Harpoceras
Harpoceras is an extinct genus of ammonite belonging to the family Hildoceratidae. These cephalopods existed in the Jurassic period, during the Toarcian age from the Falciferum zone to the Commune subzone of the Bifrons zone. They were fast-moving nektonic carnivores.

Lysippos · 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
- HarpoceratinaePBDB
- 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 29 million years on record.
The record covers at least 184.2 Mya to 154.8 Mya. No occurrence read is dated outside 201.4 Mya to 143.1 Mya.
448 occurrences of Harpoceras 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
448 occurrences- Early Jurassic99%
- Middle Jurassicunder 1%
- Late 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
38 formations
- Nishinakayama Formation · Toyora Group81
- Bugarone Formation30
- Camino Formation27
- Kisgerecse Formation23
- Jet Rock Formation17
- Kisgerecse Marl Formation14
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The named rock units Harpoceras has been recovered from, largest first. Drawn where the rock is now, not where it formed. 14 further formations hold fewer occurrences each and are not listed. 167 occurrences have no formation on record, which is common for older literature.
Harpoceras and its relatives
Early JurassicWhere Harpoceras and its relatives were recorded in the Early Jurassic.
Found in the same rock
235 taxa- Dactylioceras38 sites
- Ammonoidea35 sites
- Calliphylloceras27 sites
- Hildoceras sublevisoni27 sites
- Lytoceras26 sites
- Nodicoeloceras26 sites
- Parainoceramya matsumotoi25 sites
- Phylloceras22 sites
- Fuciniceras21 sites
- Hildaites murleyi21 sites
- Phylloceras doderleinianum21 sites
- Phylloceras heterophyllum19 sites
- Calliphylloceras nilssoni16 sites
- Ammonitina15 sites
- Lytoceras cornucopia15 sites
- Hildoceras14 sites
- Hildaites subserpentinus13 sites
- Pseudogibbirhynchia jurensis13 sites
- Hildoceras bifrons12 sites
- Hildoceras lusitanicum12 sites
- Polyplectus pluricostatus12 sites
- Hildoceras crassum11 sites
- Orthildaites douvillei11 sites
- Hildaites levisoni10 sites
The Paleobiology Database records 329 sites for Harpoceras, 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
64 references- Les Harpoceratinae, Hildoceratinae et Parinoceratinae du Toarcien de la Vendée et des Deux-Sèvres (France)83
- Early Jurrasic Macrofauna of the Oxygen-Depleted Epicontinental Marin Basin in the Toyora Area, West Japan81
- Lower Toarcian ammonite and foraminifera assemblages in the San Miguel de Aguayo Section (Basque-Cantabrian Basin, Spain)27
- Lower Toarcian Ammonitida fauna and biostratigraphy of the Gerecse Mountains (Hungary)24
- Cingolites n. gen., a new lower Toarcian Hildoceratinae (Ammonitina) from the Marchean Apennines (Cingoli, Macerata, Italy)19
- The Jet Rock Series and the Alum Shale Series of the Yorkshire coast16
- Évolution et systématique des Phymatoceratinae et des Grammoceratinae (Hildocerataceae Ammonitina) de la région de Thouars, stratotype du Toarcien15
- Toarcian (Early Jurassic) ammonoids from western North America14
- Early Toarcian (post-OAE) Hildoceratinae (Ammonitina) fauna from the Marchean Apennines (Italy)11
- Belemnites from the Upper Pliensbachian and the Toarcian (Lower Jurassic) of Tournadous (Causses, France)10
- Warming-driven mass extinction in the Early Toarcian (Early Jurassic) of northern and central Spain. Correlation with other time-equivalent European sections10
- Les Brachiopodes liasiques de la Bordure Sud du Massif Armoricain: Succession des peuplements et environnements ; chronostratigraphie9
Each of the 448 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. 52 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 Harpoceras
- Source
- Wikipedia/Commons
- Credit
- Lysippos
- Licence
- CC BY-SA 3.0
- Commercial use
- the licence allows it
3D model
- Source
- Sketchfab
- Credit
- Fossils in Shropshire
- Licence
- CC Attribution-NonCommercial
- Commercial use
- the licence does not allow 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, “Harpoceras”
- 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 itHarpoceratinae through timeFormations of the Early JurassicThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0.