Saturday, January 6, 2018

Halszkaraptor the Swimming Raptor Dinosaur




Halszkaraptor about to go Fishing
NOTE:  My main computer is still broken so I can not scan this cleanly so
there will not be a printable version for a few days.

Have you ever heard of a SWIMMING dinosaur... I don't mean a marine reptile, I mean a dinosaur that actually swims to hunt for prey...AKA fishing.  Well, you are about to hear about one...

Halszkaraptor escuilliei is a recent find from Mongolia.  The fossil was in a private collector's collection but it had been illegally exported from Mongolia.  It was so unusual that paleontologists at first thought it was a fake.  Synchrotron tomography (a type of cT x-ray scan) revealed that this was a real animal that lived an unusual lifestyle.  It had many sharp teeth and a nerve cluster in its snout called a plexus.  A plexus is what crocodilians have for detecting movement of prey underwater.  The Halszkaraptor also had flattened feet that would have made great paddles.  All these clues led paleontologists to conclude that it lived an amphibious lifestyle.  It was not an amphibian but it did live both in and out of the water.  This is an amazing discovery!

This bird looks remarkably like the flightless cormorant from the Galapagos Islands.  The cormorants in other parts of the world fly and dive into the water from up high to catch fish.  The flightless cormorant lives on the rocks of the Galapagos Islands and dives directly from land into the ocean.  It evolved to the point where it no longer needed to fly.  There were no predators and the fish were plentiful.  I think that the same conditions existed where Halzkaraptor lived in Mongolia, back in the Cretaceous Period 70 million years ago.

When two organisms evolve to have similar characteristics this is called convergent evolution.  Another example of convergent evolution would be how dolphins are shaped much like an Ichthyosaur.  Both have  long streamlined bodies, flat fluke tails, flippers for legs, and a flat tail for propulsion through the water.   These traits are all useful for living in the water so many animals that live in water have these characteristics...even though they evolved completely independently.  A dolphin and an Ichthyosaur are not related at all.  One is a mammal and the other is a reptile.


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