Branchioplax

Branchioplax is an extinct genus of crab which existed in Alaska and Washington during the Eocene period. It was first named by Mary Rathbun in 1916, and contains ten species, including Branchioplax washingtoniana from the Hoko River Formation, Branchioplax carmanahensis, and Branchioplax ballingi.

Branchioplax

Kevmin · 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
MathildellidaePBDB
Diet
carnivorePBDB, for Decapoda
Life habit
infaunalPBDB, for Mathildellidae
Motility
actively mobilePBDB, for Malacostraca
Vision
well-developedPBDB, for Malacostraca

Time the record covers

At least 14 million years on record.

The record covers at least 48.07 Mya to 33.9 Mya. No occurrence read is dated outside 66 Mya to 5.333 Mya.

Late Cretaceous — about 0 of 37 occurrencesPaleocene — about 1 of 37 occurrencesPaleoceneEocene — about 28 of 37 occurrencesEoceneOligocene — about 8 of 37 occurrencesOligoceneMiocene — about 1 of 37 occurrencesMiocenePliocene — about 0 of 37 occurrences67–65 Mya — about 0.0 occurrences65–63 Mya — about 0.0 occurrences63–61 Mya — about 0.2 occurrences61–59 Mya — about 0.4 occurrences59–57 Mya — about 0.4 occurrences57–55 Mya — about 1 occurrence55–52 Mya — about 2 occurrences52–50 Mya — about 2 occurrences50–48 Mya — about 2 occurrences48–46 Mya — about 2 occurrences46–44 Mya — about 2 occurrences44–42 Mya — about 2 occurrences42–40 Mya — about 3 occurrences40–38 Mya — about 4 occurrences38–36 Mya — about 4 occurrences36–34 Mya — about 4 occurrences34–31 Mya — about 2 occurrences31–29 Mya — about 2 occurrences29–27 Mya — about 2 occurrences27–25 Mya — about 0.7 occurrences25–23 Mya — about 0.7 occurrences23–21 Mya — about 0.1 occurrences21–19 Mya — about 0.1 occurrences19–17 Mya — about 0.1 occurrences17–15 Mya — about 0.1 occurrences15–13 Mya — about 0.1 occurrences13–10 Mya — about 0.1 occurrences10–8.3 Mya — about 0.1 occurrences8.3–6.2 Mya — about 0.1 occurrences6.2–4.1 Mya — about 0.0 occurrences48.07 Mya33.9 Mya67 Mya4 Mya

37 occurrences of Branchioplax on record, most of them in the Eocene. 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

37 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

11 formations

Cowlitz — 46.40°N, 122.93°WAldwell — 47.75°N, 122.85°WBarton Clay — 50.74°N, 1.69°WClallam — 48.12°N, 122.76°WKattachi — 33.01°N, 130.48°ECowliz — 45.76°N, 123.28°WCalcareniti di Castelgomberto — 45.43°N, 11.52°ECastelgomberto — 45.53°N, 11.48°EBecton — 50.73°N, 1.64°WHeadon — 50.67°N, 1.10°WHoko River — 48.39°N, 124.66°W

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The named rock units Branchioplax has been recovered from, largest first. Drawn where the rock is now, not where it formed. 22 occurrences have no formation on record, which is common for older literature.

Branchioplax and its relatives

Eocene

Where Branchioplax and its relatives were recorded in the Eocene.

Found in the same rock

353 taxa

The Paleobiology Database records 23 sites for Branchioplax, 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

18 references

Each of the 37 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. 6 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 Branchioplax

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

No 3D scan of Branchioplax 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 itMathildellidae through timeFormations of the EoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Rathbun 1916