Basic info Taxonomic history Classification Included Taxa
Morphology Ecology and taphonomy External Literature Search Age range and collections

Helaletidae

Mammalia - Perissodactyla - Helaletidae

Taxonomy
Helaletidae was named by Osborn (1892).

It was synonymized subjectively with Lophiodontidae by Hay (1902); it was reranked as the subfamily Helaletinae by Osborn (1923).

It was assigned to Lophiodontidae by Osborn (1923); to Perissodactyla by Hough (1955) and Dehm and Oettingen-Spielberg (1958); to Rhinocerotoidea by Radinsky (1966); to Tapiroidea by Peterson (1919), Radinsky (1963) and Holbrook (1999); and to Tapiromorpha by Bai et al. (2017).

Synonymy list
YearName and author
1892Helaletidae Osborn
1919Helaletidae Peterson p. 104
1923Helaletinae Osborn p. 2
1955Helaletidae Hough p. 29
1958Helaletidae Dehm and Oettingen-Spielberg p. 24
1963Helaletidae Radinsky p. 9
1966Helaletidae Radinsky p. 631
1999Helaletidae Holbrook p. 346
2017Helaletidae Bai et al.

Is something missing? Join the Paleobiology Database and enter the data

RankNameAuthor
kingdomAnimalia()
Bilateria
EubilateriaAx 1987
Deuterostomia
phylumChordataHaeckel 1874
subphylumVertebrata
superclassGnathostomata
Osteichthyes()
subclassSarcopterygii()
subclassDipnotetrapodomorpha(Nelson 2006)
subclassTetrapodomorpha()
Tetrapoda
Reptiliomorpha
Anthracosauria
subclassAmphibiosauriaKuhn 1967
Cotylosauria()
Amniota
subclassSynapsida
Therapsida()
infraorderCynodontia()
Mammaliamorpha
Mammaliaformes
RankNameAuthor
classMammalia
Theriamorpha(Rowe 1993)
Theriiformes()
Trechnotheria
Cladotheria
Zatheria
subclassTribosphenida()
subclassTheria
Eutheria()
Placentalia
Boreoeutheria
Laurasiatheria
Scrotifera
Euungulata
Panperissodactyla
superorderPerissodactylamorpha
orderPerissodactyla()
Tapiromorpha(Haeckel 1873)
Ceratomorpha(Wood 1937)
superfamilyTapiroideaGill 1872
familyHelaletidaeOsborn 1892
familyHelaletidaeOsborn 1892

If no rank is listed, the taxon is considered an unranked clade in modern classifications. Ranks may be repeated or presented in the wrong order because authors working on different parts of the classification may disagree about how to rank taxa.

Fm. †Helaletidae Osborn 1892
show all | hide all
G. †Desmatotherium Scott 1883
hide
Invalid names: Chasmotheroides Wood 1934 [synonym]
G. †Jhagirilophus Thewissen et al. 2001
hide
Jhagirilophus chorgalensis Thewissen et al. 2001
G. †Paracolodon Matthew and Granger 1925
hide
Paracolodon curtus Matthew and Granger 1925
Paracolodon fissus Matthew and Granger 1925
Paracolodon inceptus Matthew and Granger 1925
G. †Vastanolophus Smith et al. 2015
hide
Vastanolophus holbrooki Smith et al. 2015
Invalid names: Chasmotheriinae Viret 1858 [empty], Helaletinae Osborn 1892 [empty]
Diagnosis
ReferenceDiagnosis
L. B. Radinsky 1963Small to medium-sized cursorial tapiroids. Dental formula Ij*: 0}:°: 1
P4.3iMI.L0ng post-canine diastemata. P "* tend to become molariform, with hypocone 12
separating posteriorly from protocone. M " metacone flattened, shortened, and lingually 3
displaced, with labial cingulum. M relatively long and narrow, with metacone reduced and metaloph shorter than protoloph. Pa present only in early Eocene forms; P2_4 tend to become molariform but never develop a hypolophid. M^j, metalophid greatly reduced to absent. M3 hypoconulid short and narrow except in Dilophodon where it is lost. Greatly enlarged nasal incisions in middle Eocene and later forms.