Ptychodus is about 5.4× longer by these reference values.
Ptychodus uses a 9.7 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.
ON THE SAME SCALE
Human. Bus. Whale.
Pick your reference.
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.
THE NUMBERS
Side by side.
WHAT THE DATA CAN SAY
Size is not the whole animal.
Length and weight
Cladoselache is represented by about 1.8 m / 6 ft; Ptychodus by recent reconstructions approach 9.7 m / 32 ft. Calling it a modern-style shark hides major evolutionary distance. A body outline is rare; length estimates can change with new fossils.
Bite evidence
Cladoselache: No usable maximum-force model exists. 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
It was an early shark-like chondrichthyan with a streamlined body. Flattened crushing teeth—not knife-like teeth—defined this huge shark.
TRACE THE CLAIMS