Asteroceras obtusum
Asteroceras is an extinct genus of cephalopod belonging to the Ammonite subclass. These fast-moving nektonic carnivores lived during the Triassic and Jurassic periods.

Dlloyd · 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
- AsterocerasPBDB
- 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 most 6.6 million years on record.
Every occurrence read is dated to somewhere between 199.5 Mya and 192.9 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.
7 occurrences of Asteroceras obtusum 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
7 occurrences- Early Jurassic100%
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
1 formation
- Lower Lias Formation · Lias Group1
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The named rock units Asteroceras obtusum has been recovered from, largest first. Drawn where the rock is now, not where it formed. 6 occurrences have no formation on record, which is common for older literature.
Asteroceras obtusum and its relatives
Early JurassicWhere Asteroceras obtusum and its relatives were recorded in the Early Jurassic.
Found in the same rock
88 taxa- Angulaticeras2 sites
- Arnioceras2 sites
- Asteroceras stellare2 sites
- Eparietites denotatus2 sites
- Otapiria marshalli2 sites
- Xipheroceras2 sites
- Agassiceras1 site
- Agassiceras scipionianum1 site
- Ammonites collenotii1 site
- Ammonitida1 site
- Angulaticeras boucaultianum1 site
- Angulaticeras lacunatum1 site
- Angulaticeras leigneletii1 site
- Anningella1 site
- Arietites1 site
- Arnioceras arnouldi1 site
- Arnioceras ceratitoides1 site
- Arnioceras cuneiforme1 site
- Arnioceras miserabile1 site
- Arnioceras robustum1 site
- Arnioceras semicostatum1 site
- Asteroceras margarita1 site
- Bakevellia1 site
- Brochocoleus maculatus1 site
The Paleobiology Database records 6 sites for Asteroceras obtusum, 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
6 references- First record of the Early Jurassic Lupherella fauna (Bivalvia) in eastern Guangdong, southeast China2
- Stratigraphische Untersuchungen im Unterjura des Südteils der Provinz Antofagasta in Nord-Chile1
- The systematics and palaeogeography of the Lower Jurassic insects of Dorset, England1
- The Liassic Ammonite Faunas of the Stowell Park Borehole1
- On the Zone of Avicula contorta, and the Lower Lias of the South of England1
- Paléontologie Française - Description zoologique et géologique de tous les animaux mollusques et rayonnés fossiles de France - Terrains jurassiques. [Céphalopodes]1
Each of the 7 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 content2
Picture of Asteroceras obtusum
- Source
- Wikipedia/Commons
- Credit
- Dlloyd
- Licence
- CC BY-SA 3.0
- Commercial use
- the licence allows it
3D model
- Source
- Sketchfab
- Licence
- CC0 Public Domain
- Commercial use
- the licence allows it
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
- Source
- Wikipedia, “Asteroceras”
- 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 itAsteroceras through timeFormations of the Early JurassicThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. (Sowerby 1817)