Xenacanthiformes

Xenacanthiformes is an order or superorder of extinct shark-like chondrichthyans known from the Carboniferous to the Late Triassic. They were native to freshwater, marginal marine, and shallow marine habitats. Some xenacanths may have grown to lengths of 5 m (16 ft). Most xenacanths died out at the end of the Permian in the End-Permian Mass Extinction, with only a few forms surviving into the Triassic.

Xenacanthiformes

Gasmasque · 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
XenacanthimorphaPBDB
Diet
carnivorePBDB
Life habit
nektobenthicPBDB
Motility
actively mobilePBDB

Time the record covers

At least 108 million years on record.

The record covers at least 335.9 Mya to 227.3 Mya. No occurrence read is dated outside 339.9 Mya to 205.7 Mya.

Carboniferous — about 26 of 106 occurrencesCarboniferousPermian — about 60 of 106 occurrencesPermianEarly Triassic — about 0 of 106 occurrencesMiddle Triassic — about 5 of 106 occurrencesLate Triassic — about 15 of 106 occurrencesLate Triassic343–338 Mya — about 0.5 occurrences338–333 Mya — about 0.5 occurrences324–319 Mya — about 2 occurrences319–315 Mya — about 5 occurrences315–310 Mya — about 7 occurrences310–305 Mya — about 7 occurrences305–301 Mya — about 4 occurrences301–296 Mya — about 7 occurrences296–291 Mya — about 8 occurrences291–287 Mya — about 8 occurrences287–282 Mya — about 10 occurrences282–277 Mya — about 13 occurrences277–273 Mya — about 9 occurrences273–268 Mya — about 2 occurrences268–263 Mya — about 1 occurrence263–259 Mya — about 0.3 occurrences259–254 Mya — about 0.3 occurrences254–250 Mya — about 0.1 occurrences250–245 Mya — about 0.8 occurrences245–240 Mya — about 4 occurrences240–236 Mya — about 0.6 occurrences236–231 Mya — about 0.6 occurrences231–226 Mya — about 1 occurrence226–222 Mya — about 3 occurrences222–217 Mya — about 3 occurrences217–212 Mya — about 3 occurrences212–208 Mya — about 3 occurrences208–203 Mya — about 1 occurrence335.9 Mya227.3 Mya343 Mya203 Mya

106 occurrences of Xenacanthiformes on record, most of them in the Permian. 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

106 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

37 formations

Vale — 33.68°N, 99.58°WVale — 33.76°N, 99.55°WVale — 33.74°N, 99.41°WVale — 33.67°N, 99.78°WVale — 32.13°N, 99.75°WChinle — 34.44°N, 109.46°WChinle — 34.94°N, 109.77°WChinle — 34.68°N, 109.58°WChinle — 36.33°N, 106.47°WTecovas — 33.43°N, 101.16°WTecovas — 34.96°N, 101.70°WTecovas — 35.38°N, 102.16°WWellington — 36.16°N, 97.34°WWellington — 36.35°N, 97.43°WWellington — 36.74°N, 97.42°WWellington — 36.30°N, 97.30°WLueders — 33.75°N, 99.15°WLueders — 33.75°N, 99.12°WMattoon — 38.44°N, 87.86°WGarber — 36.77°N, 97.77°WGarber — 36.66°N, 97.69°WGarber — 34.45°N, 98.93°WAshfield Shale — 33.91°S, 151.19°EAshfield Shale — 34.22°S, 150.65°EEl Cobre Canyon — 36.14°N, 106.62°WKildare Capes — 46.12°N, 62.96°WKildare Capes — 46.18°N, 62.92°WKildare Capes — 46.19°N, 62.95°WCutler — 37.17°N, 109.85°WCutler — 36.16°N, 106.65°WChickasha — 36.01°N, 98.36°WChickasha — 35.94°N, 98.21°WBlack Prince Limestone — 31.73°N, 109.57°WBlack Prince Limestone — 31.77°N, 109.58°WBelle Plains — 33.58°N, 98.97°WBelle Plains — 33.69°N, 99.02°WGarber Sandstone — 34.58°N, 98.85°WBead Mountain — 34.13°N, 98.62°WBluewater Creek — 35.42°N, 108.49°WHennessey — 34.19°N, 98.79°WSan Angelo — 34.10°N, 99.73°WMaleri — 19.22°N, 79.58°EProsecne — 50.56°N, 15.66°EMoran — 32.50°N, 100.06°WArcher City — 33.45°N, 98.78°WBoruszowice — 50.45°N, 18.78°E

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The named rock units Xenacanthiformes has been recovered from, largest first. Drawn where the rock is now, not where it formed. 13 further formations hold fewer occurrences each and are not listed. 22 occurrences have no formation on record, which is common for older literature.

Xenacanthiformes and its relatives

Permian

Where Xenacanthiformes and its relatives were recorded in the Permian.

Found in the same rock

553 taxa

The Paleobiology Database records 78 sites for Xenacanthiformes, 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

50 references

Each of the 106 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. 38 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 Xenacanthiformes

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

No 3D scan of Xenacanthiformes 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 itXenacanthimorpha through timeFormations of the PermianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Berg 1955