Hexameroceras
Hexameroceras is a genus of nautiloid cephalopods belonging to the order Oncocerida that lived during the middle and late Silurian. Its fossils have been found in North America in Indiana, New York, Ohio, and Wisconsin, and in Europe in the Czech Republic.

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
- HemiphragmoceratidaePBDB
- Diet
- carnivorePBDB, for Oncocerida
- Life habit
- nektobenthicPBDB, for Oncocerida
- Motility
- fast-movingPBDB, for Cephalopoda
- Vision
- well-developedPBDB, for Cephalopoda
- Environment
- marinePBDB, for Cephalopoda
Time the record covers
At least 4 million years on record.
The record covers at least 426.7 Mya to 422.7 Mya. No occurrence read is dated outside 443.1 Mya to 419.62 Mya.
12 occurrences of Hexameroceras on record, most of them in the Silurian. 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
12 occurrences- Silurian100%
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
9 formations
- Syracuse Formation · Salina Group2
- Louisville Formation2
- Louisville Limestone Formation1
- Raisin River Formation1
- Racine Formation1
- Pozary Formation1
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The named rock units Hexameroceras 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.
Hexameroceras and its relatives
SilurianWhere Hexameroceras and its relatives were recorded in the Silurian.
Found in the same rock
276 taxa- Camarotoechia5 sites
- Kionoceras5 sites
- Whitfieldella5 sites
- Conularia4 sites
- Phragmoceras4 sites
- Pterinea4 sites
- Actinopteria3 sites
- Atrypa3 sites
- Bivalvia3 sites
- Calymene3 sites
- Caryocrinites3 sites
- Ceratiocaris3 sites
- Conchidium3 sites
- Dawsonoceras3 sites
- Hormotoma3 sites
- Platyceras3 sites
- Pterygotus3 sites
- Spyroceras3 sites
- Actinopterella2 sites
- Acutiramus bohemicus2 sites
- Ascoceras2 sites
- Boucia2 sites
- Cardiolinka2 sites
- Ceratiocaris bohemica2 sites
The Paleobiology Database records 11 sites for Hexameroceras, 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
9 references- Stratigraphy of Upper Silurian Cayugan Evaporites3
- Stratigraphy, structure, and zonation of large Silurian reef at Delphi, Indiana2
- A Silurian oncocerid with preserved colour pattern and muscle scars (Nautiloidea)1
- Geology of the Barrandian: A Field Trip Guide. Senckenberg-Buchen, Frankfurt1
- The Silurian (Wenlockian) reef fauna of Southeastern Wisconsin1
- Silurian field excursions: Prague Basin (Barrandian), Bohemia1
- Silurian reefs of northern Indiana: reef and interreef macrofaunas1
- Lithology, Paleoecology and Paleontology of the Vernon Shale (Late Silurian) in the Type Area1
- Faunal stratigraphy of Syracuse Formation, Onondaga and Madison Counties, New York1
Each of the 12 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 Hexameroceras
- Source
- iDigBio
- Credit
- via iDigBio
- Licence
- CC0
- Commercial use
- the licence allows it
No 3D scan of Hexameroceras was found in MorphoSource and Sketchfab.
Smithsonian Open Access was 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 itHemiphragmoceratidae through timeFormations of the SilurianThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Hyatt 1884