Archaeohippus

Archaeohippus is an extinct three-toed member of the family Equidae known from fossils of early Oligocene to middle Miocene age. The genus is noted for several distinct skeletal features. The skull possesses deeply pocketed fossa in a notably long preorbital region. The genus is considered an example of phyletic dwarfism with adults estimated at being on average 20 kilograms in weight. This is in contrast to the most common equid of the period, Miohippus. Characters of the teeth show a mix of both primitive and advanced traits. The advanced traits are very similar to those shown in the genus Parahippus. The noted similarities of Archaeohippus and Parahippus show them to be descended from a common ancestor. They are considered sister species.

Archaeohippus

Jonathan Chen · CC BY-SA 4.0 · via Wikipedia/Commons. May be a photograph of a specimen, or an artist’s reconstruction — an interpretation of a skeleton, since colour and soft tissue are almost never preserved.

On record

Recorded, not inferred
Sits inside
AnchitheriinaePBDB
Diet
browserPBDB, for Equidae
Life habit
ground dwellingPBDB, for Equidae
Motility
actively mobilePBDB, for Osteichthyes
Environment
terrestrialPBDB, for Eutheria

Time the record covers

At least 7 million years on record.

The record covers at least 23.04 Mya to 15.98 Mya. No occurrence read is dated outside 29.5 Mya to 5.333 Mya.

Oligocene — about 2 of 82 occurrencesOligoceneMiocene — about 80 of 82 occurrencesMiocenePliocene — about 0 of 82 occurrences30–29 Mya — about 0.0 occurrences29–28 Mya — about 0.1 occurrences28–27 Mya — about 0.1 occurrences27–27 Mya — about 0.2 occurrences27–26 Mya — about 0.3 occurrences26–25 Mya — about 0.3 occurrences25–24 Mya — about 0.4 occurrences24–23 Mya — about 0.4 occurrences23–22 Mya — about 0.9 occurrences22–22 Mya — about 1 occurrence22–21 Mya — about 1 occurrence21–20 Mya — about 1 occurrence20–19 Mya — about 1 occurrence19–18 Mya — about 5 occurrences18–17 Mya — about 15 occurrences17–17 Mya — about 15 occurrences17–16 Mya — about 9 occurrences16–15 Mya — about 7 occurrences15–14 Mya — about 7 occurrences14–13 Mya — about 6 occurrences13–12 Mya — about 5 occurrences12–12 Mya — about 0.6 occurrences12–11 Mya — about 0.4 occurrences11–9.9 Mya — about 0.4 occurrences9.9–9.0 Mya — about 0.4 occurrences9.0–8.2 Mya — about 0.4 occurrences8.2–7.3 Mya — about 0.4 occurrences7.3–6.5 Mya — about 0.4 occurrences6.5–5.7 Mya — about 0.4 occurrences5.7–4.8 Mya — about 0.2 occurrences23.04 Mya15.98 Mya30 Mya4.8 Mya

82 occurrences of Archaeohippus on record, most of them in the Miocene. Bar height is expected occurrences, not a count: each fossil is spread across the span it is dated to, so a tall narrow bar means tight dating and a low wide one means loose.

When

82 occurrences

These are dates about fossils, not the animal: the record can only begin after it arose and end before it died out, so either end may reach further. Shares are expected occurrences: a fossil dated to a span is counted partly in each period it straddles. More on what this infers.

Found in

31 formations

Sheep Creek — 42.40°N, 103.80°WMascall — 44.20°N, 120.50°WMascall — 44.50°N, 119.30°WMascall — 44.00°N, 120.13°WPunchbowl — 34.80°N, 117.00°WCalvert — 38.40°N, 76.50°WCalvert — 39.20°N, 75.60°WCalvert — 38.60°N, 76.51°WCalvert — 37.66°N, 77.11°WOakville — 30.10°N, 96.10°WOakville — 30.30°N, 95.70°WCaliente — 35.10°N, 120.00°WCaliente — 34.30°N, 119.00°WBopesta — 35.19°N, 118.26°WBopesta — 35.30°N, 118.50°WCypress Hills — 49.60°N, 108.80°WBox Butte — 42.20°N, 103.10°WBox Butte — 42.80°N, 103.10°WJohn Day — 44.90°N, 121.30°WJohn Day — 44.50°N, 119.30°WTorreya — 30.50°N, 84.50°WTorreya — 30.30°N, 84.20°WCucaracha — 9.10°N, 79.70°WCucaracha — 9.05°N, 79.67°WWood Mountain — 49.20°N, 106.20°WCrowder — 34.80°N, 117.00°WTemblor — 36.10°N, 120.40°WTemblor — 36.54°N, 120.55°WBranch Canyon — 34.90°N, 119.50°WCajon Valley — 34.33°N, 117.43°WRunningwater — 41.70°N, 103.10°WBatesland — 43.13°N, 101.87°WValentine — 42.78°N, 100.03°WMarks Head — 29.90°N, 82.10°WArcadia — 27.80°N, 82.80°WStatenville — 30.40°N, 83.00°WAlachua — 29.70°N, 82.60°W

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The named rock units Archaeohippus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 7 further formations hold fewer occurrences each and are not listed. 10 occurrences have no formation on record, which is common for older literature.

Archaeohippus and its relatives

Miocene

Where Archaeohippus and its relatives were recorded in the Miocene.

Found in the same rock

783 taxa

The Paleobiology Database records 79 sites for Archaeohippus, and this reads all of them. The number is how many of those sites it was catalogued from too. The 24 sharing the most are listed.

This is not a list of everything alive at the time. It is only what has come out of the same ground as this animal and been written down.

Entered from

44 references

Each of the 82 occurrences read was entered from one of these publications, ordered by how many each accounts for. This is not a search for papers mentioning the name. 32 further references are not listed. Entries link to doi.org where the Paleobiology Database holds an identifier, and to its own record where it does not. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.

Media and terms

Media content3

Picture of Archaeohippus

Credit
Jonathan Chen
Licence
CC BY-SA 4.0
Commercial use
the licence allows it

Laser scan

Licence
In Copyright
Commercial use
cannot be read from the licence given — check the record
Specimen
Archaeohippus penultimus · amnh:fm:71650

3D model

Source
Sketchfab
Licence
CC Attribution
Commercial use
cannot be read from the licence given — check the record

Smithsonian Open Access was not reached for this taxon, so this list is what the others held rather than everything there is.

The description on this site

Licence
CC BY-SA 4.0

This is what the site found, which is not the same as what exists.

Keep going

What may have been alongside itAnchitheriinae through timeFormations of the MioceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Gidley 1906