In 2001 Nigel Armstrong, a fossil collector, found the initial remains of a Lower Cretaceous plesiosaur at Speeton, just down the coast from Filey.
The ensuing excavation was organised by then Dinosaur Coast Project Officer, Will Watts, and took place over 10 bitterly cold days on November 2002. A team of volunteers mapped and recorded the fossilised skeleton, establishing the relationship between individual bones. The weather was turning bad, so Will decided to remove the fossilised aminal using a technique called plaster jacketing, which he later described as “similar to putting a plaster cast on a broken arm – we encased the various bits of plaster of Paris, strips of hessian and bits of timber, and ended up with a half-tonne lump of Lower Cretaceous Speeton Clay.”
This was then sent to fossil prepartion specialist Mike Marshall at Sandsend, near Whitby, who spent a year unearthing hundreds of bones.
The end result was a four-and-a-half metre long skeleton – the living animal would have been another two metres, but the head is missing.
Following excavation the specimen was donated to Scarborough Museums and Galleries and is currently on display in the Rotunda Museum.
It is highly likely the specimen will prove to be a new type of species, filling a 60 million year gap in plesiosaur evolution. Lower Cretaceous Plesiosaurs are rarely found throughout the world, so this specimen will be vital to support our understanding of this group of animals.
The Speeton Clay itslef is very important as it represents a period of time when fossil deposits are rare. The Speeton Plesiosaur is complete apart from the head. Other fossil material found at Speeton uncludes ammonites, shrimps, ichthyosaurs, shark teeth and hermit crabs.