Cumnoria
Encyclopedia
Cumnoria is a genus
of herbivorous iguanodont
ian dinosaur
. It is a basal
iguanodont
ian which lived during the upper Jurassic
period (Kimmeridgian
age) in what is now Oxfordshire
, United Kingdom
.
Cumnoria is known from the holotype
OXFUM J.3303, a partial skull
and postcranium, recovered from the lower Kimmeridge Clay Formation, in the Chawley Brick Pits, Cumnor Hurst
. Workers at first discarded the remains on a dump heap, but one of them later collected the bones in a sack and showed them to Professor George Rolleston
, an anatomist at the nearby Oxford University. Rolleston in turn brought them to the attention of palaeontologist Professor Joseph Prestwich
who in 1879 reported them as a new species of Iguanodon
, though without actually coining a species name. In 1880 Prestwich published an article on the geological stratigraphy
of the find. The same year John Whitaker Hulke named the species Iguanodon prestwichii, the specific epithet honouring Prestwich.
In 1888
, Harry Govier Seeley decided the taxon represented a separate and new genus which he named Cumnoria after Cumnor. Its type species
Iguanodon prestwichii was thus recombined into Cumnoria prestwichii — though Seeley spelled the epithet as prestwichi. The genus was quickly abandoned however: already in 1889 Richard Lydekker
assigned the species to Camptosaurus
, as Camptosaurus prestwichii. This opinion was generally accepted for over a century. In 1980 Peter Galton
provided the first modern description of the species.
In 1998 David Norman
concluded that Seeley's original generic distinction was valid. In 2008 this was supported by Darren Naish
and David Martill. In 2010 and 2011 cladistic analyses by Andrew T. McDonald confirmed this by showing that Cumnoria had a separate phylogenetic position from Camptosaurus dispar.
The holotype of Cumnoria is of a rather small bipedal animal, with a gracile build, about 3.5 metres long. The specimen is probably that of a juvenile though.
Camptosaurus prestwichii was traditionally assigned to the Camptosauridae. In the new analyses of McDonald Cumnoria has instead been recovered as a basal member of the Styracosterna, more closely related to more derived
("advanced") iguanodontians than to Camptosaurus dispar. Cumnoria would then be the oldest known styracostern.
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 herbivorous iguanodont
Iguanodont
Iguanodonts were herbivorous dinosaurs that lived from the mid-Jurassic to Late Cretaceous. Some members include Camptosaurus, Callovosaurus, Iguanodon, Ouranosaurus, and the hadrosaurids or "duck-billed dinosaurs". Iguanodonts were one of the first groups of dinosaurs to be found...
ian 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...
. It is a basal
Basal (phylogenetics)
In phylogenetics, a basal clade is the earliest clade to branch in a larger clade; it appears at the base of a cladogram.A basal group forms an outgroup to the rest of the clade, such as in the following example:...
iguanodont
Iguanodont
Iguanodonts were herbivorous dinosaurs that lived from the mid-Jurassic to Late Cretaceous. Some members include Camptosaurus, Callovosaurus, Iguanodon, Ouranosaurus, and the hadrosaurids or "duck-billed dinosaurs". Iguanodonts were one of the first groups of dinosaurs to be found...
ian which lived during the upper 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...
period (Kimmeridgian
Kimmeridgian
In the geologic timescale, the Kimmeridgian is an age or stage in the Late or Upper Jurassic epoch or series. It spans the time between 155.7 ± 4 Ma and 150.8 ± 4 Ma . The Kimmeridgian follows the Oxfordian and precedes the Tithonian....
age) in what is now Oxfordshire
Oxfordshire
Oxfordshire is a county in the South East region of England, bordering on Warwickshire and Northamptonshire , Buckinghamshire , Berkshire , Wiltshire and Gloucestershire ....
, United Kingdom
United Kingdom
The United Kingdom of Great Britain and Northern IrelandIn the United Kingdom and Dependencies, other languages have been officially recognised as legitimate autochthonous languages under the European Charter for Regional or Minority Languages...
.
Cumnoria is known from 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...
OXFUM J.3303, a partial skull
Skull
The skull is a bony structure in the head of many animals that supports the structures of the face and forms a cavity for the brain.The skull is composed of two parts: the cranium and the mandible. A skull without a mandible is only a cranium. Animals that have skulls are called craniates...
and postcranium, recovered from the lower Kimmeridge Clay Formation, in the Chawley Brick Pits, Cumnor Hurst
Cumnor Hurst
Cumnor Hurst, also known as Hurst Hill, is a wooded hill in the neighbourhood of the village of Cumnor, Oxfordshire, England. It lies to the north of Boars Hill. In 1974 it was transferred from Berkshire....
. Workers at first discarded the remains on a dump heap, but one of them later collected the bones in a sack and showed them to Professor George Rolleston
George Rolleston
George Rolleston MA MD FRCP FRS was an English physician and zoologist. He was the first Linacre Professor of Anatomy and Physiology to be appointed at the University of Oxford, a post he held from 1860 until his death in 1881...
, an anatomist at the nearby Oxford University. Rolleston in turn brought them to the attention of palaeontologist Professor Joseph Prestwich
Joseph Prestwich
Sir Joseph Prestwich FRS, was a British geologist and businessman, known as an expert on the Tertiary Period and for having confirmed the findings of Boucher de Perthes of ancient flint tools in the Somme valley gravel beds....
who in 1879 reported them as a new species 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...
, though without actually coining a species name. In 1880 Prestwich published an article on the geological stratigraphy
Stratigraphy
Stratigraphy, a branch of geology, studies rock layers and layering . It is primarily used in the study of sedimentary and layered volcanic rocks....
of the find. The same year John Whitaker Hulke named the species Iguanodon prestwichii, the specific epithet honouring Prestwich.
In 1888
1888 in paleontology
-Dinosaurs:-Newly named plesiosaurs:-New taxa:-Non-mammalian:...
, Harry Govier Seeley decided the taxon represented a separate and new genus which he named Cumnoria after Cumnor. Its 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...
Iguanodon prestwichii was thus recombined into Cumnoria prestwichii — though Seeley spelled the epithet as prestwichi. The genus was quickly abandoned however: already in 1889 Richard Lydekker
Richard Lydekker
Richard Lydekker was an English naturalist, geologist and writer of numerous books on natural history.-Biography:...
assigned the species to Camptosaurus
Camptosaurus
Camptosaurus is a genus of plant-eating, beaked ornithischian dinosaurs of the Late Jurassic period of western North America. The name means 'flexible lizard', ....
, as Camptosaurus prestwichii. This opinion was generally accepted for over a century. In 1980 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...
provided the first modern description of the species.
In 1998 David Norman
David B. Norman
David Bruce Norman is a British paleontologist, currently Director of the Sedgwick Museum, Cambridge University. He is a fellow at Christ's College, Cambridge where he teaches geology in the Natural Sciences tripos. He is a member of the Palaeontological Association. He has studied Iguanodon...
concluded that Seeley's original generic distinction was valid. In 2008 this was supported by Darren Naish
Darren Naish
Darren Naish is a vertebrate palaeontologist and science writer. He obtained a geology degree at the University of Southampton and later studied vertebrate palaeontology under British palaeontologist David Martill at the University of Portsmouth, where he obtained both an M. Phil...
and David Martill. In 2010 and 2011 cladistic analyses by Andrew T. McDonald confirmed this by showing that Cumnoria had a separate phylogenetic position from Camptosaurus dispar.
The holotype of Cumnoria is of a rather small bipedal animal, with a gracile build, about 3.5 metres long. The specimen is probably that of a juvenile though.
Camptosaurus prestwichii was traditionally assigned to the Camptosauridae. In the new analyses of McDonald Cumnoria has instead been recovered as a basal member of the Styracosterna, more closely related to more derived
Derived
In phylogenetics, a derived trait is a trait that is present in an organism, but was absent in the last common ancestor of the group being considered. This may also refer to structures that are not present in an organism, but were present in its ancestors, i.e. traits that have undergone secondary...
("advanced") iguanodontians than to Camptosaurus dispar. Cumnoria would then be the oldest known styracostern.