Hemicalypterus

Hemicalypterus is an extinct genus of prehistoric freshwater ray-finned fish that lived during the late Triassic period. It contains a single species, Hemicalypterus weiri. Fossils have been collected in the southwestern United States, including the Tecovas Formation of Texas, the Chinle Formation of Utah, and potentially New Mexico. Hemicalypterus belonged to the family Dapediidae, and like other members of its family, it was a deep-bodied fish with a covering of thick ganoid scales. It differed from other dapediids in lacking scales on the posterior part of the body, and in possessing unusual, multicuspid teeth. These teeth were similar to those of modern-day herbivorous fish, which indicates that Hemicalypterus may have been a herbivore as well.

Hemicalypterus

Gibson SZ (2016) · 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
SemionotidaePBDB
Diet
durophage, carnivorePBDB, for Semionotiformes
Life habit
nektonicPBDB, for Semionotiformes
Motility
actively mobilePBDB, for Semionotiformes

Time the record covers

At least 21 million years on record.

The record covers at least 227.3 Mya to 205.7 Mya. No occurrence read is dated outside 237 Mya to 201.4 Mya.

Middle Triassic — about 0 of 5 occurrencesLate Triassic — about 5 of 5 occurrencesLate TriassicEarly Jurassic — about 0 of 5 occurrences238–236 Mya — about 0.1 occurrences236–235 Mya — about 0.1 occurrences235–234 Mya — about 0.1 occurrences234–233 Mya — about 0.1 occurrences233–232 Mya — about 0.1 occurrences232–230 Mya — about 0.1 occurrences230–229 Mya — about 0.1 occurrences229–228 Mya — about 0.1 occurrences228–227 Mya — about 0.1 occurrences227–225 Mya — about 0.2 occurrences225–224 Mya — about 0.2 occurrences224–223 Mya — about 0.2 occurrences223–222 Mya — about 0.2 occurrences222–220 Mya — about 0.2 occurrences220–219 Mya — about 0.2 occurrences219–218 Mya — about 0.2 occurrences218–217 Mya — about 0.2 occurrences217–215 Mya — about 0.2 occurrences215–214 Mya — about 0.2 occurrences214–213 Mya — about 0.2 occurrences213–212 Mya — about 0.2 occurrences212–211 Mya — about 0.2 occurrences211–209 Mya — about 0.2 occurrences209–208 Mya — about 0.2 occurrences208–207 Mya — about 0.2 occurrences207–206 Mya — about 0.2 occurrences206–204 Mya — about 0.4 occurrences204–203 Mya — about 0.4 occurrences203–202 Mya — about 0.4 occurrences202–201 Mya — about 0.2 occurrences227.3 Mya205.7 Mya237.7 Mya200.7 Mya

5 occurrences of Hemicalypterus on record, most of them in the Late Triassic. 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

5 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

4 formations

Chinle — 38.13°N, 109.18°WChinle — 38.15°N, 109.20°WRedonda — 35.00°N, 103.67°WTecovas — 35.38°N, 102.16°WRock Point — 38.29°N, 108.92°W

Loading coastlines…

The named rock units Hemicalypterus has been recovered from, largest first. Drawn where the rock is now, not where it formed.

Hemicalypterus and its relatives

Late Triassic

Where Hemicalypterus and its relatives were recorded in the Late Triassic.

Found in the same rock

38 taxa

The Paleobiology Database records 5 sites for Hemicalypterus, 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

5 references

Each of the 5 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. Each entry links to the Paleobiology Database's own record for the work.

Media and terms

Media content1

Picture of Hemicalypterus

Credit
Gibson SZ (2016)
Licence
CC BY-SA 4.0
Commercial use
the licence allows it

No 3D scan of Hemicalypterus 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 itSemionotidae through timeFormations of the Late TriassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Schaeffer 1967