Hexanchiformes

The Hexanchiformes /hɛkˈsæŋkɪfɔːrmiːz/ are a primitive order of sharks, numbering just seven extant species in two families, Chlamydoselachidae and Hexanchidae. Chlamydoselachidae are also known as frilled sharks, these sharks are very rare fishes and typically reside in deeper waters. Hexanchidae are also known as cow sharks and are the lesser known of the two types of Hexanchiformes and also reside in deep waters.

Hexanchiformes

D Ross Robertson · 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
SqualomorphiPBDB
Diet
carnivorePBDB
Life habit
nektonicPBDB
Motility
actively mobilePBDB

Time the record covers

At least 264 million years on record.

The record covers at least 264.28 Mya to 11.7 ka. No occurrence read is dated outside 266.9 Mya to 0 Mya.

Permian — about 1 of 611 occurrencesEarly Triassic — about 0 of 611 occurrencesMiddle Triassic — about 0 of 611 occurrencesLate Triassic — about 0 of 611 occurrencesEarly Jurassic — about 6 of 611 occurrencesEarly JurassicMiddle Jurassic — about 4 of 611 occurrencesLate Jurassic — about 9 of 611 occurrencesEarly Cretaceous — about 71 of 611 occurrencesEarly CretaceousLate Cretaceous — about 141 of 611 occurrencesLate CretaceousPaleocene — about 59 of 611 occurrencesEocene — about 124 of 611 occurrencesOligocene — about 36 of 611 occurrencesMiocene — about 121 of 611 occurrencesPliocene — about 23 of 611 occurrencesPleistocene — about 14 of 611 occurrences272–263 Mya — about 1 occurrence200–191 Mya — about 2 occurrences191–181 Mya — about 4 occurrences172–163 Mya — about 3 occurrences163–154 Mya — about 3 occurrences154–145 Mya — about 8 occurrences145–136 Mya — about 1 occurrence136–127 Mya — about 11 occurrences127–118 Mya — about 10 occurrences118–109 Mya — about 11 occurrences109–100 Mya — about 40 occurrences100–91 Mya — about 24 occurrences91–82 Mya — about 38 occurrences82–73 Mya — about 38 occurrences73–64 Mya — about 63 occurrences64–54 Mya — about 41 occurrences54–45 Mya — about 40 occurrences45–36 Mya — about 56 occurrences36–27 Mya — about 49 occurrences27–18 Mya — about 26 occurrences18–9.1 Mya — about 83 occurrences9.1–0 Mya — about 58 occurrences264.28 Mya11.7 ka272 Mya0 Mya

611 occurrences of Hexanchiformes on record, most of them in the Late Cretaceous. The Paleobiology Database records this as a living group. 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

611 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

197 formations

Hunstanton — 54.15°N, 0.17°WHunstanton — 53.68°N, 0.50°WNorthumberland — 49.55°N, 124.70°WNorthumberland — 49.54°N, 124.71°WHinoshima — 32.40°N, 130.40°ENierental — 47.66°N, 14.86°EMarnes de Donzacq — 43.75°N, 0.84°WGehannam — 29.36°N, 30.16°EGehannam — 29.33°N, 30.08°EGehannam — 29.32°N, 30.17°EGehannam — 29.30°N, 30.05°ECalvert — 38.54°N, 76.73°WCalvert — 37.93°N, 77.51°WCalvert — 38.40°N, 76.50°WCalvert — 37.54°N, 77.44°WCalvert — 39.20°N, 75.60°WCalvert — 38.16°N, 76.83°WSpeeton Clay — 54.16°N, 0.26°WSpeeton Clay — 54.16°N, 0.24°WLillebælt Clay — 55.60°N, 9.80°EHornerstown — 40.10°N, 73.00°WHornerstown — 39.76°N, 75.13°WMenilite — 49.63°N, 22.57°EMenilite — 49.73°N, 22.05°EMenilite — 49.78°N, 22.14°EGault — 51.08°N, 1.18°EGault — 51.94°N, 0.64°WGault — 51.93°N, 0.65°WLondon Clay — 51.40°N, 0.83°ELondon Clay — 50.78°N, 0.65°WLondon Clay — 51.64°N, 0.78°EBreda — 51.97°N, 6.73°EBreda — 52.15°N, 6.61°EBreda — 51.47°N, 5.80°EWaipara Greensand — 43.05°S, 172.62°ELa Meseta — 64.24°S, 56.65°WLa Meseta — 64.24°S, 56.65°WGerhartsreit — 47.94°N, 13.01°ELópez de Bertodano — 64.26°S, 56.78°WLópez de Bertodano — 64.29°S, 56.74°WDongen — 52.73°N, 6.30°EDongen — 53.16°N, 6.22°ESanta Marta — 63.90°S, 57.90°WYamaga — 33.99°N, 130.82°ESelsey — 50.80°N, 1.21°WKøbenhavn Limestone — 55.57°N, 12.93°EBirket Qarun — 29.27°N, 30.06°EBirket Qarun — 29.28°N, 30.03°E

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The named rock units Hexanchiformes has been recovered from, largest first. Drawn where the rock is now, not where it formed. 173 further formations hold fewer occurrences each and are not listed. 149 occurrences have no formation on record, which is common for older literature.

Hexanchiformes and its relatives

Late Cretaceous

Where Hexanchiformes and its relatives were recorded in the Late Cretaceous.

Found in the same rock

3,650 taxa

The Paleobiology Database records 457 sites for Hexanchiformes, and this reads 240 of them. Of that, one read hit the database's own return limit, so every count below is a floor rather than a total. 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

256 references

Each of the 611 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. 244 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 Hexanchiformes

Credit
D Ross Robertson
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Hexanchiformes was found in MorphoSource and Sketchfab.

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 itSqualomorphi through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. de Buen 1926