''Cardiodon'' (meaning "

heart The heart is a muscular Organ (biology), organ found in humans and other animals. This organ pumps blood through the blood vessels. The heart and blood vessels together make the circulatory system. The pumped blood carries oxygen and nutrie ...

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, tea ...

", in reference to the shape) was a herbivorous

genus Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...

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 b ...

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

, based on a

from the late Bathonian-age

Middle Jurassic The Middle Jurassic is the second Epoch (geology), epoch of the Jurassic Period (geology), Period. It lasted from about 174.1 to 161.5 million years ago. Fossils of land-dwelling animals, such as dinosaurs, from the Middle Jurassic are relativel ...

Forest Marble Formation of

Wiltshire Wiltshire (; abbreviated to Wilts) is a ceremonial county in South West England. It borders Gloucestershire to the north, Oxfordshire to the north-east, Berkshire to the east, Hampshire to the south-east, Dorset to the south, and Somerset to ...

England England is a Countries of the United Kingdom, country that is part of the United Kingdom. It is located on the island of Great Britain, of which it covers about 62%, and List of islands of England, more than 100 smaller adjacent islands. It ...

. 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 171 to 165 million years ago ...

'', but recent analyses suggest that it is a distinct genus, and possibly related to '' Turiasaurus''. ''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 anatomy, comparative anatomist and paleontology, palaeontologist. Owen is generally considered to have been an outstanding naturalist with a remarkabl ...

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) is a town and civil parishes in England, civil parish in west Wiltshire (district), Wiltshire, England, near the border with Somerset. The town's canal, historic buildings, shops, pubs and restauran ...

, 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 languages, Italic branch of the Indo-European languages. Latin was originally spoken by the Latins (Italic tribe), Latins in Latium (now known as Lazio), the lower Tiber area aroun ...

.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 a British naturalist, geologist and writer of numerous books on natural history. He was known for his contributions to zoology, paleontology, and biogeography. He worked extensively in cata ...

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

Oxfordshire Oxfordshire ( ; abbreviated ''Oxon'') is a ceremonial county in South East England. The county is bordered by Northamptonshire and Warwickshire to the north, Buckinghamshire to the east, Berkshire to the south, and Wiltshire and Glouceste ...

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 near

Cirencester Cirencester ( , ; see #Pronunciation, below for more variations) is a market town and civil parish in the Cotswold District of Gloucestershire, England. Cirencester lies on the River Churn, a tributary of the River Thames. It is the List of ...

Gloucestershire Gloucestershire ( , ; abbreviated Glos.) is a Ceremonial counties of England, ceremonial county in South West England. It is bordered by Herefordshire to the north-west, Worcestershire to the north, Warwickshire to the north-east, Oxfordshire ...

. 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: People * Paul (given name), a given name, including a list of people * Paul (surname), a list of people * Paul the Apostle, an apostle who wrote many of the books of the New Testament * Ray Hildebrand, half of the singing duo ...

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

); 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, they are those of a eusauropod.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 '' Turiasaurus'', pointed out ''Cardiodon'' as a possible relative to their new, giant sauropod, placing it in the Turiasauria.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 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 in which animals have four legs that are used to bear weight and move around. An animal or machine that usually maintains a four-legged posture and moves using all four legs is said to be a quadruped (fr ...

herbivore A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...

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

References

External links

Darren Naish's reaction to ''Turiasaurus''
{{Taxonbar, from=Q1256846 Turiasauria Dinosaur genera Bathonian dinosaurs Fossil taxa described in 1841 Taxa named by Richard Owen Dinosaurs of the United Kingdom Taxa with lost type specimens