being placed within Mosasaurinae. This subfamily, in turn, is further split into smaller tribes, with Mosasaurus being grouped with Clidastes, Moanasaurus, and Liodon in the tribe Mosasaurini.
Since the genus was first named in the early 19th century, numerous species have been assigned to Mosasaurus, both from North America and Europe. Many researchers have suggested that certain European species are actually synonyms of their American counterparts, though because many of the specimens involved are incomplete, scientists have gone back and forth regarding which species are synonyms and which are not. For example, the giant American species M. maximus is regarded by most researchers as a junior synonym of the European M. hoffmanni, though a few scientists maintain that the two can be distinguished by features of their skull bones.
Five species are generally recognized as valid today: M. hoffmanni Mantell, 1829 (the type species), M. conodon Cope, 1881,M. lemonnieri Dollo, 1889, M. beaugei Arambourg, 1952, and M. missouriensis (Harlan, 1834). Two additional species from Japan - M. hobetsuensis Suzuki, 1985, and M. prismaticus Sakurai et al., 1999 - and one species from New Zealand, M. mokoroa Welles & Gregg, 1971, were considered valid species by Street and Caldwell in 2016, pending a taxonomic revision of the Mosasaurinae of the Pacific.
Capelliniosuchus is an extinct genus of mosasaur. It was discovered in Italy, and described by Simonelli, originally believing it to be a metriorhynchid crocodyliform similar to Dakosaurus. However, after re-examing the type specimen, Sirotti concluded that it was a junior synonym of Mosasaurus hoffmannii. A 2016 paper found the genus valid.Capellineosuchus is a misspelling by Romer.Clidastes
Clidastes is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like Mosasaurus and Prognathodon. Clidastes is known from deposits ranging in age from the Coniacian to the early Campanian in the United States.
Clidastes means "locked vertebrae", which originates from the Greek noun κλειδί, or kleid meaning key (akin to Latin claudere meaning to shut). This refers to how the vertebral processes allow the proximal heads of the vertebrae to interlock for stability and strength during swimming.
It was one of the earliest hydropedal mosasaurs, representing one of the first properly marine predatory forms alongside other early hydropedal genera like Tylosaurus and Platecarpus. It was likely an agile swimmer that preyed upon cephalopods, fish and other small vertebrates in shallow water.Coleophora mosasaurus
Coleophora mosasaurus is a moth of the family Coleophoridae. It is found in the Chinese provinces of Shaanxi and Qinghai and in Turkmenistan.
The wingspan is 14–15 mm.
The larvae feed on Lycium species, including Lycium kopetdaghi and Lycium barbarum. They feed on the leaves of their host plant.Dallasaurus
Dallasaurus ("Dallas lizard") is a basal mosasauroid from the Upper Cretaceous of North America. Along with Russellosaurus, Dallasaurus is one of the two oldest mosasauroid taxa currently known from North America. This small semi-aquatic lizard measured less than a meter in length, compared to such gigantic derived mosasaurs as Tylosaurus and Mosasaurus, each exceeding 14 meters.Eremiasaurus
Eremiasaurus is a genus of extinct genus of Cretaceous marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurini tribe (within the Mosasaurinae) and is exclusively known from the Maastrichtian phosphates of the Ouled Abdoun Basin in Morocco. Eremiasaurus means "desert lizard", referring to the arid climate of present-day Morocco where its fossils were recovered.
One species is known, E. heterodontus, whose specific name refers to high degree of heterodonty exhibited compared to other species of mosasaur.Goronyosaurus
Goronyosaurus is an extinct genus of marine lizard belonging to the mosasaur family. Fossils of Goronyosaurus are exclusively known from the Dukamaje Formation of Niger and Nigeria and are Maastrichtian in age. Its fossils were first described in the 1930s as Mosasaurus nigeriensis, but subsequent remains revealed a highly unique set of adaptations that prompted the species to be reclassified as the only species of the new genus Goronyosaurus in 1972. These unique adaptations have made Goronyosaurus notoriously difficult to classify within the Mosasauridae and it is often left out of phylogenetic analyses.
Goronyosaurus possesses unique teeth, which are unlike the teeth of any other mosasaur. Instead of the cutting teeth common among mosasaurs, Goronyosaurus has straight teeth with rounded apices adapted for smashing food.Hainosaurus
Hainosaurus (Haino from the river Haine, where it was first discovered, and saurus, from Greek sauros, meaning lizard) is an extinct genus of marine reptiles belonging to the mosasaur family. It is one of the largest mosasaurs, though its size has been revised more than once. At first it was estimated to be 17 metres (56 ft), and the largest mosasaurid. During the 1990s, its size was revised to 15 metres (49 ft) long; more recently, Johan Lindgren estimated that it reached lengths of up to 12.2 metres (40 ft). It was one of the top marine predators of the Late Cretaceous. Like other giant mosasaurs, this giant predator preyed on turtles, plesiosaurs, pterosaurs, cephalopods, sharks, fish, and smaller mosasaurs.
The fossils of H. pembinensis were found in the Upper Cretaceous Pierre Shale in Manitoba, Canada in 1988. It was distinguished from Tylosaurus by having a greater number of vertebrae before the tail, a larger femur to humerus ratio, and larger nostrils. However, a 2008 study found that conclusion to be problematic, and thus reclassified into the genus Tylosaurus as T. pembinensis. Likewise, Hainosaurus neumilleri Martin, 2007 is a nomen dubium within Tylosaurus.
Hainosaurus is a member of the subfamily Tylosaurinae, and it is related to the wholly North American Tylosaurus. However, it has more vertebrae from the neck to the part of the tail with chevrons (53) than Tylosaurus (35). Both genera are large marine superpredators. Hainosaurus' tail has less chevron-bearing vertebrae, making it shorter than that of Tylosaurus. The type species of Hainosaurus is H. bernardi, named after the Belgian Léopold Bernard, owner of the phosphate chalk exploitation where the fossil was unearthed. In a paper published in 2016, Hainosaurus was considered congeneric with Tylosaurus.Hornerstown Formation
The Hornerstown Formation is a Paleogene or latest Mesozoic geologic formation in New Jersey. The age of these deposits have been controversial. While most fossils are of animals types known from the earliest Cenozoic era, several fossils of otherwise exclusively Cretaceous age have been found. These include remains of the shark Squalicorax, the teleost fish Enchodus, several species of ammonite, and marine lizards referred to the genus Mosasaurus. Some of these remains show signs of severe abrasion and erosion, however, implying that they are probably re-worked from older deposits. Most of these fossils are restricted to the lowest point in the formation, one rich in fossils and known as the Main Fossiliferous Layer, or MFL. Other explanations for the out-of-place fossils in the MFL is that they represent a time-averaged assemblage that built up and remained unburied during a time of low sediment deposition, or that they were stirred up from deeper in the sediment and deposited together during a tsunami.Johann Leonard Hoffmann
Johann Leonard Hoffmann (1710–1782) was a Maastricht army surgeon and amateur geologist who collected fossils from the local Mount Saint Peter. He is known for fossils named after him, and was one of the three people contacted on the discovery of the Mosasaurus in 1766, and especially the second one in the 1770s known as "le grand animal", that was later taken to Paris by Napoleon's army in 1794.List of cloned animals in the Jurassic Park series
Jurassic Park is an American science fiction adventure media franchise based on the 1990 best-selling novel of the same name by Michael Crichton, and its sequel, The Lost World (1995). Focused on the catastrophic events following the cloning of dinosaurs through the extraction of DNA from mosquitoes fossilized in amber, the film series also explores the ethics of cloning and genetic engineering, and the morals behind bringing back extinct animals. The first Jurassic Park film was directed by Steven Spielberg and released in 1993. It was followed by two films, The Lost World: Jurassic Park (1997) and Jurassic Park III (2001), completing the first trilogy. A fourth installment, Jurassic World, was released in 2015, marking the beginning of a new trilogy. The new trilogy starts 22 years after the events of the first, but still relies on the narrative of the original films and novels. Its sequel, Jurassic World: Fallen Kingdom, was released in 2018, and a sixth and final film of the second trilogy is scheduled for release in 2021. The film series has garnered critical acclaim for its innovations in CGI technology and animatronics.
47 species of cloned animals have been portrayed in the novels and films: 39 species of dinosaurs, three transgenic dinosaurs, three species of pterosaurs, a Mosasaurus, and at least one cloned Homo sapiens. Theropod dinosaurs like Tyrannosaurus rex and Velociraptor have had major roles throughout the series. Other species, including Triceratops, Brachiosaurus, and Spinosaurus have also played significant roles.List of mosasaur-bearing stratigraphic units
This is a list of stratigraphic units from which mosasaur body fossils have been recovered. Units listed are all either formation rank or higher (e.g. group). Formations are listed by continent, and alphabetically within the individual lists.List of mosasaur genera
This list of mosasaurs is a comprehensive listing of all genera that have ever been included in the family Mosasauridae or the parent clade Mosasauroidea, excluding purely vernacular terms. The list includes all commonly accepted genera, but also genera that are now considered invalid, doubtful (nomen dubium), or were not formally published (nomen nudum), as well as junior synonyms of more established names, and genera that are no longer considered mosasauroid. Non-mosasaurid mosasauroids shall be noted as such. The list currently includes 78 genera.Mosasaur
Mosasaurs (from Latin Mosa meaning the 'Meuse river', and Greek σαύρος sauros meaning 'lizard') comprise a group of extinct, large marine reptiles containing 38 genera in total. Their first fossil remains were discovered in a limestone quarry at Maastricht on the Meuse in 1764. Mosasaurs probably evolved from an extinct group of aquatic lizards known as aigialosaurs in the Earliest Late Cretaceous. During the last 20 million years of the Cretaceous period (Turonian-Maastrichtian ages), with the extinction of the ichthyosaurs and pliosaurs, mosasaurs became the dominant marine predators. They became extinct as a result of the K-Pg event at the end of the Cretaceous period, about 66 million years ago.Mosasaurinae
The Mosasaurinae are a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the subfamily are informally and collectively known as "mosasaurines" and have been recovered from every continent except for South America.The lineage first appears in the Turonian and thrived until the mass extinction event at the end of the Maastrichtian. They ranged in size from some of the smallest known mosasaurs (Carinodens, 3–3.5 meters), to medium-sized taxa (Clidastes, 6+ meters), to the largest of the mosasaurs (Mosasaurus hoffmannii) potentially reaching about 15 m in length. Many genera of mosasaurines were either piscivorous or generalists, preying on fish and other marine reptiles, but one lineage, the Globidensini, evolved specialized crushing teeth, adapting to a diet of ammonites and/or marine turtles.
Though represented by relatively small forms throughout the Turonian and Santonian, such as Clidastes, the lineage diversified during the Campanian and had by the Maastrichtian grown into the most diverse and species-rich mosasaur subfamily.The etymology of the group derives from the genus Mosasaurus (Latin Mosa = "Meuse river" + Greek sauros = "lizard").Mosasaurini
The Mosasaurini are a tribe of mosasaurine mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the tribe, known as "mosasaurins", have been recovered from North America, Europe, Africa and Oceania with questionable occurrences in Asia. The tribe contains the closely related genera Mosasaurus, Eremiasaurus, Plotosaurus and Moanasaurus. It has historically been more inclusive, on occasion including genera such as Plesiotylosaurus, Liodon and Clidastes, all of which are now seen as more basal mosasaurines.Mosasaurins were highly derived predatory mosasaurs, containing genera like Plotosaurus, with unique adaptations towards fast swimming speeds and Mosasaurus itself, among the largest of the mosasaurs.
The etymology of the tribe derives from the genus Mosasaurus (Latin Mosa = "Meuse river" + Greek sauros = "lizard").Plesiotylosaurus
Plesiotylosaurus, meaning "near Tylosaurus", is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like Mosasaurus and Prognathodon. The genus contains one species, Plesiotylosaurus crassidens, recovered from deposits of Middle Maastrichtian age in the Moreno Formation in California.Though it is classified as a mosasaurine mosasaur, and not closely related to Tylosaurus, the name is not entirely misplaced as a number of cranial features found in the relatively intact holotype skull suggest some degree of convergent evolution with tylosaurine mosasaurs.Prognathodon
Prognathodon is an extinct genus of marine lizard belonging to the mosasaur family. It is classified as part of the Mosasaurinae subfamily, alongside genera like Mosasaurus and Clidastes. Prognathodon has been recovered from deposits ranging in age from the Campanian to the Maastrichtian in the Middle East, Europe and North America.Prognathodon means "forejaw tooth", which originates from the Latin pro- ("earlier" or "prior"), Greek gnathos ("jaw") and odṓn ("tooth"). Twelve nominal species of Prognathodon are recognised, from North America, northern and western Africa, the Middle East, western Europe and New Zealand. Due to the sometimes clear differences between them and the incomplete nature of many of the specimens, the systematics of the genus and which species should properly be considered Prognathodon is controversial.Prognathodon is known for its massively built jaws and teeth. Its distinct feeding adaptations have generated much interest in its ecology ever since its discovery, though direct evidence of its diet, such as gastric residues, is rare.Timeline of mosasaur research
This timeline of mosasaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of mosasaurs, a group of giant marine lizards that lived during the Late Cretaceous Epoch. Although mosasaurs went extinct millions of years before humans evolved, humans have coexisted with mosasaur fossils for millennia. Before the development of paleontology as a formal science, these remains would have been interpreted through a mythological lens. Myths about warfare between serpentine water monsters and aerial thunderbirds told by the Native Americans of the modern western United States may have been influenced by observations of mosasaur fossils and their co-occurrence with creatures like Pteranodon and Hesperornis.The scientific study of mosasaurs began in the late 18th century with the serendipitous discovery of a large fossilized skeleton in a limestone mine near Maastricht in the Netherlands. The fossils were studied by local scholar Adriaan Gilles Camper, who noted a resemblance to modern monitor lizards in correspondence with renowned French anatomist Georges Cuvier. Nevertheless, the animal was not scientifically described until the English Reverend William Daniel Conybeare named it Mosasaurus, after the river Meuse located near the site of its discovery.By this time the first mosasaur fossils from the United States were discovered by the Lewis and Clark expedition, and the first remains in the country to be scientifically described were reported slightly later from New Jersey. This was followed by an avalanche of discoveries by the feuding Bone War paleontologists Edward Drinker Cope and Othniel Charles Marsh in the Smoky Hill Chalk of Kansas. By the end of the century a specimen of Tylosaurus would be found that preserved its scaley skin. Later Samuel Wendell Williston mistook fossilized tracheal rings for the remains of a fringe of skin running down the animal’s back, which subsequently became a common inaccuracy in artistic restorations.The 20th century soon saw the discovery in Alabama of a strange mosasaur called Globidens, with rounded teeth suited to crushing shells. Mosasaur remains were also discovered in Africa and California. In 1967 Dale Russell published a scientific monograph dedicated to mosasaurs. Embryonic remains in the 1990s confirmed that mosasaurs gave live birth like in ichthyosaurs. The 1990s also saw a revival and escalation of a debate regarding whether or not some supposed mosasaur toothmarks in ammonoid shells were actually made by limpets. By the end of the century, the evolutionary relationship between mosasaurs and snakes as well as the possible involvement of mosasaurs in the extinction of the aforementioned ichthyosaurs became hot button controversies.The debates regarding snakes, toothmarks, and ichthyosaurs spilled over into the early 21st century. These discussions were also accompanied by the discovery of many new taxa, including new species of Globidens, Mosasaurus, and Tylosaurus as well as entirely new genera like Yaguarasaurus and Tethysaurus. In 2013, Lindgren, Kaddumi, and Polcyn reported the discovery of a Prognathodon specimen from Jordan that preserved the soft tissues of its scaley skin, flippers and tail. Significantly, the tail resembled those of modern carcharinid sharks, although the bottom lobe of the tail fin was longest in the mosasaur whereas shark tails have longer upper lobes.Tylosaurinae
The Tylosaurinae are a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates. Members of the subfamily are informally and collectively known as "tylosaurines" and have been recovered from every continent except for South America. The subfamily includes the genera Tylosaurus, Taniwhasaurus, Hainosaurus and Kaikaifilu.
Tylosaurines first appeared in the Coniacian and gave rise to some of the largest mosasaurs within the genera Tylosaurus and Hainosaurus which came to dominate as apex predators in marine ecosystems throughout the Santonian and Campanian, but appear to have been largely replaced by large mosasaurines, such as Mosasaurus, by the end of the Maastrichtian. Nevertheless, the subfamily survived to the end of the Cretaceous, covering a period lasting approximately twenty million years.
The etymology of this group derives from the genus Tylosaurus (Greek tylos = "knob" + Greek sauros = "lizard").
|Related groups and genera|