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Tiny creature from you nightmares – scary worm was patrolling ocean floor 500 million years ago

Life on Earth millions of years ago was quite different. Not only conditions were nothing like the ones we are used to, but also there were all kinds of bizarre life forms. How does getting eaten alive by a worm with 50 spines in its head sound like? Well, good thing marine predator is gone and it was too small to eat you anyway.

25 spines on each side of the head were made to devour worm’s pray. Image credit: Marianne Collins/ROM, University of Toronto

Scientists from the University of Toronto have identified a small marine predator that some 500 million years ago used to patrol the ocean floor and grab its prey with 50 spines deployed from its head. It was around 10 centimetres long and represented a group of animals known as chaetognaths – small, swimming marine carnivores also known as arrow worms. They lived more than 500 million years ago and at that time there were not many more efficient predators in the sea. Scientists say that all smaller sea creatures were figuratively terrified of just a sight of Capinatator praetermissus.

Scientists actually discovered this species in a fossil-rich area in Burgess Shale in British Columbia, Canada. Interestingly, most of specimens of Capinatator praetermissus found had a very well-preserved feeding apparatus – the scary head with 50 spines. That is why scientists can recreate how it was moving and working.

This is an animation, illustrating how scientists think head of the Capinatator praetermissus was working.

We have chaetognaths today, but they have nowhere close the number of spines the Capinatator praetermissus. There were around 25 spines on each side of the animal’s head, expanding to grab the pray and retracting to put it for digestion. Finding signs of soft tissues of these sea creatures is actually quite rare, but this time scientists were lucky. Jean-Bernard Caron, one of the authors of the study, said that gut and muscles, which normally decay away, and more decay-resistant grasping spines “show that chaetognath predators evolved during the explosion of marine diversity during the Cambrian period and were an important component of some of the earliest marine ecosystems.”

By the way, the name Capinatator praetermissus actually has a meaning. The name Capinatator is derived from capio, which means “to grasp” and natator, which means “swimmer”, while praetermissus means “overlooked.” So it is an “overlooked grasping swimmer?

 

Source: University of Toronto

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