Periarchus

via iDigBio · CC0 · via iDigBio. 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
- ProtoscutellidaePBDB
- Diet
- detritivorePBDB, for Clypeasteroida
- Life habit
- semi-infaunalPBDB, for Clypeasteroida
- Motility
- slow-movingPBDB, for Clypeasteroida
- Vision
- limitedPBDB, for Echinoidea
- Environment
- marinePBDB, for Echinodermata
Time the record covers
At least 3.3 million years on record.
The record covers at least 41.03 Mya to 37.71 Mya. No occurrence read is dated outside 56 Mya to 33.9 Mya.
82 occurrences of Periarchus on record, most of them in the Eocene. 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
82 occurrences- Eocene100%
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
14 formations
- Moodys Branch Formation · Jackson Group25
- Castle Hayne Formation · Jackson Group23
- Yazoo Clay Formation · Jackson Group7
- Lisbon Formation · Claiborne Group5
- Inglis Limestone Formation · Ocala Group4
- Santee Limestone Formation3
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The named rock units Periarchus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 4 occurrences have no formation on record, which is common for older literature.
Periarchus and its relatives
EoceneWhere Periarchus and its relatives were recorded in the Eocene.
Found in the same rock
432 taxa- Chlamys25 sites
- Chlamys deshayesii16 sites
- Gigantostrea trigonalis15 sites
- Echinolampas appendiculata14 sites
- Ostrea14 sites
- Vertebrata13 sites
- Cidaris pratti11 sites
- Venericardia11 sites
- Chlamys nupera10 sites
- Turritella10 sites
- Flabellum9 sites
- Linthia hanoverensis9 sites
- Chlamys cookei8 sites
- Eburneopecten scintillatus8 sites
- Plicatoria wilmingtonensis8 sites
- Calyptraea (Trochita) aperta7 sites
- Dentalium7 sites
- Maretia7 sites
- Protoscutella plana7 sites
- Conus6 sites
- Cubitostrea sellaeformis6 sites
- Linthia wilmingtonensis6 sites
- Paraster armiger6 sites
- Bathytormus flexurus5 sites
The Paleobiology Database records 76 sites for Periarchus, 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
15 references- Stratigraphic Distribution of Paleocene and Eocene Fossils in the Eastern Gulf Coast Region38
- The Echinoids of the Middle Eocene Warley Hill Formation, Santee Limestone, and Castle Hayne Limestone of North and South Carolina15
- Paleontology and Stratigraphy of the Castle Hayne and Trent Marls in North Carolina7
- The Mesozoic and Cenozoic Echinodermata of the United States5
- Eocene biostratigraphy of South Carolina and its relationship to Gulf Coastal Plain zonations and global changes of coastal onlap4
- Invertebrate Macropaleontolgy of the Clarke County Mississippi Area3
- Eocene Mollusks from Citrus and Levy Counties, Florida2
- Stratigraphy of outcropping Eocene and Oligocene formations-Coastal Plain of the Carolinas1
- Diversity patterns and biostratigraphy of Cenozoic echinodems from Florida1
- North American Eocene sea cows (Mammalia: Sirenia)1
- Echinoids from the Middle Eocene Lake City Formation of Georgia1
- Geologic section exposed in Lone Star Cement Company quarry at St. Stephens Bluff on Tombigbee River, 2 2 miles northeast of the present town of St Stephens, Ala1
Each of the 82 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. 3 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 Periarchus
- Source
- iDigBio
- Credit
- via iDigBio
- Licence
- CC0
- Commercial use
- the licence allows it
No 3D scan of Periarchus 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.
This is what the site found, which is not the same as what exists.
Keep going
What may have been alongside itProtoscutellidae through timeFormations of the EoceneThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Conrad 1866