Insectivores have continuous rows of similar, pointed teeth, considered
by taxonomists to be a primitive feature. There are eight British insectivores, three of
which only occur in the Channel Islands.|
The hedgehog is much larger than the others :
|1.||a)||Overall length greater than 40mm.||HEDGEHOG|
|b)||Overall length less than 40mm.||2|
|2.||a)||Overall length close to 35mm, prominent canine teeth, with zygomatic arch.||MOLE|
|b)||Overall length much less than 35mm, front pair of teeth much larger than the rest, no zygomatic arch.||3|
The remaining insectivores are shrews. Their skulls are very small and
fragile, but shrew jaws are easily recognised.|
A powerful handlens or low-power microscope is necessary for the identification of shrew skulls.
|3.||a)||Teeth pigmented (red tipped).||4|
|b)||Teeth not pigmented (Channel Islands only).||White-Tooth|
|Front upper teeth of Common Shrew, Sorex araneus.|
1 - 5) Upper single-pointed teeth.
F) First upper tooth.
|4.||a)||Upper surface of first lower tooth smooth, four upper single-pointed teeth.||WATER|
|b)||Upper surface of first lower tooth wavy, five upper single-pointed teeth.||5|
|5.||a)||Upper tooth row less than 7mm, third upper single-pointed tooth larger than second.||PYGMY|
|b)||Upper tooth row longer than 7mm, third upper single-pointed tooth smaller than second.||COMMON|
|The French Shrew, Sorex coronatus is very similar to the Common Shrew. Its British distribution is confined to Jersey.|