Mosasaurs, ancient marine reptiles, may have been faster and more efficient swimmers than previously thought, with some reaching nearly 24 km/h during attacks.
Mosasaur swimming abilities reevaluated
Paleontologists have long studied mosasaurs, large marine reptiles that lived during the Late Cretaceous period. These creatures, known for their flippers and long tails, were once thought to swim inefficiently, like crocodiles or eels, using their entire bodies to move through water.New research challenges old assumptions
In the 2010s, scientists re-examined mosasaur anatomy and found evidence suggesting they had a rigid body structure and a caudal fin similar to that of sharks. This led researchers to believe they were more efficient and dynamic swimmers than previously assumed.Mosasaur speed estimates
A recent study led by Kiersten Formoso from Rutgers University used fossil measurements and mathematical models to estimate the propulsion speed of various mosasaur species. The research, published in Current Biology, suggests some species could reach nearly 24 km/h during sudden attacks.Different hunting strategies
Mosasaurs are divided into two main lineages: Russelllosaurines, with long tails and slender snouts, and Mosasaurines, with shorter tails and robust snouts. The study examined two representatives from each group, including Platecarpus and Tylosaurus proriger for the long-tailed forms.Speed and tail structure
Long-tailed species like Platecarpus and Tylosaurus proriger had tails that could bend significantly before suddenly relaxing, creating powerful bursts of speed. A 14-meter Tylosaurus rex, for example, could reach nearly 24 km/h in a single tail movement.Hunting tactics and prey
Long-tailed mosasaurs were likely ambush predators, hiding in shallow seas before striking at large fish or other marine reptiles. Short-tailed species, such as Mosasaurus, were adapted for sustained swimming, possibly hunting in open waters like modern tuna or sharks.Evolutionary implications
According to Mike Polcyn, a mosasaur specialist, the differences in tail structure and swimming styles may explain how the group evolved. Long-tailed forms dominated shallow seas with ambush tactics, while short-tailed species later adapted to open ocean hunting.Future research directions
Kiersten Formoso and her team plan to apply their methods to other mosasaur species, such as Prognathodon and Globidens, which have specialized diets. The same techniques could also help study modern marine animals like northern minke whales, which are difficult to observe directly.Understanding marine predators
Formoso emphasizes the importance of understanding these ancient predators and their roles in their ecosystems. « These are large predators that play an essential role in their respective ecosystems, » she says, highlighting the ongoing fascination with their biology and behavior.
