Polymixia

Polymixia is the only extant genus of the order Polymixiiformes and family Polymixiidae. It contains 12 species, all of which live in deepwater marine environments. They are found in tropical and subtropical waters of the Atlantic, Indian and western Pacific Oceans. They are bottom-dwelling fish, found down to about 800 m (2,600 ft). Most are relatively small fish, although one species is over 40 cm (16 in) in length. They can be considered "living fossils" due to being the only surviving members of the once-diverse order Polymixiiformes.

Polymixia

Uncredited · Public Domain · 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
PolymixiidaePBDB
Motility
actively mobilePBDB, for Osteichthyes

Time the record covers

At least 56 million years on record.

The record covers at least 72.2 Mya to 15.98 Mya. No occurrence read is dated outside 83.6 Mya to 11.63 Mya.

Late Cretaceous — about 1 of 6 occurrencesLate CretaceousPaleocene — about 0 of 6 occurrencesEocene — about 3 of 6 occurrencesEoceneOligocene — about 0 of 6 occurrencesMiocene — about 2 of 6 occurrencesMiocene85–83 Mya — about 0.1 occurrences83–80 Mya — about 0.2 occurrences80–78 Mya — about 0.2 occurrences78–75 Mya — about 0.2 occurrences75–73 Mya — about 0.2 occurrences73–70 Mya — about 0.0 occurrences50–48 Mya — about 0.2 occurrences48–45 Mya — about 1 occurrence45–43 Mya — about 1 occurrence43–40 Mya — about 0.7 occurrences18–15 Mya — about 0.6 occurrences15–13 Mya — about 1 occurrence13–10 Mya — about 0.2 occurrences72.2 Mya15.98 Mya85 Mya10 Mya

6 occurrences of Polymixia on record, most of them in the Eocene. The Paleobiology Database records this as a living group, and the chart stops with its fossils rather than at the present. 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

6 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

3 formations

Miretrain Marl — 43.56°N, 1.11°WMishash — 30.67°N, 35.08°EDonzacq Marl — 43.75°N, 0.84°W

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The named rock units Polymixia has been recovered from, largest first. Drawn where the rock is now, not where it formed. 2 occurrences have no formation on record, which is common for older literature.

Polymixia and its relatives

Eocene

Where Polymixia and its relatives were recorded in the Eocene.

Found in the same rock

199 taxa

The Paleobiology Database records 6 sites for Polymixia, 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

4 references

Each of the 6 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. 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 Polymixia

Credit
nobody named on the record
Licence
Public Domain
Commercial use
the licence allows it

CT scan

Licence
In Copyright
Commercial use
cannot be read from the licence given — check the record
Specimen
Polymixia lowei · TCWC:Ichthyology:12751.01

3D model

Source
Sketchfab
Licence
CC0 Public Domain
Commercial use
the licence allows it

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 itPolymixiidae through timeFormations of the EoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Lowe 1836