Mosasaur tail study links flexible tails to faster hunting bursts

A Rutgers-led study published on October 7, 2026, in Current Biology estimates that flexible tails helped some mosasaurs launch faster bursts through the ancient seas. By modeling a single powerful tail stroke in four kinds of these extinct marine reptiles, the researchers found a possible explanation for different hunting strategies: some may have been better equipped to ambush prey, while others were better suited to sustained swimming. The results describe reconstructed performance, not observed attacks.

How the mosasaur tail model works

The researchers used fossil skeletons to reconstruct body size and tail shape, then applied physics-based calculations to a movement they call a ‘slam-start’. In that movement, an animal curls its tail to one side before sweeping it back against the water to drive its body forward. The question was how much speed that one stroke could produce, rather than how fast a mosasaur could swim continuously.

Fossils do not preserve a complete record of tail muscles. The team drew on the anatomy of living lizards, including Komodo dragons, to reconstruct the missing tissue. It also tested different assumptions about muscle power, tail flexibility and resistance from the water. Those choices matter when estimating the movement of an animal that cannot be measured alive; the reported speeds are model outputs, not direct measurements.

Which mosasaurs had the fastest modeled lunges?

Across the conditions tested, Platecarpus and Tylosaurus produced faster lunges for their body size than Mosasaurus and Plotosaurus. Platecarpus ranked fastest among the four kinds examined. The longer flexible sections of the first two animals’ tails let them curl farther before the power stroke. According to the Rutgers study account, the extent of that curl had a larger effect on modeled speed than the other conditions the team varied.

What tail shape suggests about hunting

The researchers interpret the stronger modeled lunges of Platecarpus and Tylosaurus as consistent with ambush hunting in shallow seas. A predator able to accelerate quickly from a near standstill could have used that ability to close on prey. That is a proposed link between anatomy and ecology: the model estimates a movement, while the hunting strategy is inferred from the movement and other fossil clues.

Mosasaurus and especially Plotosaurus appear better suited to pursuing prey in open water, according to the study account. Kiersten Formoso, who led the research, cautioned against treating a weaker modeled lunge as evidence that Plotosaurus was generally slow. ‘Its tail was built for sustained, tuna-like swimming rather than sudden bursts,’ she said. Burst acceleration and sustained swimming measure different capabilities.

National Geographic reported that Formoso sees the results as supporting an existing ambush-hunting hypothesis informed by tooth wear and head anatomy. Those clues can strengthen an interpretation, but they do not show a particular mosasaur catching prey. National Geographic also quoted mosasaur expert Mike Polcyn, who was outside the study, proposing that shorter-tailed relatives may have shifted toward longer-distance pursuit as long-tailed animals occupied shallow-sea niches. That proposed ecological shift remains an interpretation.

What the study can establish

The work addresses a different swimming question from earlier research that concentrated on cruising through repeated tail beats. Its comparison of a sudden launch suggests that tail proportions could influence the first moments of an attack even among related predators. It does not establish the exact speeds of living mosasaurs, because the muscle properties and other inputs had to be reconstructed. Nor can a calculated burst alone determine where an animal hunted or what prey it caught.

The study authors described their work as, to their knowledge, the first quantification of burst-swimming performance in a marine reptile from the age of dinosaurs. They said the tools would be made publicly available for use on other extinct swimmers. Formoso also told National Geographic that similar methods could potentially help study marine animals that are difficult to observe directly, including sei whales for which skeletons are available. Those applications would require their own evidence and assumptions.