SHARK VS SHARK

CladoselachevsBluntnose sixgill

Length, weight and bite evidence—plus context from a human, city bus and blue whale. Every number below carries its uncertainty with it.

ExtinctCladoselache fyleri×LivingHexanchus griseus
QUICK VERDICT

Bluntnose sixgill is about 2.7× longer by these reference values.

Bluntnose sixgill uses a 4.8 m upper reference, compared with 1.8 m for Cladoselache. A clean mass ratio is not shown because at least one weight is not reliably reconstructed.

01

ON THE SAME SCALE

Human. Bus. Whale.
Pick your reference.

RELATIVE LENGTH · 0–24 METERS
ACladoselacheabout 1.8 m / 6 ft
BBluntnose sixgillreported to 4.8 m / 15.8 ft
REFAdult human1.8 m · about 80 kg

Length bars use upper comparison values and do not show body depth, tail proportion or typical adult size. A long thresher tail, for example, does not equal whale-shark body mass.

02

THE NUMBERS

Side by side.

MeasureCladoselacheBluntnose sixgill
Length referenceabout 1.8 m / 6 ftreported to 4.8 m / 15.8 ft
Weight referenceNot reliably reconstructedpublished to 590 kg / 1,300 lb
Bite forceNo defensible estimate usedUnknownNo dependable maximum foundUnknown
Timeabout 370 million years agoDeep temperate and tropical waters
DietSmall fishesFishes, rays, seals and carrion
03

WHAT THE DATA CAN SAY

Size is not the whole animal.

Length and weight

Cladoselache is represented by about 1.8 m / 6 ft; Bluntnose sixgill by reported to 4.8 m / 15.8 ft. Calling it a modern-style shark hides major evolutionary distance. Deepwater sampling is difficult, so upper records are sparse.

Bite evidence

Cladoselache: No usable maximum-force model exists. Bluntnose sixgill: No standardized maximum is available.

Living versus extinct

At least one animal is known from fossils. Fossil length, weight and bite estimates depend on which living analogues and scaling equations researchers choose.

Ecology changes the matchup

It was an early shark-like chondrichthyan with a streamlined body. Its six gill slits mark an ancient branch of shark diversity.

04

TRACE THE CLAIMS

Sources and limits.

CladoselacheSmithsonian National Museum of Natural HistoryBluntnose sixgillFlorida MuseumHow we standardize comparisonsRead the methodology →