Geragnostus

Geragnostus is a genus of very small agnostid trilobites whose fossils are found Ordovician-aged marine strata from Eurasia, North America and Argentina.

Geragnostus

Dwergenpaartje · 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
MetagnostidaePBDB
Diet
detritivorePBDB, for Agnostida
Life habit
epifaunalPBDB, for Agnostida
Motility
slow-movingPBDB, for Agnostida
Vision
blindPBDB, for Metagnostidae

Time the record covers

At least 44 million years on record.

The record covers at least 494.2 Mya to 449.5 Mya. No occurrence read is dated outside 497 Mya to 443.1 Mya.

Cambrian — about 23 of 265 occurrencesCambrianOrdovician — about 242 of 265 occurrencesOrdovicianSilurian — about 0 of 265 occurrences498–496 Mya — about 0.7 occurrences496–494 Mya — about 2 occurrences494–492 Mya — about 0.7 occurrences492–491 Mya — about 2 occurrences491–489 Mya — about 9 occurrences489–487 Mya — about 9 occurrences487–485 Mya — about 18 occurrences485–483 Mya — about 26 occurrences483–481 Mya — about 24 occurrences481–479 Mya — about 23 occurrences479–478 Mya — about 23 occurrences478–476 Mya — about 14 occurrences476–474 Mya — about 16 occurrences474–472 Mya — about 15 occurrences472–470 Mya — about 16 occurrences470–468 Mya — about 13 occurrences468–466 Mya — about 5 occurrences466–464 Mya — about 5 occurrences464–463 Mya — about 5 occurrences463–461 Mya — about 5 occurrences461–459 Mya — about 8 occurrences459–457 Mya — about 7 occurrences457–455 Mya — about 4 occurrences455–453 Mya — about 4 occurrences453–451 Mya — about 4 occurrences451–449 Mya — about 3 occurrences449–448 Mya — about 3 occurrences448–446 Mya — about 0.3 occurrences446–444 Mya — about 0.3 occurrences444–442 Mya — about 0.1 occurrences494.2 Mya449.5 Mya498 Mya442 Mya

265 occurrences of Geragnostus on record, most of them in the Ordovician. 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

265 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

107 formations

Santa Rosita — 23.62°S, 65.35°WSanta Rosita — 23.75°S, 65.54°WSanta Rosita — 23.75°S, 65.53°WSanta Rosita — 23.74°S, 65.55°WSanta Rosita — 24.49°S, 65.55°WSanta Rosita — 22.51°S, 65.10°WDawan — 33.00°N, 111.00°EDawan — 28.00°N, 109.00°EDawan — 30.90°N, 111.39°EDawan — 30.86°N, 110.37°ETable Cove — 50.36°N, 57.54°WTable Cove — 48.58°N, 58.70°WTable Cove — 50.18°N, 57.62°WLandeyran — 43.47°N, 3.08°ELandeyran — 43.48°N, 3.47°ENantsinkwan — 28.62°N, 109.47°ENantsinkwan — 28.79°N, 109.29°EBliss Sandstone — 32.87°N, 107.18°WGoodwin — 39.10°N, 116.26°WGoodwin — 37.34°N, 115.38°WGoodwin — 39.20°N, 116.25°WTøyen — 59.72°N, 9.85°ETøyen — 59.73°N, 9.87°ETøyen — 59.65°N, 9.65°ELatorp — 58.00°N, 14.00°ELatorp — 59.24°N, 14.94°ETaique — 23.84°S, 66.00°WTaique — 23.87°S, 65.99°WKomstad — 55.04°N, 14.88°EMilina — 49.80°N, 13.80°EKlabava — 50.00°N, 14.00°EGuotang — 26.00°N, 108.00°EChedao — 37.00°N, 107.00°EChedao — 36.00°N, 107.00°EChedao — 36.08°N, 106.75°EDevendeus or Saladillo — 23.37°S, 65.38°WDevendeus or Saladillo — 24.54°S, 65.74°WVolcancito — 28.87°S, 67.69°WSimeh-Kuh — 36.21°N, 54.22°ESaergan — 40.64°N, 79.50°ELos Azules — 30.58°S, 68.85°WLos Azules — 32.50°S, 68.83°WDeadwood — 47.42°N, 105.59°WNinemile — 39.10°N, 116.26°WNinemile — 39.20°N, 116.25°WBjorkasholmen — 59.14°N, 11.18°EShineton Shales — 52.63°N, 2.58°WShineton Shales — 52.63°N, 2.66°W

Loading coastlines…

The named rock units Geragnostus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 83 further formations hold fewer occurrences each and are not listed. 46 occurrences have no formation on record, which is common for older literature.

Geragnostus and its relatives

Ordovician

Where Geragnostus and its relatives were recorded in the Ordovician.

Found in the same rock

1,224 taxa

The Paleobiology Database records 235 sites for Geragnostus, 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

96 references

Each of the 265 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. 84 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 Geragnostus

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

No 3D scan of Geragnostus 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 itMetagnostidae through timeFormations of the OrdovicianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Howell 1935