Micrasema

Micrasema is a genus of humpless casemaker caddisflies in the family Brachycentridae. There are more than 70 described species in Micrasema.

Micrasema

Catherinevu · 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
BrachycentridaePBDB
Motility
actively mobilePBDB, for Arthropoda
Environment
terrestrialPBDB, for Insecta

Time the record covers

At least 45 million years on record.

The record covers at least 45.9 Mya to 129 ka. No occurrence read is dated outside 51.1 Mya to 11.7 ka.

Eocene — about 1 of 2 occurrencesEoceneOligocene — about 0 of 2 occurrencesMiocene — about 0 of 2 occurrencesPliocene — about 0 of 2 occurrencesPleistocene — about 1 of 2 occurrences52–50 Mya — about 0.1 occurrences50–49 Mya — about 0.3 occurrences49–47 Mya — about 0.3 occurrences47–45 Mya — about 0.2 occurrences1.7–0 Mya — about 1 occurrence45.9 Mya129 ka52 Mya0 Mya

2 occurrences of Micrasema on record, most of them in the Eocene. The Paleobiology Database records this as a living group. 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

2 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

2 formations

Green River — 42.14°N, 109.07°WDon — 43.69°N, 79.36°W

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

Micrasema and its relatives

Eocene

Where Micrasema and its relatives were recorded in the Eocene.

Found in the same rock

19 taxa

The Paleobiology Database records 2 sites for Micrasema, and this reads all of them. The number is how many of those sites it was catalogued from too.

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

2 references

Each of the 2 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 Micrasema

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

No 3D scan of Micrasema 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 itBrachycentridae through timeFormations of the EoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. McLachlan 1876