Ellesmerocerida
The Ellesmerocerida is an extinct order of primitive cephalopods belonging to the subclass Nautiloidea with a widespread distribution that lived during the Late Cambrian and Ordovician.

The original uploader was Apokryltaros at English Wikipedia . · CC BY-SA 3.0 · via Wikidata/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
- CephalopodaPBDB
- Diet
- carnivorePBDB, for Cephalopoda
- Life habit
- nektobenthic, solitaryPBDB
- Motility
- actively mobilePBDB
- Vision
- well-developedPBDB, for Cephalopoda
- Environment
- marinePBDB
Time the record covers
At least 37 million years on record.
The record covers at least 486.85 Mya to 449.5 Mya. No occurrence read is dated outside 497 Mya to 443.1 Mya.
746 occurrences of Ellesmerocerida 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
746 occurrences- Cambrian9%
- Ordovician91%
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
111 formations
- Gasconade Formation57
- Oneota Dolomite Formation54
- Great Meadows Formation52
- Tanyard Formation · Ellenburger Group45
- Siyangshan Formation43
- Chepultepec Formation · Knox Group37
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The named rock units Ellesmerocerida has been recovered from, largest first. Drawn where the rock is now, not where it formed. 87 further formations hold fewer occurrences each and are not listed. 71 occurrences have no formation on record, which is common for older literature.
Ellesmerocerida and its relatives
OrdovicianWhere Ellesmerocerida and its relatives were recorded in the Ordovician.
Found in the same rock
1,395 taxa- Protocycloceras59 sites
- Ellesmeroceras20 sites
- Didymograptus19 sites
- Dideroceras15 sites
- Chisiloceras13 sites
- Ecculiomphalus13 sites
- Megalaspides13 sites
- Dakeoceras12 sites
- Endoceras12 sites
- Yangtzeella12 sites
- Asaphellus11 sites
- Illaenus11 sites
- Protocycloceras lamarcki11 sites
- Bathmoceras10 sites
- Drepanodus10 sites
- Orthis10 sites
- Scolopodus10 sites
- Clarkoceras9 sites
- Geragnostus9 sites
- Neseuretus9 sites
- Nileus9 sites
- Protopanderodus9 sites
- Saloceras sericeum9 sites
- Vaginoceras9 sites
The Paleobiology Database records 340 sites for Ellesmerocerida, 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
84 references- Ozarkian and Canadian cephalopods. Part II, Brevicones221
- The Nautiloid Order Ellesmeroceratida (Cephalopoda)90
- Ozarkian and Canadian cephalopods, longicones and summary57
- The Cambrian trilobites of western Zhejiang37
- The Lower Ordovician cephalopod faunas of the Durness Group, North-West Scotland35
- Part II - Fossils from the Smith Basin Limestone of the Fort Ann Region New York23
- The Earliest Ordovician Cephalopods of Eastern Laurentia - Ellesmerocerids of the Tribes Hill Formation, Eastern New York22
- Regional Stratigraphic Table of North China18
- The Lower and Middle Ordovician cephalopod faunas of England and Wales16
- Early Ordovician nautiloids from Virginia14
- Onset of the Ordovician cephalopod radiation - evidence from the Rochdale Formation (middle Early Ordovician, Stairsian)in eastern New York13
- Stratigraphic Summary of the Southwestern Region of China12
Each of the 746 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. 72 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 Ellesmerocerida
- Source
- Wikidata/Commons
- Credit
- The original uploader was Apokryltaros at English Wikipedia .
- Licence
- CC BY-SA 3.0
- Commercial use
- the licence allows it
No 3D scan of Ellesmerocerida 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.
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 itCephalopoda through timeFormations of the OrdovicianThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Flower and Kummel 1950