Fossils of plesiosaurs, long-necked marine reptiles of the age of dinosaurs, were found in a 100 million-year-old river system that is now the Sahara Desert of Morocco. The discovery suggests that some plesiosaurs, traditionally thought to be marine creatures, may have lived in freshwater.
First discovered in 1823 by fossil hunter Mary Anning, Plesiosaur was a prehistoric reptile with a small head, long neck, and four long fins. They inspired the reconstruction of the Loch Ness Monster, but unlike the Loch Ness Monster, Plesiosaurs were marine animals – or widely considered marine animals.
Now, scientists from the Universities of Bath and Portsmouth in the United Kingdom, as well as hassan II University in Morocco, have reported a small plesiosaur in a Cretaceous river in Africa.
The fossils include the bones and teeth of an adult at 3 meters long, and the arm bones of a 1.5-meter-long baby. They suggest that these creatures usually lived and ate in fresh water, fighting alongside frogs, crocodiles, turtles, fish, and the giant aquatic dinosaur Spinosaurus.
These fossils suggest that plesiosaurs adapted to fresh water and may even have spent their entire lives there, like river dolphins today.
These fossils include vertebrae in the neck, back, and tail, teeth that have fallen out, and arm bones in young and juvenile areas.
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While the bones provide information about where the animal died, the teeth are interesting because they were lost while the animal was alive – so they show where the animal lived. What's more, the teeth are badly worn, like those fish-eating dinosaurs Spinosaurus found on the same riverbed.
Scientists say that means plesiosaurs ate the same food — gritting their teeth at armored fish living in rivers. This implies that they spend a lot of time in the river and not the occasional tourist.
When marine animals such as whales and dolphins roam the river, it's either foraging or because they get lost, but the number of plesiosaur fossils in the river suggests that's unlikely.
It is more likely that plesiosaurs were able to tolerate fresh and salty water, like some whales, such as beluga whales.
It is even possible that plesiosaurs were permanent residents of rivers, like modern river dolphins. Plesiosaurs were small enough to allow them to hunt in shallow rivers, and fossils show an incredibly rich fish fauna.
Dr Longrich said: "We really don't know why plesiosaurs are in fresh water.
"It's a bit controversial, but who's to say, because we paleontologists have always called them 'marine reptiles,' they have to live in the sea?" A large amount of marine ancestry invaded the fresh water. ”
Freshwater dolphins have evolved at least four times – twice in the Ganges, Yangtze and Amazon rivers. A freshwater seal inhabits Lake Baikal in Siberia, so plesiosaurs may also have adapted to freshwater.
Plesiosaurs belonged to the family Plesiosaurs – a small family of plesiosaurs found in brackish or fresh water in England, Africa and elsewhere in Australia. Other plesiosaurs, including plesiosaurs, appeared in brackish or freshwater in North America and China.
Plesiosaurs were a diverse and adaptable group that existed for over 100 million years. Based on their findings in Africa — and those found elsewhere by other scientists — the authors suggest they may have repeatedly invaded freshwater to varying degrees.
"Honestly, we don't know yet. That's how paleontology works. How can paleontologists be sure of the lives of animals that went extinct millions of years ago, people ask? The reality is that we can't always. All we can do is make educated guesses based on the information we have. We will find more fossils. Maybe they'll confirm those speculations. Maybe not."
"," Georgina Bunker said. The study was originally an undergraduate project involving a bone, but over time more plesiosaur fossils began to emerge, slowly providing a clearer picture of the animal.
This new discovery also expanded the diversity of moroccan Cretaceous. Dr. Samir Zuhri said: ". ”
Co-author Dave Mathil said: "
But what does all this mean for the credibility of something like the Loch Ness Monster? In a way, this makes sense. Plesiosaurs were not confined to the ocean, they did inhabit freshwater. But the fossil record also shows that nearly 150 million years later, the last plesiosaur finally went extinct along with the dinosaurs, 66 million years ago.
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