Psiloceras

Psiloceras is an extinct genus of ammonite. Psiloceras is among the earliest known Jurassic ammonites, and the appearance of the earliest Psiloceras species form the definition for the base of the Jurassic. Unlike most earlier ammonites, which had complex shell shapes and ornamentation, Psiloceras had a smooth shell.

Psiloceras

Daderot · CC0 · 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
PsiloceratidaePBDB
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 63 million years on record.

Every occurrence read is dated to somewhere between 237 Mya and 174.7 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Middle Triassic — about 0 of 189 occurrencesLate Triassic — about 3 of 189 occurrencesLate TriassicEarly Jurassic — about 186 of 189 occurrencesEarly JurassicMiddle Jurassic — about 0 of 189 occurrences238–236 Mya — about 0.0 occurrences236–234 Mya — about 0.1 occurrences234–232 Mya — about 0.1 occurrences232–230 Mya — about 0.1 occurrences230–227 Mya — about 0.1 occurrences227–225 Mya — about 0.1 occurrences225–223 Mya — about 0.1 occurrences223–221 Mya — about 0.1 occurrences221–219 Mya — about 0.1 occurrences219–217 Mya — about 0.1 occurrences217–214 Mya — about 0.1 occurrences214–212 Mya — about 0.1 occurrences212–210 Mya — about 0.1 occurrences210–208 Mya — about 0.1 occurrences208–206 Mya — about 0.1 occurrences206–204 Mya — about 1 occurrence204–202 Mya — about 1 occurrence202–199 Mya — about 182 occurrences199–197 Mya — about 0.8 occurrences197–195 Mya — about 0.8 occurrences195–193 Mya — about 0.8 occurrences193–191 Mya — about 0.1 occurrences191–189 Mya — about 0.1 occurrences189–186 Mya — about 0.1 occurrences186–184 Mya — about 0.1 occurrences184–182 Mya — about 0.1 occurrences182–180 Mya — about 0.1 occurrences180–178 Mya — about 0.1 occurrences178–176 Mya — about 0.1 occurrences176–173 Mya — about 0.0 occurrences238 Mya173 Mya

189 occurrences of Psiloceras 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

189 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

25 formations

Sunrise — 38.49°N, 118.08°WFernie — 56.10°N, 123.04°WSandilands — 53.91°N, 133.15°WSandilands — 53.90°N, 133.15°WSandilands — 52.76°N, 131.56°WKendlbach — 47.48°N, 11.53°EChilingote — 6.66°S, 77.80°WBlue Lias — 50.00°N, 2.00°WBlue Lias — 51.00°N, 3.00°WBlue Lias — 51.17°N, 3.27°WBlue Lias — 50.80°N, 3.03°WAramachay — 6.38°S, 77.90°WAramachay — 9.28°S, 75.99°WGermig — 28.70°N, 86.14°ELos Molles — 32.24°S, 71.51°WGabbs — 38.49°N, 118.08°WKendelbach — 47.48°N, 11.46°EKingak — 68.33°N, 137.75°WKingak — 68.16°N, 137.97°WGijon — 43.43°N, 5.53°WGijon — 43.48°N, 5.27°WSchnöll — 47.70°N, 13.17°ECsovar Limestone — 47.82°N, 19.33°ENgutunui — 38.30°S, 174.70°EArroyo Malo — 34.80°S, 69.87°WWhite Lias — 51.12°N, 2.73°WLast Creek — 51.10°N, 123.01°WZlambach — 47.64°N, 13.66°EGijón — 43.48°N, 5.18°WLower Lias — 51.80°N, 1.88°WSuta — 6.50°S, 77.73°WPan Azúcar — 26.11°S, 70.43°W

Loading coastlines…

The named rock units Psiloceras has been recovered from, largest first. Drawn where the rock is now, not where it formed. One further formation holds fewer occurrences and is not listed. 79 occurrences have no formation on record, which is common for older literature.

Psiloceras and its relatives

Early Jurassic

Where Psiloceras and its relatives were recorded in the Early Jurassic.

Found in the same rock

222 taxa

The Paleobiology Database records 65 sites for Psiloceras, 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

33 references

Each of the 189 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. 21 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 content1

Picture of Psiloceras

Credit
Daderot
Licence
CC0
Commercial use
the licence allows it

No 3D scan was found. Smithsonian Open Access, MorphoSource and Sketchfab were all searched.

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 itPsiloceratidae through timeFormations of the Early JurassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0.