Heterodontus francisci

The horn shark is a species of bullhead shark, in the family Heterodontidae. It is endemic to the coastal waters off the western coast of North America, from California to the Gulf of California. Young sharks are segregated spatially from the adults, with the former preferring deeper sandy flats and the latter preferring shallower rocky reefs or algal beds. A small species typically measuring 1 m (3.3 ft) in length, the horn shark can be recognized by a short, blunt head with ridges over its eyes, two high dorsal fins with large spines, and a brown or gray coloration with many small dark spots.

Heterodontus francisci

Cymothoa exigua · 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
Also called
horn sharkPBDB
Sits inside
HeterodontusPBDB
Diet
carnivorePBDB, for Chondrichthyes
Life habit
nektonicPBDB, for Chondrichthyes
Motility
actively mobilePBDB, for Chondrichthyes

Time the record covers

At least 15 million years on record.

The record covers at least 15.98 Mya to 11.7 ka. No occurrence read is dated outside 23.04 Mya to 0 Mya.

Oligocene — about 0 of 11 occurrencesMiocene — about 1 of 11 occurrencesMiocenePliocene — about 3 of 11 occurrencesPliocenePleistocene — about 6 of 11 occurrencesPleistocene24–23 Mya — about 0.0 occurrences23–22 Mya — about 0.1 occurrences22–21 Mya — about 0.1 occurrences21–20 Mya — about 0.1 occurrences20–20 Mya — about 0.1 occurrences20–19 Mya — about 0.1 occurrences19–18 Mya — about 0.1 occurrences18–17 Mya — about 0.1 occurrences17–16 Mya — about 0.1 occurrences16–16 Mya — about 0.1 occurrences5.5–4.7 Mya — about 0.7 occurrences4.7–3.9 Mya — about 0.9 occurrences3.9–3.1 Mya — about 0.9 occurrences3.1–2.4 Mya — about 0.6 occurrences785 ka–0 Mya — about 7 occurrences15.98 Mya11.7 ka23.5 Mya0 Mya

11 occurrences of Heterodontus francisci on record, most of them in the Pleistocene. The Paleobiology Database records this as a living group. 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

11 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

4 formations

Palos Verdes Sand — 33.66°N, 117.90°WPalos Verdes Sand — 33.60°N, 117.88°WPalos Verdes Sand — 33.75°N, 118.29°WPalos Verdes Sand — 33.75°N, 118.29°WCoquimbo — 30.00°S, 71.33°WCoquimbo — 30.32°S, 71.44°WTimms Point Silt — 33.73°N, 118.28°WNavidad — 33.91°S, 71.84°W

Loading coastlines…

The named rock units Heterodontus francisci has been recovered from, largest first. Drawn where the rock is now, not where it formed. 1 occurrence has no formation on record, which is common for older literature.

Heterodontus francisci and its relatives

Pleistocene

Where Heterodontus francisci and its relatives were recorded in the Pleistocene.

Found in the same rock

651 taxa

The Paleobiology Database records 11 sites for Heterodontus francisci, 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

7 references

Each of the 11 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 content1

Picture of Heterodontus francisci

Credit
Cymothoa exigua
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

No 3D scan of Heterodontus francisci 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 itHeterodontus through timeFormations of the PleistoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Girard 1855)