Mesonacis

Mesonacis is an extinct genus of trilobite that lived during the Botomian, found in North-America, and the United Kingdom. Some of the species now regarded part of Mesonacis, have previously been assigned to Angustolenellus or Olenellus (Angustolenellus). Angustolenellus is now regarded a junior synonym of Mesonacis.

Mesonacis

Jonathan Chen · 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
MesonacinaePBDB
Diet
deposit feederPBDB, for Redlichiida
Life habit
low-level epifaunalPBDB, for Redlichiida
Motility
fast-movingPBDB, for Redlichiida
Vision
well-developedPBDB, for Olenellidae
Environment
marinePBDB, for Trilobita

Time the record covers

At least 4.8 million years on record.

The record covers at least 514.5 Mya to 509.7 Mya. No occurrence read is dated outside 538.8 Mya to 497 Mya.

Cambrian — about 40 of 40 occurrencesCambrian540–538 Mya — about 0.0 occurrences538–537 Mya — about 0.0 occurrences537–535 Mya — about 0.0 occurrences535–534 Mya — about 0.0 occurrences534–532 Mya — about 0.0 occurrences532–531 Mya — about 0.0 occurrences531–529 Mya — about 0.0 occurrences529–528 Mya — about 0.0 occurrences528–527 Mya — about 0.0 occurrences527–525 Mya — about 0.0 occurrences525–524 Mya — about 0.0 occurrences524–522 Mya — about 0.0 occurrences522–521 Mya — about 0.1 occurrences521–519 Mya — about 0.3 occurrences519–518 Mya — about 0.3 occurrences518–516 Mya — about 0.3 occurrences516–515 Mya — about 2 occurrences515–514 Mya — about 9 occurrences514–512 Mya — about 9 occurrences512–511 Mya — about 9 occurrences511–509 Mya — about 6 occurrences509–508 Mya — about 0.8 occurrences508–506 Mya — about 0.8 occurrences506–505 Mya — about 0.5 occurrences505–503 Mya — about 0.0 occurrences503–502 Mya — about 0.0 occurrences502–501 Mya — about 0.0 occurrences501–499 Mya — about 0.0 occurrences499–498 Mya — about 0.0 occurrences498–496 Mya — about 0.0 occurrences514.5 Mya – 509.7 Mya539.6 Mya496.2 Mya

40 occurrences of Mesonacis 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

40 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

14 formations

Carrara — 35.85°N, 116.23°WCarrara — 36.75°N, 117.07°WCarrara — 36.38°N, 116.60°WCarrara — 36.08°N, 116.23°WCarrara — 36.23°N, 116.98°WCarrara — 35.88°N, 116.16°WCarrara — 35.88°N, 116.06°WLatham — 34.54°N, 115.48°WLatham — 34.58°N, 115.52°WLatham — 35.00°N, 115.53°WForteau — 50.59°N, 57.22°WPoleta — 37.50°N, 117.50°WPoleta — 37.27°N, 118.09°WPioche Shale — 36.19°N, 115.01°WScoresby Bay — 79.00°N, 82.00°WPioche — 36.19°N, 115.01°WZabriskie Quartzite — 35.85°N, 116.23°WBuelna — 30.42°N, 111.93°WParker Slate — 44.74°N, 73.16°WCadiz — 34.59°N, 115.52°WChambless — 34.54°N, 115.48°WSekwi — 63.55°N, 129.20°WEager — 49.59°N, 115.69°W

Loading coastlines…

The named rock units Mesonacis has been recovered from, largest first. Drawn where the rock is now, not where it formed. 1 occurrence has no formation on record, which is common for older literature.

Mesonacis and its relatives

Cambrian

Where Mesonacis and its relatives were recorded in the Cambrian.

Found in the same rock

90 taxa

The Paleobiology Database records 35 sites for Mesonacis, 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

14 references

Each of the 40 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. 2 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 Mesonacis

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

No 3D scan of Mesonacis 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 itMesonacinae through timeFormations of the CambrianThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Walcott 1885)