THE collection of fossils found by Stan Wood in the Whiteadder has caused great excitement in the world of palentology and it is not difficult to see why.
Experts say the fossils, dug out of the bed of the river, near Chirnside, by Mr Wood three years ago, will rewrite a key chapter in the history of the evolution of life on land.
Hailed by naturalist and broadcaster Sir David Attenborough as a major discovery, the Whiteadder find helps overturn a long-held theory about evolution on Earth.
Scientists have always been puzzled about a period in the Earth’s history between 360 and 345 million years ago, christened “Romer’s Gap” after the American paleontologist and author of textbooks in the 1950s and 60s, Alfred Sherwood Romer.
Romer first recognized the lack of fossils from this 15-million-year period. When the fossil record resumes, a huge variety of tetrapod (four-legged) land forms had evolved. These were the ancestors of modern mammals, amphibians, reptiles, and birds.
Some experts had concluded that the reason for this gap was low levels of oxygen during the period, which limited evolution on land. But Mr Wood’s fossil haul from the Whiteadder now suggests that a large diversity of amphibians, plants, fish and invertebrates was thriving.
Scientists are examining the several hundred fossilised four-legged life forms, some of which were the first to walk the land, and which prove that animals with five fingers and toes appeared about 20 million years earlier than paleontologists had estimated.
The fossils are part of what experts believe was a whole eco-system preserved in the fossil records. One notable amphibian specimen has been nicknamed Ribbo because of its prominent and well-preserved vertebrate structure, providing scientists with enough information to interpret what the creature may have looked like as it roamed the Tweed basin about 350 million years ago.
The cache of fossils includes vertebrate forms previously unknown to science, and researchers around the world are excited at the information they will provide about the earliest development of life on land.
Mr Wood told TheSouthern this week: “There is a gap in the fossil record where we have no knowledge of life on Earth at all. These fossils fit perfectly into that gap and give an understanding of a period of Earth’s history of which we knew next to nothing.
“I think the Borders has great potential as a site for further exploration – there is definitely more down there.”
The remarkable find is the subject of a newly published paper in the prestigious American scientific journal, the Proceedings of the National Academy of Sciences (PNAS).
Professor Jenny Clack, of the University of Cambridge, one of the authors of the PNAS paper, said that knowing what was happening during Romer’s Gap was critical to understanding how life on Earth developed.
“The period known as Romer’s Gap covers the key period, the earliest Carboniferous, in both the establishment of terrestrial ecosystems and the acquisition of terrestrial capability by tetrapods, but almost nothing about it was previously known from fossils,” said Professor Clack.
“Now, for the first time anywhere in the world, abundant fossils of tetrapods and associated fauna and flora from this interval have been recovered, from localities in Scotland. We have the unique opportunity to enhance and amplify our knowledge of this time with the new material. Its analysis and that of its context, will be of global significance.”
The display of about 20 fossils at the National Museum of Scotland is a taster of the larger collection, which museum chiefs hopes to acquire with a view to further in-depth research.
A previous find by Mr Wood is one of the star exhibits in National Museums Scotland’s collections of fossils of early land-based life – rated as one of the finest in the world.
This is Westlothiana lizzae – affectionately known as Lizzie – the world’s oldest known reptile fossil. It was found by Mr Wood in a quarry in Bathgate which he leased for four years in the late 1980s.
Its discovery generated excitement and media coverage around the world. “That was the most interesting find in my career – apart from this newer find,” added Mr Wood.