Placodontia

Placodonts are an extinct order of marine reptiles that lived during the Triassic period, becoming extinct at the end of the period. They were part of Sauropterygia, the group that includes plesiosaurs. Placodonts were generally between 1 and 2 m in length, with some of the largest measuring 3 m (9.8 ft) long.

Placodontia

Ghedoghedo · CC BY-SA 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
placodontPBDB
Sits inside
SauropterygiaPBDB
Motility
actively mobilePBDB, for Osteichthyes
Environment
marinePBDB, for Sauropterygia

Time the record covers

At least 159 million years on record.

The record covers at least 243.43 Mya to 83.6 Mya. No occurrence read is dated outside 250.8 Mya to 72.2 Mya.

Permian — about 0 of 105 occurrencesEarly Triassic — about 0 of 105 occurrencesMiddle Triassic — about 79 of 105 occurrencesLate Triassic — about 25 of 105 occurrencesLate TriassicEarly Jurassic — about 0 of 105 occurrencesMiddle Jurassic — about 0 of 105 occurrencesLate Jurassic — about 0 of 105 occurrencesEarly Cretaceous — about 0 of 105 occurrencesLate Cretaceous — about 1 of 105 occurrencesLate Cretaceous254–248 Mya — about 0.3 occurrences248–242 Mya — about 32 occurrences242–236 Mya — about 48 occurrences236–230 Mya — about 6 occurrences230–223 Mya — about 3 occurrences223–217 Mya — about 0.5 occurrences217–211 Mya — about 2 occurrences211–205 Mya — about 4 occurrences205–199 Mya — about 9 occurrences87–81 Mya — about 0.2 occurrences81–75 Mya — about 0.5 occurrences75–69 Mya — about 0.2 occurrences243.43 Mya83.6 Mya254 Mya69 Mya

105 occurrences of Placodontia on record, most of them in the Middle 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

105 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

Gevanim — 30.60°N, 34.82°ECalcare di Zu — 45.83°N, 9.27°ECalcare di Zu — 45.77°N, 9.60°ECalcare di Zu — 45.82°N, 9.80°EXiaowa — 25.90°N, 105.42°EJena — 51.22°N, 11.77°EJena — 52.47°N, 13.78°EJilh — 26.39°N, 44.24°EKössener Schichten — 48.13°N, 16.24°EVossenveld — 51.97°N, 6.73°EErfurt — 49.04°N, 9.77°EErfurt — 48.90°N, 9.20°EBesano — 45.91°N, 8.94°ETemplomhegy Dolomite — 45.88°N, 18.45°EMeissner — 49.99°N, 11.64°ESaharonim — 30.60°N, 34.82°EMuschelkalk — 31.22°N, 34.77°EZorzino Limestone — 45.68°N, 9.72°EGorno — 45.92°N, 9.92°EBraies — 46.75°N, 12.33°EHauptdolomit — 48.08°N, 16.28°EKnollenmergel — 47.47°N, 7.73°EWellenkalk — 50.30°N, 18.97°ECalcare di Recoaro — 45.75°N, 11.12°ETarasci — 37.40°N, 31.85°ETrochitenkalk — 51.09°N, 11.63°EMuschelkalk — 51.37°N, 10.87°EGrabfeld — 48.53°N, 9.09°E

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The named rock units Placodontia 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. 49 occurrences have no formation on record, which is common for older literature.

Placodontia and its relatives

Middle Triassic

Where Placodontia and its relatives were recorded in the Middle Triassic.

Found in the same rock

376 taxa

The Paleobiology Database records 83 sites for Placodontia, 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 105 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 Placodontia

Credit
Ghedoghedo
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

No 3D scan of Placodontia 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 itSauropterygia through timeFormations of the Middle TriassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Cope 1871)