Calyptaulax
Calyptaulax is a genus of trilobites in the order Phacopida that existed during the middle and upper Ordovician in what is now the U.S. states of New York, Pennsylvania, Oklahoma, Illinois, Missouri, Virginia, Vermont, Nevada, Iowa, Wisconsin, Kentucky, and Iowa, as well as the Canadian provinces of Ontario, Newfoundland and Labrador, Quebec, and the territory of Nunavut. Other countries Calyptaulax fossils are known from include Ireland, Norway, Russia, and the United Kingdom.

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
- EomonorachinaePBDB
- Diet
- carnivorePBDB, for Phacopina
- Life habit
- low-level epifaunalPBDB, for Trilobita
- Motility
- fast-movingPBDB, for Trilobita
- Vision
- well-developedPBDB, for Pterygometopidae
- Environment
- marinePBDB, for Trilobita
Time the record covers
At least 26 million years on record.
The record covers at least 471.3 Mya to 445.2 Mya. No occurrence read is dated outside 488.9 Mya to 443.1 Mya.
273 occurrences of Calyptaulax 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
273 occurrences- Cambrianunder 1%
- Ordovician100%
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
85 formations
- Esbataottine Formation20
- Edinburg Formation17
- Crown Point Formation · Chazy Group16
- Witten Limestone Formation14
- Copenhagen Formation11
- Whittaker Formation10
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The named rock units Calyptaulax has been recovered from, largest first. Drawn where the rock is now, not where it formed. 61 further formations hold fewer occurrences each and are not listed. 13 occurrences have no formation on record, which is common for older literature.
Calyptaulax and its relatives
OrdovicianWhere Calyptaulax and its relatives were recorded in the Ordovician.
Found in the same rock
1,559 taxa- Isotelus48 sites
- Remopleurides35 sites
- Amphilichas33 sites
- Sphaerocoryphe31 sites
- Strophomena31 sites
- Krausella27 sites
- Sowerbyella27 sites
- Sphaerexochus25 sites
- Tetradium24 sites
- Ceraurus23 sites
- Illaenus23 sites
- Lonchodomas23 sites
- Bumastoides22 sites
- Anazyga recurvirostra21 sites
- Isotelus harrisi21 sites
- Rafinesquina21 sites
- Orthoceras20 sites
- Strophomena incurvata20 sites
- Bathyurus19 sites
- Tretaspis19 sites
- Dolichoharpes reticulata18 sites
- Isochilina18 sites
- Leperditella18 sites
- Dalmanella17 sites
The Paleobiology Database records 258 sites for Calyptaulax, and this reads 240 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
76 references- Stratigraphy of the Lower Middle Ordovician of Tazewell County, Virginia24
- The Chazy Formation and its fauna16
- Ordovician formations and faunas, southern Mackenzie Mountains14
- Silicified Middle Ordovician trilobites from the South Nahanni River Area, District of Mackenzie, Canada13
- Early Middle Ordovician (Chazy) trilobites of New York13
- The Ashgill Trilobites of the Oslo Region, Norway11
- Trilobite Biofacies along an Ordovician (Sandbian) Carbonate Buildup to Basin Gradient, Southwestern Virginia10
- Trilobites from the Ordovician Balclatchie and lower Ardwell groups of the Girvan district, Scotland10
- A trilobite zonation of Middle Ordovician rocks, southwestern District of Mackenzie9
- Ordovician Sedimentary Basin and Paleobiotas of the Gorny Altai8
- Ordovician Brachiopods, Trilobites, and Stratigraphy in Eastern and Central Nevada8
- Palaeozoic geology of the Lake Simcoe Area, Ontario8
Each of the 273 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. 64 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 Calyptaulax
- Source
- iDigBio
- Credit
- via iDigBio
- Licence
- CC0
- Commercial use
- the licence allows it
No 3D scan was found. Smithsonian Open Access, MorphoSource and Sketchfab were all searched.
The description on this site
- Source
- Wikipedia, “Calyptaulax”
- 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 itEomonorachinae through timeFormations of the OrdovicianThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Cooper 1930