Key Points
- Ichthyotitan severnensis measured approximately 25 metres, rivalling the modern blue whale in length
- Ruby Reynolds was 11 years old when she found the jawbone fragment in Somerset in May 2020
- The fossil dates to the Late Triassic period, approximately 200 million years ago
An 11-year-old girl discovered what scientists have now confirmed as the largest known marine reptile fossil on a beach in Somerset, England. Ruby Reynolds found fragments of a jawbone in May 2020 while fossil hunting with her father near Blue Anchor. A study published in PLOS ONE on Wednesday identified the creature as a new species, Ichthyotitan severnensis, which measured approximately 25 metres in length.
The discovery rewrites the record books for marine reptiles. The creature, an ichthyosaur, a type of fish-shaped reptile that breathed air and dominated the oceans during the age of dinosaurs, now stands as the largest of its kind ever documented. Its size rivals that of the modern blue whale, the largest animal currently alive on Earth.
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The find holds significance for palaeontologists worldwide, including researchers in India who study prehistoric marine life along the subcontinent’s coastline. Ichthyosaur fossils have previously been found in Gujarat‘s Kutch region, making this English discovery relevant to understanding the global distribution of these ancient creatures.
How an 11-year-old found the largest marine reptile fossil
Ruby and her father Justin Reynolds were walking along the beach near Blue Anchor, a site known for yielding ancient fossils, when they spotted an unusual bone fragment. Justin Reynolds told researchers he noticed a four-inch piece of bone that was larger than anything he had found before. He showed it to Ruby, who then discovered another fragment nearby.
“It was just sort of lying there,” Ruby Reynolds said. “I was just happy, really.”
The pair photographed their finds and sent images to Dean Lomax, a palaeontologist at the University of Manchester who specialises in marine reptiles. Lomax confirmed their identification was correct. The bones belonged to an ichthyosaur, specifically part of its lower jawbone.
The significance of the discovery became clear when Lomax compared Ruby’s fossils to a partial jawbone found in Somerset in 2016 by local collector Paul de la Salle. The fragments matched perfectly.
“They fit together perfectly like an ancient prehistoric jigsaw puzzle,” Lomax said in a statement accompanying the PLOS ONE study.
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Ichthyotitan severnensis: what the bones reveal
The reassembled jawbone measured over two metres in length. From this, researchers estimated the complete animal would have stretched approximately 25 metres from snout to tail. This makes Ichthyotitan severnensis, which translates to “giant fish lizard of the Severn” in Latin, the largest ichthyosaur ever recorded.
Ichthyosaurs were marine reptiles that evolved from land-dwelling ancestors and returned to the sea. Unlike fish, they breathed air and gave birth to live young. They dominated the world’s oceans during the Triassic period, which lasted from approximately 252 million to 201 million years ago, before dinosaurs rose to prominence on land.
The bones suggest Ichthyotitan severnensis had a streamlined body adapted for cruising through open water. Its skull likely measured over three metres in length. Paddle-shaped flippers would have propelled it through the seas as it hunted squid-like cephalopods, which were abundant during the Late Triassic.
Lomax described the creature as “genuinely enormous, about the length of a blue whale.”
What the discovery means for palaeontology
The find challenges previous assumptions about the size limits of marine reptiles during the Triassic period. Scientists had believed ichthyosaurs of this era were large but not comparable to modern whales. Ichthyotitan severnensis proves otherwise.
The discovery also reveals a more complex Triassic ocean ecosystem than previously understood. With few large predators competing for resources, marine reptiles had room to evolve to massive sizes. This parallels the evolution of whales, which grew to enormous proportions after the extinction of large marine reptiles at the end of the Cretaceous period, approximately 66 million years ago.
For Ruby Reynolds, now 15, the discovery has sparked a lasting interest in palaeontology. Her name appears as a co-author on the PLOS ONE study alongside Lomax and other researchers.
The fossils will be housed at the Bristol Museum and Art Gallery, where they will undergo further study. Researchers hope additional specimens may be found along the Somerset coastline, which continues to yield fossils as erosion exposes new layers of ancient rock.
Your Questions, Answered
How big was Ichthyotitan severnensis?
The marine reptile measured approximately 25 metres in length, making it comparable in size to a modern blue whale and the largest ichthyosaur ever discovered.
Where was the largest marine reptile fossil found?
Ruby Reynolds discovered the jawbone fragments on a beach near Blue Anchor in Somerset, England, in May 2020.
What is an ichthyosaur?
An ichthyosaur was a fish-shaped marine reptile that breathed air and gave birth to live young. These creatures dominated the oceans during the Triassic period, approximately 252 million to 201 million years ago.
Where will the Ichthyotitan severnensis fossils be displayed?
The fossils will be housed at the Bristol Museum and Art Gallery for further study and eventual public display.