Dromatheriidae Temporal range:
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Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Synapsida |
Clade: | Therapsida |
Clade: | Cynodontia |
Clade: | Prozostrodontia |
Family: | †
Dromatheriidae Gill, 1872 |
Genera | |
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Dromatheriidae is an extinct family of prozostrodontian cynodonts, closely related to mammals. Members of the family are known from the Late Triassic ( Carnian to Rhaetian) of India, [1] Europe and North America. Apart from a few jaw fragments, dromatheriids are mainly known from their sectorial (flesh-slicing) postcanine teeth. The teeth were fairly typical among early prozostrodontians, as they were labiolingually compressed (flattened sideways), with a single root and crown hosting a longitudinal row of sharp cusps. Dromatheriids in particular have a very narrow and symmetrical crown (when seen from above) without a prominent cingulum (a ridge or array of cuspules adjacent to the main cusps). [1] [2] [3]
Dromatheriid teeth on average have four main cusps, though some have as few as two ( Dromatherium) or three ( Tricuspes), or as many as six ( Inditherium, Pseudotriconodon). Although the teeth have a single root, a vertical furrow on each side of the root appears to be a trait incipient towards the two fully divided roots of mammaliaforms. [1] [3] Making note of this condition, some authors have suggested that dromatheriids are a paraphyletic group ancestral to mammaliaforms. [2] Other studies instead consider the closest relatives of dromatheriids to be the " therioherpetids" Therioherpeton and Meurthodon, which may even be placed within the family. [3] However, the broader cusps of Therioherpeton and the divided root of Meurthodon dissuade their position within Dromatheriidae. [4]
Dromatheriidae Temporal range:
| |
---|---|
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Clade: | Synapsida |
Clade: | Therapsida |
Clade: | Cynodontia |
Clade: | Prozostrodontia |
Family: | †
Dromatheriidae Gill, 1872 |
Genera | |
|
Dromatheriidae is an extinct family of prozostrodontian cynodonts, closely related to mammals. Members of the family are known from the Late Triassic ( Carnian to Rhaetian) of India, [1] Europe and North America. Apart from a few jaw fragments, dromatheriids are mainly known from their sectorial (flesh-slicing) postcanine teeth. The teeth were fairly typical among early prozostrodontians, as they were labiolingually compressed (flattened sideways), with a single root and crown hosting a longitudinal row of sharp cusps. Dromatheriids in particular have a very narrow and symmetrical crown (when seen from above) without a prominent cingulum (a ridge or array of cuspules adjacent to the main cusps). [1] [2] [3]
Dromatheriid teeth on average have four main cusps, though some have as few as two ( Dromatherium) or three ( Tricuspes), or as many as six ( Inditherium, Pseudotriconodon). Although the teeth have a single root, a vertical furrow on each side of the root appears to be a trait incipient towards the two fully divided roots of mammaliaforms. [1] [3] Making note of this condition, some authors have suggested that dromatheriids are a paraphyletic group ancestral to mammaliaforms. [2] Other studies instead consider the closest relatives of dromatheriids to be the " therioherpetids" Therioherpeton and Meurthodon, which may even be placed within the family. [3] However, the broader cusps of Therioherpeton and the divided root of Meurthodon dissuade their position within Dromatheriidae. [4]