Pterygotus is the titan of sea scorpions.
— Allen, about Pterygotus

Pterygotus ("Winged One") was a giant sea scorpion that was a distant ancestor of the modern day crab.



Pterygotus lived in the oceans during the Silurian and Early Devonian period from 420-400 million years ago. It was one of the top predators of its time.


Known as the titan of all Sea Scorpions, Pterygotus was arguably the largest arthropod of all time. Growing to measure more than three meters in length, they were the size of modern day crocodiles.

Like its smaller relative, Megalograptus, Pterygotus did not have a true stinger, its tail bearing little more than a superficial resemblance to its namesake. Instead, Pterygotus used it as a paddle for swimming in the water; more usually, however, Pterygotus crawled along the sea bottom or was just lying in ambush - it was too heavy to swim too far for too long. It was capable of relatively fast bursts of speed, though.


Pterygotus is depicted as an ambush hunter, lying in wait under the sea-bed for unsuspecting prey to arrive. The females also cared for their young, as they shared whatever "they turned the tables on" with their young.