Fantastical Jurassic Fossil Shows Crustacean Eaten by Squid Eaten by Shark

The remains of a belemnite and a crustacean. © Klug et al., Swiss Journal of Palaeontology, 2021 The remains of a belemnite and a crustacean.

Sometime in the early Jurassic, an ancient squid-like creature speared a yummy lobster-like crustacean with its many hooked tentacles. Just as it began to dig into its meal, the eater became the eaten.

A much larger predator swooped in, tore a chunk out of the squid's soft middle and dashed off, leaving the leftovers of this three-way feeding fest sinking slowly to the bottom.

Roughly 180 million years later, the fossilized scene has been discovered in a quarry in Germany, and after close analysis, archaeologists now think they've figured out who was at the top of the food chain. 

According to experts, the extinct squid-like cephalopod, known as a belemnite, was most probably killed by an ancient crocodile, shark, or other large predatory fish.

Whatever it was, the predator didn't stick around to finish its meal, likely because cephalopods have tough rostra - beaks that are hard, pointed and difficult to digest.

This means the hunter probably wasn't an ichthyosaur, even though fossils of these extinct marine reptiles suggest they were particularly skilled at picking around the hard areas of belemnites. Their stomach contents only show the mega-hooks found on belemnite tentacles and no other hard structures.

Fossilized stomachs of marine crocodiles and predatory fish, on the other hand, suggest these creatures gobbled everything down, swallowing both the mega-hooks and the hard beaks of squid.

Yet eating the whole squid isn't necessarily a good thing. A fossilized shark, also found in Germany from the Jurassic, was found with a whole pile of belemnite beaks in its stomach, and experts say these hard structures likely caused the shark's death. The diagram below shows the extreme blockage they created in the creature's stomach.

map: Screen Shot 2021 05 11 at 1.00.13 pm

Fantastical Jurassic Fossil Shows Crustacean Eaten by Squid Eaten by Shark