Onchosaurus

Searched as Titanichthys. The Paleobiology Database treats Onchosaurus as the accepted name.

Titanichthys is an extinct genus of giant, aberrant marine placoderm from shallow seas of the Late Devonian of Morocco, Eastern North America, and possibly Europe. Many of the species approached Dunkleosteus in size and build. Unlike its relative, however, the various species of Titanichthys had small, ineffective-looking mouth-plates that lacked a sharp cutting edge. It is assumed that Titanichthys was a filter feeder that used its capacious mouth to swallow or inhale schools of small, anchovy-like fish, or possibly krill-like zooplankton, and that the mouth-plates retained the prey while allowing the water to escape as it closed its mouth. A study has since confirmed this assumption as its jaws are functionally closer to that of filter feeders like baleen whales and basking sharks, and it appears to have developed from benthic durophagists that became pelagic suspension feeders. This would make it the first (known) large-sized vertebrate filter feeder. Titanichthys was estimated to have reached a length of 7–7.6 m (23–25 ft), but Engelman (2023) suggested that Titanichthys was comparable in size to Dunkleosteus, likely measuring about or just over 4.1 metres (13.5 ft) in length.

Onchosaurus

PlacodermReconstructions · CC BY 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
SclerorhynchidaePBDB
Diet
carnivorePBDB, for Chondrichthyes
Life habit
nektonicPBDB, for Chondrichthyes
Motility
actively mobilePBDB, for Chondrichthyes

Time the record covers

At least 331 million years on record.

The record covers at least 387.95 Mya to 56 Mya. No occurrence read is dated outside 393.47 Mya to 48.07 Mya.

Devonian — about 4 of 25 occurrencesDevonianCarboniferous — about 0 of 25 occurrencesPermian — about 0 of 25 occurrencesEarly Triassic — about 0 of 25 occurrencesMiddle Triassic — about 0 of 25 occurrencesLate Triassic — about 0 of 25 occurrencesEarly Jurassic — about 0 of 25 occurrencesMiddle Jurassic — about 0 of 25 occurrencesLate Jurassic — about 0 of 25 occurrencesEarly Cretaceous — about 0 of 25 occurrencesLate Cretaceous — about 20 of 25 occurrencesLate CretaceousPaleocene — about 0 of 25 occurrencesEocene — about 1 of 25 occurrences400–388 Mya — about 0.9 occurrences388–376 Mya — about 0.8 occurrences376–364 Mya — about 1 occurrence364–352 Mya — about 0.8 occurrences101–89 Mya — about 5 occurrences89–77 Mya — about 11 occurrences77–65 Mya — about 4 occurrences65–53 Mya — about 0.4 occurrences53–41 Mya — about 0.6 occurrences387.95 Mya56 Mya400 Mya41 Mya

25 occurrences of Onchosaurus on record, most of them in the Late Cretaceous. 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

25 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

15 formations

Cleveland — 41.47°N, 82.17°WPoint Lookout — 35.20°N, 107.05°WQuseir — 25.62°N, 29.29°ESan Carlos — 30.87°N, 105.09°WTamayama — 37.05°N, 140.88°EVaugirard — 48.81°N, 2.24°ECraie de Meudon — 48.82°N, 2.23°EDukamaje — 15.47°N, 6.26°ENidaguila — 42.73°N, 3.94°WDundee Limestone — 42.25°N, 83.28°WClymenia Limestone — 50.84°N, 20.39°EScaglia Rossa — 45.65°N, 10.94°EItombe — 8.29°S, 13.35°ERmah — 34.35°N, 38.00°ESan Carlos — 29.35°N, 105.65°W

Loading coastlines…

The named rock units Onchosaurus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 9 occurrences have no formation on record, which is common for older literature.

Onchosaurus and its relatives

Late Cretaceous

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

Found in the same rock

147 taxa

The Paleobiology Database records 21 sites for Onchosaurus, 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

20 references

Each of the 25 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. 8 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 Onchosaurus

Credit
PlacodermReconstructions
Licence
CC BY 4.0
Commercial use
the licence allows it

No 3D scan of Onchosaurus 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 itSclerorhynchidae through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Dames 1887