Thursday 21 December, 2000
Creatures From The Black Lagoon
Three hundred and thirty five million years ago strange creatures lurked in the waters of a Scottish lagoon. Giant scorpions and arthropods roamed the waters, until bush fires and volcanic hot springs forced them underground where they became entombed.
In Life Story, producer Martin Redfern travels the world in search of fossils that record key events in the history of life. Here he reports on his journey of discovery to East Kirkton in Scotland, where a commercial fossil hunter unearthed the preserved remains of some of the first ever four-legged creatures.
Balanerpeton and Eucritta melanolimnetes may sound like big names, but when you translate the scientific Latin names of these creatures they sound more fun: “the crawler from the bath” and “the beautiful creature from the black lagoon”.
The black lagoon in question now lies just west of the Scottish capital Edinburgh, at a place called the East Kirkton. When I visited the site, which is now a disused quarry, it really did look like a black lagoon. Weeks of heavy rain had flooded its floor to a depth of well over a metre and the dark rocks and glowering grey winter sky made it look black indeed.
Three hundred and thirty five million years ago it was a very different place. It was a shallow tropical lagoon - at that stage what is now Scotland had not drifted north of the equator. The muddy shores were fringed with dense vegetation, a mixture of primitive plants such as tree ferns and cycads, towering ten metres high and dense undergrowth beneath. Lurking in that undergrowth were strange creatures.
Discovery
A commercial fossil hunter, Stan Wood, first tracked them down. He spotted interesting looking blocks of limestone in a dilapidated farm wall. Thinking they might contain interesting fossils, he bought the wall! It was due to be cleared anyway, so he only needed to pay £25 for it, but the fossils he found within brought more than £50,000.
He re-invested some of that money by taking a lease on the small quarry where he believed the limestone originated and hired heavy machinery to reopen it. What he was looking for were the rarest fossils, land vertebrates, and at a very early stage in their evolution, here in the early Carboniferous period.
The first four legged creatures, or tetrapods, had crawled from the sea perhaps 30 or 40 million years earlier in the Devonian period but these were more like large fish with four limbs rather than land animals. Maybe they crawled but they probably couldn't run. There is then a big gap in the fossil record; a gap that the East Kirkton site goes some way to filling.
Land vertebrates
Land vertebrates were not the only creatures on land at the time. Insects and other arthropods were already well established.
At the National Museum of Scotland in Edinburgh, palaeontologist Bobbie Paton showed me some of the more spectacular specimens. There was a giant scorpion 30 centimetres long with a vicious looking barbed tail, and there was, what looked to me, a great black mask 60 centimetres across but which turned out to be the carapace of a giant arthropod called a Eurypterid. The complete creature may have grown longer than a person is tall. This one may have fed on tiny creatures in the lagoon, but its cousins were carnivores and may have eaten the young vertebrates, reversing the pecking order that was established later by the dinosaurs.
| 'There was a giant scorpion 30 centimetres long with a vicious looking barbed tail' | |
By contrast, the tetrapod fossils are quite small. The commonest is Balanerpeton – “the crawler from the bath”. It had a broad skull and robust looking limbs and may well have been an ancestor of modern amphibians such as frogs and toads. A small groove in the skull may have enabled it to hear above the water and suggests that perhaps it croaked.
One of the stars of East Kirkton was first discovered by Stan Wood and sold for a considerable sum to the Scottish Museum. The scientists call it Westlothiana, but to Wood it looked very lizard-like so he called it Lizzie. There’s still argument about its true relationship to modern animals, but it could be an ancestor of reptiles.
The most intriguing creature is Eucritter malanolimnetes – “the beautiful creature from the black lagoon” named by Jenny Clack of Cambridge University. She recognised amphibian-like features, particularly in its broad skull, but reptile-like features in its body and thinks it could be a common ancestor, both of modern amphibians and reptiles and possibly even of ourselves.
What next?
East Kirkton has given scientists a valuable window into life on land 335 million years ago, but what the fossil hunters are searching for now is an even earlier site, which might show their more primitive ancestors. Already, Stan Wood is out looking and has found one of two promising bones on the other side of Edinburgh, but it is rare to get fossils preserved as well as they are at East Kirkton.
Only a few kilometres from the black lagoon there were active volcanoes and they may have showered the animals with hot ash, killing them and burying them at the same time. They may also have started forest fires, sending the creatures running for the safety of the lagoon.
The lagoon itself was not always safe. It was probably fed by volcanic hot springs, which may have been corrosive or dangerously hot. And there could have been matted algae on top of them. One can imagine Eucritter scampering across the algal mats to escape a bush fire only to fall through the thin surface layer and become entombed in the lagoon. But its misfortune is the fossil hunters’ delight as they unearth the cooked remains 335 million years later.
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| Commercial fossils |
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When Stan Wood first began his work he supplied museums with fossils for research and display. His finds have included over 30 new species of animal.
In 1988 the Stan Wood firm opened a shop, allowing the public to purchase fossils from all over the world. Each fossil purchased is sent with information cards detailing their name, age and the location where they were found. |
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