Aetiocetidae

Aetiocetidae is an extinct family of toothed baleen whales known from the Oligocene and latest Eocene, so far only from rocks deposited in the North Pacific Ocean. The whales ranged in size from 3 to 8 metres long. Many of the described specimens were discovered from the Upper Oligocene of the Japanese Morawan Formation, the largest known one from the Morawan's Upper tuffaceous siltstone. Other formally described extinct toothed mysticetis from this time are smaller, from 3 to 4 metres in length. Mysticeti with true baleen are seen in fossils from the Upper Oligocene. The monophyly of the family is still uncertain, as are the evolutionary relationship between the early toothed baleen whales and the early and extant edentulous baleen whales. However, the cladistic analyses of Coronodon and Mystacodon seem to indicate that Aetiocetidae and Llanocetidae are more closely related to crown Mysticeti than to Mammalodontidae, Coronodon, and Mystacodon.

Aetiocetidae

Nobu Tamura ( https://spinops.blogspot.com ) · CC BY 3.0 · 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
MysticetiPBDB
Diet
carnivore, suspension feederPBDB, for Mysticeti
Life habit
aquaticPBDB, for Mysticeti
Motility
actively mobilePBDB, for Cetacea
Environment
marinePBDB, for Mysticeti

Time the record covers

At least 8.8 million years on record.

The record covers at least 27.3 Mya to 18.5 Mya. No occurrence read is dated outside 33.9 Mya to 15.98 Mya.

Eocene — about 0 of 35 occurrencesOligocene — about 33 of 35 occurrencesOligoceneMiocene — about 2 of 35 occurrencesMiocene34–34 Mya — about 0.1 occurrences34–33 Mya — about 0.3 occurrences33–33 Mya — about 0.3 occurrences33–32 Mya — about 0.3 occurrences32–31 Mya — about 0.3 occurrences31–31 Mya — about 0.3 occurrences31–30 Mya — about 0.3 occurrences30–29 Mya — about 0.3 occurrences29–29 Mya — about 0.3 occurrences29–28 Mya — about 0.3 occurrences28–27 Mya — about 0.3 occurrences27–27 Mya — about 4 occurrences27–26 Mya — about 5 occurrences26–26 Mya — about 5 occurrences26–25 Mya — about 5 occurrences25–24 Mya — about 4 occurrences24–24 Mya — about 4 occurrences24–23 Mya — about 4 occurrences23–22 Mya — about 0.1 occurrences22–22 Mya — about 0.1 occurrences22–21 Mya — about 0.1 occurrences21–21 Mya — about 0.1 occurrences21–20 Mya — about 0.1 occurrences20–19 Mya — about 0.1 occurrences19–19 Mya — about 0.1 occurrences19–18 Mya — about 0.3 occurrences18–17 Mya — about 0.3 occurrences17–17 Mya — about 0.3 occurrences17–16 Mya — about 0.3 occurrences16–15 Mya — about 0.0 occurrences27.3 Mya18.5 Mya34.4 Mya15.5 Mya

35 occurrences of Aetiocetidae on record, most of them in the Oligocene. 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

35 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

14 formations

Morawan — 43.30°N, 143.77°EMorawan — 43.24°N, 143.54°EEl Cien — 24.38°N, 110.75°WEl Cien — 25.19°N, 110.91°WEl Cien — 24.44°N, 110.70°WEl Cien — 24.47°N, 110.70°WScotts Mills — 45.02°N, 122.60°WKokoamu Greensand — 44.87°S, 170.72°EYaquina — 44.51°N, 124.08°WLincoln Creek — 46.28°N, 123.81°WLincoln Creek — 47.29°N, 123.47°WYamaga — 33.86°N, 130.89°EVaqueros — 33.64°N, 117.77°WVaqueros — 34.05°N, 118.67°WSooke — 48.60°N, 124.72°WPysht — 48.16°N, 123.95°WPort Willunga — 35.32°S, 138.45°EOtekaike Limestone — 44.51°S, 170.37°EMakah — 48.33°N, 124.53°WJinnobaru — 33.97°N, 130.85°E

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The named rock units Aetiocetidae 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.

Aetiocetidae and its relatives

Oligocene

Where Aetiocetidae and its relatives were recorded in the Oligocene.

Found in the same rock

84 taxa

The Paleobiology Database records 23 sites for Aetiocetidae, 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

24 references

Each of the 35 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. 12 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 content1

Picture of Aetiocetidae

Credit
Nobu Tamura ( https://spinops.blogspot.com )
Licence
CC BY 3.0
Commercial use
the licence allows it

No 3D scan of Aetiocetidae was found in Sketchfab.

Smithsonian Open Access and MorphoSource were 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 itMysticeti through timeFormations of the OligoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Emlong 1966