Tresus nuttallii

Tresus nuttallii, common name the Pacific gaper, is a species of saltwater clam, a marine bivalve mollusk in the family Mactridae. It also shares the common name horse clam with Tresus capax, a species which is similar in morphology and lifestyle. Both species are somewhat similar to the Geoduck, though smaller, with shells up to eight inches long (20 cm), weight to 3–4 lb (1.4–1.8 kg).

Tresus nuttallii

Charles Howard Edmondson · 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
Also called
Pacific gaperPBDB
Sits inside
TresusPBDB
Diet
suspension feederPBDB, for Mactridae
Life habit
infaunalPBDB, for Mactridae
Motility
facultatively mobilePBDB, for Mactridae
Vision
blindPBDB, for Bivalvia

Time the record covers

At least 5.2 million years on record.

The record covers at least 5.333 Mya to 129 ka. No occurrence read is dated outside 11.63 Mya to 0 Mya.

Miocene — about 17 of 147 occurrencesMiocenePliocene — about 39 of 147 occurrencesPliocenePleistocene — about 91 of 147 occurrencesPleistoceneHolocene — about 0 of 147 occurrences12–11 Mya — about 0.5 occurrences11–11 Mya — about 0.6 occurrences11–11 Mya — about 0.6 occurrences11–10 Mya — about 0.6 occurrences10–9.7 Mya — about 0.6 occurrences9.7–9.3 Mya — about 0.6 occurrences9.3–8.9 Mya — about 0.6 occurrences8.9–8.5 Mya — about 0.6 occurrences8.5–8.1 Mya — about 0.6 occurrences8.1–7.7 Mya — about 0.6 occurrences7.7–7.3 Mya — about 0.6 occurrences7.3–6.9 Mya — about 2 occurrences6.9–6.5 Mya — about 2 occurrences6.5–6.1 Mya — about 2 occurrences6.1–5.7 Mya — about 2 occurrences5.7–5.3 Mya — about 3 occurrences5.3–4.9 Mya — about 5 occurrences4.9–4.4 Mya — about 5 occurrences4.4–4.0 Mya — about 5 occurrences4.0–3.6 Mya — about 5 occurrences3.6–3.2 Mya — about 7 occurrences3.2–2.8 Mya — about 8 occurrences2.8–2.4 Mya — about 11 occurrences2.4–2.0 Mya — about 16 occurrences2.0–1.6 Mya — about 9 occurrences1.6–1.2 Mya — about 1 occurrence1.2–809 ka Mya — about 1 occurrence809 ka–404 ka Mya — about 6 occurrences404 ka–0 Mya — about 51 occurrences5.333 Mya129 ka12.1 Mya0 Mya

147 occurrences of Tresus nuttallii on record, most of them in the Pleistocene. 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

147 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

21 formations

Careaga Sandstone — 34.88°N, 120.51°WCareaga Sandstone — 34.83°N, 120.38°WCareaga Sandstone — 34.90°N, 120.32°WCareaga Sandstone — 34.74°N, 120.41°WCareaga Sandstone — 34.77°N, 120.48°WPalos Verdes Sand — 33.80°N, 118.16°WPalos Verdes Sand — 33.99°N, 118.45°WPalos Verdes Sand — 33.60°N, 117.88°WPalos Verdes Sand — 33.74°N, 118.28°WPalos Verdes Sand — 33.66°N, 117.94°WPico — 34.36°N, 118.56°WPico — 34.33°N, 118.72°WPico — 34.42°N, 118.70°WPico — 34.35°N, 118.52°WPico — 34.34°N, 118.51°WSisquoc — 34.81°N, 120.22°WSisquoc — 34.90°N, 120.31°WEtchegoin — 36.25°N, 120.31°WEtchegoin — 36.12°N, 120.41°WEtchegoin — 36.23°N, 120.33°WEtchegoin — 36.01°N, 120.31°WEtchegoin — 36.21°N, 120.67°WEtchegoin — 36.15°N, 120.64°WEtchegoin — 36.19°N, 120.64°WJacalitos — 36.08°N, 120.48°WJacalitos — 36.09°N, 120.41°WJacalitos — 36.04°N, 120.39°WJacalitos — 36.01°N, 120.31°WJacalitos — 36.14°N, 120.64°WPuerto Madryn — 42.97°S, 64.31°WPuerto Madryn — 42.57°S, 64.28°WPuerto Madryn — 44.50°S, 65.27°WPancho Rico — 36.03°N, 120.80°WPancho Rico — 36.03°N, 120.86°WPancho Rico — 35.90°N, 120.84°WUnnamed — 33.24°N, 119.51°WSan Pedro — 33.85°N, 118.06°WSan Pedro — 33.80°N, 118.16°WFoxen Mudstone — 34.86°N, 120.50°WSan Pedro Sand — 33.74°N, 118.28°WSaanich — 47.58°N, 122.42°WWildcat — 40.64°N, 124.31°WMerced — 38.37°N, 122.92°WTimms Point Silt — 33.73°N, 118.28°WBay Point — 32.78°N, 117.24°WPalos Verdes — 33.63°N, 117.90°WAnchor — 34.04°N, 118.40°WTowsley — 34.34°N, 118.54°WSan Diego — 32.54°N, 117.11°W

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The named rock units Tresus nuttallii has been recovered from, largest first. Drawn where the rock is now, not where it formed. 36 occurrences have no formation on record, which is common for older literature.

Tresus nuttallii and its relatives

Pleistocene

Where Tresus nuttallii and its relatives were recorded in the Pleistocene.

Found in the same rock

1,267 taxa

The Paleobiology Database records 122 sites for Tresus nuttallii, 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

40 references

Each of the 147 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. 28 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 Tresus nuttallii

Credit
Charles Howard Edmondson
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Tresus nuttallii 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 itTresus through timeFormations of the PleistoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. (Conrad 1837)