''Cardiodon'' (meaning "

heart The heart is a muscular organ in most animals. This organ pumps blood through the blood vessels of the circulatory system. The pumped blood carries oxygen and nutrients to the body, while carrying metabolic waste such as carbon dioxide t ...

tooth 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 ...

", in reference to the shape) was a herbivorous

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 ...

sauropod Sauropoda (), whose members are known as sauropods (; from '' sauro-'' + '' -pod'', 'lizard-footed'), is a clade of saurischian ('lizard-hipped') dinosaurs. Sauropods had very long necks, long tails, small heads (relative to the rest of their bo ...

dinosaur Dinosaurs are a diverse group of reptiles of the clade Dinosauria. They first appeared during the Triassic period, between 243 and 233.23 million years ago (mya), although the exact origin and timing of the evolution of dinosaurs is t ...

, based on a

from the late Bathonian-age

Middle Jurassic The Middle Jurassic is the second epoch of the Jurassic Period. It lasted from about 174.1 to 163.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relatively rare, but geological formations co ...

Forest Marble Formation The Forest Marble is a geological formation in England. Part of the Great Oolite Group, it dates to the late Bathonian stage of the Middle Jurassic.Weishampel, David B; et al. (2004). "Dinosaur distribution (Middle Jurassic, Europe)." In: Weisha ...

Wiltshire Wiltshire (; abbreviated Wilts) is a historic and ceremonial county in South West England with an area of . It is landlocked and borders the counties of Dorset to the southwest, Somerset to the west, Hampshire to the southeast, Gloucestershire ...

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 ...

. Historically, it is very obscure and usually referred to ''

Cetiosaurus ''Cetiosaurus'' () meaning 'whale lizard', from the Greek '/ meaning 'sea monster' (later, 'whale') and '/ meaning 'lizard', is a genus of herbivorous sauropod dinosaur from the Middle Jurassic Period, living about 168 million years ago in what ...

'', but recent analyses suggest that it is a distinct genus, and possibly related to ''

Turiasaurus ''Turiasaurus'' (meaning " Turia lizard") is a genus of sauropod dinosaurs. It is known from a single fossil specimen representing the species ''Turiasaurus riodevensis'', found in the Kimmeridgian Villar del Arzobispo Formation of Teruel, Spain ...

''. ''Cardiodon'' was the first sauropod genus named.Taylor, Michael P., 2010, "Sauropod dinosaur research: a historical review", pp. 361-386 in: Richard T. J. Moody, Eric Buffetaut, Darren Naish and David M. Martill (eds.), ''Dinosaurs and Other Extinct Saurians: a Historical Perspective''. Geological Society of London, Special Publication 343

History and taxonomy

Richard Owen Sir Richard Owen (20 July 1804 – 18 December 1892) was an English biologist, comparative anatomist and paleontologist. Owen is generally considered to have been an outstanding naturalist with a remarkable gift for interpreting fossils. Owe ...

named the genus for a now-lost tooth, part of the collection of naturalist Joseph Chaning Pearce, found near

Bradford-on-Avon Bradford-on-Avon (sometimes Bradford on Avon or Bradford upon Avon) is a town and civil parish in west Wiltshire, England, near the border with Somerset, which had a population of 9,402 at the 2011 census. The town's canal, historic buildings, s ...

, but did not assign it a specific name at the time. The generic name is derived from Greek καρδία, ''kardia'', "heart", and ὀδών, ''odon'', "tooth", in reference to its heart-shaped profile.Owen, R. (1841). Odontography, Part II. ''Hippolyte Baillière.'' 655 p. A few years later, in 1844, he added the specific name ''rugulosus'', meaning "wrinkled" in

Latin Latin (, or , ) is a classical language belonging to the Italic branch of the Indo-European languages. Latin was originally a dialect spoken in the lower Tiber area (then known as Latium) around present-day Rome, but through the power of the ...

.Owen, R. (1844). Odontography, Part III. ''Hippolyte Baillière.'' 655 p. ''Cardiodon'' was the first sauropod given a formal name to, though Owen was at the time completely unaware of the sauropod nature of the find. Within a few decades, he and others were viewing ''Cardiodon'' as a possible synonym of his most well-known sauropod genus, ''

''.Phillips, J. (1871). ''Geology of Oxford and the Valley of the Thames''. Clarendon Press:Oxford, 529 p.Owen, R. (1875). Monographs of the fossil Reptilia of the Mesozoic formations (part III) (genera ''Bothriospondylus'', ''Cetiosaurus'', ''Omosaurus''). Palaeontographical Society Monographs 29:15-93.

Richard Lydekker Richard Lydekker (; 25 July 1849 – 16 April 1915) was an English naturalist, geologist and writer of numerous books on natural history. Biography Richard Lydekker was born at Tavistock Square in London. His father was Gerard Wolfe Lydekker, ...

formalized this view in a roundabout way in 1890, by assigning ''Cetiosaurus oxoniensis'' to ''Cardiodon'' on the basis of teeth from

Oxfordshire Oxfordshire is a ceremonial and non-metropolitan county in the north west of South East England. It is a mainly rural county, with its largest settlement being the city of Oxford. The county is a centre of research and development, primarily ...

associated with a skeleton of ''C. oxoniensis''.Lydekker, R. (1890). Suborder Sauropoda. In: Lydekker, R. (ed.). ''Catalogue of the Fossil Reptile and Amphibia of the British Museum (Natural History).'' Part 1. Taylor and Francis:London, p. 131-152. He also added a second tooth (BMNH R1527) from the

Great Oolite The Great Oolite Group is a Middle Jurassic stratigraphic unit that outcrops in southern England. It consists of a complex set of marine deposits primarily mudstone and bioclastic ooidal and fine grained limestone, deposited in nearshore to she ...

near

Cirencester Cirencester (, ; see below for more variations) is a market town in Gloucestershire, England, west of London. Cirencester lies on the River Churn, a tributary of the River Thames, and is the largest town in the Cotswolds. It is the home of ...

Gloucestershire Gloucestershire ( abbreviated Glos) is a county in South West England. The county comprises part of the Cotswold Hills, part of the flat fertile valley of the River Severn and the entire Forest of Dean. The county town is the city of Gl ...

. More typically, ''Cardiodon'' has been assigned to ''Cetiosaurus'', sometimes as a separate species ''Cetiosaurus rugulosus'',Steel, R. (1970). Part 14. Saurischia. ''Handbuch der Paläoherpetologie/Encyclopedia of Paleoherpetology''. Part 14. Gustav Fischer Verlag:Stuttgart, p. 1-87. in spite of its priority. In 2003,

Paul Upchurch Paul may refer to: *Paul (given name), a given name (includes a list of people with that name) *Paul (surname), a list of people People Christianity * Paul the Apostle (AD c.5–c.64/65), also known as Saul of Tarsus or Saint Paul, early Chri ...

and John Martin, reviewing ''Cetiosaurus'', found that there is little evidence to assign the ''C. oxoniensis'' teeth to the skeleton, and the "''C. oxoniensis''" teeth differ from the ''Cardiodon'' teeth (''Cardiodon'' teeth are convex facing the

tongue The tongue is a muscular organ (anatomy), organ in the mouth of a typical tetrapod. It manipulates food for mastication and swallowing as part of the digestive system, digestive process, and is the primary organ of taste. The tongue's upper surfa ...

); therefore, they supported ''Cardiodon'' being retained as its own genus.Upchurch, P.M., and Martin, J. (2003). The anatomy and taxonomy of ''Cetiosaurus'' (Saurischia, Sauropoda) from the Middle Jurassic of England. ''Journal of Vertebrate Paleontology'' 23(1):208-231. Upchurch ''et al.'' (2004) repeated this assessment, and found that though the teeth have no known

autapomorphies In phylogenetics, an autapomorphy is a distinctive feature, known as a derived trait, that is unique to a given taxon. That is, it is found only in one taxon, but not found in any others or outgroup taxa, not even those most closely related to t ...

, they are those of a

eusauropod Eusauropoda (meaning "true sauropods") is a derived clade of sauropod dinosaurs. Eusauropods represent the node-based group that includes all descendant sauropods starting with the basal eusauropods of ''Shunosaurus'', and possibly ''Barapasaurus ...

.Upchurch, P.M., Barrett, P.M., and Dodson, P. (2004). Sauropoda. In: Weishampel, D.B., Dodson, P., and Osmólska, H. (eds.). ''The Dinosauria'' (2nd edition). University of California Press:Berkeley, p. 259-322. More recently, Royo-Torres ''et al.'' (2006), in their description of ''

'', pointed out ''Cardiodon'' as a possible relative to their new, giant sauropod, placing it in the

Turiasauria Turiasauria is an unranked clade of basal sauropod dinosaurs known from Middle Jurassic to Early Cretaceous deposits in Europe, North America, and Africa. Description Turiasauria was originally erected by Royo-Torres et al. (2006) to include '' ...

.Royo-Torres, R., Cobos, A., and Alcalá, L. (2006). A giant European dinosaur and a new sauropod clade. ''Science'' 314:1925-1927. Earlier, ''Cardiodon'' had been usually assigned to the

Cetiosauridae Cetiosauridae is a family of sauropod dinosaurs which was first proposed by Richard Lydekker in 1888. While traditionally a wastebasket taxon containing various unrelated species, some recent studies have found that it may represent a natural c ...

or a Cardiodontidae of its own.

Description

The original tooth shows, as far as can be deduced from the surviving illustrations, the rare combination of being spatulate and having a convex inner side, though the convexity is slight. Its crown is short and wide, slightly curving to the inside. The outer side is strongly convexly curved from the front to the rear. On this side a shallow groove is present, running parallel to the rear edge. The crown tapers towards its tip. The edges have no denticles. The enamel shows the little wrinkles to which the specific name refers.

Paleobiology

As a sauropod, ''Cardiodon'' would have been a large,

quadruped Quadrupedalism is a form of locomotion where four limbs are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four limbs is said to be a quadruped (from Latin ''quattuor' ...

herbivore A herbivore is an animal anatomically and physiologically adapted to eating plant material, for example foliage or marine algae, for the main component of its diet. As a result of their plant diet, herbivorous animals typically have mouthpart ...

, but because of the scanty remains, much more cannot be said.

References

External links

Darren Naish's reaction to ''Turiasaurus''
{{Taxonbar, from=Q1256846 Turiasauria Bathonian life Middle Jurassic dinosaurs of Europe Jurassic England Fossils of England Fossil taxa described in 1841 Taxa named by Richard Owen