A rare, spider-like harvestman in amber has been donated to the Natural History Museum by Rochester fossil collector Terence Collingwood. The tiny arachnid is 34–40 million years old and is only the second example of its species, Dicranopalpus ramiger, to join the national collection.
The harvestman looks similar to a spider, with an oval body the size of a pinhead and very thin, six-millimetre-long legs . It is preserved in a lump of Baltic amber slightly larger than a £2 coin. While spiders have their head and abdomen separated by a waist, harvestmen’s bodies and heads are fused together, and they do not produce silk.
‘Being able to contribute to the Museum’s collection is a dream come true,’ said Terence Collingwood, who gave up a career in IT support to run I Dig Dinos fossil shop on Rochester High Street. ‘I buy bulk lots of amber to sell, and I have to search through them carefully looking for unusual items that other people may have missed. Finding this was pure chance, but I realised straight away that it was something special.’
Amber acts as nature’s time capsule, telling us about life in ancient forests. It is fossilised resin that once exuded from tree bark, a gluey trap that can capture and hold small insects and other animal or plant debris. Amber is extremely important for understanding the history of land-living animals, particularly small insects, that are not often preserved in rocks. The Museum’s palaeontology collection includes 5,000 pieces of amber, many with more than one insect.
‘Complete harvestmen are rare finds,’ said Andrew Ross, a collections manager of fossil invertebrates and plants at the Natural History Museum. ‘It’s more common to find just the legs in amber, where a trapped leg or two were sacrificed so the harvestman could escape the sticky resin. This is a particularly impressive example because all its legs are present and still attached to the body. It is a very welcome addition to our collection.’
Baltic amber comes from countries surrounding the Baltic Sea, such as Germany, Poland, Denmark, Russia and Lithuania. It originates from a deposit known as blue earth, which lies beneath the water table and extends out into the Baltic Sea. Storms can rip amber out from this bed, which was produced by a huge subtropical forest millions of years ago.