Ichthyotitan Severnensis: A new species of this extinct group of lizard fishdiscovered by chance by two paleontology enthusiasts and analyzed by several European scientists, the Ichthyotitan Severnensis It is 25 meters long. It is believed to have become extinct during the event. Mass extinction in the Late Triassic.
Justin and Ruby Reynolds, father and daughter, share a common interest: the search for fossils. In 2020, while walking on Blue Anchor beach in Somerset, United Kingdom, they discovered a fossil in a rock that someone had left next to a piece of limestone with pyrite crystals.
It was a huge bone that fascinated Justin, who stared at it as his daughter continued her search until she found an even larger bone, partially buried in a mud slope. They were the remains of a gigantic ichthyosaur, as he was later able to confirm. Dean Lomaxa paleontologist at the University of Manchester who they contacted when they suspected it was an important find.
“I was very excited. It was the second piece that we were able to identify the remains as part of a jaw of the ichthyosaur by searching the internet and finding the 2018 paper by Lomax, Paul de la Salle and others,” says Reynolds Sr.
“Since I first contacted Lomax, we have met locally to look for more pieces. My family and I were also with Paul de la Salle and his wife Carol several times and that is when most of the different pieces were collected from the studio,” he adds. The last piece of bone was recovered in October 2022.
The fossilized remains of this second gigantic jaw are over two meters long. The experts confirmed that it came from a new species of huge ichthyosaur, a type prehistoric marine reptile, as big as a blue whale. Estimates suggest it would have been more than 25 meters long. The study is published today in the magazine PLoS ONE.
Lomax was very impressed that Ruby and Justin correctly identified the discovery: “They recognized that it matched the discovery we described years earlier. I asked them if they would like to join my team to study, describe and name this fossil. “They accepted the opportunity.”
“Especially for Ruby, a scientist who not only found a kind of gigantic prehistoric reptile, but also helped name it. “There probably aren’t many 15-year-olds who can say that!” he continues.
Ichthyotitan Severnensis: Victims of a Mass Extinction
These animals, many of which resembled modern dolphins, first evolved during this period Trias asked, about 250 million years ago. Within a few million years, some of them evolved to at least 15 meters in length, and by the Late Triassic (about 200 million years ago) into larger specimens, including the recently described specimen called Ichthyotitan Severnensisthat means ‘Severn giant fish lizard‘.
“Ichthyosaurs like these probably had few predators to worry about, except the larger ones of their kind. Of course, the story is different for the juveniles: they were certainly easy prey for most animals, such as sharks or plesiosaurs, and therefore they would be selected to grow quickly in order to find refuge as quickly as possible in their large size. To explain Marcelo Perilloco-author of the study at the University of Bonn (Germany).
However, his reign did not necessarily last long. Although some species of ichthyosaurs continued to roam the oceans for millions of years, they are thought to have become extinct during the Late Triassic mass extinction. After this time, the giant ichthyosaurs of the family known as shastasaurids became extinct. Today, these bones represent the last of their kind.
“This event mainly affected the marine kingdom and appears to have been caused by drastic climate change and ocean acidification due to the enormous greenhouse gas released by the opening of the Central Atlantic Magmatic Province (this process separated North America from Europe and formed the North Atlantic Ocean). ),” says Perillo.
Paul de la Salle, an experienced fossil collector who found the first giant jaw of this species elsewhere on the coast in Lilstock in May 2016, is also involved in its characterization.
“Loose copies of Lilstock and Blue Anchor They come from the top of the Westbury Formation, which means they are 15 million years later than their closest relatives. We don’t know what changes took place in the size and shape of the animals and in their way of life during that enormous period,” he tells SINC.
For Lomax, this find is astonishing: “In 2018, my team (including Paul de la Salle) described Paul’s gigantic jaw and we hoped that one would appear again one day. This new specimen is more complete, better preserved and shows that we now have two of these giant bones (called surangulars) that have a unique shape and structure. “I was very excited.”
Having two examples of the same bone with the same unique features from the same geological area supports their identifications.
Ichthyotitan Severnensis: a very special discovery
Giant ichthyosaurs swam in a sea full of life. Schools of squid and ammonites (extinct cephalopod mollusks) were a very important part of the ecosystem. The fish were a little different from today’s fish; many of them had heavy scales covering their bodies, but like today they could range from small to large size. In the Late Triassic, marine reptiles were very diverse.
“Squid was certainly an important part of that Your diet, but we still need to understand more about their skulls to see whether the giant ichthyosaurs we studied were macropredators (which ate other marine reptiles), specialized hunters (for large squids, for example), or ‘bulk’ predators (which ate a large amount ). number of smaller prey such as today’s blue whales),” says Perillo. The bones are about 202 million years old, at a time known as the Rhaetian.
Ichthyotitan Severnensis They’re not the world’s first giant ichthyosaur, but they are unique among species known to science. These two bones appear about 13 million years after their most recent geological relatives: Shonisaurus sikanniensis of British Columbia, Canada, and Himalayasaurus tibetensis from Tibet, China.
“Every fossil fan dreams of an experience like Ruby’s. It is truly special to be the first human eyes to see this incredible fossil. “Justin sets a great example by supporting his daughter’s interests in science and paleontology,” he concluded. Jimmy Waldron, research team member and founder of the DWABA Museum in Orlando, Florida. Today, Waldron creates scaled 3D replicas of the giant bones for exhibitions and outreach programs around the world.