''Kimmerosaurus'' ("lizard from

Kimmeridge Kimmeridge () is a small village and civil parish on the Isle of Purbeck, a peninsula on the English Channel coast in Dorset, England. It is situated about south of Wareham and west of Swanage. In 2013 the estimated population of the civil p ...

") is an

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In the hierarchy of biological classification, genus com ...

plesiosaur The Plesiosauria (; Greek: πλησίος, ''plesios'', meaning "near to" and ''sauros'', meaning "lizard") or plesiosaurs are an order or clade of extinct Mesozoic marine reptiles, belonging to the Sauropterygia. Plesiosaurs first appeared ...

from the

family Family (from la, familia) is a Social group, group of people related either by consanguinity (by recognized birth) or Affinity (law), affinity (by marriage or other relationship). The purpose of the family is to maintain the well-being of its ...

Cryptoclididae Cryptoclididae is a family (biology), family of medium-sized plesiosaurs that existed from the Middle Jurassic to the Early Cretaceous. They had long necks, broad and short skulls and densely packed teeth. They fed on small soft-bodied preys such ...

. ''Kimmerosaurus'' is most closely related to ''

Tatenectes ''Tatenectes'' is a genus of cryptoclidid plesiosaur known from the Upper Jurassic of Wyoming. Its remains were recovered from the Redwater Shale Member of the Sundance Formation, and initially described as a new species of '' Cimoliosaurus ...

''.

Discovery

There are very few fossil remains of ''Kimmerosaurus'' known. In fact, nothing has been found to show what ''Kimmerosaurus'' may have looked like below the

neck The neck is the part of the body on many vertebrates that connects the head with the torso. The neck supports the weight of the head and protects the nerves that carry sensory and motor information from the brain down to the rest of the body. In ...

, although the

atlas An atlas is a collection of maps; it is typically a bundle of maps of Earth or of a region of Earth. Atlases have traditionally been bound into book form, but today many atlases are in multimedia formats. In addition to presenting geographic ...

and the

axis An axis (plural ''axes'') is an imaginary line around which an object rotates or is symmetrical. Axis may also refer to: Mathematics * Axis of rotation: see rotation around a fixed axis *Axis (mathematics), a designator for a Cartesian-coordinate ...

are similar to those of the plesiosaur ''

Colymbosaurus ''Colymbosaurus'' is a genus of cryptoclidid plesiosaur from the Late Jurassic (Callovian-Tithonian) of the UK and Svalbard, Norway. There are two currently recognized species, ''C. megadeirus'' and ''C. svalbardensis''. Both species are relati ...

''. It is this lack of any post-

cranial Standard anatomical terms of location are used to unambiguously describe the anatomy of animals, including humans. The terms, typically derived from Latin or Greek roots, describe something in its standard anatomical position. This position pro ...

fossils, and the bone similarities that has led to the belief that ''Kimmerosaurus'' fossils could be the missing head of ''Colymbosaurus'', a similar plesiosaur with no known skull fossils. The first part of the genus name of ''Kimmerosaurus'' comes from the location of the first ''Kimmerosaurus''

fossil A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved ...

Kimmeridge Clay The Kimmeridge Clay is a sedimentary deposit of fossiliferous marine clay which is of Late Jurassic to lowermost Cretaceous age and occurs in southern and eastern England and in the North Sea. This rock formation is the major source rock for North ...

deposits of

Dorset Dorset ( ; archaically: Dorsetshire , ) is a county in South West England on the English Channel coast. The ceremonial county comprises the unitary authority areas of Bournemouth, Christchurch and Poole and Dorset (unitary authority), Dors ...

England England is a country that is part of the United Kingdom. It shares land borders with Wales to its west and Scotland to its north. The Irish Sea lies northwest and the Celtic Sea to the southwest. It is separated from continental Europe b ...

(these deposits are also the root word for the

Kimmeridgian stage In the geologic timescale, the Kimmeridgian is an age in the Late Jurassic Epoch and a stage in the Upper Jurassic Series. It spans the time between 157.3 ± 1.0 Ma and 152.1 ± 0.9 Ma (million years ago). The Kimmeridgian follows the Oxfordian ...

of the Jurassic period). The second part comes from the

Greek Greek may refer to: Greece Anything of, from, or related to Greece, a country in Southern Europe: *Greeks, an ethnic group. *Greek language, a branch of the Indo-European language family. **Proto-Greek language, the assumed last common ancestor ...

word ('), "

lizard Lizards are a widespread group of squamate reptiles, with over 7,000 species, ranging across all continents except Antarctica, as well as most oceanic island chains. The group is paraphyletic since it excludes the snakes and Amphisbaenia alt ...

Description

As ''Kimmerosaurus'' is known from only a

skull The skull is a bone protective cavity for the brain. The skull is composed of four types of bone i.e., cranial bones, facial bones, ear ossicles and hyoid bone. However two parts are more prominent: the cranium and the mandible. In humans, the ...

(and a few cervical

vertebra The spinal column, a defining synapomorphy shared by nearly all vertebrates,Hagfish are believed to have secondarily lost their spinal column is a moderately flexible series of vertebrae (singular vertebra), each constituting a characteristic ...

e), much of the plesiosaur's description comes from its

teeth A tooth ( : teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

, which are recurved and buccolingually compressed (compressed cheek-side to tongue-side). The

premaxilla The premaxilla (or praemaxilla) is one of a pair of small cranial bones at the very tip of the upper jaw of many animals, usually, but not always, bearing teeth. In humans, they are fused with the maxilla. The "premaxilla" of therian mammal has b ...

has only eight teeth, while there are thirty-six teeth on each

ramus Ramus can refer to: * A branch (botany) * A portion of a bone (from Latin ''ramus'', "branch"), as in the Ramus of the mandible or Superior pubic ramus * A nerve ramus such as the Dorsal ramus of spinal nerve * A taxonomic rank ("branch" in English ...

.Brown, David S.; 1981b; The English Upper Jurassic Plesiosauroidea (Reptilia) and a review of the phylogeny and classification of the Plesiosauria; Bulletin of the British Museum (Natural History), Geology; 35(4) pp.253-347 The parietals of ''Kimmerosaurus'' do not form a

sagittal crest A sagittal crest is a ridge of bone running lengthwise along the midline of the top of the skull (at the sagittal suture) of many mammalian and reptilian skulls, among others. The presence of this ridge of bone indicates that there are exceptiona ...

. The overall skull of ''Kimmerosaurus'' is similar to ''

Cryptoclidus ''Cryptoclidus'' ( ) is a genus of plesiosaur reptile from the Middle Jurassic Period (geology), period of England, France, and Cuba. Discovery ''Cryptoclidus'' was a plesiosaur whose specimens include adult and juvenile skeletons, and remai ...

'' but much more broad.

Palaeoecology

''Kimmerosaurus'' fossils are found in the

Formation near the town of

, in

. This animal may have ranged through much of what is now the

Jurassic Coast The Jurassic Coast is a World Heritage Site on the English Channel coast of southern England. It stretches from Exmouth in East Devon to Studland Bay in Dorset, a distance of about , and was inscribed on the World Heritage List in mid-December ...

, a

World Heritage Site A World Heritage Site is a landmark or area with legal protection by an international convention administered by the United Nations Educational, Scientific and Cultural Organization (UNESCO). World Heritage Sites are designated by UNESCO for h ...

in the southern

United Kingdom The United Kingdom of Great Britain and Northern Ireland, commonly known as the United Kingdom (UK) or Britain, is a country in Europe, off the north-western coast of the continental mainland. It comprises England, Scotland, Wales and North ...

References

External links

Entry on ''Kimmerosaurus''
at The Plesiosaur Site

{{Taxonbar, from=Q619384 Late Jurassic plesiosaurs of Europe Cryptoclidids Fossil taxa described in 1981 Sauropterygian genera

Discovery

Description

Palaeoecology

See also

References

External links