PBDB Taxon

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

Heptodon

Mammalia - Perissodactyla

Taxonomy

Heptodon was named by Cope (1882). It was considered paraphyletic by Colbert (2005).

It was assigned to Lophiodontidae by Hay (1902) and Scott (1913); to Helaletidae by Radinsky (1963); to Helaletinae by Radinsky (1966); to Tapiridea by Prothero and Schoch (1989); to Ceratomorpha by Cope (1882) and Colbert and Schoch (1998); to Heptodontidae by Holbrook (1999); and to Tapiroidea by Hooker and Dashzeveg (2004) and Colbert (2005).

Species

H. calciculus (syn. Lophiodon ventorum), H. minimus, H. niushanensis, H. posticus (syn. H. brownorum), H. tienshanensis

Synonymy list

Year	Name and author
1882	Heptodon Cope
1902	Heptodon Hay p. 625
1913	Heptodon Scott p. 291
1963	Heptodon Radinsky p. 24
1966	Heptodon Radinsky p. 633
1989	Heptodon Prothero and Schoch p. 533
1998	Heptodon Colbert and Schoch p. 573
1999	Heptodon Holbrook p. 347
2004	Heptodon Hooker and Dashzeveg p. 1377
2005	Heptodon Colbert p. 12

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Rank	Name	Author
kingdom	Animalia	()
—	Bilateria
—	Eubilateria	Ax 1987
—	Deuterostomia
phylum	Chordata	Haeckel 1874
subphylum	Vertebrata
superclass	Gnathostomata
—	Osteichthyes	()
subclass	Sarcopterygii	()
subclass	Dipnotetrapodomorpha	(Nelson 2006)
subclass	Tetrapodomorpha	()
—	Tetrapoda
—	Reptiliomorpha
—	Anthracosauria
subclass	Amphibiosauria	Kuhn 1967
—	Cotylosauria	()
—	Amniota
subclass	Synapsida
—	Therapsida	()
infraorder	Cynodontia	()

Rank	Name	Author
—	Mammaliamorpha
—	Mammaliaformes
class	Mammalia
—	Cladotheria
—	Zatheria
subclass	Tribosphenida	()
subclass	Theria
—	Eutheria	()
—	Placentalia
—	Boreoeutheria
—	Laurasiatheria
—	Scrotifera
—	Euungulata
—	Panperissodactyla
superorder	Perissodactylamorpha
order	Perissodactyla	()
—	Tapiromorpha	(Haeckel 1873)
—	Ceratomorpha	(Wood 1937)
superfamily	Tapiroidea	Gill 1872
genus	Heptodon

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.

G. †Heptodon Cope 1882

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†Heptodon calciculus Cope 1880

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Invalid names: Lophiodon ventorum Cope 1880 [synonym]

†Heptodon minimus Qi 1987

†Heptodon niushanensis Chow and Li 1965

†Heptodon posticus Cope 1882

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Invalid names: Heptodon brownorum Seton 1931 [synonym]

†Heptodon tienshanensis Zhai 1978

Diagnosis

Reference	Diagnosis
L. B. Radinsky 1963	Small to medium-sized helaletids. Canines relatively large. P1 simple; P2-4 non-molariform, with metaloph less prominent than protoloph and with only one lingual 1-2 cusp, a steeply conical protocone. M1-2 metacones slightly convex to flat; not shortened and not as lingually displaced as in later helaletids. M3 metacone not as reduced as in later helaletids. p1 usually present. p2 a high elongate cusp with small median posterior cuspule. p3-4 trigonids relatively high, with long paralophids. Small entoconid variably present on p4. Nasal incision not enlarged.

Measurements

No measurements are available

Composition:

phosphaticsubp

Environment:

terrestrialsubc

Locomotion:

actively mobilec

Life habit:

ground dwellingsuperf

Diet:

browsersuperf

Reproduction:

viviparoussubc

Created:

2005-08-31 15:03:27

Modified:

2005-08-31 17:03:27

Source: superf = superfamily, subc = subclass, c = class, subp = subphylum

References: Ji et al. 2002, Hendy et al. 2009, Colbert and Schoch 1998, Carroll 1988, Lillegraven 1979

Age range: base of the Lysitean to the top of the Early/Lower Eocene or 55.80000 to 48.60000 Ma

Collections (96 total)

Time interval	Ma	Country or state	Original ID and collection number
Lostcabinian	55.8 - 50.3	USA (Wyoming)	H. posticus (15945 15998 16078) H. posticus, H. ventorum (15903 15915 15917 15930)
Lysitean - Lostcabinian	55.8 - 50.3	USA (Wyoming)	H. sp. (15451)
Wasatchian	55.8 - 50.3	USA (Colorado)	H. calciculus (15302 15325 15338 15393 15395 15426) H. posticus (15410 15413) H. sp. (15220 15221 15225 15270 15272 15277 15350 15372 15407 15649) H. sp., H. calciculus (15293)
Wasatchian	55.8 - 50.3	Canada (British Columbia)	H. sp. (161203)
Wasatchian	55.8 - 50.3	USA (New Mexico)	Homogalax protapirinus (15440)
Wasatchian	55.8 - 50.3	USA (Wyoming)	H. brownorum (15904 15905 15906 15910 15996) H. calciculus (15454 15548 15551 15552 15553 15554 15557 15558 15560 15565 15576 15852 15934 15935 15964 46692 46699 46700 46703 46706 46711 46715 46746 46810 46811 46849 186937 186940 186951) H. calciculus, H. posticus (15486 15555 15556 15839) H. posticus (15566 15567) H. posticus, H. ventorum (15662 15942) H. sp. (15559 15597 15642 15689 15842 15902 15931 15937 15958) H. sp., H. calciculus, H. posticus (15564) H. ventorum (15479 15661 15710 15963)
Early/Lower Eocene	55.8 - 48.6	China (Jiangxi)	H. sp. (182565)
Early/Lower Eocene	55.8 - 48.6	China (Nei Mongol)	H. minimus (174920)
Early/Lower Eocene	55.8 - 48.6	USA (Wyoming)	H. calciculus (15680 15684) H. sp. (15690 15691)
Early/Lower Eocene	55.8 - 48.6	China (Shandong)	H. niushanensis (180879)
Bridgerian	50.3 - 46.2	USA (Wyoming)	H. sp. (16505) H. sp., H. posticus, H. ventorum (16207) H. ventorum (16397 16415)