Small is beautiful: fossil voles as stratigraphic aids

David Mayhew (The  Netherlands) When you walk through the countryside,youwill not often come across a vole. However, they are present in most habitats and are one of the most successful groups of small mammals, widely distributed in both Eurasia and North America. Broadly speaking, Voles are blunt- nosed, short-eared, mouse-like rodents and many of them are specialised for burrowing. They can eat hard vegetation such as grasses that are very abrasive due to the presence of silica spicules. Therefore, many species of voles haveevolvedcontinuously growing cheek teeth (that consist of molar teeth: three upper and three lower) as well as the continuously- growing incisors that are typical of rodents. Finding fossil remains of voles This evolution took place largely in the last three million years.For this reason, fossil remains of voles are very useful for helping us unravel the stratigraphy of deposits from the Pliocene and Pleistocene periods. And, as you can see from the photographs, they are beautiful objects in their ownright. We are talking here of quite small fossils, for example, the molar teeth are between 1 and 3mm in size. So, where and how are they found? Many, even thousands of specimens, can be found in cave and fissure deposits, such as Foxholes at High Wheeldon in Derbyshire. Often, such localities have no stratigraphic context other than the fauna contained in the sediments. However, the material may be very complete (skulls, lower jaws and limb bones). Fig. 1. Remains of vole Microtus sp. from Foxholes cave, High … Read More