Agnostida

Agnostida are an order of extinct arthropods which have classically been seen as a group of highly modified trilobites, though some recent research has doubted this placement. Regardless, they appear to be close relatives as part of the Artiopoda. They are present in the Lower Cambrian fossil record along with trilobites from the Redlichiida, Corynexochida, and Ptychopariida orders, and were highly diverse throughout the Cambrian. Agnostidan diversity severely declined during the Cambrian-Ordovician transition, and the last agnostidans went extinct in the Late Ordovician.

Agnostida

Parent Géry · 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
ArtiopodaPBDB
Diet
detritivorePBDB
Life habit
epifaunalPBDB
Motility
slow-movingPBDB

Time the record covers

At least 75 million years on record.

The record covers at least 521 Mya to 445.2 Mya. No occurrence read is dated outside 538.8 Mya to 443.1 Mya.

Cambrian — about 5708 of 6457 occurrencesCambrianOrdovician — about 749 of 6457 occurrencesOrdovicianSilurian — about 0 of 6457 occurrences541–537 Mya — about 2 occurrences537–534 Mya — about 5 occurrences534–531 Mya — about 5 occurrences531–527 Mya — about 5 occurrences527–524 Mya — about 5 occurrences524–521 Mya — about 12 occurrences521–517 Mya — about 93 occurrences517–514 Mya — about 113 occurrences514–511 Mya — about 119 occurrences511–508 Mya — about 154 occurrences508–504 Mya — about 466 occurrences504–501 Mya — about 805 occurrences501–498 Mya — about 1219 occurrences498–494 Mya — about 962 occurrences494–491 Mya — about 1009 occurrences491–488 Mya — about 598 occurrences488–484 Mya — about 203 occurrences484–481 Mya — about 107 occurrences481–478 Mya — about 99 occurrences478–474 Mya — about 63 occurrences474–471 Mya — about 68 occurrences471–468 Mya — about 57 occurrences468–464 Mya — about 21 occurrences464–461 Mya — about 18 occurrences461–458 Mya — about 45 occurrences458–454 Mya — about 51 occurrences454–451 Mya — about 48 occurrences451–448 Mya — about 56 occurrences448–445 Mya — about 48 occurrences445–441 Mya — about 3 occurrences521 Mya445.2 Mya541 Mya441 Mya

6,457 occurrences of Agnostida 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

6,457 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

493 formations

Huaqiao — 28.39°N, 109.53°EHuaqiao — 28.72°N, 109.97°EHuaqiao — 28.05°N, 109.42°EHuaqiao — 29.10°N, 110.92°EZhumabai — 43.53°N, 69.95°EBestogai — 43.53°N, 69.95°EMachari — 37.18°N, 128.48°EMachari — 37.31°N, 128.44°EShallow Bay — 49.83°N, 57.87°WShallow Bay — 49.02°N, 55.52°WShallow Bay — 49.92°N, 57.83°WShallow Bay — 49.25°N, 65.57°WShallow Bay — 49.92°N, 57.90°WShallow Bay — 49.83°N, 57.85°WAktas — 43.53°N, 69.95°EHuayansi — 28.82°N, 118.60°EHuayansi — 28.90°N, 118.50°ERabbitkettle — 64.67°N, 132.00°WRabbitkettle — 62.70°N, 128.38°WRabbitkettle — 63.37°N, 128.60°WRabbitkettle — 64.59°N, 130.01°WRabbitkettle — 61.78°N, 127.95°WChatsworth — 22.00°S, 140.30°EChatsworth — 21.94°S, 140.33°EChatsworth — 21.95°S, 140.37°EDeadwood — 44.42°N, 103.71°WDeadwood — 47.42°N, 105.59°WDeadwood — 44.25°N, 103.78°WDeadwood — 44.28°N, 103.73°WDeadwood — 44.25°N, 103.57°WDeadwood — 44.07°N, 103.22°WDeadwood — 44.45°N, 104.42°WDeadwood — 44.35°N, 104.00°WDeadwood — 43.82°N, 103.77°WDeadwood — 43.72°N, 103.67°WDeadwood — 43.53°N, 103.55°WDeadwood — 43.60°N, 103.58°WDeadwood — 44.77°N, 107.53°WDeadwood — 44.25°N, 103.45°WDeadwood — 44.63°N, 104.38°WOgon'or — 71.28°N, 127.63°ELampazar — 23.00°S, 66.00°WLampazar — 23.15°S, 65.60°WLampazar — 23.88°S, 65.71°WLampazar — 23.54°S, 65.41°WLampazar — 23.05°S, 65.47°WLampazar — 23.17°S, 65.44°WLampazar — 23.62°S, 65.69°WLampazar — 22.92°S, 66.62°WSiyangshan — 28.85°N, 118.65°ESiyangshan — 28.80°N, 118.58°ESiyangshan — 28.90°N, 118.50°EWheeler — 39.52°N, 113.00°WWheeler — 39.22°N, 113.40°WWheeler — 40.47°N, 111.45°WV-Creek Limestone — 19.52°S, 138.79°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 — 19.79°S, 138.65°EV-Creek Limestone — 20.23°S, 138.29°EV-Creek Limestone — 20.19°S, 138.45°EV-Creek Limestone — 19.79°S, 138.92°EV-Creek Limestone — 19.68°S, 138.69°EYangliugang — 28.82°N, 118.60°EYangliugang — 31.37°N, 120.95°EYangliugang — 32.27°N, 118.25°EAlum Shale — 58.58°N, 13.38°EAlum Shale — 58.55°N, 13.33°EAlum Shale — 55.72°N, 13.23°EAlum Shale — 55.48°N, 14.30°EAlum Shale — 55.72°N, 13.98°EAlum Shale — 58.76°N, 15.52°EAlum Shale — 56.35°N, 16.42°EHolm Dal — 82.42°N, 39.75°WInca — 19.50°S, 138.93°EInca — 20.21°S, 138.86°EInca — 20.25°S, 138.82°EInca — 20.03°S, 138.78°EInca — 19.98°S, 138.92°EFjällbränna — 64.06°N, 15.37°EFjällbränna — 64.23°N, 15.59°EFjällbränna — 64.43°N, 15.54°EKaili — 26.40°N, 107.88°EKaili — 26.73°N, 108.42°EBaguamiao — 32.22°N, 108.42°ERiley — 30.64°N, 99.26°WRiley — 30.92°N, 98.61°WRiley — 30.81°N, 98.28°WRiley — 30.91°N, 99.00°WRiley — 30.76°N, 99.41°WRiley — 30.54°N, 99.09°WRiley — 30.49°N, 98.52°WRiley — 30.81°N, 98.37°WRiley — 30.36°N, 98.47°WSanta Rosita — 23.00°S, 66.00°WSanta Rosita — 23.59°S, 65.37°WSanta Rosita — 23.75°S, 65.54°WSanta Rosita — 23.75°S, 65.53°WSanta Rosita — 23.74°S, 65.55°WSanta Rosita — 22.18°S, 65.26°WSanta Rosita — 24.49°S, 65.55°WSanta Rosita — 24.50°S, 65.75°WSanta Rosita — 22.21°S, 64.89°WSanta Rosita — 23.47°S, 65.34°WSanta Rosita — 23.58°S, 65.34°WSanta Rosita — 23.36°S, 65.34°WSanta Rosita — 22.77°S, 66.20°WSanta Rosita — 22.76°S, 65.20°WSanta Rosita — 22.66°S, 65.17°WSanta Rosita — 22.51°S, 65.10°W

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The named rock units Agnostida has been recovered from, largest first. Drawn where the rock is now, not where it formed. 469 further formations hold fewer occurrences each and are not listed. 287 occurrences have no formation on record, which is common for older literature.

Agnostida and its relatives

Cambrian

Where Agnostida and its relatives were recorded in the Cambrian.

Found in the same rock

1,701 taxa

The Paleobiology Database records at least 1,022 sites for Agnostida, and this reads 240 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

550 references

Each of the 6,457 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. 538 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 content3

Picture of Agnostida

Credit
Parent Géry
Licence
CC BY-SA 3.0
Commercial use
the licence allows it

CT scan

Licence
not stated by the source
Commercial use
cannot be read from the licence given — check the record
Specimen
Agnostida indet. · L-JH:Eb18 03 C1

3D model

Source
Sketchfab
Licence
Free Standard
Commercial use
cannot be read from the licence given — check the record

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 itArtiopoda through timeFormations of the CambrianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Salter 1864