Rhynchocephalia

Rhynchocephalia is an order of lizard-like reptiles that includes only one living species, the tuatara of New Zealand. Despite its current lack of diversity, during the Mesozoic rhynchocephalians were a speciose group with high morphological and ecological diversity. The oldest record of the group is dated to the Middle Triassic around 244 million years ago, and they had achieved global distribution by the Early Jurassic. Most rhynchocephalians belong to the suborder Sphenodontia ('wedge-teeth'). Their closest living relatives are lizards and snakes in the order Squamata, with the two orders being grouped together in the superorder Lepidosauria.

Rhynchocephalia

KeresH · 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
Also called
rhynchocephalianPBDB
Sits inside
LepidosauriaPBDB
Motility
actively mobilePBDB, for Osteichthyes
Environment
terrestrialPBDB, for Amniota

Time the record covers

At least 248 million years on record.

The record covers at least 248.6 Mya to 11.7 ka. No occurrence read is dated outside 251.902 Mya to 0 Mya.

Permian — about 0 of 132 occurrencesEarly Triassic — about 4 of 132 occurrencesMiddle Triassic — about 3 of 132 occurrencesLate Triassic — about 37 of 132 occurrencesLate TriassicEarly Jurassic — about 15 of 132 occurrencesEarly JurassicMiddle Jurassic — about 1 of 132 occurrencesLate Jurassic — about 26 of 132 occurrencesEarly Cretaceous — about 21 of 132 occurrencesEarly CretaceousLate Cretaceous — about 7 of 132 occurrencesLate CretaceousPaleocene — about 2 of 132 occurrencesEocene — about 0 of 132 occurrencesOligocene — about 0 of 132 occurrencesMiocene — about 2 of 132 occurrencesPliocene — about 0 of 132 occurrencesPleistocene — about 3 of 132 occurrences257–248 Mya — about 3 occurrences248–240 Mya — about 3 occurrences240–231 Mya — about 10 occurrences231–223 Mya — about 10 occurrences223–214 Mya — about 6 occurrences214–206 Mya — about 6 occurrences206–197 Mya — about 11 occurrences197–188 Mya — about 7 occurrences188–180 Mya — about 2 occurrences180–171 Mya — about 0.6 occurrences171–163 Mya — about 1 occurrence163–154 Mya — about 1 occurrence154–146 Mya — about 21 occurrences146–137 Mya — about 8 occurrences137–128 Mya — about 1 occurrence128–120 Mya — about 0.1 occurrences120–111 Mya — about 7 occurrences111–103 Mya — about 8 occurrences103–94 Mya — about 0.8 occurrences77–69 Mya — about 4 occurrences69–60 Mya — about 4 occurrences60–51 Mya — about 1 occurrence26–17 Mya — about 1 occurrence17–8.6 Mya — about 0.9 occurrences8.6–0 Mya — about 14 occurrences248.6 Mya11.7 ka257 Mya0 Mya

132 occurrences of Rhynchocephalia on record, most of them in the Late Triassic. The Paleobiology Database records this as a living group. 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

132 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

41 formations

Morrison — 41.89°N, 106.00°WMorrison — 38.73°N, 111.27°WMorrison — 38.54°N, 105.19°WMorrison — 40.44°N, 109.32°WMorrison — 38.81°N, 108.32°WMorrison — 38.32°N, 108.83°WMorrison — 40.47°N, 109.18°WMorrison — 39.15°N, 108.78°WMorrison — 39.24°N, 109.00°WChinle — 34.44°N, 109.46°WChinle — 35.84°N, 111.25°WChinle — 35.65°N, 111.12°WChinle — 35.05°N, 109.84°WChinle — 34.68°N, 109.58°WChinle — 35.03°N, 109.83°WCandeleros — 39.62°S, 69.35°WCandeleros — 39.71°S, 68.60°WCandeleros — 39.63°S, 68.70°WKlettgau — 47.50°N, 8.02°EKlettgau — 47.71°N, 8.45°EKlettgau — 47.71°N, 8.45°ELos Alamitos — 41.95°S, 66.33°WTorleite — 49.11°N, 11.90°ETorleite — 48.91°N, 11.14°ETecovas — 33.43°N, 101.16°WTecovas — 35.38°N, 102.16°WHillgrove — 45.13°S, 170.97°ELa Boca — 26.60°N, 99.52°WQuebrada del Barro — 31.60°S, 67.40°WQuebrada del Barro — 31.60°S, 67.29°WTlayúa — 18.59°N, 97.90°WForest Sandstone — 16.22°S, 30.10°EForest Sandstone — 16.12°S, 29.50°EBannockburn — 44.91°S, 169.86°EBannockburn — 44.88°S, 169.75°EPainten — 48.92°N, 11.58°EPainten — 49.01°N, 11.83°ELulworth — 50.61°N, 2.03°WMörnsheim — 48.86°N, 10.99°EMörnsheim — 48.84°N, 10.85°EKayenta — 35.88°N, 111.41°WKayenta — 35.76°N, 111.08°WCerro Barcino — 43.15°S, 68.43°WCerro Barcino — 43.13°S, 68.47°WHuincul — 39.40°S, 68.62°WChorrillo — 50.52°S, 72.56°WTrossingen — 51.90°N, 11.07°EKota — 19.27°N, 79.52°EMarnes de Jamoigne — 49.72°N, 5.22°EAllen — 40.06°S, 66.80°W

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The named rock units Rhynchocephalia has been recovered from, largest first. Drawn where the rock is now, not where it formed. 17 further formations hold fewer occurrences each and are not listed. 43 occurrences have no formation on record, which is common for older literature.

Rhynchocephalia and its relatives

Late Triassic

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

Found in the same rock

1,142 taxa

The Paleobiology Database records 120 sites for Rhynchocephalia, 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

83 references

Each of the 132 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. 71 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 Rhynchocephalia

Credit
KeresH
Licence
CC BY 3.0
Commercial use
the licence allows it

No 3D scan of Rhynchocephalia 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 itLepidosauria through timeFormations of the Late TriassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Günther 1867)