Cryptosaurus
Encyclopedia
Cryptosaurus is a dubious genus
of dinosaur
known from a partial femur
from the Late Jurassic
of England
.
The femur was found by the geologist
Lucas Ewbank and donated by him to the Woodwardian Museum at Cambridge
in 1869. Cryptosaurus was the same year named by British paleontologist
Harry Seeley
; the type species
is Cryptosaurus eumerus. The genus name is derived from Greek kryptos, "hidden", a reference to he rarity of the find. The specific name name means "well-formed thigh" in Greek, a reference to the stout build of the bone. The description of 1869, part of a catalogue of the Cambridge University collection, was rather minimal, consisting of the single sentence "On Shelf g is temporarily placed the femur of a Dinosaur from the Oxford Clay, Cryptosaurus eumerus". From this it is sometimes concluded that the name remained a nomen nudum
until a full description by Seeley in 1875.
The holotype
, OUM J.46882, was discovered in the Great Gransden brick pit, in strata of the Ampthill Clay Formation (Oxford Clay
), dating from the upper Oxfordian. The right femur is about 33 centimetres long and has a thick shaft. It belonged to an adult or at least subadult individual, meaning that the species was rather small.
Seeley thought that Cryptosaurus was a relative of Iguanodon
, the first such discovered from the Oxford Clay — hence the generic name. Friedrich von Huene
classified it in the Camptosauridae in 1909. The work of Peter Galton
however, showed that Cryptosaurus is an ankylosauria
n of unknown affinities. Today it is commonly considered to be a nomen dubium
because of the limited remains.
Cryptosaurus was for a long time known as Cryptodraco, which is an unnecessary replacement name. In 1889, Richard Lydekker
renamed Cryptosaurus as he believed the name Cryptosaurus was already previously in use for another animal (Cystosaurus Geoffroy, described in 1832). This was in error, a mistake originally caused by a wrong spelling of Cystosaurus in the French Bibliothèque universelle des sciences, belles-lettres, et arts, and the name Cryptosaurus has precedence.
Genus
In biology, a genus is a low-level taxonomic rank used in the biological classification of living and fossil organisms, which is an example of definition by genus and differentia...
of dinosaur
Dinosaur
Dinosaurs are a diverse group of animals of the clade and superorder Dinosauria. They were the dominant terrestrial vertebrates for over 160 million years, from the late Triassic period until the end of the Cretaceous , when the Cretaceous–Paleogene extinction event led to the extinction of...
known from a partial femur
Femur
The femur , or thigh bone, is the most proximal bone of the leg in tetrapod vertebrates capable of walking or jumping, such as most land mammals, birds, many reptiles such as lizards, and amphibians such as frogs. In vertebrates with four legs such as dogs and horses, the femur is found only in...
from the Late Jurassic
Jurassic
The Jurassic is a geologic period and system that extends from about Mya to Mya, that is, from the end of the Triassic to the beginning of the Cretaceous. The Jurassic constitutes the middle period of the Mesozoic era, also known as the age of reptiles. The start of the period is marked by...
of England
England
England is a country that is part of the United Kingdom. It shares land borders with Scotland to the north and Wales to the west; the Irish Sea is to the north west, the Celtic Sea to the south west, with the North Sea to the east and the English Channel to the south separating it from continental...
.
The femur was found by the geologist
Geologist
A geologist is a scientist who studies the solid and liquid matter that constitutes the Earth as well as the processes and history that has shaped it. Geologists usually engage in studying geology. Geologists, studying more of an applied science than a theoretical one, must approach Geology using...
Lucas Ewbank and donated by him to the Woodwardian Museum at Cambridge
Cambridge
The city of Cambridge is a university town and the administrative centre of the county of Cambridgeshire, England. It lies in East Anglia about north of London. Cambridge is at the heart of the high-technology centre known as Silicon Fen – a play on Silicon Valley and the fens surrounding the...
in 1869. Cryptosaurus was the same year named by British paleontologist
Paleontology
Paleontology "old, ancient", ὄν, ὀντ- "being, creature", and λόγος "speech, thought") is the study of prehistoric life. It includes the study of fossils to determine organisms' evolution and interactions with each other and their environments...
Harry Seeley
Harry Seeley
Harry Govier Seeley was a British paleontologist.-Career:Seeley was born in London, the son of Richard Hovill Seeley, goldsmith, and his second wife Mary Govier. He attended classes at the Royal School of Mines, Kensington before becoming an assistant to Adam Sedgwick at the Woodwardian Museum,...
; the type species
Type species
In biological nomenclature, a type species is both a concept and a practical system which is used in the classification and nomenclature of animals and plants. The value of a "type species" lies in the fact that it makes clear what is meant by a particular genus name. A type species is the species...
is Cryptosaurus eumerus. The genus name is derived from Greek kryptos, "hidden", a reference to he rarity of the find. The specific name name means "well-formed thigh" in Greek, a reference to the stout build of the bone. The description of 1869, part of a catalogue of the Cambridge University collection, was rather minimal, consisting of the single sentence "On Shelf g is temporarily placed the femur of a Dinosaur from the Oxford Clay, Cryptosaurus eumerus". From this it is sometimes concluded that the name remained a nomen nudum
Nomen nudum
The phrase nomen nudum is a Latin term, meaning "naked name", used in taxonomy...
until a full description by Seeley in 1875.
The holotype
Holotype
A holotype is a single physical example of an organism, known to have been used when the species was formally described. It is either the single such physical example or one of several such, but explicitly designated as the holotype...
, OUM J.46882, was discovered in the Great Gransden brick pit, in strata of the Ampthill Clay Formation (Oxford Clay
Oxford Clay
The Oxford Clay Formation is a Jurassic marine sedimentary rock formation underlying much of southeast England, from as far west as Dorset and as far north as Yorkshire. The Oxford Clay is of middle Callovian to lower Oxfordian age and comprises 2 main facies. The lower facies comprises the...
), dating from the upper Oxfordian. The right femur is about 33 centimetres long and has a thick shaft. It belonged to an adult or at least subadult individual, meaning that the species was rather small.
Seeley thought that Cryptosaurus was a relative of Iguanodon
Iguanodon
Iguanodon is a genus of ornithopod dinosaur that lived roughly halfway between the first of the swift bipedal hypsilophodontids and the ornithopods' culmination in the duck-billed dinosaurs...
, the first such discovered from the Oxford Clay — hence the generic name. Friedrich von Huene
Friedrich von Huene
Friedrich von Huene was a German paleontologist who named more dinosaurs in the early 20th century than anyone else in Europe.-Biography:...
classified it in the Camptosauridae in 1909. The work of Peter Galton
Peter Galton
Peter M. Galton is a British vertebrate paleontologist working in America, who has to date written or co-written about a hundred papers in scientific journals or chapters in paleontology textbooks, especially on ornithischian and prosauropod dinosaurs.With Robert Bakker in a joint article...
however, showed that Cryptosaurus is an ankylosauria
Ankylosauria
Ankylosauria is a group of herbivorous dinosaurs of the order Ornithischia. It includes the great majority of dinosaurs with armor in the form of bony osteoderms. Ankylosaurs were bulky quadrupeds, with short, powerful limbs. They are first known to have appeared in the early Jurassic Period of...
n of unknown affinities. Today it is commonly considered to be a nomen dubium
Nomen dubium
In zoological nomenclature, a nomen dubium is a scientific name that is of unknown or doubtful application...
because of the limited remains.
Cryptosaurus was for a long time known as Cryptodraco, which is an unnecessary replacement name. In 1889, Richard Lydekker
Richard Lydekker
Richard Lydekker was an English naturalist, geologist and writer of numerous books on natural history.-Biography:...
renamed Cryptosaurus as he believed the name Cryptosaurus was already previously in use for another animal (Cystosaurus Geoffroy, described in 1832). This was in error, a mistake originally caused by a wrong spelling of Cystosaurus in the French Bibliothèque universelle des sciences, belles-lettres, et arts, and the name Cryptosaurus has precedence.