New research into prehistoric pond terrapins

Many of you will be unaware that Britain was once home to some rather exotic species - including freshwater turtles. Today, the European pond terrapin Emys orbicularis is confined to warmer parts of Europe today, but during the 'Atlantic warm period' about 6000-9000 years ago, this warm-loving species was able to thrive in Norfolk of all places.

CGO Ecology is currently working on a research project for Amphibian and Reptile Conservation, on behalf of Natural England, to review the evidence available in museums and other collections of England's herpetofaunal past. The aim is to determine whether some amphibian and reptile species that are now extinct, were once present here; and whether others were formerly more widespread than they are now.

We already know that several frog species have become extinct in the last thousand years in eastern England, and one of them - the pool frog Pelophylax lessonae - has even been reintroduced to Norfolk by conservationists. The European pond terrapin is another species that once colonised Britain, but later become extinct.

So how do we know that pond terrapins were here? Well, their subfossil remains have been unearthed from archaeological sites in southeast England. Most of the specimens date back hundreds of thousands of years, before the last ice age; but at one site in Norfolk, postglacial or 'Holocene' remains have been found.

The specimen above is from East Wretham in Norfolk. Remains of two adult terrapins were discovered in 1836, during peat excavations. (Some of the remains appear to have been glued together incorrectly in the 19th century). It has never been radiocarbon dated, but is thought to be between 6000-9000 years old.

The Wretham discovery was brought to scientific attention by Alfred Newton in 1862, and again by Tony Stuart in 1979. More recently, genetic work carried out by Robert Sommer et al. show that the Norfolk terrapins were among the first to colonise northern Europe after the last ice age ended and climate ameliorated.

The Wretham specimens are held by the University Museum of Zoology, Cambridge. Access for photography was kindly provided by the Collections Manager, Matt Lowe.