Garamaudo bauciensis resided in what is now Europe throughout the Santonian age of the Late Cretaceous, approximately 84 million years earlier.

The types was a kind of the tethysaurine, a group of early mosasaurs within the superfamily Mosasauroidea.

“Mosasauroidea is an extinct group of water squamates that got into and diversified in the marine environment at the start of the Cenomanian, spreading out worldwide from the Santonian to the end of the Maastrichtian, and ending up being extinct throughout the biological crisis of the end-Cretaceous mass termination,” stated lead author Dr. Nathalie Bardet and Dr. Alexandra Houssaye from France’s National Museum of Natural History and their coworkers.

“They have extended skulls and bodies, and long, laterally compressed tails. They include a high variety of sizes, from 1 to 15 m (3.3-50 feet) in length, in ecology, from freshwater, shallow marine to open waters, and in diet plan, from mollusks and arthropods to big fish and reptiles.”

“Most mosasauroids have a morphology highly customized for a marine way of life, with paddles and the loss of connection in between the vertebral column and the hips– that is, the lack of a real sacrum.”

“More primitive types show limbs looking adjusted for a terrestrial mobility and a sacrum, showing a plesiopedal and plesiopelvic condition.”

“Most mosasauroid remains are from marine deposits,” they included.

“However, a couple of types and undetermined mosasauroid remains have actually been experienced in freshwater environments, such as shallow estuarine and fluvial deposits.”

“Particularly typical are freshwater incidents in the Santonian-Campanian continental deposits of Europe, from Portugal to Hungary and Austria, travelling through southern France.”

Garamaudo bauciensisfossilized remains were discovered in 1997 at the Bouc-Bel-Air– Sousquières area in the city of Bouc-Bel-Air, Provence, southeastern France.

The fossils consist of part of a lower jaw, vertebrae, ribs, a hips and a humerus. They originates from a minimum of 4 people, though the majority of it appears to come from one.

“The Bouc-Bel-Air– Sousquières region represents a freshwater environment, most likely a reasonably eutrophic, carbonate-producing lake regularly affected by flooding and shallowing occasions, within the continental deposits of the Aix-en-Provence Basin,” the paleontologists stated.

“Such fast flooding episodes might discuss the state of conservation of the holotype specimen of Garamaudo bauciensisthat includes damaged bones having nevertheless unspoiled surface areas.”

Garamaudo bauciensis had to do with 2.5 m long and, unlike the better-known mosasaurs, kept limbs that look fit to strolling on land, together with a hips securely connected to the spinal column.

Its ribs were long and directly, recommending a deep however narrow, side-to-side flattened body.

The scientists recommend the animal swam by swelling like an eel.

CT scans revealed thick, compact bone in the vertebrae, ribs and humerus, a characteristic they connect to buoyancy control.

They propose that Garamaudo bauciensis might dive to shallow depths and might have been an ambush predator, however the density of its bones appears incompatible with life on land.

The animal was most likely amongst the leading predators in its environment, potentially eating little fish, reptiles or amphibians, though its diet plan stays unidentified.

“The task of this brand-new freshwater mosasaurid to the tethysaurines highlights an extra incident of a freshwater types in this clade and the reality that, based upon present understanding, it is just within the Tethysaurinae that freshwater types developed amongst mosasaurids,” the researchers stated.

“During the very same duration, hydropedal and hydropelvic mosasaurs with a greater development rate and spongious bones, showing an active carangiform swimming mode, developed and radiated in open marine environments, spreading out throughout the world.”

“This brand-new discovery for that reason adds to a much better understanding of a more varied and complicated development and history of post-Turonian mosasaurids, consisting of more substantial specific niche partitioning than formerly recognized.”

The research study was released on September 28, 2026 in the Peer Community Journal

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N. Bardet et al2026. Garamaudo bauciensisa brand-new freshwater mosasaurid (Reptilia, Squamata) from the Santonian (Late Cretaceous) of Provence, southeastern France. Peer Community Journal 6: e99; doi: 10.24072/ pcjournal.804