Mactra
Searched as Mactra vitaliana eichwaldi. The Paleobiology Database treats Mactra as the accepted name.
Mactra is a large genus of medium-sized marine bivalve mollusks or clams, commonly known as trough shells or duck clams. Mactra is the type genus within the family Mactridae.

Hans Hillewaert · 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- Also called
- duck clamPBDB
- Sits inside
- MactrinaePBDB
- Diet
- suspension feederPBDB
- Life habit
- infaunalPBDB
- Motility
- facultatively mobilePBDB
- Vision
- blindPBDB, for Bivalvia
Time the record covers
At most 1.2 million years on record.
The one occurrence read is dated to somewhere between 12.8 Mya and 11.63 Mya, which is a dating window rather than a span.
1 occurrence of Mactra on record, most of them in the Miocene. The Paleobiology Database records this as a living group, and the chart stops with its fossils rather than at the present. 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
1 occurrences- Miocene100%
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.
Mactra and its relatives
MioceneWhere Mactra and its relatives were recorded in the Miocene.
Found in the same rock
3,863 taxa- Cardium30 sites
- Tellina27 sites
- Turritella25 sites
- Glycymeris24 sites
- Polinices (Polinices) subtenuis24 sites
- Corbula22 sites
- Natica21 sites
- Saxolucina sharmani21 sites
- Eurhomalea newtoni20 sites
- Ostrea18 sites
- Pitar18 sites
- Cerithium17 sites
- Anadara16 sites
- Dentalium16 sites
- Dosinia16 sites
- Panopea16 sites
- Polinices16 sites
- Barbatia15 sites
- Conus15 sites
- Nuculana15 sites
- Colposigma euthenia14 sites
- Donax14 sites
- Nassarius14 sites
- Nucula14 sites
The Paleobiology Database records 183 sites for Mactra, and this reads all of them. Of that, one read hit the database's own return limit, so every count below is a floor rather than a total. 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
1 referenceEach of the 1 occurrence 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 the Paleobiology Database's own record for the work.
Media and terms
Media content2
Picture of Mactra
- Source
- Wikipedia/Commons
- Credit
- Hans Hillewaert
- Licence
- CC BY-SA 4.0
- Commercial use
- the licence allows it
3D model
- Source
- Sketchfab
- Licence
- CC0 Public Domain
- Commercial use
- the licence allows it
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
- Source
- Wikipedia, “Mactra”
- 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 itMactrinae through timeFormations of the MioceneThe world it lived on
Occurrence data from the Paleobiology Database, CC BY 4.0. Linnaeus 1767