Triarthrus

Triarthrus is a genus of Upper Ordovician ptychopariid trilobite found in New York, Ohio, Kentucky, and Indiana, eastern and northern Canada, China and Scandinavia. It is the last of the Olenid trilobites, a group which flourished in the Cambrian period. The specimens of T. eatoni that are found in the Beecher's Trilobite Bed, Rome, New York area are exquisitely preserved showing soft body parts in iron pyrite. Pyrite preservation has given scientists a rare opportunity to examine the gills, walking legs, antennae, digestive systems, and eggs of trilobites, which are rarely preserved. Triarthrus is therefore commonly used in science texts to illustrate trilobite anatomy and physiology.

Triarthrus

DardS8Br · 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
OleninaePBDB
Diet
carnivorePBDB, for Trilobita
Life habit
low-level epifaunalPBDB, for Trilobita
Motility
fast-movingPBDB, for Trilobita
Vision
well-developedPBDB, for Olenidae
Environment
marinePBDB, for Trilobita

Time the record covers

At least 28 million years on record.

The record covers at least 477.1 Mya to 449 Mya. No occurrence read is dated outside 486.85 Mya to 443.1 Mya.

Cambrian — about 0 of 150 occurrencesOrdovician — about 150 of 150 occurrencesOrdovicianSilurian — about 0 of 150 occurrences488–486 Mya — about 0.3 occurrences486–485 Mya — about 2 occurrences485–483 Mya — about 2 occurrences483–482 Mya — about 2 occurrences482–480 Mya — about 2 occurrences480–479 Mya — about 2 occurrences479–477 Mya — about 2 occurrences477–476 Mya — about 2 occurrences476–474 Mya — about 2 occurrences474–473 Mya — about 2 occurrences473–471 Mya — about 2 occurrences471–470 Mya — about 2 occurrences470–468 Mya — about 2 occurrences468–466 Mya — about 0.6 occurrences466–465 Mya — about 0.6 occurrences465–463 Mya — about 0.6 occurrences463–462 Mya — about 0.6 occurrences462–460 Mya — about 1 occurrence460–459 Mya — about 2 occurrences459–457 Mya — about 8 occurrences457–456 Mya — about 8 occurrences456–454 Mya — about 6 occurrences454–453 Mya — about 9 occurrences453–451 Mya — about 11 occurrences451–450 Mya — about 62 occurrences450–448 Mya — about 9 occurrences448–447 Mya — about 3 occurrences447–445 Mya — about 3 occurrences445–444 Mya — about 0.7 occurrences444–442 Mya — about 0.3 occurrences477.1 Mya449 Mya487.7 Mya442.2 Mya

150 occurrences of Triarthrus on record, most of them in the Ordovician. 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

150 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

44 formations

Kope — 39.00°N, 84.00°WKope — 39.03°N, 84.42°WKope — 39.05°N, 84.39°WKope — 38.80°N, 84.21°WKope — 38.77°N, 84.10°WWhitby — 45.50°N, 81.00°WWhitby — 43.88°N, 78.86°WWhitby — 43.87°N, 79.03°WWhitby — 43.80°N, 79.12°WWhitby — 44.53°N, 80.38°WLas Aguaditas — 30.33°S, 68.80°WLas Aguaditas — 30.40°S, 68.90°WAnderson Shale — 63.08°N, 14.48°EAnderson Shale — 63.19°N, 14.54°ENicolet River — 45.37°N, 73.44°WNicolet River — 46.00°N, 72.00°WNicolet River — 45.66°N, 72.93°WNicolet River — 45.79°N, 72.86°WPointe-Bleue Shale — 48.65°N, 71.22°WChasmops Limestone — 63.37°N, 15.06°EChasmops Limestone — 63.00°N, 14.63°EChasmops Limestone — 63.00°N, 14.73°EUtica Shale — 43.21°N, 75.46°WUtica Shale — 42.99°N, 74.80°WUtica Shale — 43.24°N, 75.26°WFjacka Shale — 61.00°N, 15.00°EFjacka Shale — 58.00°N, 12.00°EFjacka Shale — 60.00°N, 16.00°EUtica — 42.98°N, 74.82°WUtica — 42.99°N, 74.87°WYinzhupu — 28.00°N, 118.00°EYinzhupu — 29.00°N, 119.00°ERoad River — 62.12°N, 126.68°WRoad River — 61.63°N, 125.73°WVal d'Homs — 43.00°N, 3.00°EMacasty — 49.50°N, 63.00°WValhallfonna — 79.00°N, 18.00°ELorraine — 46.21°N, 72.32°WLorraine — 46.22°N, 72.62°WAmadjuak — 63.72°N, 68.97°WDaduhe — 27.57°N, 104.92°EÖrån Shale — 63.32°N, 14.98°EMalachis Hill — 33.22°S, 148.91°EMalachis Hill — 33.42°S, 148.95°EDolgeville Facies — 43.21°N, 75.46°WOnny Shale — 52.60°N, 2.55°WPerkins Canyon — 38.92°N, 116.87°WVenstop — 60.00°N, 11.00°E

Loading coastlines…

The named rock units Triarthrus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 20 further formations hold fewer occurrences each and are not listed. 26 occurrences have no formation on record, which is common for older literature.

Triarthrus and its relatives

Ordovician

Where Triarthrus and its relatives were recorded in the Ordovician.

Found in the same rock

598 taxa

The Paleobiology Database records 105 sites for Triarthrus, 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

53 references

Each of the 150 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. 41 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 content2

Picture of Triarthrus

Credit
DardS8Br
Licence
CC BY-SA 4.0
Commercial use
the licence allows it

3D model

Source
Sketchfab
Licence
CC0 Public Domain
Commercial use
the licence allows it

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 itOleninae through timeFormations of the OrdovicianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Green 1832