Trigonotarbida

The order Trigonotarbida is a group of extinct arachnids whose fossil record extends from the late Silurian to the early Permian. These animals are known from several localities in Europe and North America, as well as a single record from Argentina. Trigonotarbids can be envisaged as spider-like arachnids, but without silk-producing spinnerets. They ranged in size from a few millimetres to a few centimetres in body length and had segmented abdomens (opisthosoma), with the dorsal exoskeleton (tergites) across the backs of the animals' abdomens, which were characteristically divided into three or five separate plates. Probably living as predators on other arthropods, some later trigonotarbid species were quite heavily armoured and protected themselves with spines and tubercles. About seventy species are currently known, with most fossils originating from the Carboniferous coal measures.

Trigonotarbida

Junnn11 · CC BY-SA 4.0 · 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
PantetrapulmonataPBDB
Life habit
solitaryPBDB, for Arachnida
Motility
actively mobilePBDB, for Arachnida
Environment
terrestrialPBDB, for Arachnida

Time the record covers

At least 126 million years on record.

The record covers at least 419.62 Mya to 293.52 Mya. No occurrence read is dated outside 422.7 Mya to 283.3 Mya.

Silurian — about 1 of 182 occurrencesDevonian — about 36 of 182 occurrencesDevonianCarboniferous — about 141 of 182 occurrencesCarboniferousPermian — about 4 of 182 occurrencesPermian425–421 Mya — about 0.7 occurrences421–416 Mya — about 0.9 occurrences416–411 Mya — about 12 occurrences411–406 Mya — about 5 occurrences406–401 Mya — about 3 occurrences401–396 Mya — about 1.0 occurrences392–387 Mya — about 4 occurrences387–382 Mya — about 10 occurrences367–363 Mya — about 0.4 occurrences363–358 Mya — about 0.6 occurrences348–343 Mya — about 0.5 occurrences343–339 Mya — about 0.9 occurrences339–334 Mya — about 2 occurrences334–329 Mya — about 2 occurrences329–324 Mya — about 1 occurrence324–319 Mya — about 4 occurrences319–314 Mya — about 77 occurrences314–310 Mya — about 25 occurrences310–305 Mya — about 20 occurrences305–300 Mya — about 9 occurrences300–295 Mya — about 2 occurrences295–290 Mya — about 1 occurrence290–285 Mya — about 0.5 occurrences285–281 Mya — about 0.2 occurrences419.62 Mya293.52 Mya425 Mya281 Mya

182 occurrences of Trigonotarbida on record, most of them in the Carboniferous. 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

182 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

51 formations

Kladno — 50.10°N, 13.72°EKladno — 49.71°N, 13.21°EKladno — 49.83°N, 14.59°EKladno — 50.17°N, 14.09°EKladno — 49.85°N, 18.49°EPanther Mountain — 42.43°N, 74.43°WDryden Flags — 57.34°N, 2.84°WDryden Flags — 57.34°N, 2.85°WCarbondale — 41.34°N, 88.39°WCarbondale — 41.29°N, 88.19°WZacler — 50.58°N, 16.50°ELancaster — 45.24°N, 66.08°WMiddle Coal Measures — 52.99°N, 1.31°WBrooch — 52.66°N, 2.17°WNellenköpfchen — 50.24°N, 7.45°EWigan Four-Foot Coal — 53.55°N, 2.52°WLower Saarbrucker layer — 49.32°N, 7.07°ELower Saarbrucker layer — 49.29°N, 7.03°EUpper Saarbrucker layer — 49.26°N, 7.00°EUpper Saarbrucker layer — 51.01°N, 7.14°EFlénu — 50.45°N, 3.90°EBerthelsdorf — 51.12°N, 12.50°ENetzkater — 51.58°N, 10.79°EPennine Lower Coal Measures — 53.53°N, 2.51°WSenora — 35.63°N, 95.87°WSenora — 35.45°N, 94.80°WDownton Castle Sandstone — 51.37°N, 2.73°WCatskill — 41.34°N, 77.68°WZwickau — 50.70°N, 12.54°ECraigola Seam — 51.62°N, 3.33°WOttweiler — 49.45°N, 7.35°EPennant Sandstone — 51.65°N, 3.24°WGrovesend — 51.79°N, 3.24°W

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The named rock units Trigonotarbida has been recovered from, largest first. Drawn where the rock is now, not where it formed. 27 further formations hold fewer occurrences each and are not listed. 69 occurrences have no formation on record, which is common for older literature.

Trigonotarbida and its relatives

Carboniferous

Where Trigonotarbida and its relatives were recorded in the Carboniferous.

Found in the same rock

575 taxa

The Paleobiology Database records 117 sites for Trigonotarbida, 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

84 references

Each of the 182 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. 72 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 Trigonotarbida

Credit
Junnn11
Licence
CC BY-SA 4.0
Commercial use
the licence allows it

No 3D scan of Trigonotarbida 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 itPantetrapulmonata through timeFormations of the CarboniferousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Petrunkevitch 1949