Dendraster excentricus

Dendraster excentricus, also known as the eccentric sand dollar, sea-cake, biscuit-urchin, western sand dollar, or Pacific sand dollar, is a species of echinoderm in the family Dendrasteridae. It is a flattened, burrowing sea urchin found in the north-eastern Pacific Ocean from Alaska to Baja California.

Dendraster excentricus

louisiv826 · CC BY 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
eccentric sand dollarPBDB
Sits inside
DendrasterPBDB
Diet
detritivorePBDB, for Clypeasteroida
Life habit
semi-infaunalPBDB, for Clypeasteroida
Motility
slow-movingPBDB, for Clypeasteroida
Vision
limitedPBDB, for Echinoidea
Environment
marinePBDB, for Echinodermata

Time the record covers

At least 3.4 million years on record.

The record covers at least 3.6 Mya to 129 ka. No occurrence read is dated outside 5.333 Mya to 0 Mya.

Miocene — about 0 of 29 occurrencesPliocene — about 1 of 29 occurrencesPliocenePleistocene — about 28 of 29 occurrencesPleistoceneHolocene — about 0 of 29 occurrences5.4–5.3 Mya — about 0.0 occurrences5.3–5.1 Mya — about 0.1 occurrences5.1–4.9 Mya — about 0.1 occurrences4.9–4.7 Mya — about 0.1 occurrences4.7–4.5 Mya — about 0.1 occurrences4.5–4.3 Mya — about 0.1 occurrences4.3–4.1 Mya — about 0.1 occurrences4.1–3.9 Mya — about 0.1 occurrences3.9–3.7 Mya — about 0.1 occurrences3.7–3.5 Mya — about 0.1 occurrences2.7–2.5 Mya — about 0.1 occurrences2.5–2.3 Mya — about 0.3 occurrences2.3–2.1 Mya — about 0.3 occurrences2.1–1.9 Mya — about 0.3 occurrences1.9–1.8 Mya — about 0.3 occurrences1.8–1.6 Mya — about 0.3 occurrences1.6–1.4 Mya — about 0.3 occurrences1.4–1.2 Mya — about 0.3 occurrences1.2–972 ka Mya — about 0.3 occurrences972 ka–778 ka Mya — about 0.3 occurrences778 ka–583 ka Mya — about 1 occurrence583 ka–389 ka Mya — about 1 occurrence389 ka–194 ka Mya — about 1 occurrence194 ka–0 Mya — about 21 occurrences3.6 Mya129 ka5.8 Mya0 Mya

29 occurrences of Dendraster excentricus 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

29 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

5 formations

Palos Verdes Sand — 33.60°N, 117.88°WPalos Verdes Sand — 33.71°N, 118.27°WPalos Verdes Sand — 33.80°N, 118.17°WPalos Verdes Sand — 33.66°N, 117.94°WSan Pedro Sand — 33.74°N, 118.28°WUnnamed — 33.24°N, 119.47°WAnchor — 34.04°N, 118.40°WPico — 34.34°N, 118.47°W

Loading coastlines…

The named rock units Dendraster excentricus has been recovered from, largest first. Drawn where the rock is now, not where it formed. 13 occurrences have no formation on record, which is common for older literature.

Dendraster excentricus and its relatives

Pleistocene

Where Dendraster excentricus and its relatives were recorded in the Pleistocene.

Found in the same rock

867 taxa

The Paleobiology Database records 28 sites for Dendraster excentricus, 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

12 references

Each of the 29 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. 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 Dendraster excentricus

Credit
louisiv826
Licence
CC BY 4.0
Commercial use
the licence allows it

3D model

Source
Sketchfab
Credit
Gabri
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 itDendraster through timeFormations of the PleistoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Eschscholz 1826)