Mollisonia

Mollisonia is an extinct genus of Cambrian marine arthropod. Four species have been described from North America and China. Studies suggest it is a basal member of Chelicerata, a group which includes horseshoe crabs and arachnids.

Mollisonia

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
MollisoniidaePBDB
Diet
detritivorePBDB
Life habit
epifaunalPBDB
Motility
actively mobilePBDB

Time the record covers

At least 38 million years on record.

The record covers at least 516 Mya to 477.1 Mya. No occurrence read is dated outside 521 Mya to 471.3 Mya.

Cambrian — about 13 of 14 occurrencesCambrianOrdovician — about 1 of 14 occurrencesOrdovician522–520 Mya — about 0.3 occurrences520–519 Mya — about 0.6 occurrences519–517 Mya — about 0.6 occurrences517–515 Mya — about 0.4 occurrences515–513 Mya — about 0.2 occurrences513–512 Mya — about 0.2 occurrences512–510 Mya — about 0.2 occurrences510–508 Mya — about 2 occurrences508–506 Mya — about 2 occurrences506–505 Mya — about 2 occurrences505–503 Mya — about 1 occurrence503–501 Mya — about 1 occurrence501–500 Mya — about 1 occurrence500–498 Mya — about 1.0 occurrences498–496 Mya — about 0.5 occurrences477–475 Mya — about 0.3 occurrences475–474 Mya — about 0.3 occurrences474–472 Mya — about 0.3 occurrences472–470 Mya — about 0.1 occurrences516 Mya477.1 Mya522 Mya470 Mya

14 occurrences of Mollisonia 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

14 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

10 formations

Burgess Shale — 51.44°N, 116.47°WBurgess Shale — 51.39°N, 116.43°WLangston — 41.59°N, 112.04°WWheeler — 39.40°N, 113.28°WStephen — 51.17°N, 116.08°WShuijingtuo — 30.50°N, 111.16°EWheeler Shale — 39.29°N, 113.31°WBøggild Fjord Formation — 82.97°N, 34.42°WYuanshan — 24.81°N, 102.58°EBalang — 28.42°N, 109.42°EZhangxia — 35.13°N, 118.07°E

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

Mollisonia and its relatives

Cambrian

Where Mollisonia and its relatives were recorded in the Cambrian.

Found in the same rock

467 taxa

The Paleobiology Database records 13 sites for Mollisonia, 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

11 references

Each of the 14 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. Each entry links to doi.org. Relayed as the Paleobiology Database holds them, not checked against what they resolve to.

Media and terms

Media content1

Picture of Mollisonia

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

No 3D scan of Mollisonia 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 itMollisoniidae through timeFormations of the CambrianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Walcott 1912