From left, Dean Lomax, Ruby Reynolds, Justin Reynolds, and Paul de la Salle with some of the fossils from the newly identified species of ichthyosaur (Credit: Dr. Dean Lomax/ CC-BY-SA-4.0)

Fossils found by a father-daughter team has led to the discovery of a new, massive species of ichthyosaur. The marine reptiles dominated the seas during the Triassic and Jurassic periods (251 to 145 million years ago). Often referred to as "fish-lizards," they shared physical similarities with dolphins and whales but were, in fact, members of the reptile family.

The events leading to the exciting find began in spring 2020, when Justin Reynolds and his 11-year-old daughter Ruby went fossil hunting on Blue Anchor Beach in Somerset, England. The region is well-known for its rich deposits of fish and reptile fossils from the Triassic-era.

After carefully scouring the beach, the amateur paleontologists discovered a four-inch (10 cm) long oval fossil. Shortly after, Ruby found another piece of fossilized bone in the same area. This one was twice as big. Following some research, Justin made an educated guess that the bones were from an ichthyosaur. An email to Dr. Dean Lomax, a marine reptile expert at the University of Manchester, confirmed his hunch.

"It's interesting because 95 percent of the time, it turns out to be an odd-shaped rock. You have to politely and gently let them down,” Dr. Lomax said. "Justin and Ruby’s email is an example of the other 5 percent of the time."

Dr. Lomax and his team invited the Reynolds to help them find additional pieces of the intriguing fossil. Their quest ended in October 2022 when they finally gathered enough pieces to reconstruct a section of the marine reptile's lower jaw. Analysis revealed that, if complete, the jaw would have measured over six feet (1.8 m) long. By comparing the bone fragments to those of other giant ichthyosaurs, the scientists estimated the new specimen's length to be a staggering 80 feet (24 m) — the equivalent of two buses parked end to end. If true, it would rank as one of the largest marine animals to ever live.

A size comparison of Ichthyotitan severnensis and a human (Credit: SlvrHwk /CC-BY-SA-4.0)

The remains of the new specimen, along with those of another similar ichthyosaur found in 2016, enabled the scientists to classify it as a new species. The researchers named the creature Ichthyotitan severnensis, meaning "giant fish lizard of the Severn." Ruby and Justin were listed as co-authors in the study published in the journal PLOS One on April 17, 2024.

Ruby, now 15, is eager to continue her fossil-hunting adventures. “I didn’t realize when I first found the piece of ichthyosaur bone how important it was and what it would lead to,” she says. “I think the role that young people can play in science is to enjoy the journey of exploring as you never know where a discovery may take you.”