Hildoceras bifrons

Hildoceras bifrons is an extinct species of ammonite in the family Hildoceratidae. It dates from about 175 million years ago in the Early Jurassic when it was both widespread and common. Fossils have been found in North Africa and Europe, including several regions of England.

Hildoceras bifrons

Hildoceras_bifrons_Bruguière.jpg : Notafly derivative work: Cwmhiraeth · 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
HildocerasPBDB
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 9.5 million years on record.

Every occurrence read is dated to somewhere between 184.2 Mya and 174.7 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Early Jurassic — about 127 of 127 occurrencesEarly JurassicMiddle Jurassic — about 0 of 127 occurrences184–184 Mya — about 0.5 occurrences184–184 Mya — about 0.9 occurrences184–183 Mya — about 0.9 occurrences183–183 Mya — about 0.9 occurrences183–183 Mya — about 5 occurrences183–182 Mya — about 6 occurrences182–182 Mya — about 6 occurrences182–182 Mya — about 6 occurrences182–181 Mya — about 6 occurrences181–181 Mya — about 6 occurrences181–181 Mya — about 6 occurrences181–180 Mya — about 5 occurrences180–180 Mya — about 5 occurrences180–179 Mya — about 5 occurrences179–179 Mya — about 5 occurrences179–179 Mya — about 5 occurrences179–178 Mya — about 5 occurrences178–178 Mya — about 5 occurrences178–178 Mya — about 5 occurrences178–177 Mya — about 5 occurrences177–177 Mya — about 5 occurrences177–177 Mya — about 5 occurrences177–176 Mya — about 5 occurrences176–176 Mya — about 5 occurrences176–176 Mya — about 5 occurrences176–175 Mya — about 5 occurrences175–175 Mya — about 5 occurrences175–175 Mya — about 3 occurrences184.7 Mya174.2 Mya

127 occurrences of Hildoceras bifrons 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

127 occurrences

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

12 formations

Alum Shale — 54.49°N, 0.60°WAlum Shale — 54.40°N, 0.47°WBugarone — 43.33°N, 13.22°EMarnes de Fontaneilles — 43.85°N, 3.12°ECastillo Pedros — 42.89°N, 3.98°WSubbetic Basin — 37.59°N, 3.21°WSubbetic Basin — 38.13°N, 1.47°WKisgerecse — 47.70°N, 18.43°EKisgerecse Marl — 47.70°N, 18.49°ECamino — 43.05°N, 4.07°WOzirovo — 43.08°N, 23.23°EAdnet — 48.89°N, 19.08°EAït Athmane — 32.07°N, 4.38°WAmergou — 34.50°N, 5.13°W

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The named rock units Hildoceras bifrons has been recovered from, largest first. Drawn where the rock is now, not where it formed. 63 occurrences have no formation on record, which is common for older literature.

Hildoceras bifrons and its relatives

Early Jurassic

Where Hildoceras bifrons and its relatives were recorded in the Early Jurassic.

Found in the same rock

155 taxa

The Paleobiology Database records 112 sites for Hildoceras bifrons, 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

24 references

Each of the 127 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. 12 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 Hildoceras bifrons

Credit
Hildoceras_bifrons_Bruguière.jpg : Notafly derivative work: Cwmhiraeth
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

3D model

Source
Sketchfab
Licence
CC Attribution-NonCommercial-ShareAlike
Commercial use
the licence does not allow it

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 itHildoceras through timeFormations of the Early JurassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Bruguiere 1792)