Sixty five million years ago, during the Cretaceous Period, the tentacular kings of the seas were the Giant Ammonites of the genus, Parapuzosia; massive mollusks who were the evolutionary grandfathers of today's giant squids and octopuses. The biggest difference between them and most of today's living cephalopods, though, was the presence of a massive, hard, whorled shell, similar in shape to the shells we see made by both terrestrial and aquatic snails today.

But imagine a snail shell six feet across, or even larger! The largest known species of ammonites is the Parapuzosia seppenradensis, which roamed the seas of the late Cretaceous. The biggest fossil shell ever found was from Germany and measured 5.9 ft across! Wilder still is the fact that the shell was incomplete and would have been larger if fully intact, so animals with armored homes larger than six feet were very much possible. This armored giant squid would have traveled in open water, using a jet type propulsion - similar to today's cephalopods - to swim either in a backwards motion,  or up and down in the water column. Though speed most likely wasn't his biggest asset, this beast was certainly a carnivore capable of catching substantial prey, ranging from other ammonites, large fish, occasionally smaller sharks, and even some marine reptiles.

Though he was a formidable predator, the Parapuzosia seppenradnesis would have been on the menu for many Cretaceous predators even larger than him, like massive marine reptiles in the Mosasaur and Plesiosaur families, and the shell crushing behemoth, Ptychodus, a huge shark whose strange, grinding flat teeth would have made short work of even the biggest Parapuzosia shell.

Ammonites are certainly one of the most common fossils found today, with the smallest specimens making for great souvenirs, mantle pieces, and even jewelry. But there is something about a "kraken" like squid beast, tucked into an armored shell, grabbing its prey with long, strong tentacles and eviscerating them with its powerful and enormous beak (think a nightmare combination of a parrot's beak and a snapping turtle's jaw to get an idea what a Parapuzosia's maw would look like) that can capture the imagination like no other prehistoric marine monster can. They've always been a personal favorite of mine, and so when author, and renowned marine biologist, Dr. Helen Scales (photo directly to the right), asked me to illustrate her natural history book, Spirals in Time: The Secret Life and Curious Afterlife of Seashells, assuring me there would be a chapter dedicated to such beasts and thus in need of a specific illustration of one, I jumped at the chance to draw this iconic paleo-monster; the result of which you see here.


Giant Ammonite

Giant Ammonite, tentacles, paleontology, prehistoric, Cretaceous Period, squid, octopus,
prehistoric, squid, octopus, giant ammonite, shell, dinosaur, marine animal, paleontology, fossil, tentacles
giant ammonite, squid, octopus, tentacles, prehistoric, fossil, paleontology

Company owner and illustrator, Aaron John Gregory.

Dr. Helen Scales appearing on the BBC show, "Worlds Weirdest Events."

Cart: (0)‏
  • Facebook Basic Square
  • Instagram Social Icon
  • Twitter Basic Square

Pacifica, CA 94044  -


All images are ©Cotton Crustacean and can not be 

reproduced in any manner without written consent

from illustrator, Aaron John Gregory.