Hypsodont is a pattern of

dentition Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiology ...

characterized by with high crowns, providing extra material for wear and tear. Some examples of animals with hypsodont dentition are

cows Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are called co ...

and horses; all animals that feed on gritty, fibrous material. The opposite condition is called

brachydont The molars or molar teeth are large, flat teeth at the back of the mouth. They are more developed in mammals. They are used primarily to grind food during chewing. The name ''molar'' derives from Latin, ''molaris dens'', meaning "millstone tooth ...

Evolution

Since the morphology of the hypsodont tooth is suited to a more abrasive diet, hypsodonty was thought to have evolved concurrently with the spread of grasslands. Grass contains phytoliths, silica-rich granules, which wear away dental tissue more quickly. Analysis has shown, however, that the development of this morphology is out of sync with the spread and flourishing of grasslands. Instead, the ingestion of grit and soil is hypothesized to be the primary driver of hypsodonty, a hypothesis termed the

grit, not grass hypothesis The grit, not grass hypothesis is an evolutionary hypothesis that explains the evolution of high-crowned teeth, particularly in New World mammals. The hypothesis is that the ingestion of gritty soil is the primary driver of hypsodont tooth developm ...

Morphology

Hypsodont dentition is characterized by: * high-crowned

teeth 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 ...

* A rough, flattish occlusal surface adapted for crushing and grinding * Cementum both above and below the

gingiva The gums or gingiva (: gingivae) consist of the mucosal tissue that lies over the mandible and maxilla inside the mouth. Gum health and disease can have an effect on general health. Structure The gums are part of the soft tissue lining of the ...

l line * Enamel which covers the entire length of the body and likewise extends past the gum line * The cementum and the enamel invaginate into the thick layer of dentin A mammal may have exclusively hypsodont molars or have a mix of dentitions.

Examples

Hypsodonty is observed both in the fossil record and the modern world. It is a characteristic of large clades (equids) as well as subspecies level specialization. For example, the

Sumatran rhinoceros The Sumatran rhinoceros (''Dicerorhinus sumatrensis''), also known as the Sumatran rhino, hairy rhinoceros or Asian two-horned rhinoceros, is a rare member of the family Rhinocerotidae and one of five extant species of rhinoceros; it is the o ...

and the

Javan rhinoceros The Javan rhinoceros (''Rhinoceros sondaicus''), Javan rhino, Sunda rhinoceros or lesser one-horned rhinoceros is a critically endangered member of the genus ''Rhinoceros'', of the rhinoceros family Rhinocerotidae, and one of the five remainin ...

both have brachydont, lophodont cheek teeth whereas the

Indian rhinoceros The Indian rhinoceros (''Rhinoceros unicornis''), also known as the greater one-horned rhinoceros, great Indian rhinoceros or Indian rhino, is a species of rhinoceros found in the Indian subcontinent. It is the second largest living rhinocer ...

has hypsodont dentition. Examples of extant animals with hypsodont dentition include: *

Cows Cattle (''Bos taurus'') are large, domesticated, bovid ungulates widely kept as livestock. They are prominent modern members of the subfamily Bovinae and the most widespread species of the genus '' Bos''. Mature female cattle are called co ...

Horses The horse (''Equus ferus caballus'') is a domesticated, one-toed, hoofed mammal. It belongs to the taxonomic family Equidae and is one of two extant subspecies of ''Equus ferus''. The horse has evolved over the past 45 to 55 milli ...

Deer A deer (: deer) or true deer is a hoofed ruminant ungulate of the family Cervidae (informally the deer family). Cervidae is divided into subfamilies Cervinae (which includes, among others, muntjac, elk (wapiti), red deer, and fallow deer) ...

At least two lineages of allotheres,

Taeniolabidoidea Taeniolabidoidea is a group of extinct mammals known whose fossils can be found in North America and Asia. They were the largest members of the extinct order Multituberculata, as well as the largest non-therian mammals. '' Lambdopsalis'' even pr ...

and

Gondwanatheria Gondwanatheria is an extinct group of mammaliaforms that lived in parts of Gondwana, including Madagascar, India, South America, Africa, and Antarctica during the Upper Cretaceous through the Miocene (and possibly much earlier, if '' Allostaffia' ...

, developed hypsodont teeth, the latter being probably among the first mammals to be able to process grass.Gondwanatheria
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External links

The Diversity of Cheek Teeth

References

{{reflist Dentition types Veterinary dentistry

Evolution

Morphology

Examples

See also

External links

References