Hemigrapsus oregonensis

Hemigrapsus oregonensis is a small shore crab of the family Varunidae; formerly classified under the family Grapsidae. It is known under several common names, including yellow shore crab, hairy shore crab, green shore crab, mud-flat crab, bay shore crab and Oregon shore crab. Despite its common name, the crab actually has a wide variety of coloration. It is found along the West Coast of the United States and Canada, specifically along shorelines and similar geographical areas. In 2009, H. oregonensis was included on a list of animals petitioning for the endangered species label, but there was not enough scientific information available for it to be considered as such, so it remains unevaluated to the present day.

Hemigrapsus oregonensis

Ciar · 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
Also called
yellow shore crabPBDB
Sits inside
HemigrapsusPBDB
Diet
detritivorePBDB, for Grapsoidea
Life habit
infaunalPBDB, for Varunidae
Motility
actively mobilePBDB, for Malacostraca
Vision
well-developedPBDB, for Malacostraca

Time the record covers

At most 2.6 million years on record.

Every occurrence read is dated to somewhere between 2.58 Mya and 0 Mya, and nothing in the dating separates them, so that window is what the record shows rather than a span.

Pliocene — about 0 of 4 occurrencesPleistocene — about 4 of 4 occurrencesPleistoceneHolocene — about 0 of 4 occurrences2.7–2.6 Mya — about 0.0 occurrences2.6–2.5 Mya — about 0.1 occurrences2.5–2.4 Mya — about 0.1 occurrences2.4–2.3 Mya — about 0.1 occurrences2.3–2.2 Mya — about 0.1 occurrences2.2–2.1 Mya — about 0.1 occurrences2.1–2.0 Mya — about 0.1 occurrences2.0–1.8 Mya — about 0.1 occurrences1.8–1.7 Mya — about 0.1 occurrences1.7–1.6 Mya — about 0.1 occurrences1.6–1.5 Mya — about 0.1 occurrences1.5–1.4 Mya — about 0.1 occurrences1.4–1.3 Mya — about 0.1 occurrences1.3–1.2 Mya — about 0.1 occurrences1.2–1.1 Mya — about 0.1 occurrences1.1–1.0 Mya — about 0.1 occurrences1.0–924 ka Mya — about 0.1 occurrences924 ka–821 ka Mya — about 0.1 occurrences821 ka–719 ka Mya — about 0.2 occurrences719 ka–616 ka Mya — about 0.2 occurrences616 ka–513 ka Mya — about 0.2 occurrences513 ka–411 ka Mya — about 0.2 occurrences411 ka–308 ka Mya — about 0.2 occurrences308 ka–205 ka Mya — about 0.2 occurrences205 ka–103 ka Mya — about 0.4 occurrences103 ka–0 Mya — about 0.9 occurrences3.08 Mya0 Mya

4 occurrences of Hemigrapsus oregonensis on record, most of them in the Pleistocene. 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

4 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

San Pedro Sand — 33.74°N, 118.28°WPalos Verdes Sand — 33.60°N, 117.88°W

Loading coastlines…

The named rock units Hemigrapsus oregonensis has been recovered from, largest first. Drawn where the rock is now, not where it formed. 2 occurrences have no formation on record, which is common for older literature.

Hemigrapsus oregonensis and its relatives

Pleistocene

Where Hemigrapsus oregonensis and its relatives were recorded in the Pleistocene.

Found in the same rock

628 taxa

The Paleobiology Database records 3 sites for Hemigrapsus oregonensis, 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

2 references

Each of the 4 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 Hemigrapsus oregonensis

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

No 3D scan of Hemigrapsus oregonensis 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 itHemigrapsus through timeFormations of the PleistoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Dana 1851)