Flashback to 2001: Scientists hit the jackpot with Shropshire fossil

What they discovered at an old quarry site shed new light on some of the early life on Earth, from the days when Shropshire was covered by a shallow sea.

In July 2001 they disclosed that some of the oldest known ancestors of crabs and lobsters, dating back more than 500 million years, had been discovered near Church Stretton.

The fossilised creatures, said to be “exquisitely preserved” in limestone, were found by experts carrying out research in rocks near Comley, in the Shropshire Hills.

Scientists said the fossils were the oldest known crustacean and contained the tiny creatures’ soft parts, including the appendages with which they ate, which were preserved in extraordinary detail.

At just 0.3 millimetres long, the specimens were minuscule, but nevertheless considered of great significance.

One reason for the excitement was not just that the soft parts of the creatures' anatomy had been preserved, but they had been preserved in three dimensions, rather than being flattened.

The Cambrian period was when most major animal groups appear on the fossil record, and in most Cambrian rocks the teeming life of the era is evidenced in the fossil record by the hard shells of the creatures, while there is nothing to show of the soft-bodied animals which must also have existed.

Mark Williams, a British Geological Survey palaeontologist, said at the time of the discovery that the crustacean unearthed at Comley dwelt in the ocean 511 million years ago and was an ancient relative of the crustaceans that live today, including crabs, lobsters, shrimps and crayfish.

He said the find could force scientists to re-evaluate current beliefs about the emergence of many complex organisms.

The creature lived more than 50 million years before the first fish appeared and 280 million years before the first dinosaur.

He worked with colleagues David Siveter of Britain’s University of Leicester and Dieter Waloszek of the University of Ulm in Germany.

Mr Williams said: “They are very, very small fossils. But even though they’re so small, they’ve got all the morphology that we need to work out that they’re crustaceans.”

Comley was already known as an internationally important site for palaeontologists. In this niche between Caer Caradoc and The Lawley Britain’s earliest trilobites were discovered in 1888.

And it was a playground for a celebrated local amateur geologist, Edgar Sterling Cobbold, whose work gained international recognition.

David Siveter and Mark Williams later wrote a joint account of their discovery for the British Geological Survey.

They dug a trench in an excavation to look for Lower Comley Limestones, the oldest carbonate deposits in England, and rich in phosphate, which was known to preserve the soft parts of animals in similar rocks.

The excavated rocks were taken to the micropalaeontological laboratory at the University of Leicester to be treated to reveal their secrets, using acid to dissolve the limestone and yield a residue containing fossils.

"The search was on for ostracods (small aquatic crustaceans) with soft parts, or indeed similarly preserved specimens of any other group. However, even by narrowing the odds by looking in the right kind of rocks, the chances of finding such examples of exceptional preservation is the palaeontological equivalent of winning the lottery," they reported.

Yet after weeks of painstakingly picking through the fine residue using a binocular microscope, two tiny crustacean specimens with preserved soft parts were recovered.

"The preservation is so detailed that the animals look almost as though they had died yesterday. Hairs less than 10 microns in length are present on the limbs."

The creatures were significant not just in themselves, but also because of where they were found, in lower Cambrian rocks, placing them early in the timeline of the development of complex life, and raising the question of when the lifeforms which preceded them had started to evolve.

"The Shropshire fossils represent the oldest post-embryonic animals preserved in three dimensions with their full complement of articulated appendages."

And they finished their report: "With the recovery of two key specimens comes the tantalising prospect that soft-bodied specimens of other animal groups may also occur in the same deposits. The hunt is on!"

Well maybe that is the case for the authorised experts, but not for you, because Comley Quarry is now a nature reserve, described by Shropshire Wildlife Trust as a holy place for geologists, and be advised that fossil hunting is banned.