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The return of the Predator that terrorized the ancient seas5 min read

January 22, 2021 4 min read

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The return of the Predator that terrorized the ancient seas5 min read

Reading Time: 4 minutes

The year 2021 may seem ordinary to many, but palaeontologists have already had a deadly beginning. That’s right, they’ve found one of the best-preserved fossils of a prehistoric shark to date. This 150 million-year-old shark roamed the planet’s seas in the Jurassic Period, terrorizing the creatures of the ocean with its 150 teeth!

So, let’s find out a little bit about this toothy predator.

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Solnhofen limestone - Simple English Wikipedia, the free encyclopedia

Palaeontologists found the fossil on the 15th of Jan in famous limestones of Solnhofen in Germany. The once petrifying creature’s bones were embedded deep in the limestone. In fact, they created a good enough dent for scientists to finally get a picture of the entire shark. After taking a good look at the imprinted rock, they were able to tell that the shark was an Asteracanthus ornatissimus, and belonged to a family of Hybodontiform Shark.

<<The Solnholfen limestone caves in Germany are famous for their fossils. Image: Wikipedia

A little about Hybodonts

Hybodontiform Sharks or Hybodonts are a family of ancient sharks that are the closest relatives of modern sharks and rays. That’s right if there was anything that looked like the terrifying creature from the movie jaws it was the Hybodonts.

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Image: GIPHY

The first evidence of these sharks was in the Devonian Period which occurred about 362 million years ago. Then, these deadly creatures survived two whole mass extinctions by chomping their way through the seas. However, about 66 million years ago, after a good run of a few hundred million years, these chompers went extinct.

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Hybodont’s came about during the Devonian period of the Palaezoic Era and went extinct in the Merozoic Era, at the end of the cretaceous period. Image: Pinterest

Hybodonts were vertebrates as they had a prominent spine that ran through the centre of their bodies. This spine supported two dorsal fins on the top or back of their bodies, and these dorsal fins helped them navigate the seas.

These fish could be anywhere between few centimetres and 3 metres or ten feet in length. The fossil that’s been found in Germany belonged to a subgroup of Hybodonts called Asteracanthus ornatissimus, and these were the largest Hybodonts around!

Owliver’s Obscure Observation: Modern Sharks and Rays already existed by the Jurassic Period or the time at which this Asteracanthus lived. They were about 3 feet long at the time.

Animal Classification

Asteracanthus ornatissimus is a genus of the animal family of Hybodonts. What does that mean? Well, in. order to better categorise animals scientists have divided them into various subgroups, while bears and sharks both belong to the same family and Phylum, sharks are cold-blooded fish whereas bears are warm-blooded mammals. Just take a look at this classification of a Grizzly bear to get an idea of how the classification of species works.

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Image: Wikipedia

Asteracanthus ornatissimus

An scientific representation of the Asteracanthus ornatissimus. Image: SciHub

You’re probably wondering, to what species does this new fossil belong? The answer is scientists probably can’t tell, but they are able to identify it’s genus which is just a step broader than it’s species identification. As we’ve mentioned before this fossil is of an Asteracanthus that belongs to a the family of Hybodont Sharks.

Asteracanthus - Wikiwand
The fossilised teeth of an Aresthacatus found at another time. Image: Wikipedia

Asteracanthus were about 10 feet long, and possibly the largest fish in the sea at the time! This particular shark had 150 giant teeth. Moreover, the markings on its jaw prove that it was an active predator, that preyed on a wide range of fish.

Asteracanthus was certainly not only one of the largest [vertibrate] fishes of its time, but also one of the most impressive.”

SciNews
Asteracanthus ornatissimus from the lower Tithonian of Solnhofen, Bavaria, Germany: (A) interpretative line drawing; (B) slab containing specimen; (C) close-up view of anterior dorsal fin spine; (D) close-up view of posterior dorsal fin spine; (E) tentative life reconstruction of female Asteracanthus ornatissimus. Abbreviations: adfs - anterior dorsal fin spine, af - anal fin, bv – basiventral, cf - caudal fin, ebr – epibranchial, lal - lateral line, Mc – Meckel’s cartilage, nc – neurocranium, notc – notochord, pcf - pectoral fin, pdfs - posterior dorsal fin spine, plr - pleural rib, pq – palatoquadrate, pvf - pelvic fin, scc - scapulacoracoid. Scale bars - 50 cm in (A, B) and 10 cm in (C, D). Image credit: Stumpf et al., doi: 10.1002/spp2.1350.
Take a look at the fossil alongside an artistic representation of what the the fish probably looked like. Asteracanthus ornatissimus from Solnhofen, Germany.

Owliver’s Obscure Observation: Prior to this, Scientists had only found little bits of the Arestecanthus. During one excavation, they found some dorsal fin spines of the Astrecanthus. Using just that much information, Swiss-American naturalist Louis Agassiz described these deadly creatures more than 180 years ago! Scientists relied on the predictions of this man.
Until Now! This was the first time ever that an entire skeleton of the Astrecanthus was discovered. How exciting!!

With Excerpts From: Sci News, Wikipedia and Wikipedia