Trinacromerum

Trinacromerum is an extinct genus of sauropterygian reptile, a member of the polycotylid plesiosaurs. It contains two species, T. bentonianum and T. kirki. Specimens have been discovered in the Late Cretaceous fossil deposits of what is now modern Kansas and Manitoba. Some fossils are also found in the Southern United States such as in the Mooreville Chalk of Alabama.

Trinacromerum

Thomas Quine · CC BY 2.0 · 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
PolycotylinaePBDB
Diet
carnivorePBDB, for Plesiosauria
Life habit
aquatic, depth=surfacePBDB, for Plesiosauria
Motility
actively mobilePBDB, for Plesiosauria
Environment
marinePBDB, for Plesiosauria
Length
3 mWikidata

Time the record covers

At least 16 million years on record.

The record covers at least 100.5 Mya to 83.6 Mya. No occurrence read is dated outside 106.3 Mya to 66 Mya.

Early Cretaceous — about 1 of 18 occurrencesEarly CretaceousLate Cretaceous — about 17 of 18 occurrencesLate CretaceousPaleocene — about 0 of 18 occurrences107–106 Mya — about 0.1 occurrences106–104 Mya — about 0.2 occurrences104–103 Mya — about 0.2 occurrences103–102 Mya — about 0.2 occurrences102–100 Mya — about 0.4 occurrences100–99 Mya — about 0.8 occurrences99–97 Mya — about 0.8 occurrences97–96 Mya — about 0.8 occurrences96–95 Mya — about 0.8 occurrences95–93 Mya — about 2 occurrences93–92 Mya — about 4 occurrences92–90 Mya — about 4 occurrences90–89 Mya — about 2 occurrences85–83 Mya — about 0.0 occurrences83–82 Mya — about 0.2 occurrences82–81 Mya — about 0.2 occurrences81–79 Mya — about 0.2 occurrences79–78 Mya — about 0.2 occurrences78–76 Mya — about 0.2 occurrences76–75 Mya — about 0.2 occurrences75–74 Mya — about 0.2 occurrences74–72 Mya — about 0.2 occurrences72–71 Mya — about 0.1 occurrences71–69 Mya — about 0.1 occurrences69–68 Mya — about 0.1 occurrences68–67 Mya — about 0.1 occurrences67–65 Mya — about 0.0 occurrences100.5 Mya83.6 Mya107.1 Mya65.2 Mya

18 occurrences of Trinacromerum 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

18 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

7 formations

Carlile Shale — 39.38°N, 98.54°WCarlile Shale — 38.87°N, 99.18°WCarlile Shale — 38.91°N, 98.81°WCarlile Shale — 39.10°N, 99.04°WCarlile Shale — 38.88°N, 97.37°WGreenhorn Limestone — 39.53°N, 97.66°WGreenhorn Limestone — 38.91°N, 98.53°WGreenhorn Limestone — 38.78°N, 99.22°WGreenhorn Limestone — 39.16°N, 98.33°WPierre Shale — 49.22°N, 98.20°WPierre Shale — 53.30°N, 102.30°WTropic Shale — 37.29°N, 112.69°WLake Waco — 31.60°N, 97.22°WFavel — 49.74°N, 98.76°WMowry Shale — 44.23°N, 104.69°W

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The named rock units Trinacromerum has been recovered from, largest first. Drawn where the rock is now, not where it formed. 3 occurrences have no formation on record, which is common for older literature.

Trinacromerum and its relatives

Late Cretaceous

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

Found in the same rock

8 taxa

The Paleobiology Database records 18 sites for Trinacromerum, and this reads all of them. The number is how many of those sites it was catalogued from too.

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

8 references

Each of the 18 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 Trinacromerum

Credit
Thomas Quine
Licence
CC BY 2.0
Commercial use
the licence allows it

No 3D scan of Trinacromerum 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 itPolycotylinae through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Cragin 1888