LONDON — Millions of years before the Cotswolds, in western England, became a popular vacation destination, romanticized for its ancient woodlands, honey-colored stone villages and medieval abbeys, it was a shallow, warm sea, home to a Jurassic marine ecosystem.
Over 167 million years later, two amateur paleontologists, Neville and Sally Hollingworth, uncovered fossils in a limestone quarry there, the largest find of Jurassic starfish and their relatives ever to be made in Britain.
More than 1,000 scientifically significant specimens were unearthed at an undisclosed location during a three-day excavation in June, London’s Natural History Museum said in a statement this past week. The site is not being revealed for security reasons.
The find by the Hollingworths, a husband-and-wife team, includes three new species and an entire ecosystem of echinoderms — a group of animals that includes starfish, brittle stars, feather stars, sea lilies, sea cucumbers and echinoids. Fossils of such animals are extremely rare because they have fragile skeletons that are not often preserved.
The exquisite detail of the collected fossils capture the creatures’ last moments before they were buried by what experts have said could have been an underwater mudslide.
Mr. Hollingworth, 60, is not new to fossil hunting. He discovered his first fossil — a small opalescent ammonite — in Somerset, in southwest England, when he was 12, which ignited a passion for paleontology and led to his getting a Ph.D. in the subject.
“I went fossil collecting every day,” he said. “A lot of my friends thought I was odd.”
The Hollingworths met in 2016 at a local science festival under the skeleton of a Gorgosaurus, perhaps foreshadowing the couple’s big discovery. While many people turned to sourdough and banana bread recipes to keep occupied through three pandemic lockdowns in England, the couple scoured Google Earth to pinpoint the site of their next excavation.
The location Mr. and Mrs. Hollingworth identified last August was a privately owned limestone quarry surrounded by Jurassic rock beds. The site had been mentioned in research papers published over a century ago as a place where some marine fossil specimens had been found. Lockdown restrictions, however, meant that the couple were not able to visit the quarry until November.
Mr. Hollingworth was already familiar with the Cotswolds’ geology — he discovered a five-foot mammoth skull there in 2004. And in November, after digging less than two feet into the quarry’s clay, he said, he “instantly recognized” evidence of fossils.
“Within 10 minutes,” Mr. Hollingworth said, he thought to himself, “‘There is something really special here.’”
“If it was just left,” he added, “it would be lost.”
His wife was more skeptical. “We found really tiny, fingernail-sized fragments of fossils,” said Mrs. Hollingworth, 50, who works in accounting for a construction company.
“I was going to have a cup of tea,” she said laughing. “It was all a bit boring.”
But Mr. Hollingworth would not be deterred. While he expected little from the excavated slabs of clay, he said, he still he spent hours in his garage removing layers of sediment, grain by grain, with a microsandblaster. Then he caught a glimpse of a sea lily fossil.
“The whole block came alive,” Mrs. Hollingworth said. “I’ve never seen anything like it.”
“They’ve got this beautiful, ornate crown cup, and little, tiny featherlike projections sticking out of them,” Mr. Hollingworth said, describing the sea lily fossil. “The minutest detail is preserved beautifully.”
He promptly reached out to a senior curator at the Natural History Museum with whom he had become acquainted on previous digs. Mr. Hollingworth invited the curator, Tim Ewin, to visit the excavation site, enticing him by email with photographs of the fossils.
“To my joy and surprise, they were beautifully preserved fossils — sea urchins, starfish and some really rare feather stars,” Mr. Ewin said.
“In the Natural History Museum collections,” he added, “we don’t have any complete specimens of those types of fossils, so I knew instantly it was important.”
A winter lockdown and inclement weather causing flooding at the quarry delayed the museum’s excavation of the site until June. But the find’s significance was swiftly recognized.
“The museum collection previously only had 25 incomplete specimens,” Mr. Ewin said. Now, there are about 150 complete specimens from the Cotswolds site alone.
Among the echinoderms found at the excavation site, the feather stars — marine invertebrate crinoids with feathery arms — were the rarest.
“That gives you an idea of how rich in abundance this site is,” Mr. Ewin added.
In January, on a beach in Wales, a 4-year-old girl stumbled across a 200-million-year-old footprint from an unknown herbivorous dinosaur that lived during the Upper Triassic Period. The fossil is now on display at the National Museum Cardiff.
While the Natural History Museum has no immediate plans to put its newest treasures on display, preservation work will probably yield new information about their evolutionary histories. Experts “can scan them in 3-D,” Mr. Hollingworth said.
“That will bring a lot of new information on the evolution and the geological history of this truly iconic group,” he added.