Ischnacanthiformes

Ischnacanthiformes is a prehistoric order of "acanthodian" stem-chondrichthyans found in Canada, Ukraine and United Kingdom. Members of this order were nektonic carnivores, eating animals that swim rather than plankton. They had slender builds, light armor, deeply inserted spines, shark-like teeth, and two dorsal fins. Some species were around 2 meters long. It was described by Berg in 1940.

Ischnacanthiformes

Danielle Dufault · CC BY 2.5 · 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
AcanthodiiPBDB
Diet
carnivorePBDB, for Acanthodii
Life habit
nektonicPBDB, for Acanthodii
Motility
actively mobilePBDB, for Acanthodii

Time the record covers

At least 107 million years on record.

The record covers at least 422.7 Mya to 315.2 Mya. No occurrence read is dated outside 432.9 Mya to 307 Mya.

Silurian — about 28 of 90 occurrencesSilurianDevonian — about 58 of 90 occurrencesDevonianCarboniferous — about 4 of 90 occurrencesCarboniferous435–431 Mya — about 0.2 occurrences431–427 Mya — about 0.4 occurrences427–422 Mya — about 11 occurrences422–418 Mya — about 24 occurrences418–414 Mya — about 18 occurrences414–409 Mya — about 5 occurrences409–405 Mya — about 4 occurrences405–401 Mya — about 4 occurrences401–396 Mya — about 5 occurrences396–392 Mya — about 4 occurrences392–387 Mya — about 2 occurrences387–383 Mya — about 3 occurrences383–379 Mya — about 4 occurrences374–370 Mya — about 0.2 occurrences370–366 Mya — about 0.3 occurrences366–361 Mya — about 1.0 occurrences361–357 Mya — about 0.6 occurrences348–344 Mya — about 1.0 occurrences344–339 Mya — about 1 occurrence339–335 Mya — about 0.6 occurrences318–313 Mya — about 0.2 occurrences313–309 Mya — about 0.5 occurrences309–304 Mya — about 0.2 occurrences422.7 Mya315.2 Mya435 Mya304 Mya

90 occurrences of Ischnacanthiformes on record, most of them in the Devonian. 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

90 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

43 formations

Cavan Bluff Limestone — 35.01°S, 148.86°EDundee Flagstone — 57.00°N, 4.00°WDundee Flagstone — 56.48°N, 3.12°WDundee Flagstone — 56.67°N, 2.77°WDundee Flagstone — 56.61°N, 3.00°WJura — 55.29°N, 20.98°EJura — 55.19°N, 21.80°EJura — 55.24°N, 23.51°ESevernaya Zemlya — 79.50°N, 96.00°EIvane Suite — 48.62°N, 25.87°EYanglugou — 34.05°N, 103.22°EYanglugou — 33.57°N, 102.95°EOhesaare — 58.00°N, 22.02°EWater Canyon — 41.62°N, 111.66°WWater Canyon — 41.84°N, 111.59°WWater Canyon — 41.98°N, 111.09°WOverton — 52.48°N, 2.63°WMiaogao — 25.45°N, 103.77°EWindmill Limestone — 39.96°N, 116.58°WMiaokao — 25.48°N, 103.78°EPendleside Limestones — 53.59°N, 1.95°WVievis — 55.24°N, 23.51°EVievis — 55.00°N, 23.30°ETyver — 48.64°N, 25.72°EDrake Bay — 73.46°N, 100.49°WPsammosteus Limestone — 52.53°N, 2.48°WRoad River — 63.33°N, 126.81°WChester Bjerg — 81.76°N, 61.77°WChester Bjerg — 81.75°N, 60.53°WCatavi — 18.45°S, 64.80°WLankey Limestone — 42.12°S, 171.85°ECunningham Creek — 45.38°N, 66.32°WKaugatuma — 58.12°N, 22.19°ETordalen — 78.67°N, 16.22°E

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The named rock units Ischnacanthiformes has been recovered from, largest first. Drawn where the rock is now, not where it formed. 19 further formations hold fewer occurrences each and are not listed. 8 occurrences have no formation on record, which is common for older literature.

Ischnacanthiformes and its relatives

Devonian

Where Ischnacanthiformes and its relatives were recorded in the Devonian.

Found in the same rock

500 taxa

The Paleobiology Database records 63 sites for Ischnacanthiformes, 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

43 references

Each of the 90 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. 31 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 Ischnacanthiformes

Credit
Danielle Dufault
Licence
CC BY 2.5
Commercial use
the licence allows it

No 3D scan of Ischnacanthiformes 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 itAcanthodii through timeFormations of the DevonianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Berg 1940