Isurolamna

Isurolamna is an extinct genus of mackerel shark from the Paleogene period. It contains at least three species and a fourth is sometimes placed in it. It is thought to be closely related to Macrorhizodus, Isurus, and Carcharodon. Isurolamna arose in the Paleocene epoch during the Selandian age, and was extinct by the close of the Rupelian age of the Oligocene epoch. Some features which define this genus include a small, elliptical foramen (hole) in the middle of the lingual side of the root, triangular cusps except on lower interior teeth, and a relatively thick root with nearly vertical margins. The genus has a complicated taxonomic past.

Isurolamna

Mason Hintermeister · CC BY-SA 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
Sits inside
LamnidaePBDB
Diet
carnivorePBDB, for Lamniformes
Life habit
nektonicPBDB, for Lamniformes
Motility
actively mobilePBDB, for Lamniformes

Time the record covers

At least 41 million years on record.

The record covers at least 61.66 Mya to 20.45 Mya. No occurrence read is dated outside 66 Mya to 15.98 Mya.

Late Cretaceous — about 0 of 77 occurrencesPaleocene — about 14 of 77 occurrencesPaleoceneEocene — about 45 of 77 occurrencesEoceneOligocene — about 17 of 77 occurrencesOligoceneMiocene — about 1 of 77 occurrencesMiocene67–65 Mya — about 0.2 occurrences65–64 Mya — about 0.4 occurrences64–62 Mya — about 0.4 occurrences62–60 Mya — about 0.7 occurrences60–58 Mya — about 4 occurrences58–57 Mya — about 6 occurrences57–55 Mya — about 4 occurrences55–53 Mya — about 3 occurrences53–51 Mya — about 3 occurrences51–50 Mya — about 3 occurrences50–48 Mya — about 3 occurrences48–46 Mya — about 5 occurrences46–44 Mya — about 5 occurrences44–43 Mya — about 5 occurrences43–41 Mya — about 5 occurrences41–39 Mya — about 5 occurrences39–38 Mya — about 4 occurrences38–36 Mya — about 1 occurrence36–34 Mya — about 1 occurrence34–32 Mya — about 4 occurrences32–31 Mya — about 4 occurrences31–29 Mya — about 4 occurrences29–27 Mya — about 4 occurrences27–25 Mya — about 0.8 occurrences25–24 Mya — about 0.8 occurrences24–22 Mya — about 0.3 occurrences22–20 Mya — about 0.1 occurrences20–18 Mya — about 0.4 occurrences18–17 Mya — about 0.4 occurrences17–15 Mya — about 0.2 occurrences61.66 Mya20.45 Mya67 Mya15 Mya

77 occurrences of Isurolamna 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

77 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

37 formations

Marnes de Miretrain — 43.69°N, 1.13°WLondon Clay — 51.40°N, 0.83°ELondon Clay — 51.51°N, 0.24°ELondon Clay — 51.64°N, 0.78°ESelsey — 50.80°N, 1.21°WSables de Bracheux — 49.58°N, 2.65°ESables de Bracheux — 49.53°N, 2.75°EOsinovaya — 48.36°N, 41.85°EOsinovaya — 48.38°N, 41.93°EOsinovaya — 48.46°N, 41.83°ETuffeau de St-Omer — 50.53°N, 3.15°ETuffeau de St-Omer — 50.44°N, 3.07°EBoom — 51.09°N, 4.36°EBoom — 51.13°N, 4.27°EArgiles d'Lignite du Soissonnais — 49.33°N, 2.66°EKortrijk Clay — 50.80°N, 3.22°EMarnes de Donzacq — 43.75°N, 0.84°WTavda — 55.34°N, 65.35°ETavda — 56.70°N, 63.15°EBrussel Sand — 50.79°N, 4.37°ELisbon — 31.36°N, 86.52°WElmore — 50.80°N, 1.21°WCouche II — 32.65°N, 6.68°WRzehakia — 48.33°N, 14.30°EKuma — 45.10°N, 34.63°EBuchak — 49.53°N, 39.07°EKalinino — 52.51°N, 46.58°EMiretrain Marl — 43.57°N, 1.11°WSables de Kerniel — 50.88°N, 5.59°EMenilite — 49.20°N, 17.20°EImo — 5.55°N, 7.64°EBoom Clay — 51.19°N, 4.32°E

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The named rock units Isurolamna has been recovered from, largest first. Drawn where the rock is now, not where it formed. 13 further formations hold fewer occurrences each and are not listed. 15 occurrences have no formation on record, which is common for older literature.

Isurolamna and its relatives

Eocene

Where Isurolamna and its relatives were recorded in the Eocene.

Found in the same rock

1,017 taxa

The Paleobiology Database records 73 sites for Isurolamna, 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

41 references

Each of the 77 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. 29 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 Isurolamna

Credit
Mason Hintermeister
Licence
CC BY-SA 4.0
Commercial use
the licence allows it

No 3D scan of Isurolamna 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 itLamnidae through timeFormations of the EoceneThe world it lived on

Occurrence data from the Paleobiology Database, CC BY 4.0. Cappetta 1976