Suchosaurus

Suchosaurus (meaning "crocodile lizard") is a spinosaurid theropod dinosaur from Cretaceous England, originally believed to be a genus of crocodile. The type material consists of teeth. Two species, S. cultridens and S. girardi have been named.

Suchosaurus
Temporal range: Early Cretaceous
Suchosaurus
Holotype tooth of S. cultridens
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Clade: Dinosauria
Order: Saurischia
Suborder: Theropoda
Family: Spinosauridae
Genus: Suchosaurus
Owen, 1841
Species
  • S. cultridens Owen, 1841 (type)
  • S. girardi Sauvage, 1897
Synonyms

History of discovery

About 1820, Gideon Mantell acquired teeth discovered near Cuckfield in the Wadhurst Clay of East Sussex, part of a lot with the present inventory number BMNH R36536. In 1822, he reported these, after an identification by William Clift, as belonging to crocodiles.[1] In 1824, the teeth were mentioned and illustrated by Georges Cuvier, representing the first illustration of a spinosaurid fossil (though this group wouldn't be recognized for nearly another century).[2] In 1827 Mantell described additional teeth, pointing out the similarities to the crocodylian Teleosaurus and Gavialis.[3] One of these teeth is the present specimen BMNH R4415, others are part of BMNH R36536.

In 1841, Richard Owen named, based on BMNH R36536 as a syntype series, a subgenus Crocodylus (Suchosaurus) with as type species Crocodylus (Suchosaurus) cultridens.[4] The subgeneric name was derived from Greek σοῦχος, souchos, the name of the Egyptian crocodile god Sobek. This reflected the presumed taxonomic affinities; at the time the crocodile-like snouts of spinosaurids were not known. The specific name is derived from Latin culter, "dagger", and dens, "tooth", in reference to the elongated form of the teeth. In 1842, Owen again mentioned the taxon as a subgenus,[5] subsequently he and other workers would use it as a full genus Suchosaurus. In 1842 and 1878 Owen referred some vertebrae to Suchosaurus,[6] but these likely belong to Ornithischia instead.[7] In 1884, Owen indicated a tooth as "Suchosaurus leavidens" in a caption,[8] this is usually seen as a lapsus calami because this species is not further mentioned.

Suchosaurus girardi
Type mandible and tooth of S. girardi

In 1897, Henri-Émile Sauvage named a second species: Suchosaurus girardi, based on two jaw fragments (specimen MG324) and a tooth, found in Portugal by Paul Choffat. The specific name honours French geologist Albert Girard.[9] The tooth was considered lost but was rediscovered and in 2013 reported as specimen MNHN/UL.I.F2.176.1, part of remains recovered after a fire in 1978.[10]

During the nineteenth and most of the twentieth century, Suchosaurus was usually considered to have been some obscure crocodilian, perhaps belonging to the Pholidosauridae.[11] Single comparable teeth discovered in England were referred to the genus.[7] However, when publishing a redescription of Baryonyx in 1998, Angela Milner realised that the teeth of that spinosaurid dinosaur were extremely similar to those of Suchosaurus. In 2003, she suggested both genera represented one and the same animal.[12] An identity would imply the name Suchosaurus has priority. However, the Suchosaurus teeth are also indistinguishable from those of Cristatusaurus and Suchomimus, making it an indeterminate baryonychine.

In 2007 Eric Buffetaut considered the teeth of S. girardi very similar to those of Baryonyx (and S. cultridens) except for the stronger development of the crown ribs, suggesting that the remains belonged to the same genus. Buffetaut agreed with Milner that the teeth of S. cultridens were almost identical to those of B. walkeri, but with a ribbier surface. The former taxon might be a senior synonym of the latter (since it was published first), depending on whether the differences were within a taxon or between different ones. According to Buffetaut, since the holotype specimen of S. cultridens is one worn tooth and that of B. walkeri is a skeleton it would be more practical to retain the newer name.[13]

In 2011 Portuguese palaeontologist Octávio Mateus and colleagues agreed that Suchosaurus was closely related to Baryonyx, but considered both species in the former genus (Suchosaurus) nomina dubia (dubious names) since their holotype specimens were not considered diagnostic (lacking distinguishing features) and could not be definitely equated with other taxa.[14]

References

  1. ^ Mantell, G.A., 1822, The fossils of the South Downs or Illustrations of the Geology of Sussex, London, Rupton Relfe
  2. ^ Cuvier, G., 1824, Recherches sur les ossemens fossiles, deuxième édition. Dufour & d’Ocagne, Paris. 547 pp
  3. ^ Mantell, G.A., 1827, Illustrations of the geology of Sussex, London, Lupton Relfe. 92 pp
  4. ^ Owen, R. (1840–1845). Odontography. London: Hippolyte Baillière, 655 pp, 1–32
  5. ^ Owen, R., 1842, Report on British fossil reptiles. Part II. Reports of the meetings of the British Association for the Advancement of Science. 11, pp 61-204
  6. ^ Owen, R., 1878, Monograph on the fossil Reptilia of the Wealden and Purbeck Formations. Supplement VIII, (Goniopholis, Petrosuchus, and Suchosaurus). Palaeontolographical Society Monographs, 32, pp 1-15
  7. ^ a b Lydekker, R., 1888, Catalogue of the Fossil Reptilia and Amphibia in the British Museum (Natural History), Cromwell Road, S.W., Part 1. Containing the Orders Ornithosauria, Crocodilia, Dinosauria, Squamata, Rhynchocephalia, and Proterosauria. British Museum of Natural History, London. 309 pp
  8. ^ *Owen, R., 1884, A History of British Fossil Reptiles, Volume II. Cassell, London. 224 pp
  9. ^ Sauvage, H. E. (1897–1898). Vertébrés fossiles du Portugal. Contribution à l’étude des poissons et des reptiles du Jurassique et du Crétacique. Lisbonne: Direction des Travaux géologiques du Portugal, 46p
  10. ^ Malafaia, E.; Ortega, F.; Escaso, F.; Mocho, P., 2013, "Rediscovery of a lost portion of the holotype of Suchosaurus girardi (Sauvage, 1897-98), now related to the spinosaurid theropod Baryonyx", In: Torcida Fernández-Baldor, F.; Huerta, P. (Eds.). Abstract book of the VI International Symposium about Dinosaurs Palaeontology and their Environment pp 82-84
  11. ^ Buffetaut, E., 2010, "Spinosaurs before Stromer: Early finds of spinosaurid dinosaurs and their interpretations", Geological Society, London, Special Publications. 343, pp 175-188
  12. ^ Milner, A., 2003, "Fish-eating theropods: A short review of the systematics, biology and palaeobiogeography of spinosaurs". In: Huerta Hurtado and Torcida Fernandez-Baldor (eds.). Actas de las II Jornadas Internacionales sobre Paleontologýa de Dinosaurios y su Entorno (2001). pp 129-138
  13. ^ Buffetaut, E. (2007). "The spinosaurid dinosaur Baryonyx (Saurischia, Theropoda) in the Early Cretaceous of Portugal." Geological Magazine, 144(6): 1021-1025. doi:10.1017/S0016756807003883
  14. ^ Mateus, O.; Araújo, R.; Natário, C.; Castanhinha, R. (2011). "A new specimen of the theropod dinosaur Baryonyx from the early Cretaceous of Portugal and taxonomic validity of Suchosaurus" (PDF). Zootaxa. 2827. 2827: 54–68. doi:10.11646/zootaxa.2827.1.3.

External links

1841 in paleontology

Paleontology or palaeontology is the study of prehistoric life forms on Earth through the examination of plant and animal fossils. This includes the study of body fossils, tracks (ichnites), burrows, cast-off parts, fossilised feces (coprolites), palynomorphs and chemical residues. Because humans have encountered fossils for millennia, paleontology has a long history both before and after becoming formalized as a science. This article records significant discoveries and events related to paleontology that occurred or were published in the year 1841.

Baryonyx

Baryonyx () is a genus of theropod dinosaur which lived in the Barremian stage of the Early Cretaceous Period, about 130–125 million years ago. The first skeleton was discovered in 1983 in the Weald Clay Formation of Surrey, England, and became the holotype specimen of B. walkeri, named by palaeontologists Alan J. Charig and Angela C. Milner in 1986. The generic name, Baryonyx, means "heavy claw" and alludes to the animal's very large claw on the first finger; the specific name, walkeri, refers to its discoverer, amateur fossil collector William J. Walker. The holotype specimen is one of the most complete theropod skeletons from the UK (and remains the most complete spinosaurid), and its discovery attracted media attention. Specimens later discovered in other parts of the United Kingdom and Iberia have also been assigned to the genus.

The holotype specimen, which may not have been fully grown, was estimated to have been between 7.5 and 10 m (25 and 33 ft) long and to have weighed between 1.2 and 1.7 t (1.3 and 1.9 short tons). Baryonyx had a long, low, and narrow snout, which has been compared to that of a gharial. The tip of the snout expanded to the sides in the shape of a rosette. Behind this, the upper jaw had a notch which fitted into the lower jaw (which curved upwards in the same area). It had a triangular crest on the top of its nasal bones. Baryonyx had a large number of finely serrated, conical teeth, with the largest teeth in front. The neck formed an S-shape, and the neural spines of its dorsal vertebrae increased in height from front to back. One elongated neural spine indicates it may have had a hump or ridge along the centre of its back. It had robust forelimbs, with the eponymous first-finger claw measuring about 31 cm (12 in) long.

Now recognised as a member of the family Spinosauridae, Baryonyx's affinities were obscure when it was discovered. Some researchers have suggested that Suchosaurus cultridens is a senior synonym (being an older name), and that Suchomimus tenerensis belongs in the same genus; subsequent authors have kept them separate. Baryonyx was the first theropod dinosaur demonstrated to have been piscivorous (fish-eating), as evidenced by fish scales in the stomach region of the holotype specimen. It may also have been an active predator of larger prey and a scavenger, since it also contained bones of a juvenile Iguanodon. The creature would have caught and processed its prey primarily with its forelimbs and large claws. Baryonyx may have had semiaquatic habits, and coexisted with other theropod, ornithopod, and sauropod dinosaurs, as well as pterosaurs, crocodiles, turtles and fishes, in a fluvial environment.

Goniopholis

Goniopholis is an extinct genus of goniopholidid crocodyliform that lived in Europe and Africa during the Late Jurassic and Early Cretaceous. Being semi-aquatic it is very similar to modern crocodiles. It ranged from 2–4 metres in length, and would have had a very similar lifestyle to the American alligator or Nile crocodile.

Hastings Beds

The Hastings Beds is a geological unit that includes interbedded clays, silts, siltstones, sands and sandstones in the High Weald of southeast England. These strata make up the component geological formations of the Ashdown Formation, the Wadhurst Clay Formation and the Tunbridge Wells Sand Formation. The term 'Hastings Beds' has been superseded and the component formations are included in the Wealden Group.The sediments of the Weald, including the Hastings Beds, were deposited during the Early Cretaceous Period, which lasted for approximately 40 million years from 140 to 100 million years ago. The Hastings Beds are of Early Berriasian to Late Valanginian age. The Group takes its name from the fishing town of Hastings in East Sussex.

Dinosaur remains are among the fossils that have been recovered from the included formations.

Henri Émile Sauvage

Henri Émile Sauvage (22 September 1842 in Boulogne-sur-Mer – 3 January 1917 in Boulogne-sur-Mer) was a French paleontologist, ichthyologist, and herpetologist. He was a leading expert on Mesozoic fish and reptiles.He worked as a curator at the Muséum d'Histoire Naturelle in Boulogne-sur-Mer, and published extensively on Late Jurassic dinosaurs and other vertebrates from the Boulonnais region of northern France. He made important contributions involving vertebrate palaeontology in Portugal, describing in 1897, Suchosaurus girardi from jaw fragments found in that country.From 1883 to 1896 he served as director of the station aquicole in Boulogne-sur-Mer. He was a member of the Société géologique de France.

In 1893 Philippe Thomas published the palaeontological results of the Tunisian Scientific Exploration Mission (1885–1886) in six installments plus an atlas, including the work of Victor-Auguste Gauthier (sea urchins), Arnould Locard (Mollusca), Auguste Péron (Brachiopods, Bryozoa and Pentacrinitess) and Henri Émile Sauvage (fish).The plesiosaurid species Lusonectes sauvagei commemorates his name, as do the crustacean species Pseudanthessius sauvagei and the gecko species Bavayia sauvagii.

Irritator

Irritator is a genus of spinosaurid theropod dinosaur that lived in what is now Brazil during the Albian stage of the Early Cretaceous Period, about 110 million years ago. It is known from a nearly complete skull found in the Romualdo Formation of the Araripe Basin. Fossil dealers had acquired this skull and illegally sold it to the State Museum of Natural History Stuttgart. In 1996, the specimen became the holotype of the type species Irritator challengeri. The genus name comes from the word "irritation", reflecting the feelings of paleontologists who found the skull had been heavily damaged and altered by the collectors. The species name is an homage to the fictional character Professor Challenger from Arthur Conan Doyle's novels.

Many paleontologists regard Angaturama limai—known from a snout tip that was described later in 1996—as a potential junior synonym of Irritator. Both animals hail from the same stratigraphic units of the Araripe Basin. It was also previously proposed that Irritator and Angaturama's skull parts belonged to the same specimen. Although this has been cast into doubt, more overlapping fossil material is needed to confirm whether they are the same animal or not. Other spinosaurid skeletal material, some of which could belong to Irritator or Angaturama, was retrieved from the Romualdo Formation, allowing for a replica skeleton to be made and mounted for display at the National Museum of Rio de Janeiro in 2009.

Estimated at between 6 and 8 meters (20 and 26 ft) in length, Irritator weighed around 1 tonne (1.1 short tons), making it one of the smallest spinosaurids known. Its long, shallow and slender snout was lined with straight and unserrated conical teeth. Lengthwise atop the head ran a thin sagittal crest, to which powerful neck muscles were likely anchored. The nostrils were positioned far back from the tip of the snout, and a rigid secondary palate on the roof of the mouth would have strengthened the jaw when feeding. Belonging to a subadult, Irritator challengeri's holotype remains the most completely preserved spinosaurid skull yet found. The Angaturama snout tip expanded to the sides in a rosette-like shape, bearing long teeth and an unusually tall crest. One possible skeleton indicates it, like other spinosaurids, had enlarged first-finger claws and a sail running down its back.

Irritator had been mistaken initially for a pterosaur, and later a maniraptoran dinosaur. In 1996, the animal was identified as a spinosaurid theropod. The holotype skull was thoroughly prepared before being redescribed in 2002, confirming this classification. Both Irritator and Angaturama belong to the Spinosaurinae subfamily. A generalist diet—like that of today's crocodilians—has been suggested; Irritator might have preyed mainly on fish and any other small prey animals it could catch. Fossil evidence is known of an individual that ate a pterosaur, either from hunting or scavenging it. Irritator may have had semiaquatic habits, and inhabited the tropical environment of a coastal lagoon surrounded by dry regions. It coexisted with other carnivorous theropods as well as turtles, crocodyliforms, and a large number of pterosaur and fish species.

List of European dinosaurs

Dinosaurs evolved partway through the Triassic period of the Mesozoic era, around 230 Ma (million years ago). At that time, the earth had one supercontinental landmass, called Pangaea, of which Europe was a part. So it remained throughout the Triassic. By the start of the Jurassic period, some 30 million years later, the supercontinent began to split into Laurasia and Gondwana. The largest inlet from Panthalassa, the superocean that surrounded Pangaea, was called the Tethys Ocean, and as this inlet cut deeper into the supercontinent, much of Europe was flooded.

By the Cretaceous, from 145 to 66 million years ago, the continents were beginning to approach their present shapes, but not their present positions, and Europe remained tropical. At times, it was a chain of island-microcontinents including Baltica and Iberia.

Europe is relatively rich in fossils from the Jurassic-Cretaceous boundary, and much of what is known about European dinosaurs dates from this time. During the Maastrichtian the end of the Cretaceous dinosaurs were dominating western and Central Europe as the Tremp Formation in Spain dates back to that age. Examples of dinosaurs from Maastrichtian Europe are Struthiosaurus and Canardia.

List of crurotarsan genera

This list of crurotarsans is a comprehensive listing of all genera that have ever been included in the clade Crurotarsi, excluding purely vernacular terms. Under some definitions Crurotarsi includes all archosaurs, but this list excludes archosaur genera that are included in Avemetatarsalia (pterosaurs, nonavian dinosaurs, and birds). 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 crurotarsan. Extinct taxa are denoted with a dagger (†). The list contains 570 names, of which approximately 480 are considered either valid crurotarsan genera or nomina dubia.

List of dinosaur genera

This list of dinosaurs is a comprehensive listing of all genera that have ever been included in the superorder Dinosauria, excluding class Aves (birds, both living and those known only from fossils) and 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 dinosaurs. Many listed names have been reclassified as everything from birds to crocodilians to petrified wood. The list contains 1559 names, of which approximately 1192 are considered either valid dinosaur genera or nomina dubia.

Pholidosauridae

Pholidosauridae is an extinct family of aquatic neosuchian mesoeucrocodylian crocodylomorphs. Fossils have been found in Europe (Denmark, England, France, Germany, Spain and Sweden), Africa (Algeria, Niger, Mali, Morocco and Tunisia), North America (Canada and the United States) and South America (Brazil and Uruguay). The pholidosaurids first appeared in the fossil record during the Bathonian stage of the Middle Jurassic and became extinct during the Late Turonian stage of the Late Cretaceous.Sarcosuchus is one of the best known pholidosaurs. It is believed to have attained lengths of up to 12 metres (39 ft 4 in) and weighed up to 8 tonnes (7.9 long tons; 8.8 short tons). One genus, Suchosaurus, once thought to be a pholidosaur, has since been shown to be a spinosaurid theropod dinosaur.

Pholidosaurus

Pholidosaurus is an extinct genus of neosuchian crocodylomorph. It is the type genus of the family Pholidosauridae. Fossils have been found in northwestern Germany. The genus is known to have existed during the Berriasian stage of the Early Cretaceous. Fossil material found from the Annero and Jydegård Formations in Skåne, Sweden and on the island of Bornholm, Denmark, have been referred to as a mesoeucrocodylian, and possibly represent the genus Pholidosaurus.

Spinosauridae

Spinosauridae (meaning "spined lizards") is a family of megalosauroidean theropod dinosaurs. The genus Spinosaurus, from which the family, subfamily, and tribe borrow their names, is the longest terrestrial predator known from the fossil record, and likely reached lengths of 15 m (49 ft). Most spinosaurids lived during the Cretaceous Period, with possible origins in the Late Jurassic, and fossils of them have been recovered worldwide, including in Africa, Europe, South America, Asia, and Australia, although none have been formally named from the latter continent. Spinosaur remains have generally been attributed to the Early to Mid Cretaceous, with the exception of the Ostafrikasaurus from the Late Jurassic.

Spinosaurids were large bipedal carnivores with elongated, crocodile-like skulls lined with conical teeth bearing little to no serrations, and small crests on top of their heads. The teeth in the front end of their lower jaws fanned out into a spoon-shaped structure similar to a rosette, which gave the animal a characteristic look. Their shoulders were robust, prominent and bore stocky forelimbs with giant "hooked" claws on the first finger of their hands. Many genera had unusually tall neural spines on their vertebrae, which supported sails or humps of skin or fat tissue.

Direct fossil evidence and anatomical adaptations indicate that spinosaurids were at least partly piscivorous, with additional fossil finds indicating they also hunted pterosaurs and small to medium-sized dinosaurs. Osteological analyses have suggested a semiaquatic lifestyle for some members of this clade.

Wessex Formation

The Wessex Formation is a fossil-rich English geological formation that dates from the Berriasian to Barremian stages (about 145–125 million years ago) of the Early Cretaceous. It forms part of the Wealden Group and underlies the younger Vectis Formation and overlies the Durlston Formation. The dominant lithology of this unit is mudstone with some interbedded sandstones.

Piatnitzkysauridae
Megalosauria

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