Throwing fresh insight into the initial environment of mosasaurs -- a gigantic marine lizard -- researchers have found that the iconic predator gave birth in the open ocean, not on or near shore.
The mighty mosasaurs, which could grow to 50 feet long, were seen in most waters of the earth before their extinction 65 million years ago.
"Mosasaurs are among the best-studied groups of Mesozoic vertebrate animals, but evidence regarding how they were born and what baby mosasaur ecology was like has historically been elusive," said Daniel Field, a doctoral candidate in Yale University's department of geology and geophysics and lead author.
In their study, Field and his colleagues describe the youngest mosasaur specimens ever found.
Field had come across the fossils in the Yale Peabody Museum's extensive collections.
"These specimens were collected over 100 years ago," Field noted.
"They had previously been thought to belong to ancient marine birds," Field pointed out.
Field and Aaron LeBlanc, a doctoral candidate at University of Toronto at Mississauga, said the specimens showed a variety of jaw and teeth features that are only found in mosasaurs.
Also, the fossils were found in deposits in the open ocean.
"Really, the only bird-like feature of the specimens is their small size," LeBlanc said.
"Contrary to classic theories, these findings suggest that mosasaurs did not lay eggs on beaches and that newborn mosasaurs likely did not live in sheltered nearshore nurseries," LeBlanc concluded.
The study was published online in the journal Palaeontology.
