Sphenacanthus

Sphenacanthus is an extinct genus of a chondrichtyan xenacanthiform that belongs to the Sphenacanthidae family and lived from the Late Devonian, through Carboniferous until the Late Permian period in Scotland, Spain, Russia and Brazil. It lived 359 million years ago, and probably it was one of the first member of the elasmobranchians, the lineage that leads to the modern sharks. Sphenacanthus probably hunted small fishes and, unlike their modern-day relatives, it inhabited fresh water lagoons. Sphenacanthus had seven fins, two in the upper part and five in the underside, and it had a heterodont dentition and mandibles relatively long and deeper. Sphenacanthus serrulatus is still only known from incomplete neurocranial remains and associated dermal material. These suggest that it was a relatively large shark, probably well over one meter in length when fully grown. Its body form was probably similar to that of other phalacanthous sharks.

Sphenacanthus

Creator: Dmitry Bogdanov · 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
SphenacanthidaePBDB
Diet
carnivorePBDB, for Chondrichthyes
Life habit
nektonicPBDB, for Chondrichthyes
Motility
actively mobilePBDB, for Chondrichthyes

Time the record covers

At least 94 million years on record.

The record covers at least 358.86 Mya to 264.28 Mya. No occurrence read is dated outside 372.15 Mya to 259.857 Mya.

Devonian — about 1 of 11 occurrencesDevonianCarboniferous — about 4 of 11 occurrencesCarboniferousPermian — about 6 of 11 occurrencesPermian374–371 Mya — about 0.1 occurrences371–367 Mya — about 0.3 occurrences367–363 Mya — about 0.3 occurrences363–359 Mya — about 0.3 occurrences347–343 Mya — about 0.5 occurrences343–339 Mya — about 0.5 occurrences324–320 Mya — about 0.4 occurrences320–316 Mya — about 0.5 occurrences316–312 Mya — about 0.1 occurrences308–304 Mya — about 1 occurrence304–300 Mya — about 0.7 occurrences300–297 Mya — about 0.2 occurrences293–289 Mya — about 0.2 occurrences289–285 Mya — about 0.6 occurrences285–281 Mya — about 0.5 occurrences281–277 Mya — about 0.4 occurrences277–273 Mya — about 0.8 occurrences273–269 Mya — about 2 occurrences269–265 Mya — about 1.0 occurrences265–262 Mya — about 0.6 occurrences262–258 Mya — about 0.4 occurrences358.86 Mya264.28 Mya374 Mya258 Mya

11 occurrences of Sphenacanthus 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

11 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

5 formations

Cutoff — 31.82°N, 104.83°WIrati — 22.42°S, 47.65°WGlencartholm Volcanic Beds — 55.20°N, 3.07°WRio do Rasto — 23.17°S, 49.96°WMattoon — 38.44°N, 87.86°W

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The named rock units Sphenacanthus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 4 occurrences have no formation on record, which is common for older literature.

Sphenacanthus and its relatives

Permian

Where Sphenacanthus and its relatives were recorded in the Permian.

Found in the same rock

101 taxa

The Paleobiology Database records 11 sites for Sphenacanthus, 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

9 references

Each of the 11 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 content1

Picture of Sphenacanthus

Credit
Creator: Dmitry Bogdanov
Licence
CC BY 3.0
Commercial use
the licence allows it

No 3D scan of Sphenacanthus 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 itSphenacanthidae through timeFormations of the PermianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Agassiz 1837