Giant Tooth of Ancient Marine Reptile Discovered in Alps

The root of the thickest ichthyosaur tooth found so far with a diameter of 60 millimeters. Rosi ROTH EUREKALERT!/AFP
The root of the thickest ichthyosaur tooth found so far with a diameter of 60 millimeters. Rosi ROTH EUREKALERT!/AFP
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Giant Tooth of Ancient Marine Reptile Discovered in Alps

The root of the thickest ichthyosaur tooth found so far with a diameter of 60 millimeters. Rosi ROTH EUREKALERT!/AFP
The root of the thickest ichthyosaur tooth found so far with a diameter of 60 millimeters. Rosi ROTH EUREKALERT!/AFP

The fossils of three ichthyosaurs -- giant marine reptiles that patrolled primordial oceans -- have been discovered high up in the Swiss Alps, and include the largest ever tooth found for the species, a study said Thursday.

With elongated bodies and small heads, the prehistoric leviathans weighed up to 80 metric tons (88 US tons) and grew to 20 meters (yards), making them among the largest animals to have ever lived, AFP reported.

They first appeared 250 million years ago in the early Triassic, and a smaller, dolphin-like subtype survived until 90 million years ago. But the gigantic ichthyosaurs, which comprised most of the species, died out 200 million years ago.

Unlike dinosaurs, ichthyosaurs barely left a trace of fossil remains, and "why that is remains a great mystery to this day," said Martin Sander of the University of Bonn, lead author of the paper in the Journal of Vertebrate Paleontology.

The specimens in question, dated to 205 million years ago in the study, were unearthed between 1976 and 1990 during geological surveys, but were only recently analyzed in detail.

Fun fact: they were discovered at an altitude of 2,800 meters (9,100 feet). During their lifetimes the three swam in waters around the supercontinent Pangea-- but due to plate tectonics and the folding of the Alps, the fossils kept rising.

Ichthyosaurs were previously thought to have only inhabited the deep ocean, but the rocks from which the new fossils derive are believed to have been at the bottom of a shallow coastal area. It could be that some of the giants followed schools of fish there.

There are two sets of skeletal remains. One consists of ten rib fragments and a vertebra, suggesting an animal some 20 meters long, which is more or less equivalent to the largest ichthyosaur to have been found, in Canada.

The second animal measured 15 meters, according to an estimate from the seven vertebrae found.

"From our point of view, however, the tooth is particularly exciting," explained Sander.

"Because this is huge by ichthyosaur standards: Its root was 60 millimeters (2.4 inches) in diameter - the largest specimen still in a complete skull to date was 20 millimeters and came from an ichthyosaur that was nearly 18 meters long."

While this could indicate a beast of epic proportions, it's more likely to have come from an ichthyosaur with particularly gigantic teeth, rather than a particularly gigantic ichthyosaur.

Current research holds that extreme gigantism is incompatible with a predatory lifestyle requiring teeth.

That's why the largest known animal to have ever lived -- the blue whale at 30 meters long and 150 tons -- lacks teeth.

Blue whales are filter feeders, while the much smaller sperm whales, at 20 meters long and 50 tons, are hunters, and use more of their energy to fuel their muscles.

"Marine predators therefore probably can't get much bigger than a sperm whale," Sander said, though more fossils would need to be found to know for certain. "Maybe there are more remains of the giant sea creatures hidden beneath the glaciers," he said.



Bull Sharks Linger in Warming Sydney Waters

A man watches large waves on Bondi Beach in Sydney on July 2, 2025, as large swells and high winds hit the east coast of Australia. (Photo by SAEED KHAN / AFP)
A man watches large waves on Bondi Beach in Sydney on July 2, 2025, as large swells and high winds hit the east coast of Australia. (Photo by SAEED KHAN / AFP)
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Bull Sharks Linger in Warming Sydney Waters

A man watches large waves on Bondi Beach in Sydney on July 2, 2025, as large swells and high winds hit the east coast of Australia. (Photo by SAEED KHAN / AFP)
A man watches large waves on Bondi Beach in Sydney on July 2, 2025, as large swells and high winds hit the east coast of Australia. (Photo by SAEED KHAN / AFP)

Bull sharks are lingering off Sydney's beaches for longer periods each year as oceans warm, researchers said Friday, predicting they may one day stay all year.

The predators are migratory, swimming north in winter when Sydney's long-term ocean temperatures dip below 19 degrees Celsius (66 degrees Fahrenheit) to bask in the balmier waters off Queensland.

A team of scientists looked at 15 years of acoustic tracking of 92 tagged migratory sharks in an area including Bondi Beach and Sydney Harbour.

Records show the sharks now spend an average of 15 days longer off Sydney's coast in summer than they did in 2009, said James Cook University researcher Nicolas Lubitz.

"If they're staying longer, it means that people and prey animals have a longer window of overlap with them."

Shark attacks are rare in ocean-loving Australia, and most serious bites are from three species: bull sharks, great whites, and tiger sharks, according to a national database.

There have been more than 1,200 shark incidents around Australia since 1791, of which over 250 resulted in death.

Researchers found an average warming of 0.57C in Bondi for the October-May period between 2006 and 2024, said the study published in the peer-reviewed journal Science of The Total Environment.

Over a longer period, remotely sensed summer sea-surface temperatures in the area rose an average 0.67C between 1982 and 2024, they said.

"If this trend persists, which it likely will, it just means that these animals are going to spend more and more time towards their seasonal distributional limit, which currently is southern and central New South Wales," Lubitz said.

"So it could be that a few decades from now, maybe bull sharks are present year-round in waters off Sydney," he added.

"While the chances of a shark bite, and shark bites in Australia in general, remain low, it just means that people have to be more aware of an increased window of bull shark presence in coastal waters off Sydney."

Climate change could also change breeding patterns, Lubitz said, with early evidence indicating juvenile sharks were appearing in rivers further south.

There was some evidence as well that summer habitats for great whites, which prefer colder waters, were decreasing in northern New South Wales and Queensland, he said.

Tagged sharks trigger an alarm when they swim within range of a network of receivers dotted around parts of the Australian coast, giving people real-time warnings on a mobile app of their presence at key locations.