The research, published in Current Biology, was led by Kiersten Formoso, an assistant professor in the Department of Ecology, Evolution, and Natural Resources in the Rutgers School of Environmental and Biological Sciences. Her team reconstructed the bodies of four kinds of mosasaurs from their nearly complete fossil skeletons and then applied principles of physics to estimate how quickly each animal could surge forward with a single, powerful sweep of its tail. The answer, she says, helps explain how these predators caught their meals and, in turn, how ancient ocean ecosystems functioned.

At the heart of the study is a movement the researchers call a slam-start. An animal curls its tail to one side and then forcefully sweeps it back, pushing against the water and driving its body forward. Formoso compares the initial surge to a swimmer pushing off the wall of a pool. It is the tail itself pushing off the water, she said. That single burst of acceleration could mean the difference between a successful ambush and a meal that swims away, or between life and death for a smaller animal trying to escape a larger hunter.

The scientific question began with an observation about the fossils themselves. Two major branches of the mosasaur family tree had differently proportioned tails, and Formoso wondered whether those anatomical differences affected how quickly the animals could launch an attack. Previous research on swimming reptiles had largely focused on cruising, the steady type of swimming in which an animal beats its tail repeatedly to move through the water. Burst performance, the sudden acceleration that helps a predator seize prey, had gone largely unquantified.

The nearly complete fossils provided detailed information about body size and tail shape, but one crucial ingredient was missing: muscle. To reconstruct the tail muscles that no longer exist, the researchers drew on the anatomy of living lizards, including the Komodo dragon, one of the closest things the modern world offers to a giant predatory reptile. With bodies and musculature estimated, the team modeled the physics of the slam-start for each of the four mosasaurs, calculating how quickly each could surge forward with one powerful tail stroke.

The calculations produced striking results. A particularly large Tylosaurus, one of the animals modeled, could have reached about 15 miles per hour with a single tail stroke. That estimate describes a brief burst rather than a speed the animal could maintain over distance, and the researchers caution that exact speeds remain uncertain. What matters more, they say, are the differences among the animals. Across the tested conditions, two species, Platecarpus and Tylosaurus, achieved faster lunges for their body size than Mosasaurus and Plotosaurus, with Platecarpus emerging as the fastest of the four.

The advantage came largely from a longer, more flexible section of the tail, which allowed Platecarpus and Tylosaurus to curl their tails farther before sweeping them back. In the models, how far the tail could curl had a much larger effect on the resulting speeds than any other variable the team tested. To make sure the findings were robust, the researchers ran the numbers across a range of assumptions about muscle power, tail flexibility, and resistance from the water. The pattern held up under all of them: the animals with the most curlable tails were the ones best built for a lightning first strike.

Such an advantage, the researchers said, would favor ambush hunting in shallow seas, where a predator could lie in wait and explode toward prey before it could react. Mosasaurus and especially Plotosaurus appear to have been better suited to a different strategy, pursuing prey across the open ocean. That does not mean Plotosaurus was slow, Formoso said. Its tail was built for sustained, tuna-like swimming rather than sudden bursts. In other words, the mosasaur family tree contained specialists in two very different hunting styles, much as modern predatory fish divide the water between sprinters and endurance swimmers.

The findings also agree with other independent clues to how mosasaurs lived. Studies of bite force, patterns of tooth wear, and the chemical makeup of fossils have all been used to reconstruct mosasaur diets and habitats, and the new burst-swimming results fit comfortably alongside that earlier evidence. The study additionally carries a New Jersey connection: alongside the four main reconstructions, the team modeled exceptionally large animals, including a Mosasaurus based on a fossil from New Jersey held by the New Jersey State Museum in Trenton, a reminder that the remains of these ocean giants lie beneath some surprisingly familiar ground.

To the authors’ knowledge, this is the first study to put numbers on burst swimming performance in any marine reptile from the age of dinosaurs, and the team is making its tools freely and publicly available so other researchers can apply the approach to additional extinct swimmers, including animals with no close living equivalent. For Formoso, whose broader research examines how animals with land-dwelling ancestors evolved to live in water, the work rests on a simple and powerful premise: the physical rules that govern swimming today also applied millions of years ago. Physics is physics, she said, and by applying those unchanging rules to fossil bones, scientists can watch long-extinct predators move again, one tail stroke at a time.

Subject of Research: Burst swimming performance and hunting strategies of mosasaur marine reptiles based on tail morphology

Article Title: Some of those ancient sea predators were built for surprise attacks

Article References: Some of those ancient sea predators were built for surprise attacks. (n.d.). Original publication

Image Credits: AI Generated

DOI: Not provided

Keywords: mosasaurs, marine reptiles, burst swimming, tail morphology, ambush predation, Current Biology, Rutgers University, paleontology, Cretaceous seas, biomechanics, Tylosaurus, Plotosaurus

The study, conducted by Dikansh S. Parmar of the Leibniz-Institut zur Analyse des Biodiversitätswandels, Museum Koenig in Bonn, and Hinrich Kaiser of Victor Valley College, was published in the journal Discover Ecology. Between January 2022 and May 2025, the researchers carried out intermittent road-based visual encounter surveys along two forest roads in Dangs District, documenting 44 individual Bamboo Pitvipers. The species reaches the northern limit of its range in this part of western India, making the local population particularly significant for conservation.

The survey corridors were chosen for a practical reason: the roads are flanked by steep, eroding cut slopes whose near-vertical faces are studded with vegetation jutting out into open air. This arrangement offered researchers what amounted to a two-dimensional view of an otherwise cryptic arboreal snake, with the animals visible against a dark earthen background. Corridor α, a 7.7-kilometre road connecting the villages of Dhulda and Mahal, and Corridor β, a 15.2-kilometre route linking Mahal and Subir, became the study’s focal landscapes. Surveyors rode slowly along the roads at night on a motorcycle, scanning the slopes with a powerful searchlight.

The results revealed a striking pattern in how these snakes use their habitat. Of the 44 individuals recorded, 25 were perched on exposed tree roots, 13 on dry or green shrubs and bushes, and 6 on bamboo. The vast majority, 77 percent, were found at heights of 3 to 7 metres above road level, with some perches extending as much as 3 metres out from the slope face. Only 16 percent were seen at low heights of 1 to 3 metres, and just 7 percent at heights of 7 to 9 metres. The snakes emerged from subterranean shelters shortly after dusk, around 19:00 hours, and were never observed during the daytime.

Perhaps the most remarkable finding involved site fidelity, a behaviour never before specifically investigated in arboreal pitvipers. The researchers confirmed that six snakes reliably remained on their respective perches for a one-month period, then collected them, recorded their morphology, and kept them in captivity for 48 hours before releasing them at knee height on seemingly suitable perches roughly 6 metres below their original positions. Every single snake returned to its exact original perch. One individual was back within 24 hours, four returned after 48 hours, and one took up to 72 hours to find its way home.

Statistical analysis showed that the two corridors differed dramatically in snake abundance. Corridor α recorded an encounter rate of 3.38 snakes per kilometre, nearly three times the 1.18 snakes per kilometre logged along Corridor β. A Mann-Whitney U-test confirmed the difference was statistically significant, and Cliff’s Delta revealed a large effect size of 0.71, indicating an 85 percent probability that any random survey on Corridor α would yield higher encounter rates than on Corridor β. A generalized linear mixed model with a Poisson error distribution further confirmed that per-survey encounter frequencies differed significantly between the corridors. The researchers suggest that differences in slope height, vegetation density, and the extent of habitat fragmentation along Corridor β may explain the disparity.

Behavioural observations painted a picture of a patient, ambush-oriented predator. The snakes emerged exclusively at night, between 19:00 and 03:00 hours, and were rarely seen moving. They typically rested on branches or roots facing cracks in the packed earth that could serve as retreat sites, never straying more than two feet from a potential shelter. When threatened, they adopted the classic coiled strike-ready posture of vipers, sometimes accompanied by tail vibrations. During handling, the researchers documented an unexpected and previously unreported behaviour: the snakes alternately extended and retracted their fangs while presenting a gaping mouth, a defensive display not previously described in any pitviper species.

The study also yielded intriguing insights into reproduction. Between February and June, before the monsoon rains arrived, 18 of the 44 individuals, some 41 percent, were observed in pairs consisting of one male and one female, perched within 1 to 2 metres of each other. The same pairs were detected repeatedly at the same locations throughout the survey period, leading the researchers to propose that the species may practice seasonal monogamy, with males and females locating each other via pheromonal cues and remaining together until the female produces offspring. A gravid female observed in late April 2023, along with juvenile sightings during June and July, provided the first evidence of the breeding season for pitvipers in Gujarat.

Seasonality proved to be a defining feature of the species’ ecology. During the monsoon months from June to September, and throughout the post-monsoon and winter seasons, the snakes became virtually undetectable on their dry-season perches. The researchers received more frequent rescue calls during the monsoon regarding pitvipers found in human habitations, suggesting the snakes move to drier and warmer microhabitats when the rains arrive. In winter, when temperatures in the Dangs forest drop significantly, the snakes likely retreat into wood or bamboo clusters to hibernate. The researchers predict that as climate change increases aridity in the region, these arboreal pitvipers may adjust their seasonal movements, potentially remaining on perches for longer periods each year.

The conservation implications of the study are sobering. The species’ IUCN assessment, last conducted 13 years ago, noted no significant threats, yet the researchers documented landslides, soil erosion from deforestation, forest fires, and illegal wildlife trade as growing dangers. In May 2023, the first author encountered snake smugglers equipped with flashlights, snake bags, hooks, knives, and a jeep searching the slopes; investigation via their vehicle and social media revealed involvement in trafficking snakes from regions as far afield as Northeast India, Maharashtra, and Goa. Because the species displays strong site fidelity and slow movement, it is especially vulnerable to such pressures. Discussions with the Deputy Conservator of Forests, North Division, Dangs, have prompted efforts to designate the two corridors as no-cut zones for bamboo and trees, a measure expected to reduce soil erosion and protect pitviper habitat. The researchers argue that the Bamboo Pitviper’s predictable habits make it an ideal model species for studying arboreal pitviper ecology, and that targeted conservation, combined with village education programs, offers the best hope for its survival at the edge of its range.

Subject of Research: Ecology, site fidelity, and conservation threats of the Bamboo Pitviper in the Dangs Forest of Gujarat, India

Article Title: Hanging in the balance: an ecological and conservation assessment reveals growing threats to the Bamboo Pitviper, Trimeresurus (Craspedocephalus) gramineus (Shaw, 1802), in the Dangs Forest of Gujarat, India

Article References: Parmar, D. S., & Kaiser, H. (2026). Hanging in the balance: an ecological and conservation assessment reveals growing threats to the Bamboo Pitviper, Trimeresurus (Craspedocephalus) gramineus (Shaw, 1802), in the Dangs Forest of Gujarat, India. Discover Ecology, 2(1), Article 9. https://doi.org/10.1007/s44396-026-00025-0

Image Credits: AI Generated

DOI: 10.1007/s44396-026-00025-0

Keywords: Bamboo Pitviper, Trimeresurus gramineus, Gujarat, Dangs Forest, site fidelity, habitat fragmentation, wildlife trafficking, arboreal snakes, pitviper ecology, IUCN Red List, monsoon seasonality, ambush predation