Dactylioceras
Dactylioceras was a widespread genus of ammonites from the Lower Jurassic period, approximately 180 million years ago (mya).Like many other ammonites, the genus Dactylioceras is extremely important in biostratigraphy, being a key index fossil for identifying their region of the Jurassic. It had a nearly cosmopolitan distribution during the time it existed.

Kevmin · CC BY-SA 3.0 · 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
- DactylioceratinaePBDB
- Diet
- carnivorePBDB, for Ammonoidea
- Life habit
- nektonicPBDB, for Ammonoidea
- Motility
- fast-movingPBDB, for Ammonoidea
- Vision
- well-developedPBDB, for Cephalopoda
- Environment
- marinePBDB, for Cephalopoda
Time the record covers
At least 19 million years on record.
The record covers at least 199.5 Mya to 180.4 Mya. No occurrence read is dated outside 201.4 Mya to 161.5 Mya.
496 occurrences of Dactylioceras on record, most of them in the Early Jurassic. 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
496 occurrences- Early Jurassic100%
- Middle Jurassicunder 1%
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
49 formations
- Nishinakayama Formation · Toyora Group35
- Alum Shale Formation35
- Camino Formation35
- Sunrise Formation15
- Spatsizi Formation · Hazelton Group13
- Jet Rock Formation13
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The named rock units Dactylioceras has been recovered from, largest first. Drawn where the rock is now, not where it formed. 25 further formations hold fewer occurrences each and are not listed. 179 occurrences have no formation on record, which is common for older literature.
Dactylioceras and its relatives
Early JurassicWhere Dactylioceras and its relatives were recorded in the Early Jurassic.
Found in the same rock
275 taxa- Harpoceras39 sites
- Ammonoidea28 sites
- Parainoceramya matsumotoi22 sites
- Fuciniceras20 sites
- Lytoceras20 sites
- Harpoceras falciferum19 sites
- Ammonitina15 sites
- Hildaites murleyi14 sites
- Eleganticeras exaratum13 sites
- Phylloceras heterophyllum13 sites
- Protogrammoceras12 sites
- Calliphylloceras11 sites
- Hildoceras sublevisoni11 sites
- Nodicoeloceras11 sites
- Hildaites subserpentinus10 sites
- Hildoceras crassum10 sites
- Lioceratoides9 sites
- Nodicoeloceras crassoides9 sites
- Peronoceras9 sites
- Phylloceras9 sites
- Bositra buchi8 sites
- Hildaites8 sites
- Hildaites striatus8 sites
- Phymatoceras8 sites
The Paleobiology Database records 297 sites for Dactylioceras, 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
71 references- The Jet Rock Series and the Alum Shale Series of the Yorkshire coast48
- Toarcian (Early Jurassic) ammonoids from western North America46
- Lower Toarcian ammonite and foraminifera assemblages in the San Miguel de Aguayo Section (Basque-Cantabrian Basin, Spain)35
- Early Jurrasic Macrofauna of the Oxygen-Depleted Epicontinental Marin Basin in the Toyora Area, West Japan35
- The Toarcian in the Subbetic basin (southern Spain): Bio-events (ammonite and calcareous nannofossils) and carbon-isotope stratigraphy33
- Les Harpoceratinae, Hildoceratinae et Parinoceratinae du Toarcien de la Vendée et des Deux-Sèvres (France)27
- Warming-driven mass extinction in the Early Toarcian (Early Jurassic) of northern and central Spain. Correlation with other time-equivalent European sections24
- Biozonación del Toarciense en el área de La Almunia de Doña Godina-Ricla (Sector Central de la Cordillera Ibérica)18
- Pliensbachian–Toarcian (Early Jurassic) Ammonoids from the Luning Embayment, West-Central Nevada, U.S.A.15
- Évolution et systématique des Phymatoceratinae et des Grammoceratinae (Hildocerataceae Ammonitina) de la région de Thouars, stratotype du Toarcien14
- High-resolution carbon isotope records of the Toarcian Oceanic Anoxic Event (Early Jurassic) from North America and implications for the global drivers of the Toarcian carbon cycle12
- Early Toarcian (post-OAE) Hildoceratinae (Ammonitina) fauna from the Marchean Apennines (Italy)10
Each of the 496 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. 59 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 content2
Picture of Dactylioceras
- Source
- Wikipedia/Commons
- Credit
- Kevmin
- Licence
- CC BY-SA 3.0
- Commercial use
- the licence allows it
3D model
- Source
- Sketchfab
- Licence
- CC Attribution
- Commercial use
- cannot be read from the licence given — check the record
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 itDactylioceratinae through timeFormations of the Early JurassicThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. (Hyatt 1867)