Expert annotations for this species! See below.
The European mole (Talpa europaea) is widely distributed throughout temperate parts of Europe and Asia. It does not extend south beyond the Pyrenees (and is therefore absent from the Iberian Peninsula) and is missing from the north of Scandinavia. It is also missing from Ireland. Although broadly resembling a rather fat glossy mouse, the European mole belongs to the mammalian group Insectivora, along with hedgehogs, shrews and desmans. It is effectively a large (120-180 mm) subterranean shrew, living under deciduous woodland and grassland where there is sufficient depth of soil. All talpids (moles) with the exception of the water-living desman (and the rather ambulatory shrew mole which lacks digging specialisations) live in self-made subterranean burrows.
Barring accidental emergence into daylight, the European mole spends the entirety of its life underground. It uses specialised enlarged forelimbs to dig a complex system of tunnels that it patrols on a regular (roughly 4 hour) basis, picking up worms and soil living insects. In this environment, eyes are a liability since they may clog with earth. They are extremely reduced and skin covered, able only to detect light and dark so that the animal is aware if it accidentally breaks through onto the surface. The main sense organs are the long mobile nose (both for smell but also the sensitive bristles) and the ears. Some authors have suggested that the nose of Talpa may also be sensitive to electrical or magnetic signals. Hearing is acute but the ears are without auricles (outer ear), again a liability underground. The vestibular system is also well developed. This is probably in compensation for the absence of visual cues (McVean, 1999) with respect to body position in space and the navigation of horizontal mazes.
The skull is around 35 mm long, and is slender with an elongated rostrum. The importance of the nose and ears is reflected in the extraordinary skull shown here. The nasal cavity is enormous, filled with a complex but exquisite arrangement of turbinate bones that greatly enlarge the surface area for mucous and olfactory epithelium. The sutures between cranial bones fuse early and the zygomatic arches are complete (lost in some other insectivores, e.g. shrews). The dental formula is 3/3 1/1 4/4 3/3. The teeth are sharp and the enlarged upper canines are used to bite and paralyse worms without killing them, so that they may be stored in large numbers.
In true digging moles, the front limbs are anatomically adapted for the biomechanical requirement of producing great force, sufficient to tunnel in soils. This extreme specialisation of the forelimbs is added to what is anatomically a rather primitive (underived) mammalian body design: the rest of Talpaís skeleton (especially the skull) is still very similar to those of the rat-sized ancient fossil mammals that existed contemporaneously with the dinosaurs during the Mesozoic Era. Talpids are gerbil- to rat-sized, solitary (except in the breeding season) insectivores and are ecologically diverse in their degree of subterraneity, fossoriality and life styles. They have a broad global distribution and occupy a wider variety of habitats than other subterranean mammals such as rodents and rabbits. Moles feed on invertebrates, from tough armoured beetles to soft worms. However the desert-living chrysochlorid (golden) moles of Africa can kill and eat scorpions and even small lizards.
In overall general proportions, the skull of Talpa europaea is very similar to that of the Mesozoic mammal Hadrocodium. Nevertheless, the cranium of T. europaea has its own distinctive and intriguing anatomical features, as described below.
Additional Information on the Skull
Click on the thumbnails below for a detailed description of the skull in standard anatomical views.
Click on the thumbnail below for a description of internal features of the skull based on selected coronal slices.
Crompton, A. W. 1963. On the lower jaw of Diarthrognathus, and the origin of the mammalian lower jaw. Proceedings of the Zoological Society of London 140:697-753.
Gorman, M. L., and R. D. Stone. 1990. The Natural History of Moles. Helm, London. 138 pp.
McVean, A. 1999. Are the vestibular canals of T. europaea adapted to a subterranean habitat? Comparative Biochemistry and Physiology 123:173-178.
Mason, M. J. 2001. Middle ear structures in fossorial mammals: a comparison with non-fossorial species. Journal of Zoology 255:467-486.
Pye, A., and R. Hinchcliffe. 1968. Structural variations in the mammalian middle ear. Medical and Biological Illustration 18:122-127.
Talpa europaea page on Trallo.com
T. europaea page on the FMD module
T. europaea page from The Mammal Society (UK)
T. europaea page from borealforest.org