Petraster

Petraster is a genus of extinct starfish that lived from the upper Ordovician to the late Silurian. The genus has a large distribution range, fossils have been found in North America, and Australia.

Petraster

Bloopityboop · 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
PalasterinidaePBDB
Diet
carnivorePBDB, for Asteroidea
Life habit
low-level epifaunalPBDB, for Asteroidea
Motility
slow-movingPBDB, for Asteroidea
Vision
limitedPBDB, for Asteroidea
Environment
marinePBDB, for Echinodermata

Time the record covers

At least 22 million years on record.

The record covers at least 449.6 Mya to 426.7 Mya. No occurrence read is dated outside 457.3 Mya to 422.7 Mya.

Ordovician — about 7 of 8 occurrencesOrdovicianSilurian — about 1 of 8 occurrencesSilurian458–457 Mya — about 0.1 occurrences457–456 Mya — about 0.2 occurrences456–454 Mya — about 0.2 occurrences454–453 Mya — about 0.2 occurrences453–452 Mya — about 0.3 occurrences452–451 Mya — about 0.3 occurrences451–450 Mya — about 1 occurrence450–448 Mya — about 0.9 occurrences448–447 Mya — about 0.9 occurrences447–446 Mya — about 0.9 occurrences446–445 Mya — about 0.8 occurrences445–444 Mya — about 0.7 occurrences444–442 Mya — about 0.3 occurrences427–426 Mya — about 0.3 occurrences426–424 Mya — about 0.3 occurrences424–423 Mya — about 0.3 occurrences423–422 Mya — about 0.1 occurrences449.6 Mya426.7 Mya458 Mya422 Mya

8 occurrences of Petraster 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

8 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

Fairview — 39.00°N, 84.00°WCorryville — 39.00°N, 84.00°WWaynesville — 39.00°N, 84.00°WLiberty — 39.00°N, 84.00°WWhitewater — 39.00°N, 84.00°WBromide — 34.00°N, 97.00°WKermeur — 48.23°N, 4.50°W

Loading coastlines…

The named rock units Petraster has been recovered from, largest first. Drawn where the rock is now, not where it formed. 1 occurrence has no formation on record, which is common for older literature.

Petraster and its relatives

Ordovician

Where Petraster and its relatives were recorded in the Ordovician.

Found in the same rock

274 taxa

The Paleobiology Database records 8 sites for Petraster, 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

4 references

Each of the 8 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 content2

Picture of Petraster

Credit
Bloopityboop
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 itPalasterinidae through timeFormations of the OrdovicianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Billings 1858