The study is performed by researchers from Yale University and University of Toronto.
Researchers have discovered specimens of mosasaurs which they mistook it as the specimen of some ancient birds.
They found that the mosasaurs gave birth to the young ones not on or near the shore but in the open ocean.
Masasaurs are from the period of Dinosaurs, they became extinct about 65 million years ago.
This baby lizard can grow up to 50 feet.
The study helped the researchers in understanding the environment of the mosasaurs.
These lizards populated most of the oceans on the Earth.
Daniel Field,lead author of the study said, “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.”
The specimens are not newly discovered but they are discovered more than hundred years ago.
Field found the specimen in the Yale Peabody Museum.
Aaron LeBlanc, co-author of the study said, “Really, the only bird-like feature of the specimens is their small size, 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.”
These fossils were found in the middle of the open ocean.
The findings of the study are published in the journal Paleontology on April 10.