The dinosaur coast

Exploring Britain’s miraculous window on a lost world

Take a dip in the waters of Dorset's coast and you'll be sharing them with heavily-armoured fish. You may see long-beaked hunting lizards surging through the surf too: all looked upon by ponderous giants browsing ferns in the undergrowth and sharp-toothed, multicoloured birds that resemble nightmarish crocodiles in miniature.

You may be separated from these beasts by a few hundred million years, of course, but that doesn't make the richness of ancient finds along this incredible coastline a marvel on the global scale.

Rich pickings

To earn UNESCO World Heritage Site status, a place has to be truly special. These sites are considered to be of outstanding value to humanity, and therefore belong to all peoples of the world, irrespective of the territory they are located in.

Classed as either natural, cultural or mixed, such sites include Australia’s Great Barrier Reef, the entire Galapagos islands, the Imperial Palaces in China – and 95 miles of Dorset’s coastline. The Dorset cliffs earned their status in 2001 because they contain an almost continuous sequence of rock formations from the Triassic, Jurassic and Cretaceous eras, spanning 185 million years of the Earth’s history.

“The rock is much more accessible here than in any other part of the world because the North Atlantic is still expanding,” says Dr. Ian West, a geologist from the University of Southampton who has studied this coastline for over 50 years. “This is tilting Britain, tipping it towards the East, and pushing up the layers of rock in the West.

“Coupled with this, the English Channel is getting wider, causing rapid erosion of the South Coast’s cliffs. This exposes new belts of rock periodically, untouched by enthusiastic fossil collectors, and creating an open laboratory in which paleontologists can work.”

In other important geological areas, such as South America, one has to travel hundreds of miles to reach the next layer of rock. In Dorset and East Devon, an entire era of prehistory can be accessed within just 95 miles. It is also within easy reach of the educational centres of London and Oxford – another reason why it is, and always has been, the most visited area in the world by geologists.

A warmer world

The Jurassic period (150-200 million years ago) is such a large chunk of history that it can be heavily sub-divided. In general, the climate would have been much warmer than the present. Britain was closer to the equator, and the Earth was in a ‘greenhouse’ phase, with no ice at the poles. Atmospheric CO2 was at 4-5 times today’s levels, making the Jurassic climate similar to the Mediterranean climate of today, only much more humid.

Vegetation would have been lush and plentiful, with an abundance of conifers, ferns and cycads. Grass did not exist yet, and flowering plants did not appear until the early Cretaceous, after the mass extinction of the dinosaurs. Fossilised plant remains are common in the Jurassic cliffs, but larger tree trunks are not found so often here. This could be due to the area‘s changing prehistoric landscape - from a shallow sea to land.

There were many types of dinosaur living in the Jurassic period, both aquatic and terrestrial. It is true that many beasts were often much bigger and fiercer than today, but this is not always the case. Larger land-based species included sauropods, stegosaurs, carnosaurs, and flying pterosaurs. Marine life was also thriving: as well as older crocodilia and amphibians, large sea-reptiles like ichthyosaurs and plesiosaurs ruled the waves as mammals do today. Sea urchins were very common, along with starfish and sponges, and a variety of small sharks existed. There were also a few fish, which would have had armour of heavy scales. Back on land, mammals were common but small in size, and the first birds and lizards were emerging.

The cliff detectives

It is due to the meticulous and methodical (and often overlooked) work of paleontologists that we have this incredible wealth of information from the past. Researching fossils and rock formations is a slow process, involving a vast network of museums, laboratories, libraries and scientists.

The best paleontologists are the ones who have seen the most specimens, not just read about them in books. Hours can be spent in dusty museum basements, measuring bones, and geological laboratory work takes years.

Dr. David Martill, resident paleontologist at Portsmouth University, says: “Fossil discoveries are made by spending many long hours walking across exposed rocks, in all weathers, often on the coast, but also in quarries and mines. You spend your time looking for anomalies in the rock - something unusual. A dark patch, a rounded hard concretion in soft clays, a thin shell bed. Anything that looks out of the ordinary.

“When you have found what might be a fossil, you have to appraise it. Is it in rock that is hard and will need a hammer and chisel, or is it in soft clay and may come out with a knife? Possibly there will be a complete skeleton, or it could be in a loose block. If it is in a loose block, you must try to find the layer it came from and check if there are any more remains in that layer. If not, then you can just bag it up and take it back to the lab. Much better to try to get it out of the rock in the laboratory rather than in the field.

“If it is a large and potentially complete skeleton, you must cover it up and protect it from more cliff falls and theft. Also check to see if an incoming tide will inundate it. Then organise a full-blown dig if the fossil is important. This could take several weeks for a really big animal. If the tide or a cliff fall are serious threats, then a rescue dig is put in place.”

Revealing new species

Uncovering fossils can be highly dangerous as well as slow, even in England. Dr. Martill says: “In Dorset, the most dangerous things are the rising tide and the cliff falls. The cliffs are very dangerous, and getting cut off by a high spring tide can result in a very uncomfortable few hours clinging to a cliff ledge, or a rather dangerous climb without proper gear.”

“If a new specimen is discovered,” says Richard Forrest, paleontologist and creator of Plesiosaur.com, “paleontologists write a scientific paper describing it in detail and give it a name. The specimen is set up as the example of the species, called the holotype.”

This is happening all the time: a new road being built near Weymouth has uncovered a clutch of never-seen-before fossilised ammonite eggs. Considering the huge number of ammonite fossils available, it is a wonder their eggs have never been found before. And just last month, Richard Forrest was involved in the discovery of one of the biggest pliosaurs ever found, right here on the Jurassic Coast.

Black gold in Dorset

The Dorset and East Devon Coastline keeps turning out these big discoveries. We can only imagine the secrets of the past it holds in its unstable cliffs, and this is why it is imperative to protect it. The area’s UNESCO status is a huge help in its conservation, and in the education of the public. The dedicated Jurassic Coast World Heritage Team provides geological expertise on the ground, working with coastal engineers, local fossil collectors and research scientists. The site is also protected by UK conservation law as a Site of Special Scientific Interest. Planning applications are regularly turned down.

Believe it or not, the oil industry has also helped to fund research and protection of the area. BP run the largest onshore oilfield in the UK from the cliff top at Poole, with a pipeline out to sea, just beyond Bournemouth Pier, although careful landscaping renders it almost invisible. The industry has been carrying out extensive and detailed technical work on rock samples since the 1930s oil boom, and have a special interest in the rich clay oil shale of Kimmeridge – a source rock for North Sea oil. The clay once formed the bed of an ancient tropical sea, where oil was formed, and contains such important prehistoric records that similar rocks all around the world are now termed ‘Kimmeridgian’.

Anyone can access the hugely important cliffs and beaches, and fossils are yours for the taking, but you may well be better off handing them in to a professional for identification. Who knows – you could go home with an entirely new species of Dino in the boot of your car.

Find out more at www.jurassiccoast.com and www.soton.ac.uk/~imw