SHARK VS SHARK

Common threshervsPtychodus

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

LivingAlopias vulpinus×ExtinctPtychodus mortoni
QUICK VERDICT

Ptychodus is about 1.28× longer by these reference values.

Ptychodus uses a 9.7 m upper reference, compared with 7.6 m for Common thresher. 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
ACommon thresherreported to 7.6 m / 24.9 ft
BPtychodusrecent reconstructions approach 9.7 m / 32 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.

MeasureCommon thresherPtychodus
Length referencereported to 7.6 m / 24.9 ftrecent reconstructions approach 9.7 m / 32 ft
Weight referencerecorded over 340 kg / 750 lbNot reliably reconstructed
Bite forceNo dependable maximum foundUnknownNo defensible estimate usedUnknown
TimeTemperate and tropical open watersabout 100–85 million years ago
DietSchooling fishes and squidHard-shelled prey
03

WHAT THE DATA CAN SAY

Size is not the whole animal.

Length and weight

Common thresher is represented by reported to 7.6 m / 24.9 ft; Ptychodus by recent reconstructions approach 9.7 m / 32 ft. Length comparisons can exaggerate body bulk because the tail is exceptionally long. A body outline is rare; length estimates can change with new fossils.

Bite evidence

Common thresher: Its hunting performance cannot be reduced to jaw force. Ptychodus: Hard-prey specialization does not justify inventing a force number.

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

Much of its length is tail, which it uses to stun prey. Flattened crushing teeth—not knife-like teeth—defined this huge shark.

04

TRACE THE CLAIMS

Sources and limits.

Common thresherFlorida MuseumPtychodusPaleobiology DatabaseHow we standardize comparisonsRead the methodology →