Ptychagnostus

Ptychagnostus is a genus of trilobites in the order Agnostida that lived during the Cambrian period. Their remains are rarely found in empty tubes of the polychaete worm Selkirkia. The genus probably ranged throughout the water column. It has two glabellar lobes, and three pygidial lobes.

Ptychagnostus

TheoricienQuantique · Public Domain · 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
PtychagnostidaePBDB
Diet
suspension feederPBDB
Life habit
nektonicPBDB
Motility
actively mobilePBDB
Vision
blindPBDB, for Ptychagnostidae

Time the record covers

At least 9.5 million years on record.

The record covers at least 506.5 Mya to 497 Mya. No occurrence read is dated outside 516.2 Mya to 486.85 Mya.

Cambrian — about 227 of 227 occurrencesCambrianOrdovician — about 0 of 227 occurrences517–516 Mya — about 0.0 occurrences516–515 Mya — about 0.1 occurrences515–514 Mya — about 0.1 occurrences514–513 Mya — about 0.1 occurrences513–512 Mya — about 0.1 occurrences512–511 Mya — about 0.1 occurrences511–510 Mya — about 0.1 occurrences510–509 Mya — about 0.3 occurrences509–508 Mya — about 2 occurrences508–507 Mya — about 3 occurrences507–506 Mya — about 22 occurrences506–505 Mya — about 31 occurrences505–504 Mya — about 31 occurrences504–503 Mya — about 31 occurrences503–502 Mya — about 31 occurrences502–501 Mya — about 31 occurrences501–499 Mya — about 16 occurrences499–498 Mya — about 11 occurrences498–497 Mya — about 10 occurrences497–496 Mya — about 5 occurrences496–495 Mya — about 0.5 occurrences495–494 Mya — about 0.3 occurrences494–493 Mya — about 0.3 occurrences493–492 Mya — about 0.3 occurrences492–491 Mya — about 0.3 occurrences491–490 Mya — about 0.3 occurrences490–489 Mya — about 0.3 occurrences489–488 Mya — about 0.3 occurrences488–487 Mya — about 0.3 occurrences487–486 Mya — about 0.1 occurrences506.5 Mya497 Mya516.8 Mya486.3 Mya

227 occurrences of Ptychagnostus on record, most of them in the Cambrian. 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

227 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

45 formations

Aktas — 43.53°N, 69.95°EHuaqiao — 28.39°N, 109.53°EHuaqiao — 28.72°N, 109.97°EHuaqiao — 29.10°N, 110.92°EShallow Bay — 49.02°N, 55.52°WShallow Bay — 49.83°N, 57.87°WShallow Bay — 49.25°N, 65.57°WWheeler — 39.52°N, 113.00°WWheeler — 39.22°N, 113.40°WInca — 19.50°S, 138.93°EInca — 20.25°S, 138.82°EInca — 20.03°S, 138.78°EInca — 20.21°S, 138.86°EInca — 19.98°S, 138.92°EMarjum — 39.00°N, 113.00°WMarjum — 39.22°N, 113.40°WMarjum — 39.27°N, 113.31°WWheeler Shale — 39.36°N, 111.59°WWheeler Shale — 39.54°N, 112.92°WWheeler Shale — 39.20°N, 113.30°WWheeler Shale — 39.29°N, 113.31°WCurrant Bush — 19.54°S, 138.86°ECurrant Bush — 19.99°S, 138.90°EV-Creek Limestone — 19.56°S, 138.81°EV-Creek Limestone — 20.25°S, 138.63°EV-Creek Limestone — 19.67°S, 138.76°EV-Creek Limestone — 20.19°S, 138.45°EV-Creek Limestone — 19.79°S, 138.92°EMenevia — 51.87°N, 5.22°WYangliugang — 28.82°N, 118.60°EAlum Shale — 55.72°N, 13.23°EAlum Shale — 58.76°N, 15.52°ELower Alum Shale — 55.00°N, 15.00°ESecret Canyon — 39.40°N, 115.95°WEl Mogallón — 28.91°N, 109.28°WBlacksmith — 41.30°N, 111.72°WBlacksmith — 41.43°N, 111.94°WBaguamiao — 32.22°N, 108.42°EGeddes Limestone — 39.50°N, 115.98°WHenson Gletscher — 80.25°N, 62.50°WHenson Gletscher — 82.17°N, 40.40°WEmpozada — 32.87°S, 69.01°WAsbill Pond — 34.00°N, 82.00°WUpper Wheeler Shale — 39.00°N, 113.00°WUpper Wheeler Shale — 40.00°N, 114.00°WDuchesnay — 51.10°N, 115.95°WDuchesnay — 50.63°N, 115.60°WAlum Shale — 59.75°N, 10.50°EAlum Shale — 59.73°N, 10.50°E

Loading coastlines…

The named rock units Ptychagnostus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 21 further formations hold fewer occurrences each and are not listed. 2 occurrences have no formation on record, which is common for older literature.

Ptychagnostus and its relatives

Cambrian

Where Ptychagnostus and its relatives were recorded in the Cambrian.

Found in the same rock

474 taxa

The Paleobiology Database records 95 sites for Ptychagnostus, 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

49 references

Each of the 227 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. 37 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 Ptychagnostus

Credit
TheoricienQuantique
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Ptychagnostus was found in MorphoSource and Sketchfab.

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 itPtychagnostidae through timeFormations of the CambrianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Jaekel 1909)