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Information about Tylosaurinae

Tylosaurinae
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Tylosaurus

Tylosaurus
Conservation status
Extinct (fossil)
Scientific classification
Kingdom:Animalia
Phylum:Chordata
Class:Sauropsida
Order:Squamata
Family:Mosasauridae
Subfamily:Tylosaurinae
Williston, 1895
Genera
See text.
Tylosaurinae (Williston, 1895; Williston, 1897) is a subfamily of mosasaurs, a diverse group of Late Cretaceous marine squamates.

Russell (1967, pp. 170) defined the Tylosaurinae as follows: "Large rostrum present anterior to premaxillary teeth. Twelve or more teeth in dentary and maxilla. Cranial nerves X, XI, and XII leave lateral wall of opisthotic through a single foramen. No canal in basioccipital or basispehnoid for basilar artery. Suprastapedial process of quadrate moderately large, distally pointed. Dorsal edge of surangular rounded and longitudinally horizontal...Twenty nine presacral vertebrae present. Length of presacral series less than that of postsacral series in Tylosaurus, neural spines of posterior caudal vertebrae at most only slightly elongated, do not form an appreciable fin. Haemal arches unfused to caudal centra. Appendicular elements lack smoothly finished articular surfaces."

Genera referrable to the Tylosaurinae (informally and collectively known as "tylosaurines" or "tylosaurs") have been found on all continents except Australia and South America. The etymology for the subfamily is derived from the genus of the type species, Tylosaurus. In general, tylosaurs were large-bodied marine lizards armed with sturdy teeth and a "battering ram" snout composed of the elongated premaxilla and dentaries. Stomach contents from a tylosaur recovered in South Dakota (Martin et Bjork, 1987) included remains of other mosasaurs, bony fish, the large seabird Hesperornis, and sharks, indicating that tylosaurs were generalists. Lingham-Soliar (1992) suggested that tylosaurines were not among the fastest swimming nor the strongest mosasaurids. However, they are lightly built, having greatly reduced the weight of their bodies and possessing relatively small pectoral and pelvic girdles, fore- and hindlimbs. Their bone is highly cancellous and may have been impregated with fat cells during life, adding buoyancy. These traits suggest that tylosaurs may have been ambush predators. Tylosaurs were among the largest mosasaurs, with some species of Tylosaurus and Hainosaurus reaching lengths of 9-15+ meters, making them among the largest of all marine reptiles. A small species of Tylosaurus reported by Russell (1967), T. "zangerli" has since proven to be a juvenile individual of T. proriger (Kiernan, 2002).

Polcyn and Bell (2005, p. 322) have erected a more inclusive clade, the parafamily Russellosaurina, which includes the "subfamilies Tylosaurinae and Plioplatecarpinae and their sister-clade containing the genera Tethysaurus, Russellosaurus, and Yaguarasaurus."

Tylosaurs first appear in the fossil record in the Coniacian and persist well into the Maastrichtian, a period of approximately twenty million years.

Species and Taxonomy

  • Tylosaurinae
  • Tylosaurus (?paraphyletic)
  • T. proriger
  • T. nepaeolicus
  • T. kansasensis
  • T. ivoensis
  • Hainosaurus
  • H. bernardi
  • H. pembinensis
  • H. gaudryi
  • Taniwhasaurus
  • T. oweni (=Tylosaurus haumuriensis)
  • Lakumasaurus
  • L. antarcticus

References

  • Bell, G. L. Jr., 1997. A phylogenetic revision of North American and Adriatic Mosasauroidea. pp. 293-332 In Callaway J. M. and E. L Nicholls, (eds.), Ancient Marine Reptiles, Academic Press, 501 pp.
  • Kiernan, C. R., 2002. Stratigraphic distribution and habitat segregation of mosasaurs in the Upper Cretaceous of western and central Alabama, with an historical review of Alabama mosasaur discoveries. Journal of Vertebrate Paleontology 22(1):91-103.
  • Lindgren, J. et. Siverson, M. 2002.Tylosaurus ivoensis: a giant mosasaur from the early Campanian of Sweden. Royal Society of Edinburgh Transactions: Earth Sciences Vol. 93(1):73-93.
  • Lingham-Soliar, T. 1992. The tylosaurine mosasaurs (Reptilia, Mosasauridae) from the upper Cretaceous of Europe and Africa. Bulletin de L’Institut Royal des Sciences Naturelles de Belgique. Sciences de la Terre 62:171-194.
  • Martin, J. E. and Bjork, P. R. 1987. Gastric residues associated with a mosasaur from the late Cretaceous (Campanian) Pierre Shale in South Dakota. Dakoterra 3:68-72.
  • Polcyn, M. J. et Bell, G. L., Jr. 2005. Russellosaurus coheni n. gen., n. sp., a 92 million-year-old mosasaur from Texas (USA), and the definition of the parafamily Russellosaurina. Netherlands Journal of Geosciences 84(3): 321-333.
  • Russell, D. A., 1967. Systematics and morphology of American mosasaurs. Peabody Museum of Natural History, Yale University, Bulletin 23.
  • Russell, D. A. 1970. The vertebrate fauna of the Selma Formation of Alabama, Part VII, The mosasaurs, Fieldiana, Geology Memoirs 3(7):369-380.
  • Williston, S. W. 1895. New or little-known extinct vertebrates. Kansas University Quarterly 6:95-98.
  • Williston, S. W. 1897. Range and distribution of the mosasaurs with remarks on synonymy. Kansas University Quarterly 4(4):177-185.
conservation status of a species is an indicator of the likelihood of that species continuing to survive either in the present day or the future. Many factors are taken into account when assessing the conservation status of a species: not simply the number remaining, but the
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For other uses of the term, see Fossil (disambiguation)


FOSSIL is a standard for allowing serial communication for telecommunications programs under the DOS operating system.
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Scientific classification or biological classification is a method by which biologists group and categorize species of organisms. Scientific classification also can be called scientific taxonomy, but should be distinguished from folk taxonomy, which lacks scientific basis.
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Chordata
Bateson, 1885

Typical Classes

See below

Chordates (phylum Chordata) are a group of animals that includes the vertebrates, together with several closely related invertebrates.
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Sauropsida*
Goodrich, 1916

Subclasses
  • Anapsida
  • Diapsida
Synonyms
  • Reptilia Laurenti, 1768
Reptiles are tetrapods and amniotes, animals whose embryos are surrounded by an amniotic membrane, and members of the class
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Squamata
Oppel, 1811

black: range of Squamata


Suborders
see text

This article is about the Squamata order of reptiles. For the Roman scale armour see: Lorica squamata.

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Mosasauridae
Gervais, 1853

Subfamilies

Halisaurinae
Mosasaurinae
Plioplatecarpinae
Tylosaurinae

Mosasaurs (from Latin Mosa meaning the 'Meuse river' in the Netherlands, and Greek sauros
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genus (plural: genera) is part of the Latinized name for an organism. It is a name which reflects the classification of the organism by grouping it with other closely similar organisms.
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family (Latin: familia, plural familiae) is a rank, or a taxon in that rank. Exact details of formal nomenclature depend on the Nomenclature Code which applies.
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Mosasauridae
Gervais, 1853

Subfamilies

Halisaurinae
Mosasaurinae
Plioplatecarpinae
Tylosaurinae

Mosasaurs (from Latin Mosa meaning the 'Meuse river' in the Netherlands, and Greek sauros
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The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i.e. from 145.5 ± 4.0 million years ago (Ma)) to the beginning of the Paleocene epoch of the Tertiary Period (about 65.5 ± 0.3 Ma).
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Squamata
Oppel, 1811

black: range of Squamata


Suborders
see text

This article is about the Squamata order of reptiles. For the Roman scale armour see: Lorica squamata.

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Rostrum can mean one of several different things:
  • Rostrum (anatomy), an anatomical structure resembling a bird's beak, such as the snout of crocodiles and dolphins or the part of the carapace of a crustacean.

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The premaxilla is a pair of small cranial bones at the very tip of the jaws of many animals, usually bearing teeth, but not always. They are connected to the maxilla and the nasals.
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mandible (from Latin mandibūla, "jawbone") or inferior maxillary bone is, together with the maxilla, the largest and strongest bone of the face . It forms the lower jaw and holds the lower teeth in place.
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The maxilla (plural: maxillae) is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible, which is also a fusion of two halves at the mental symphysis.
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In anatomy, a foramen is any opening.

Examples

Skull

See Foramina of skull

Other

  • the apical foramen is the hole at the tip of the root of a tooth.
  • the foramen ovale (heart) is a hole between the venous and arterial sides of the fetal heart.

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Quadrate may refer to:
  • Quadrate bone
  • Quadrate (heraldry)

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In anatomy, the dorsum is the upper side of animals that typically run, fly or swim in a horizontal position, and the back side of animals (like humans) that walk upright. In vertebrates the dorsum contains the backbone.
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The Vertebral Column (singular: vertebra) are the individual irregular bones that make up the spinal column (aka ischis) — a flexuous and flexible column.
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Tylosaurus
Marsh, 1872

Species
  • T. proriger
  • T. nepaeolicus
  • T. haumuriensis
  • T. kansasensis
  • T.

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In sciences dealing with the anatomy of animals, precise anatomical terms of location are necessary for a variety of reasons. Non-scientists often wonder why zoological and human anatomists use complex terminology to describe locations on a body, when common terms like "up",
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A haemal arch is a bony arch on the underside of a tail vertebra of a vertebrate. It may represent the ribs of that tail vertebra.

The hole so formed is the haemal canal.

It sometimes has a haemal spine on.
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Etymology is the study of the history of words - when they entered a language, from what source, and how their form and meaning have changed over time.

In languages with a long written history, etymology makes use of philology, the study of how words change from culture to
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genus (plural: genera) is part of the Latinized name for an organism. It is a name which reflects the classification of the organism by grouping it with other closely similar organisms.
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A type species fixes the name of a genus (or of a taxon in a rank lower than genus).

Strictly speaking, a type species exists only in zoological nomenclature. As set in article 42.
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State of South Dakota

Flag of South Dakota Seal
Nickname(s): The Mount Rushmore State (official),
The Sunshine State
Motto(s): Under God the people rule

Official language(s) English

Capital
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Osteichthyes
Huxley, 1880

Classes

Actinopterygii
Sarcopterygii

Osteichthyes (IPA: /ˌɒstiːˈɪkθiːz/) are a taxonomic superclass of fish, also called
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Seabirds are birds that have adapted to life within the marine environment. While seabirds vary greatly in lifestyle, behaviour and physiology, they often exhibit striking convergent evolution, as the same environmental problems and feeding niches have resulted in similar
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