Unionida

Unionida is a monophyletic order of freshwater mussels, aquatic bivalve molluscs. The order includes most of the larger freshwater mussels, including the freshwater pearl mussels. The most common families are the Unionidae and the Margaritiferidae. All have in common a larval stage that is temporarily parasitic on fish, nacreous shells, high in organic matter, that may crack upon drying out, and siphons too short to permit the animal to live deeply buried in sediment.

Unionida

Joel Berglund · Public Domain · 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
PalaeoheterodontaPBDB
Diet
suspension feederPBDB, for Bivalvia
Life habit
infaunalPBDB, for Bivalvia
Motility
facultatively mobilePBDB, for Bivalvia
Vision
blindPBDB, for Bivalvia
Environment
freshwaterPBDB

Time the record covers

At least 358 million years on record.

The record covers at least 358.86 Mya to 11.7 ka. No occurrence read is dated outside 365.2 Mya to 0 Mya.

Devonian — about 1 of 662 occurrencesCarboniferous — about 0 of 662 occurrencesPermian — about 18 of 662 occurrencesPermianEarly Triassic — about 2 of 662 occurrencesMiddle Triassic — about 48 of 662 occurrencesLate Triassic — about 68 of 662 occurrencesLate TriassicEarly Jurassic — about 11 of 662 occurrencesMiddle Jurassic — about 33 of 662 occurrencesLate Jurassic — about 34 of 662 occurrencesEarly Cretaceous — about 50 of 662 occurrencesEarly CretaceousLate Cretaceous — about 115 of 662 occurrencesLate CretaceousPaleocene — about 14 of 662 occurrencesEocene — about 60 of 662 occurrencesOligocene — about 13 of 662 occurrencesMiocene — about 76 of 662 occurrencesPliocene — about 29 of 662 occurrencesPleistocene — about 65 of 662 occurrences373–360 Mya — about 0.8 occurrences360–348 Mya — about 0.2 occurrences298–286 Mya — about 0.7 occurrences286–273 Mya — about 0.5 occurrences273–261 Mya — about 3 occurrences261–248 Mya — about 15 occurrences248–236 Mya — about 54 occurrences236–224 Mya — about 25 occurrences224–211 Mya — about 19 occurrences211–199 Mya — about 21 occurrences199–186 Mya — about 8 occurrences186–174 Mya — about 3 occurrences174–161 Mya — about 32 occurrences161–149 Mya — about 19 occurrences149–137 Mya — about 20 occurrences137–124 Mya — about 13 occurrences124–112 Mya — about 24 occurrences112–99 Mya — about 12 occurrences99–87 Mya — about 20 occurrences87–75 Mya — about 39 occurrences75–62 Mya — about 57 occurrences62–50 Mya — about 19 occurrences50–37 Mya — about 30 occurrences37–25 Mya — about 31 occurrences25–12 Mya — about 48 occurrences12–0 Mya — about 149 occurrences358.86 Mya11.7 ka373 Mya0 Mya

662 occurrences of Unionida on record, most of them in the Late Cretaceous. 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

662 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

222 formations

Schlern — 46.51°N, 11.57°EWoodbine — 32.93°N, 97.08°WWoodbine — 33.40°N, 96.96°WWoodbine — 33.63°N, 97.13°WWoodbine — 33.76°N, 96.54°WWoodbine — 33.64°N, 96.61°WWoodbine — 33.69°N, 96.39°WMorrison — 41.89°N, 106.00°WMorrison — 37.53°N, 103.68°WMorrison — 38.25°N, 110.81°WMorrison — 38.81°N, 108.32°WMorrison — 39.15°N, 108.77°WMorrison — 39.15°N, 108.77°WMorrison — 44.46°N, 104.73°WMorrison — 39.01°N, 111.02°WMorrison — 44.06°N, 106.72°WMorrison — 44.05°N, 107.46°WSolimões — 10.94°S, 69.34°WSolimões — 8.82°S, 69.23°WSolimões — 7.63°S, 72.67°WSolimões — 6.50°S, 69.67°WOldman — 50.75°N, 111.51°WOldman — 49.10°N, 110.94°WOldman — 49.08°N, 110.68°WOldman — 49.08°N, 110.84°WOldman — 49.16°N, 110.72°WHell Creek — 45.53°N, 101.63°WHell Creek — 46.90°N, 101.50°WHell Creek — 45.46°N, 104.16°WHell Creek — 47.57°N, 106.95°WChinle — 35.03°N, 109.83°WChinle — 36.33°N, 106.47°WChinle — 35.84°N, 111.25°WChinle — 36.09°N, 111.36°WChinle — 35.88°N, 111.28°WChinle — 35.65°N, 111.12°WChinle — 35.92°N, 111.45°WChinle — 37.56°N, 110.28°WChinle — 34.93°N, 109.70°WRavenscrag — 49.70°N, 109.00°WRavenscrag — 49.57°N, 108.81°WRavenscrag — 49.40°N, 105.63°WRavenscrag — 49.13°N, 104.88°WRavenscrag — 49.70°N, 110.50°WRavenscrag — 49.10°N, 102.88°WFort Crittenden — 31.69°N, 110.81°WHeadon Beds — 50.72°N, 1.59°WLoncoche — 35.52°S, 69.72°WLoncoche — 36.52°S, 69.45°WLoncoche — 36.53°S, 69.67°WLoncoche — 35.83°S, 69.67°WLoncoche — 36.25°S, 69.85°WLealt Shale — 56.92°N, 6.15°WCassian — 46.54°N, 11.62°ECassian — 46.68°N, 12.15°ECassian — 46.57°N, 11.94°ECassian — 46.51°N, 11.76°ELance — 41.57°N, 108.67°WLance — 43.13°N, 104.49°WLance — 43.12°N, 104.64°WLance — 43.00°N, 104.50°WLance — 43.15°N, 104.57°WLance — 43.17°N, 104.53°WLameta — 22.92°N, 79.32°ELameta — 20.75°N, 79.48°ELameta — 20.85°N, 79.25°ELameta — 23.77°N, 78.72°ELameta — 20.71°N, 79.29°ELameta — 20.35°N, 79.05°EQuemuoco — 33.33°N, 92.00°EUlakhan-Krest — 71.74°N, 127.82°EPebas — 3.67°S, 71.77°WPebas — 4.25°S, 73.38°WPebas — 3.33°S, 71.83°WPebas — 3.50°S, 73.10°WPebas — 4.03°S, 73.38°WPebas — 7.36°S, 74.96°WHempstead — 50.72°N, 1.45°WUpper Freshwater Molasse — 47.92°N, 10.59°EUpper Freshwater Molasse — 48.15°N, 9.88°EUpper Freshwater Molasse — 48.09°N, 10.03°EUpper Freshwater Molasse — 48.16°N, 10.11°EChhidru — 32.55°N, 71.78°EChhidru — 32.47°N, 71.97°EChhidru — 32.72°N, 71.75°EElrhaz — 16.70°N, 9.33°EZiliujing — 31.86°N, 104.73°EZiliujing — 29.39°N, 104.03°EZiliujing — 29.45°N, 107.38°EZiliujing — 31.05°N, 110.75°EKuwajima — 36.17°N, 136.63°E

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The named rock units Unionida has been recovered from, largest first. Drawn where the rock is now, not where it formed. 198 further formations hold fewer occurrences each and are not listed. 170 occurrences have no formation on record, which is common for older literature.

Unionida and its relatives

Late Cretaceous

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

Found in the same rock

2,713 taxa

The Paleobiology Database records 484 sites for Unionida, and this reads 240 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

304 references

Each of the 662 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. 292 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 Unionida

Credit
Joel Berglund
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Unionida was found in MorphoSource and Sketchfab.

Smithsonian Open Access was 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 itPalaeoheterodonta through timeFormations of the Late CretaceousThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Stoliczka 1871