170-Million-Year-Old Fossils Reveal Oldest Mega-Predatory Pliosaur, Offer Insight Into Prehistoric Marine Evolution

Fossils from a 170-million-year-old marine reptile, dating back to the Age of Dinosaurs, have been recognized as the earliest mega-predatory pliosaur. These creatures are closely related to the renowned long-necked plesiosaurs, and this discovery is a rare addition to our understanding of plesiosaur evolution.

Mega-Predatory Dinosaur Dominated Ancient Seas

A study published in Scientific Reports by an international team of paleontologists from institutions in Germany, Poland, Luxembourg, and Sweden reported a detailed analysis of ancient fossils unearthed 40 years ago in northeastern France. Their research led to the identification of a new pliosaur genus, named Lorrainosaurus.

Pliosaurs, a subgroup of marine reptiles closely related to the more famous long-necked plesiosaurs, are known for their distinctive short necks and massive skulls. They first appeared over 200 million years ago but initially held a minor role in marine ecosystems. However, they eventually underwent a remarkable transformation, evolving into massive apex predators.

Lorrainosaurus, which represents the oldest large-bodied pliosaur ever identified with an associated skeleton, possessed jaws that extended over 1.3 meters, equipped with large conical teeth. Its body had a robust, torpedo-like shape and was propelled by four flipper-like limbs.

This ancient marine reptile, estimated to have reached lengths of over 6 meters, thrived during the early Middle Jurassic period, a time about which we have limited information regarding plesiosaurs.

Sven Sachs, a researcher at the Naturkunde-Museum Bielefeld, who led the study, emphasized Lorrainosaurus's significance in the evolutionary history of pliosaurs. It was one of the first of the truly enormous pliosaurs, giving rise to a lineage of marine reptile mega-predators that reigned over the oceans for approximately 80 million years.

This discovery highlights a significant shift in marine predator ecosystems around 175-171 million years ago when mega-predatory pliosaurs like Lorrainosaurus became dominant, surpassing other large predatory plesiosaurs and marine reptiles. Pliosaurs, being carnivorous, likely focused on hunting fish and marine creatures using their long necks and keen vision, contributing to their success.

The exact cause of their extinction, along with other ancient creatures, is still debated, but it's often associated with the mass extinction event at the end of the Mesozoic Era, coinciding with the dinosaur extinction. Pliosaur fossils worldwide continue to enhance our understanding of their biology, behavior, and ecological roles.

First Large-Bodied Creature of Its Type

The recently examined pliosaur marks the earliest occurrence of a large-bodied creature of this type. Sven Sachs, a researcher at the Naturkunde-Museum Bielefeld leading the study, described Lorrainosaurus as one of the first massive pliosaurs, serving as the progenitor of marine reptile mega-predators that dominated the oceans for approximately 80 million years.

Before this recent investigation, knowledge about Lorrainosaurus was limited, with only a brief 1994 paper providing minimal documentation.

The new analysis suggests that the era of colossal mega-predatory pliosaurs likely began earlier than previously thought and was responsive to significant ecological changes during the early Middle Jurassic period, particularly affecting maritime ecosystems in Western Europe.

Senior co-author Benjamin Kear, Curator of Vertebrate Palaeontology and Researcher in Palaeontology at The Museum of Evolution, Uppsala University, noted that Lorrainosaurus represents a crucial addition to the understanding of ancient marine reptiles during a period in the Age of Dinosaurs that remains incompletely explored.

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