Walking with Dinosaurs: Hesperornis

Hesperornis regalis
Named by Othniel Charles Marsh, 1872
Diet: Piscivore (also fed on belemnites)
Type: Avialae Euavialae Avebricaudia Pygostylia Ornithothoraces Euornithes Ornithurae (Hesperornithes) theropod dinosaur
Size: 5.9 feet (1.8 meters) long and 200 kg
Region: North America (Kansas USA)
Age: Late Cretaceous (83.5 to 80.5 million BC; Early Campanian)
Enemies: Large marine reptiles such as mosasaurs like Tylosaurus (The remains of a Hesperornis was found in its stomach content) and juvenile plesiosaurs (a legbone of a Hesperornis was found with a bite mark made by a polycotylid plesiosaur, probably either Dolichornynchops or a related animals, but signs of infection, meaning that it escaped the attack and survived); sharks such as Squalicorax and Cretoxyrhina mantelli (Ginsu shark); large predatory fish such as Xiphactinus; carnivorous predatory dinosaurs when on the beach of the Western Interior Seaway.
Episode: Sea Monsters-The Most Dangerous Sea Ever
Info: Resembling a modern-day loon albeit with teeth like its dinosaur ancestors and a member of the now extinct highly specialized group of aquatic avialans related modern-day birds known as hesperornithes (which since they first evolved around 99.6 million years ago in the Cenomanian age with Enaliornis, they diversified and thrived in the Late Cretaceous seas as well as freshwater habitats, occupying a niche now filled by today diving birds such as loons, until they died out during the Cretaceous-Paleogene/K-Pg mass extinction event, along with enantiornithes, the non-avian dinosaurs, and 75% of all plants and animal species, 66 million years ago), Hesperornis swam through the Western Interior Seaway that covers most of the interior of what is now western North America, using its paddle-like hind-limbs to swim through the sea and catch fish and belemnites using its beak lined with sharp teeth, while its wings were practically non-existing. Discovered in 1871 by American paleontologist Othniel Charles Marsh and named and described it in 1873, this discovery allowed him to make a much stronger demonstration of an evolutionary link between reptiles and birds than had been possible before.

Note: Used this site as a source of reference dinogoss.blogspot.com/2011/05/…. The fish I included here is Lepticodon.

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