Tourist finds rare chunk of oldest sea crocodile

Discovery and Initial Reaction

A fossil enthusiast discovered a rare piece of the earliest marine crocodile known to science, initially mistaking it for a wooden fragment with nails. The fossil, a partial upper jawbone, was uncovered during a guided stroll along the Dorset coast at Lyme Regis. Experts estimate it represents one of just 11 known remains from this ancient creature.

“I really just wanted to find a little ammonite,” Heather Salt shared. “It was by where there’s an old dump eroding onto the beach, and there’s lots of bits of metal, so I looked down and thought it was nails stuck into something.”

When she lifted the object and noticed it was stone, she began to question her assumption. Salt then showed the find to Casey, her guide, who erupted in excitement. “Are you kidding me!” he exclaimed, prompting others to gather and examine it. Rich, a fossil walk guide affiliated with Lyme Regis Museum, later confirmed its significance. “I’m just grateful it was on one of my walks,” he remarked.

Significance of the Find

Dr. Paul Davis, geology curator at Lyme Regis Museum, highlighted the fossil’s role in understanding the hunting techniques of Jurassic-era crocodiles. The specimen, dated to 200 million years old, is part of the museum’s display on the “Charmouth Crocodile,” a species first identified in 2017 near Charmouth.

“He said to Casey: ‘Well, I just wanted to find a little ammonite.’ He replied: ‘I would trade you my entire collection of ammonites for that.'”

The “Charmouth crocodile” was a slender, approximately 2-metre-long predator adapted for life in the ocean, coming ashore only to reproduce. Though classified as a marine crocodile, it belongs to the thalattosuchian group, distinct from true crocodilians. Both modern crocodiles and thalattosuchians are part of the broader Crocodylomorpha family, which has a history dating back 230 million years to the early Jurassic.

Evolutionary Insights

Dr. Davis noted that the 11 known fossils of this species are pivotal for studying the early development of crocodylomorphs. “These are some of those critical fossils,” he explained. “It shows that even 200 million years ago, they were already highly evolved for marine environments.”

“Bits of ichthyosaur are rare enough, so even if it was a piece of ichthyosaur it would have been a fantastic day,” Rich said. “When you hear ‘croc,’ you instantly think of the rarity. How special that find potentially is really started to hit home.”

Following the discovery, the specimen was shared in a group chat, revealing its importance. Davis emphasized that such fragments provide glimpses into the creature’s biology. “We’re getting these tantalising fragments,” he added. “What we would love to find eventually would be a complete skull—something that could help us solve some of the issues we have about their evolution and biology.”