Scotland's Top 10 Dinosaur and Fossil Discoveries

Thursday, May 3, 2018

Skye Ichthyosaur. Picture: Todd Marshall

Scotland's Top 10 Dinosaur and Fossil Discoveries.

A FEW weeks ago my team at the University of Edinburgh announced the newest dinosaur discovery in Scotland: a site on Skye that preserves about 50 footprints made by plant-eating and meat-eating species that lived 170 million years ago.

But this is merely the latest in a long line of fossil discoveries that have made Scotland one of the world's great hunting grounds for palaeontologists.

I chronicle some of these discoveries in my new book, The Rise and Fall of the Dinosaurs, an adult pop science tome that tells the story of dinosaur history: their origins, rise to dominance, development into colossal species and feathered ancestors of today's birds, and ultimate extinction.

Here is a list of what I consider the top 10 Scottish fossil discoveries:

Dinosaur footprints on Skye

The first clue that dinosaurs once lived in Scotland was a single footprint of a beaked, plant-eating species, found in the 1980s on a block of limestone that had fallen from a cliff on the Trotternish Peninsula of north-eastern Skye and described by geologists Julian Andrews and John Hudson.

Since that time, hundreds (or perhaps thousands) of other dinosaur tracks have been discovered across Skye, including a collection of over 100 prints discovered by Tom Challands and me in 2015 near Duntulm Castle. These tracks were made in an ancient lagoon by sauropods, members of that group of long-necked, pot-bellied plant-eating behemoths that includes Brontosaurus and Diplodocus.

Tracks of meat-eating theropods – early cousins of T. rex – can be seen on location at Staffin Slipway, and tiny theropod tracks (some of the smallest dinosaur footprints ever found) can be seen on exhibit at the charming Staffin Museum, built by Skye native and palaeontology enthusiast Dugald Ross from the ruins of a one-room schoolhouse.

The footprints announced a few weeks ago are located not too far from the museum, along the coast near the dramatic headland of Brothers' Point. They were discovered in 2016 by my PhD student Davide Foffa and mapped using drones by my Master's student Paige dePolo.

Dinosaur bones on Skye

There are other types of dinosaur fossils found on Skye: the bones and teeth of the animals themselves. The first two bones from Skye were announced in 1995: a small hindlimb bone of a fast-running meat-eater and a huge, stocky limb bone from one of the lagoon-dwelling sauropods.

Many other dinosaur bones have turned up since then, many of which have been studied by Neil Clark at the Hunterian Museum in Glasgow and Dugald Ross of the Staffin Museum, who over the last five years have been collaborating with my Edinburgh team and colleagues from National Museums Scotland on new fieldwork expeditions.

These bones include the teeth and tail bones of sauropods, the arm bones of one of the oldest armoured dinosaurs from anywhere in the world, and several serrated, razor-sharp teeth of meat-eaters.

Together the bones, teeth and footprints tell us that a diverse community of dinosaurs thrived on Skye about 170 million years ago, during the middle part of the Jurassic Period, at a time when the Earth was much warmer and Scotland was located closer to the equator, with a subtropical climate.

While the dinosaurs were dominating the land, a menagerie of swimming reptiles ruled the oceans. Chief among these were the ichthyosaurs, fast-swimmers with flippers and long snouts that looked like dolphins. In 2015, my team and I named the first ichthyosaur from Scotland, giving it the Gaelic name Dearcmhara.

Dob's Linn graptolites

Dinosaurs get most of the attention, but there are many other globally famous fossils that come from Scotland, many of which are much older than the dinosaurs. A prime example are the specimens found at Dob's Linn in the Borders, a gorgeous and well-hidden waterfall that courses over dark rocks that were deposited in the ocean some 445 million years ago.

These small fossils can fit in the palm of your hand, and look like pencil scratchings on the black rock. But they are graptolites: colonial animals with a fleshy skeleton that floated around in the oceans. The Dob's Linn graptolites were studied by the pioneering palaeontologist Charles Lapworth and are among the best examples of these animals from anywhere in the world.

Rhynie Chert

The first living things evolved in the ocean, and that's where life stayed for hundreds of millions of years. Then some plants gained a foothold on land, and bugs followed, and life was set on a radical new course. The oldest fossil record of a land ecosystem comes from the 410-million-year-old Rhynie Chert, a rock deposit formed in a hot spring and today exposed in Aberdeenshire.

The Rhynie plants were bizarre twig-like growths that rarely grew more than a metre tall, and lacked any of the flowers or leaves so common on plants today.

Devonian fishes

A thick sequence of red and brown rocks called the Old Red Sandstone stretches across patches of the Highlands, recording a series of river and lake environments that covered much of Scotland during the Devonian Period, some 419-358 million years ago.

These lakes were teeming with fishes – but not the sharks, salmon, tunas, and other species we're so familiar with today. Some of them were early members of the major groups of modern fishes, but others were weird critters called placoderms, whose heads were covered with plates of bone that looked like a helmet.

These fishes can be found in the flagstones once quarried for roofing slates, particularly near Caithness. They were first studied in detail by the famous Scottish preacher, poet, and palaeontologist Hugh Miller.

Granton conodont animal

For well over a century, palaeontologists had been finding a variety of tiny, pointy, tooth-like scraps around the world, in rocks that formed between about 540 and 200 million years ago. These so-called "conodonts" became important fossils for dating rocks and finding oil reservoirs, but nobody knew what type of animal they belonged to ... until a chance discovery in a museum drawer in the 1980s.

On a slab of rock pried out of Granton Harbour in Edinburgh, scientists found the remnants of a small, eel-like animal with a tail fin and a short head, with conodonts inside the mouth. This was the long-awaited conodont animal.

Wardie coprolites

Down the shore from Granton Harbour is another stretch of Forth coast in Edinburgh, called Wardie. A series of rock layers pokes out from the shore during low tide, stacked one on top of each other like the pages in a novel. They are cyclothems: repeated cycles of ocean rocks, coals, and rocks formed on land, during the Carboniferous Period (359-299 million years ago).

Fishes can be found in the ocean rocks, along with another type of much less glamorous fossil: coprolites, fossilised poo. In fact, the Wardie coprolites are celebrated as some of the finest petrified dung from anywhere in the world!

Bearsden shark

The animals that left the Wardie coprolites were most likely sharks. Back in the Carboniferous Period, sharks were not the enormous, great white terrors that inspire horror films. They were smaller and more primitive, and some were quite weird.

The best fossil of one of these sharks was discovered by Stan Wood in the 1980s at Bearsden, north of Glasgow. It is called Akmonistion, and it was about one metre long, had a skeleton made of cartilage, and had a spiky, anvil-shaped fin jutting upwards from its back.

Stan Wood's tetrapods

Stan Wood was probably the best fossil hunter Scotland has ever known. He had no formal training in science, but served a series of jobs (shipbuilder, navy officer, engineer, insurance salesman). In his thirties, he became smitten with fossils and for the next 40 years he scoured Scotland for whatever he could find, from sharks to reptiles and everything in between.

Some of his most important discoveries were early tetrapods: some of the first fishes that developed arms and legs, and fingers and toes, and moved onto the land.

A few months before his death in 2012, Stan and colleagues (including Jenny Clack, one of England's pre-eminent palaeontologists) announced the discovery of several new tetrapod fossils from the Borders, which dated from the very beginning of the Carboniferous Period, some 350+ million years old.

Elgin Reptiles

Once tetrapods moved onto land, they found a new environment ripe for the taking. During the remainder of the Carboniferous Period they diversified, and split into the lines leading to reptiles and mammals. In the following two intervals of geological time, the Permian and Triassic Periods, tetrapods lived across Scotland, and their fossils are found today as decayed voids in the sandstones of Elgin, slightly inland from the Moray Firth.

Among the so-called "Elgin reptiles" is Saltopus, a svelte, cat-sized reptile that raced around on its stilty hind legs, sometime around 230 million years ago.

Saltopus is what scientists call a dinosauromorph: one of the very closest cousins of dinosaurs, and the type of animal that eventually evolved into the great T. rex, Triceratops, Brontosaurus, and those long-necked and sharp-tooth species splashing around in the lagoons of Jurassic Skye.

Dr Steve Brusatte is reader in vertebrate palaeontology on the faculty of School of GeoSciences at the University of Edinburgh. His new book The Rise and Fall of the Dinosaurs is published by Macmillan, priced £20, on May 3.