THEY are traces of the animal and plant life that once existed in ancient Scotland, ranging from huge carnivorous ­dinosaurs which roamed the earth to tiny prehistoric shrimps which swam in lagoons.

Now the hunt is on to find the country's most important five fossils, with the public being asked to vote for their favourites in a poll organised by the Scottish Geodiversity Forum.

The candidates on the list of 16 include remnants of dinosaurs of the mid-Jurassic period which have been found on the Isle of Skye, including the world's only example of footprints from a family of carnivorous dinosaurs which walked on two legs, known as theropods.

Footprint trails from a 12-feet long crocodile-like reptile found on the Isle of Arran, the remains of huge trees which once flourished in dense tropical rainforest and preserved traces of long-extinct sea scorpions which could grow up to two metres in length are also contenders for the title.

Angus Miller, chair of the Scottish Geodiversity Forum, a volunteer organisation which aims to promote Scotland's rocks and landscapes, said the idea for the poll stemmed from a similar survey on Scotland's best loved wildlife, which was won by the golden eagle.

He said: "You don't tend to link Scotland with lots of fossils, but once we started putting it all together, we realised not only is there an amazing amount of fossils, but there is also stuff that is really interesting to the general public and perhaps people just don't realise it is there."

Miller said research currently taking place in Scotland was putting the country "more on the map" for fossils than ever before.

This includes investigations on fossils recently found in the Borders, which are helping shed light on a "missing chapter" of the evolution story linking how amphibians moved from water on to land. Previously, there was a significant gap in the fossil record between around 345 and 360 million years ago, which led to some experts concluding there was limited evolution on land.

But the early tetrapod fossils - which are also included as contenders in the poll - suggest there was a wide diversity of amphibians, plants, fish and invertebrates during that period.

The survey will run until spring next year and an open day will be held at Our Dynamic Earth in Edinburgh on Sunday, January 18, to encourage the public to vote.

Miller said his own favourite fossil was the eurypterid, a giant six-legged scorpion-like creature which measured two metres long. Preserved tracks left by the ancient animal as it crawled over damp sand, which measure around six metres long and a metre wide, have been discovered in northeast Fife.

He said: "They are ugly monsters and you can actually see footprints and its tail drag just going across the rock. You can imagine that thing actually moving about 250 million years ago when it walked the earth and made these footprints.

"I just love the thought of that big beast crawling around in Scotland."

FROM GIANT ELK TO TINY SHRIMP ... THE CREATURES THAT ROAMED OUR LAND

Jurassic dinosaurs

of the Isle of Skye

Fossils found on the Isle of Skye have revealed that middle Jurassic dinosaurs once roamed the land around 165 million years ago. At that time, the island was part of a landmass called Laurentia, which also included North America. As well as footprints from large carnivourous dinosaurs known as theropods, the world's tiniest dinosaur footprint was discovered on Skye in 2004 by

Dr Neil Clark from Glasgow University's Hunterian Museum. Measuring just 1.78cm, it is thought to have belonged to a Coelophysis-type creature - a small, slenderly

built, ground-dwelling, bipedal carnivore.

Triassic reptiles

Huge footprints from a 12-feet long crocodile-like reptile known as chirotherium have been found in four different places on the Isle of

Arran. The footprints, complete with large talons, are up to 40cm in

length and are the largest chirotherium prints ever found. Skulls and

fossils of dicynodonts, a group of toothless pig-sized, mammal-like reptiles, were discovered in a sandstone quarry in Elgin in the late 19th century.

Fossil trees

Around 310 million years ago, the Lowlands of Scotland were covered in dense tropical rainforest similar to that found in modern Brazil. The lush forest eventually provided the coalfields under the central belt which were extensively mined during the last century. Famous examples of its preserved remains include Fossil Grove in Glasgow's Victoria Park, which has 11 tree stumps of club-mosses or Lepidodendron, which could grow to up to 30 metres in height. Other famous fossil trees include a 15-metre high conifer on Mull, known as MacCulloch's tree, which became "frozen in time"

when it was engulfed by lava from a volcano eruption around 60 million years ago.

Tealliocaris

The fossils of tiny shrimps which date from between 359 and 327 million years ago can be found in southern and central Scotland. Not vastly different looking from the modern-day shrimp, they swam in and walked on the bottom of low salt-water lagoons or lakes. The fossils are often found preserved in various stages of

life, giving a great insight into their biology.

Irish Elk/Megaloceros

Fossilised remains of the Irish elk, also known as giant deer megaloceros, were found in Maybole in Ayrshire in 1827. The huge creatures were one of the largest deer to ever walk the earth, at around two metres high with antlers spanning around nine feet in diameter. It is one of the most recent fossils in Scotland, dating from before and after the Ice Age.

For the full list visit www.scottishgeology.com/poll