Raninidae

Raninidae, sometimes known as "frog crabs" on account of their frog-like appearance, is a family of unusual raninoid crabs. They are taken by most scientists to be quite primitive among the true crabs. They closely resemble the (unrelated) mole crabs, due to parallel evolution or convergent evolution. In both groups, the claws are modified into tools for digging, and the body is a rounded shape that is easy to bury in sand. Unlike most other true crabs, the abdomens of raninids are not curled under the cephalothorax.

Raninidae

Velela at English Wikipedia · 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
Sits inside
RaninoideaPBDB
Diet
carnivorePBDB, for Decapoda
Life habit
semi-infaunalPBDB, for Raninoidia
Motility
actively mobilePBDB, for Malacostraca
Vision
well-developedPBDB, for Malacostraca

Time the record covers

At least 100 million years on record.

The record covers at least 100.5 Mya to 11.7 ka. No occurrence read is dated outside 113.2 Mya to 0 Mya.

Early Cretaceous — about 4 of 342 occurrencesEarly CretaceousLate Cretaceous — about 55 of 342 occurrencesLate CretaceousPaleocene — about 23 of 342 occurrencesPaleoceneEocene — about 197 of 342 occurrencesEoceneOligocene — about 26 of 342 occurrencesOligoceneMiocene — about 26 of 342 occurrencesMiocenePliocene — about 7 of 342 occurrencesPleistocene — about 3 of 342 occurrences115–112 Mya — about 0.4 occurrences112–108 Mya — about 0.9 occurrences108–104 Mya — about 1 occurrence104–100 Mya — about 2 occurrences100–96 Mya — about 6 occurrences96–92 Mya — about 7 occurrences92–89 Mya — about 5 occurrences89–85 Mya — about 2 occurrences85–81 Mya — about 5 occurrences81–77 Mya — about 5 occurrences77–73 Mya — about 5 occurrences73–69 Mya — about 10 occurrences69–65 Mya — about 11 occurrences65–62 Mya — about 11 occurrences62–58 Mya — about 8 occurrences58–54 Mya — about 15 occurrences54–50 Mya — about 22 occurrences50–46 Mya — about 37 occurrences46–42 Mya — about 54 occurrences42–38 Mya — about 40 occurrences38–35 Mya — about 27 occurrences35–31 Mya — about 11 occurrences31–27 Mya — about 8 occurrences27–23 Mya — about 11 occurrences23–19 Mya — about 5 occurrences19–15 Mya — about 5 occurrences15–12 Mya — about 6 occurrences12–7.7 Mya — about 8 occurrences7.7–3.8 Mya — about 6 occurrences3.8–0 Mya — about 7 occurrences100.5 Mya11.7 ka115 Mya0 Mya

342 occurrences of Raninidae on record, most of them in the Eocene. 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

342 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

95 formations

Castle Hayne — 34.64°N, 77.65°WCastle Hayne — 34.63°N, 77.75°WCastle Hayne — 34.37°N, 77.84°WCastle Hayne — 34.37°N, 77.87°WCastle Hayne — 34.80°N, 78.02°WSerraduy — 42.32°N, 0.54°EBateque — 26.75°N, 113.00°WBateque — 26.95°N, 113.06°WBateque — 26.45°N, 113.00°WBateque — 26.42°N, 112.58°WBateque — 24.17°N, 110.92°WSandakan — 5.88°N, 118.05°ESandakan — 5.88°N, 118.06°EChiampo Marble — 45.54°N, 11.26°EMaastricht — 50.86°N, 5.83°EMaastricht — 50.84°N, 5.69°ELookingglass — 42.56°N, 124.02°WLookingglass — 43.03°N, 123.64°WGlendon — 31.54°N, 88.06°WGlendon — 30.90°N, 84.58°WGlendon — 31.56°N, 88.03°WRancho Nuevo — 25.89°N, 101.12°WSantee Limestone — 33.45°N, 80.16°WSantee Limestone — 33.33°N, 80.15°WSantee Limestone — 33.33°N, 79.69°WSan Juan — 16.73°N, 93.13°WSan Juan — 16.50°N, 93.07°WSanta Marta — 63.91°S, 57.81°WSanta Marta — 63.87°S, 57.90°WOwl Creek — 34.75°N, 88.93°WOwl Creek — 34.45°N, 89.00°WOwl Creek — 34.23°N, 89.00°WAldwell — 47.75°N, 122.85°WEl Bosque — 16.50°N, 93.07°WPierre Shale — 43.25°N, 104.27°WPierre Shale — 44.70°N, 103.26°WPflugerville — 30.33°N, 97.71°WIsland Sandstone — 42.03°S, 171.35°EStepovak — 55.37°N, 161.36°WTepetate — 24.10°N, 110.55°WTepetate — 27.31°N, 112.77°WLlajas — 34.27°N, 118.71°WBlakeley — 47.58°N, 122.48°WBlakeley — 48.26°N, 124.26°WNdalithoni Limestone — 17.23°S, 178.95°EFutuna Limestone — 18.22°S, 178.78°EFutuna Limestone — 18.45°S, 178.48°E

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The named rock units Raninidae has been recovered from, largest first. Drawn where the rock is now, not where it formed. 71 further formations hold fewer occurrences each and are not listed. 167 occurrences have no formation on record, which is common for older literature.

Raninidae and its relatives

Eocene

Where Raninidae and its relatives were recorded in the Eocene.

Found in the same rock

1,984 taxa

The Paleobiology Database records 197 sites for Raninidae, 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

144 references

Each of the 342 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. 132 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 Raninidae

Credit
Velela at English Wikipedia
Licence
Public Domain
Commercial use
the licence allows it

No 3D scan of Raninidae 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 itRaninoidea through timeFormations of the EoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. de Haan 1833