A new study published in the journal Palaeontology has revealed some interesting new details about the process of reproduction in Mosasaurs, the large marine lizards that once populated the waters about 65 million years ago.

According to the researchers, Mosasaurs, which could grow up to 50 feet in length, gave birth in the open ocean and not on the shores of the coasts.  While little is known about their relationship to other forms of reptiles, they appear to be closely related to a species of monitor lizard.

The main focus of the study was aimed at learning about the environment in which these iconic predators lived before they were finally doomed to extinction.  The Mosasaurs existed in the waters of the oceans at the same time as dinosaurs dominated the land. While much has been learned about these large, ocean dwelling sea predators, how they reproduced has remained largely a mystery, until now. 

Daniel Field of Yale University and the Smithsonian National Museum of Natural History and his team of researchers studies young specimens that were available at Yale's Peabody Museum and had been collected over a century ago and were originally thought to be ancient marine birds.  Instead, the team realized that the specimens had jaw and teeth features only found on mosasaurs, and they were found in the deep ocean.

The researchers realized that the only reason to believe they are birds was because of their size.  The fact that they were found out in the ocean indicates they were not birthed from eggs found on beaches or near in-shore nurseries, but out in the open ocean.

"Really, the only bird-like feature of the specimens is their small size," said co-author Dr. Aaron LeBlanc of the University of Toronto Mississauga.

This latest discovery offers solid proof that the mosasaurs didn't give birth as originally thought by scientists in the past.  These reptiles gave birth in the ocean deep, and went on to grow to enormous size dominated the seas positioning themselves at the top of the food chain with their superior speed and agility. 

Preying on mollusks, turtles and giant prawns, these vicious swimming predators were the kings of their domain.  Today, learning how these animals gave birth to their young allows us to add yet another piece of the puzzle to better understand how these creatures lived so long ago before humans evolved and mammals were simply small prey to some of the largest reptiles to ever have roamed the planet.