Micraster

Micraster is an extinct genus of echinoids from the Late Cretaceous to the early Eocene. Its remains have been found in Africa, Antarctica, Europe, and North America. Micraster was an infaunal echinoid living in a burrow below the sediment surface. The test is clearly bilateral and there is a deep anterior groove to take in water containing organic particles to the mouth. The tube feet keep a supply of nutrient-laden water moving into the burrow. The anus has a waste tube behind it.

Micraster

Francisco Ruiz · 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
MicrasteridaePBDB
Diet
deposit feeder, detritivorePBDB, for Spatangoida
Life habit
shallow infaunalPBDB, for Spatangoida
Motility
slow-movingPBDB, for Spatangoida
Vision
limitedPBDB, for Echinoidea
Environment
marinePBDB, for Spatangoida

Time the record covers

At least 34 million years on record.

The record covers at least 93.9 Mya to 59.24 Mya. No occurrence read is dated outside 143.1 Mya to 56 Mya.

Late Jurassic — about 0 of 192 occurrencesEarly Cretaceous — about 1 of 192 occurrencesEarly CretaceousLate Cretaceous — about 188 of 192 occurrencesLate CretaceousPaleocene — about 3 of 192 occurrencesPaleoceneEocene — about 0 of 192 occurrences145–142 Mya — about 0.0 occurrences142–139 Mya — about 0.1 occurrences139–136 Mya — about 0.1 occurrences136–133 Mya — about 0.1 occurrences133–130 Mya — about 0.1 occurrences130–127 Mya — about 0.1 occurrences127–124 Mya — about 0.1 occurrences124–121 Mya — about 0.1 occurrences121–118 Mya — about 0.1 occurrences118–115 Mya — about 0.1 occurrences115–112 Mya — about 0.1 occurrences112–109 Mya — about 0.1 occurrences109–106 Mya — about 0.1 occurrences106–103 Mya — about 0.1 occurrences103–100 Mya — about 0.7 occurrences100–97 Mya — about 2 occurrences97–94 Mya — about 4 occurrences94–90 Mya — about 19 occurrences90–87 Mya — about 24 occurrences87–84 Mya — about 46 occurrences84–81 Mya — about 33 occurrences81–78 Mya — about 17 occurrences78–75 Mya — about 17 occurrences75–72 Mya — about 17 occurrences72–69 Mya — about 4 occurrences69–66 Mya — about 4 occurrences66–63 Mya — about 1 occurrence63–60 Mya — about 0.8 occurrences60–57 Mya — about 0.8 occurrences57–54 Mya — about 0.4 occurrences93.9 Mya59.24 Mya145 Mya54 Mya

192 occurrences of Micraster on record, most of them in the Late Cretaceous. 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

192 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

32 formations

Olazagutia — 42.88°N, 2.20°WAhlen — 51.80°N, 8.05°EAhlen — 51.80°N, 8.00°EAhlen — 51.72°N, 8.03°EAhlen — 51.70°N, 7.92°ELewes Nodular Chalk — 50.70°N, 3.10°WLewes Nodular Chalk — 50.75°N, 2.97°WSaratoga Chalk — 34.08°N, 93.12°WSaratoga Chalk — 33.80°N, 93.70°WSaratoga Chalk — 34.04°N, 93.14°WSaratoga Chalk — 33.76°N, 93.90°WGulpen — 50.73°N, 5.67°EGulpen — 50.75°N, 5.67°EEl Zadorra — 42.88°N, 2.20°WHerba-savina Clays — 42.17°N, 0.90°ECorsicana Marl — 29.37°N, 98.78°WCorsicana Marl — 29.48°N, 98.81°WCraie de Villedieu — 45.00°N, 0.37°EAbu Qada — 29.13°N, 33.28°EAnseroles — 42.25°N, 0.97°ETexanitid Marls — 42.17°N, 0.90°ESant Corneli — 42.17°N, 0.90°EVila Vella — 42.17°N, 0.90°EMontesquiu — 42.17°N, 0.90°EVallcarga — 42.25°N, 0.97°ERipley — 34.12°N, 88.88°WWata — 29.13°N, 33.28°ESanta Marta — 63.00°S, 57.00°WCampanien 1-2 — 45.75°N, 0.47°WCollades de Basturs — 42.17°N, 0.90°EPodega — 42.17°N, 0.90°EMerfeg — 34.93°N, 9.40°EMarlbrook Marl — 34.08°N, 93.14°W

Loading coastlines…

The named rock units Micraster has been recovered from, largest first. Drawn where the rock is now, not where it formed. 8 further formations hold fewer occurrences each and are not listed. 65 occurrences have no formation on record, which is common for older literature.

Micraster and its relatives

Late Cretaceous

Where Micraster and its relatives were recorded in the Late Cretaceous.

Found in the same rock

845 taxa

The Paleobiology Database records 156 sites for Micraster, 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

37 references

Each of the 192 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. 25 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 content2

Picture of Micraster

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

3D model

Source
Sketchfab
Licence
CC Attribution
Commercial use
cannot be read from the licence given — check the record

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 itMicrasteridae through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Agassiz 1836