A 170-million-year-old ancient marine reptile’s fossils have revealed that the animal from the Age of Dinosaurs is the oldest-known mega-predatory pliosaur. Pliosaurs were close relatives of plesiosaurs, and were ancient reptiles that lived in oceans. Plesiosaurs first appeared on Earth 170 million years ago, and were highly skilled swimmers. They appeared like fat dolphins with lock necks, and their heads had the shape of a snake, according to HubPages, an online publishing platform. They were famously known for their long necks.
Meanwhile, pliosaurs had short necks, plump bodies, and their heads were like that of crocodiles. Pliosaurs were a type of plesiosaur, and appeared over 200 million years ago. For about 30 million years, they remained minor components of marine ecosystems. Then, they suddenly developed into gargantuan apex predators.
The new study, which has identified the oldest-known mega-predatory pliosaur, is important because the findings are unique, and help scientists understand more about the evolution of plesiosaurs. The study, led by an international team of scientists, was recently published in the journal Scientific Reports.
When were the fossils first discovered? What have scientists named the genus as?
Researchers had found the fossils 40 years ago in north-eastern France. Now, the new team of scientists has analysed the fossils, and identified them as a new pliosaur genus called Lorrainosaurus.
Why did pliosaurs become apex predators about 30 million years after they came to Earth?
According to the new study, the reasons why the adaptive shift of pliosaurs becoming massive apex predators 30 million years after appearing on Earth occurred include feeding niche differentiation, and the global decline of other predatory marine reptiles more than 170 million years ago.
What must Lorrainosaurus have looked like?
The scientists have found a decomposed skeleton of Lorrainosaurus. The organism had jaws more than 1.3 metres long with large conical teeth. Its body was shaped like a torpedo, and it has four flipper-like wings.
What organisms did Lorrainosaurus give rise to?
In a statement released by Uppsala University, Sven Sachs, a researcher at the Naturkunde-Museum Bielefeld in Germany, and the one who led the study, said that Lorrainosaurus was one of the first truly huge pliosaurs, and gave rise to a dynasty of marine reptiles mega-predators that ruled the oceans for around 80 million years.
When did Lorrainosaurus exist, and what size did it grow to?
Lorrainosaurus probably grew to an enormous size of more than six metres from snout to tail. The organism probably lived during the early Middle Jurassic Period, which was about 174.7 million years ago. Scientists do not know much about plesiosaurs from that time.
Dominance of pliosaurids over other marine animals
In the statement, Daniel Madzia from the Institute of Paleobiology of the Polish Academy of Sciences in Poland, who co-led the study, said that the team’s identification of Lorrainosaurus as one of the earliest mega-predatory pliosaurs demonstrates that these creatures emerged immediately after a landmark restructuring of marine predator ecosystems across the Early-to-Middle Jurassic boundary, which was about 175 to 171 million years ago. Due to this landmark restructuring event, many marine reptile groups were profoundly affected, and pliosaurids obtained dominance over fish-like ichthyosaurs, which were ancient marine crocodile relatives, and other large-bodied predatory plesiosaurs.
What was special about pliosaurs?
According to Uppsala University, the short-necked marine reptiles with plump bodies were some of the most successful marine predators of their time.
What did pliosaurs eat?
In the statement, Benjamin Kear, a researcher from Uppsala University, and a senior co-author on the paper, said that Kronosaurs, which were some of the world’s largest pliosaurs, were “absolutely” enormous with body lengths exceeding 10 metres, and were ecological equivalents of today’s Killer whales, and would have eaten a range of prey including squid-like cephalopods, large fish, and other marine reptiles, all of which have been found as preserved gut contents.
Scientists recovered a decomposed skeleton of Lorrainosaurus
The scientists have recovered bones and teeth from Lorrainosaurus which represent the remnants of what was once a complete skeleton that decomposed, and was dispersed by currents and scavengers across the ancient sea floor.
Ben Thuy from the Natural History Museum in Luxembourg, and a co-author on the paper, said that the remains were unearthed in 1983 from a road cutting near Mertz in Lorraine, which is located in north-eastern France. Palaeontology enthusiasts recognised the significance of the discovery, and donated the fossils to the Natural History Museum in Luxembourg.
A brief report was published in 1994. However, the fossils of Lorrainosaurus were not explored further until this new study was conducted.
Gigantic mega-predatory pliosaurs started reigning earlier than previously thought
The scientists inferred after studying Lorrainosaurus that gigantic mega-predatory pliosaurs started reigning earlier than previously thought, and that the organism was locally responsive to major ecological changes affecting marine environments during the early Middle Jurassic, located in regions which are now in western Europe.
Benjamin Kear said that Lorrainosaurus is a critical knowledge to scientists’ knowledge of ancient marine reptiles from a time in the Age of Dinosaurs that is yet to be completely understood.