Cetiosaurus
Encyclopedia
Cetiosaurus meaning 'whale lizard', from the Greek
cetus/κητος meaning 'sea monster' (later, 'whale') and saurus/σαυρος meaning 'lizard', was a sauropod dinosaur
from the Mid to Late Jurassic
Period (181-169 million years ago) in what are now Europe
and Africa
. It is estimated to have been about 53 feet (16.2 m) long and to have weighed roughly 24.8 tonnes (27.3 ST). It was so named because its discoverer, Sir Richard Owen
supposed it was a marine
creature, initially an extremely large crocodile
.
It was a primitive, quadruped
al, long-necked, small-headed herbivore
, with a shorter tail than most sauropods.
Cetiosaurus was a long-necked quadruped
al animal approximately 18 meters (59 ft) long. Its neck was as long as its body, and the tail was considerably longer, consisting of at least 40 caudal vertebrae. Its dorsal vertebrae, the bones along the back, were heavy and primitive, unlike the hollowed-out bones of advanced sauropods like Brachiosaurus
. Its forearm
, too, was as long as the upper arm
, unlike most other sauropods. Its thigh bone
was approximately six feet in length.
and Morocco
. Remains consisting of a vertebra, rib and arm bone had been discovered on the Isle of Wight
and named by English
biologist
, comparative anatomist
and palaeontologist
Sir Richard Owen
, in 1841, the year before he coined the term Dinosaur
ia. More limb bones were found in the late 1840s and a fairly complete skeleton in 1868. Owen thought it had crocodilia
n features. Ironically, Cetiosaurus's true nature was not realized until Thomas Huxley
named it as a dinosaur in 1869.
Cetiosaurus Species
Numerous species have been assigned to Cetiosaurus over the years and belong to several different groups of dinosaurs. The best known of these is C. oxoniensis, from the Middle Jurassic
(Bajocian
) of Oxfordshire
and Rutland
, However, the type species
is C. medius, known from undiagnostic material (note that Upchurch and Martin [2003] reported C. brevis as the type species, but no longer hold this view; the problem stems from the fact that Richard Owen described four species in the same paper and did not designate one as the type). To improve this situation, Upchurch and colleagues have proposed making C. oxoniensis the type species of Cetiosaurus, which will retain the name Cetiosaurus for the animal with which it has been traditionally associated.
and the South American Patagosaurus
. Together they comprise the Cetiosauridae, which was previously a large ill-defined family of primitive sauropods. It must also be noted that Chebsaurus
is often referred to the Cetiosauridae, and that Barapasaurus has been assigned to the Vulcanodontidae
, due to its having cervical vertebrae
that resemble other cetiosaurids, but a narrow sacrum
that is a defining factor for vulcanodontids.
and Eustreptospondylus
. The environment in which Cetiosaurus lived was floodplain
and open woodland.
Ancient Greek
Ancient Greek is the stage of the Greek language in the periods spanning the times c. 9th–6th centuries BC, , c. 5th–4th centuries BC , and the c. 3rd century BC – 6th century AD of ancient Greece and the ancient world; being predated in the 2nd millennium BC by Mycenaean Greek...
cetus/κητος meaning 'sea monster' (later, 'whale') and saurus/σαυρος meaning 'lizard', was a sauropod 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...
from the Mid to 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...
Period (181-169 million years ago) in what are now Europe
Europe
Europe is, by convention, one of the world's seven continents. Comprising the westernmost peninsula of Eurasia, Europe is generally 'divided' from Asia to its east by the watershed divides of the Ural and Caucasus Mountains, the Ural River, the Caspian and Black Seas, and the waterways connecting...
and Africa
Africa
Africa is the world's second largest and second most populous continent, after Asia. At about 30.2 million km² including adjacent islands, it covers 6% of the Earth's total surface area and 20.4% of the total land area...
. It is estimated to have been about 53 feet (16.2 m) long and to have weighed roughly 24.8 tonnes (27.3 ST). It was so named because its discoverer, Sir Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
supposed it was a marine
Marine (ocean)
Marine is an umbrella term. As an adjective it is usually applicable to things relating to the sea or ocean, such as marine biology, marine ecology and marine geology...
creature, initially an extremely large crocodile
Crocodile
A crocodile is any species belonging to the family Crocodylidae . The term can also be used more loosely to include all extant members of the order Crocodilia: i.e...
.
It was a primitive, quadruped
Quadruped
Quadrupedalism is a form of land animal locomotion using four limbs or legs. An animal or machine that usually moves in a quadrupedal manner is known as a quadruped, meaning "four feet"...
al, long-necked, small-headed herbivore
Herbivore
Herbivores are organisms that are anatomically and physiologically adapted to eat plant-based foods. Herbivory is a form of consumption in which an organism principally eats autotrophs such as plants, algae and photosynthesizing bacteria. More generally, organisms that feed on autotrophs in...
, with a shorter tail than most sauropods.
Description
Quadruped
Quadrupedalism is a form of land animal locomotion using four limbs or legs. An animal or machine that usually moves in a quadrupedal manner is known as a quadruped, meaning "four feet"...
al animal approximately 18 meters (59 ft) long. Its neck was as long as its body, and the tail was considerably longer, consisting of at least 40 caudal vertebrae. Its dorsal vertebrae, the bones along the back, were heavy and primitive, unlike the hollowed-out bones of advanced sauropods like Brachiosaurus
Brachiosaurus
Brachiosaurus is a genus of sauropod dinosaur from the Jurassic Morrison Formation of North America. It was first described by Elmer S. Riggs in 1903 from fossils found in the Grand River Canyon of western Colorado, in the United States. Riggs named the dinosaur Brachiosaurus altithorax,...
. Its forearm
Radius
In classical geometry, a radius of a circle or sphere is any line segment from its center to its perimeter. By extension, the radius of a circle or sphere is the length of any such segment, which is half the diameter. If the object does not have an obvious center, the term may refer to its...
, too, was as long as the upper arm
Humerus
The humerus is a long bone in the arm or forelimb that runs from the shoulder to the elbow....
, unlike most other sauropods. Its thigh bone
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...
was approximately six feet in length.
Discovery and species
Cetiosaurus was the first sauropod to be discovered and named as well as being the best known sauropod from England. Fossilized remains have been found in EnglandEngland
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...
and Morocco
Morocco
Morocco , officially the Kingdom of Morocco , is a country located in North Africa. It has a population of more than 32 million and an area of 710,850 km², and also primarily administers the disputed region of the Western Sahara...
. Remains consisting of a vertebra, rib and arm bone had been discovered on the Isle of Wight
Isle of Wight
The Isle of Wight is a county and the largest island of England, located in the English Channel, on average about 2–4 miles off the south coast of the county of Hampshire, separated from the mainland by a strait called the Solent...
and named by English
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...
biologist
Biologist
A biologist is a scientist devoted to and producing results in biology through the study of life. Typically biologists study organisms and their relationship to their environment. Biologists involved in basic research attempt to discover underlying mechanisms that govern how organisms work...
, comparative anatomist
Comparative anatomy
Comparative anatomy is the study of similarities and differences in the anatomy of organisms. It is closely related to evolutionary biology and phylogeny .-Description:...
and palaeontologist
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...
Sir Richard Owen
Richard Owen
Sir Richard Owen, FRS KCB was an English biologist, comparative anatomist and palaeontologist.Owen is probably best remembered today for coining the word Dinosauria and for his outspoken opposition to Charles Darwin's theory of evolution by natural selection...
, in 1841, the year before he coined the term 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...
ia. More limb bones were found in the late 1840s and a fairly complete skeleton in 1868. Owen thought it had crocodilia
Crocodilia
Crocodilia is an order of large reptiles that appeared about 84 million years ago in the late Cretaceous Period . They are the closest living relatives of birds, as the two groups are the only known survivors of the Archosauria...
n features. Ironically, Cetiosaurus's true nature was not realized until Thomas Huxley
Thomas Huxley
Thomas Henry Huxley PC FRS was an English biologist, known as "Darwin's Bulldog" for his advocacy of Charles Darwin's theory of evolution....
named it as a dinosaur in 1869.
Cetiosaurus Species
- C. medius(typeType speciesIn 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...
) - C. brevis
- C. mogrebiensis Lapparent, 1955
- C. oxoniensis Phillips, 1871
Numerous species have been assigned to Cetiosaurus over the years and belong to several different groups of dinosaurs. The best known of these is C. oxoniensis, from the Middle Jurassic
Middle Jurassic
The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from 176-161 million years ago. In European lithostratigraphy, rocks of this Middle Jurassic age are called the Dogger....
(Bajocian
Bajocian
In the geologic timescale, the Bajocian is an age or stage in the Middle Jurassic. It lasted from approximately 171.6 Ma to around 167.7 Ma . The Bajocian age succeeds the Aalenian age and precedes the Bathonian age....
) of Oxfordshire
Oxfordshire
Oxfordshire is a county in the South East region of England, bordering on Warwickshire and Northamptonshire , Buckinghamshire , Berkshire , Wiltshire and Gloucestershire ....
and Rutland
Rutland
Rutland is a landlocked county in central England, bounded on the west and north by Leicestershire, northeast by Lincolnshire and southeast by Peterborough and Northamptonshire....
, However, 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 C. medius, known from undiagnostic material (note that Upchurch and Martin [2003] reported C. brevis as the type species, but no longer hold this view; the problem stems from the fact that Richard Owen described four species in the same paper and did not designate one as the type). To improve this situation, Upchurch and colleagues have proposed making C. oxoniensis the type species of Cetiosaurus, which will retain the name Cetiosaurus for the animal with which it has been traditionally associated.
Classification
The closest relatives of Cetiosaurus appear to be BarapasaurusBarapasaurus
Barapasaurus is a genus of sauropod dinosaur from Early Jurassic rocks of India. The specific name for its only species, B. tagorei, means 'Tagore's', which honors Bengali poet, writer, painter, and musician Rabindranath Tagore.-Description:...
and the South American Patagosaurus
Patagosaurus
Patagosaurus was a large herbivorous dinosaur from the long-necked group Sauropoda. It reached a length of 18 meters. Similar to other primitive eusauropods, it was rather heavily built and similar to Cetiosaurus in general appearance. It is known from a dozen individuals, though some referred...
. Together they comprise the Cetiosauridae, which was previously a large ill-defined family of primitive sauropods. It must also be noted that Chebsaurus
Chebsaurus
Chebsaurus is a genus of quadrupedal, herbivorous, cetiosaurid sauropod dinosaur, specifically a eusauropod. It lived in present day Algeria, in the Middle Jurassic Period. The type species, C. algeriensis, was named in 2005 by Farida Mahammed and is the most complete Algerian sauropod known...
is often referred to the Cetiosauridae, and that Barapasaurus has been assigned to the Vulcanodontidae
Vulcanodontidae
The Early Jurassic sauropod dinosaurs Zizhongosaurus, Barapasaurus, Tazoudasaurus, and Vulcanodon may form a natural group of basal sauropods called the Vulcanodontidae. Basal vulcanodonts include some of the earliest known examples of sauropods. The family-level name Vulcanodontidae was erected by...
, due to its having cervical vertebrae
Cervical vertebrae
In vertebrates, cervical vertebrae are those vertebrae immediately inferior to the skull.Thoracic vertebrae in all mammalian species are defined as those vertebrae that also carry a pair of ribs, and lie caudal to the cervical vertebrae. Further caudally follow the lumbar vertebrae, which also...
that resemble other cetiosaurids, but a narrow sacrum
Sacrum
In vertebrate anatomy the sacrum is a large, triangular bone at the base of the spine and at the upper and back part of the pelvic cavity, where it is inserted like a wedge between the two hip bones. Its upper part connects with the last lumbar vertebra, and bottom part with the coccyx...
that is a defining factor for vulcanodontids.
Paleobiology
It shared its time period with, and was possibly prey to, MegalosaurusMegalosaurus
Megalosaurus is a genus of large meat-eating theropod dinosaurs of the Middle Jurassic period of Europe...
and Eustreptospondylus
Eustreptospondylus
Eustreptospondylus is a genus of megalosaurid dinosaur, from the Callovian stage of the Middle Jurassic period in southern England, at a time when Europe was a series of scattered islands Eustreptospondylus ("well-curved vertebra", in reference to the arrangement of the spine in the original...
. The environment in which Cetiosaurus lived was floodplain
Floodplain
A floodplain, or flood plain, is a flat or nearly flat land adjacent a stream or river that stretches from the banks of its channel to the base of the enclosing valley walls and experiences flooding during periods of high discharge...
and open woodland.