True sea monsters of the late Cretaceous seas, the marine lizards called mosasaurs, that are related to modern snakes and monitor lizards could breast stroke, says a new study.
The prehistoric creatures, that grew as long as fifty feet was known to shred their victims with their enormous and powerful jaws.
Now, new research claims that the muscular breast stroke of the mosasaurs allowed them ambush-worthy bursts of speed, according to a report in Science Daily.
Speaking about the same, lead author Kiersten Formoso from the University of Southern California said that while it is known that mosasaurs most likely used their tails for locomotion, now it is being thought that they also used their forelimbs, or their tail and forelimbs together.
According to her, the dual swimming style could make mosasaurs unique among tetrapods.
Earlier studies have shown that the mosasaurs had extemely large pectoral girdle. However, most assumed the creature's swimming was mainly driven by their long tails, something like alligators or whales.
According to co-author Mike Habib, Assistant Professor of Anatomical Sciences at USC, not many animals are good at both and that the way in which alligators swim is called 'cruising' as opposed to the 'burst' motion.
To find out more closely if the mosasaurs were a balance of burst-adapted and cruise-adapted, or excelled in either one, Formoso and co-authors focused on the oversized pectoral girdle.
The study authors studied a fossil Plotosaurus, a type of of mosasaur, at the Natural History Museum of Los Angeles County and used measurements of mosasaur pectoral girdles published in other studies.
They came to the conclusion that the mosasaurs' unusually large and low-placed pectoral girdle supported large muscle attachments.
This, according to Habib, and asymmetry in the bone structure is a telltale sign of the strong, inward pull-down motion called adduction.
Thus, study authors concluded that mosasaurs used their forelimbs to swim, breast-stroke style, adding powerful bursts of propulsion to their ability to cruise.