Asthenoceras

Asthenoceras is a genus of ammonoid from the Middle Jurassic with dwarfish, evolute, smooth, compressed, discoidal, strongly keeled shell. Asthenoceras belongs to the Sonniniidae and may be a subgenus of the Lower Jurassic Grammoceras.

No picture of Asthenoceras is on file. This entry was cached before the site began recording which collections were searched, so one that had nothing cannot be told from one that was never asked.

On record

Recorded, not inferred
Sits inside
WitchelliinaePBDB
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 6.5 million years on record.

Every occurrence read is dated to somewhere between 174.7 Mya and 168.2 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Early Jurassic — about 0 of 12 occurrencesMiddle Jurassic — about 12 of 12 occurrencesMiddle Jurassic175–174 Mya — about 0.4 occurrences174–174 Mya — about 0.4 occurrences174–174 Mya — about 0.4 occurrences174–174 Mya — about 0.4 occurrences174–173 Mya — about 0.4 occurrences173–173 Mya — about 0.4 occurrences173–173 Mya — about 0.4 occurrences173–173 Mya — about 0.4 occurrences173–172 Mya — about 0.4 occurrences172–172 Mya — about 0.4 occurrences172–172 Mya — about 0.4 occurrences172–172 Mya — about 0.4 occurrences172–171 Mya — about 0.4 occurrences171–171 Mya — about 0.4 occurrences171–171 Mya — about 0.4 occurrences171–171 Mya — about 0.5 occurrences171–170 Mya — about 0.6 occurrences170–170 Mya — about 0.6 occurrences170–170 Mya — about 0.6 occurrences170–170 Mya — about 0.6 occurrences170–169 Mya — about 0.6 occurrences169–169 Mya — about 0.6 occurrences169–169 Mya — about 0.6 occurrences169–169 Mya — about 0.6 occurrences169–168 Mya — about 0.5 occurrences168–168 Mya — about 0.4 occurrences175.2 Mya167.7 Mya

12 occurrences of Asthenoceras on record, most of them in the Middle 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

12 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

3 formations

Agoudim — 32.24°N, 4.26°WKialagvik — 57.31°N, 156.42°WSnowshoe — 44.47°N, 119.53°W

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The named rock units Asthenoceras has been recovered from, largest first. Drawn where the rock is now, not where it formed.

Asthenoceras and its relatives

Middle Jurassic

Where Asthenoceras and its relatives were recorded in the Middle Jurassic.

Found in the same rock

42 taxa

The Paleobiology Database records 12 sites for Asthenoceras, 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

3 references

Each of the 12 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 content0

No picture of Asthenoceras is on file.

This entry was cached before the site began recording which collections were searched, so one that had nothing cannot be told from one that was never asked.

No 3D scan is on file for Asthenoceras.

This entry was cached before the site began recording what Smithsonian Open Access, MorphoSource and Sketchfab did, so a search that failed cannot be told from one that found nothing.

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 itWitchelliinae through timeFormations of the Middle JurassicThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0.