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Mammal Skulls & Teeth By The Nature Collection for British Wildlife

Cover photo shows a Fallow deer skull and jaw bone, from the front.

Grey squirrel, skull

Explore the skulls of British mammals:

Local Wildlife

Learn about the wide range of mammals which live in the UK, in our parks, fields, woods and gardens. From a tiny shrew to majestic deer, study their skulls to understand their very different lifestyles.

Classification

What makes a mammal a mammal? See the skulls for different groups of mammals and discover how similar the skulls are, for the animals in each group. We will look at Rodents, Insectivores, Carnivores, Deer & Rabbits.

Adaptations

Enjoy the beauty and intricate detail of the skulls. Learn how the skulls have adapted, over millions of years, to suit the lifestyle of each animal.

Teeth and Diet

Study the number and type of teeth in the skulls. See how they have adapted to the animal's diet and method of collecting food.

Alternative Link for Younger Children

Click here for a web page aimed at younger children.

Mammals

Mammals are a large group of animals. Other large groups include Birds, Reptiles, Amphibians & Fish.

Classification: What are Mammals?

  • Mammals are warm-blooded
  • Mammals have hair
  • Mammals breathe through lungs
  • Mammals give birth to live young. They do not lay eggs.
  • Mammals produce milk to feed their young
  • Mammals have a backbone
  • Most mammals live on land, not in the water or air

Mammals can be sub-divided into smaller groups, including Rodents, Insectivores, Carnivores, Deer and Rabbits.

The skulls, teeth and skeletons of animals in these groups are similar because they feed and live in a similar way. You will see this, if we explore the skulls, group by group.

Rabbit skull

We will look at the skulls, in this order:

  • Rodents: Squirrels, Rats, Mice and Voles
  • Insectivores: Hedgehogs and Moles
  • Carnivores: Foxes, Badgers and Stoats
  • Deer
  • Rabbits

These are all British animals.

Skulls. What to look for!

Skulls are all different shapes and sizes. The different animal species have evolved over millions of years. The skull and skeleton of each animal has adapted to suit the animal's diet, habitat and way of life.

Deer and Mouse skulls
  • Size. Some skulls are tiny and some are large.
  • Eyes. The eye sockets may be big or small, face forwards or out to the sides, be high on the head or low, in line with the nose.
  • Noses. Some animals have short noses and other have long, pointed snouts for sniffing out prey or danger.
  • Ear Holes. If animals have very good hearing, their skulls have large ear holes.
  • Teeth. Animals have different types and numbers of teeth. The teeth have adapted to the way each animal gathers food and what they eat.

Rodents

Rodents are small, furry animals with short legs and a long, thin tail. They are often prey animals but some are predators, too. They can use their front legs to collect and handle food. Squirrels, rats, mice and voles are all rodents.

The photo shows a Field vole.

The word 'rodent' comes from the Latin word 'rodere', which means to gnaw, or chew again and again.

See how similar the rodent skulls are.

Field mouse skull

It is very light and tiny, just 2.4cm long x 0.8cm high.

Brown rat skull

It is very small, just 4.5cm long x 1.3cm high.

Grey squirrel skull

This is bigger and more solid, at 6cm long x 2cm high.

These animals are all rodents.

Starting top left: House mouse, Black rat, Grey squirrel, Field vole and Water vole, eating grass.
Grey squirrel skull, 6cm long x 2cm high

Rodent Skulls

Rodents have solid skulls. The proportions on all these three skulls are 3:1. The skulls are three times as long, as they are high.

Rodents have proportionally large eyes. Many are prey animals, as well as predators and they need to keep watch for danger.

They have large, upright ears, with a very good sense of hearing. The ear holes are therefore relatively big.

House mouse at The British Wildlife Centre

Rodents have long snouts, or noses, which are useful to sniff out prey or sense a predator nearby. They use long whiskers to feel their way around in the dark and in the undergrowth. They help them to sense where prey and predators are. The jaw bone is solid.

Grey squirrel, jaw bone or lower jaw, 4cm long x 1.6cm high

Rodents: Teeth & Diet

Rodents eat mainly plants such as seeds, nuts, berries, fungi, roots and bark. Rats have a wider diet, eating almost anything including smaller mammals and birds.

Rodents have a huge pair of incisors at the top and bottom, at the front of their mouth. They use these to gnaw and nibble at tough food such as tree bark and nuts.

The front of the incisors is coated in orange enamel, which is very hard. The back of the incisors is softer. As they gnaw, the back of these teeth wears down more quickly than the front. This makes a sharp, curved cutting edge.

Field vole incisors and molars, found inside a Barn owl pellet!

The incisors keep growing throughout the animal's life.

Field vole, teeth

Rodents have no canine teeth.

Further back in the mouth, rodents have 3-5 pairs of small, ridged premolars/molars, which they use to chew and grind up their food.

Mouse skull, 2.4cm long x 0.8cm high

Between the front and back teeth, rodents have a large gap. This is called the 'diastema'. They can suck in their cheeks while they are gnawing to close off the back of their mouth. This prevents them choking on nut shells or chunks of tree bark, before it is ready to be swallowed.

Dentition Formula

Scientists study animal teeth and describe the number and type of teeth which a species has, in a standard format. They state the number of teeth of each type on one side of the mouth, first giving the number in the top jaw, followed by the number in the lower jaw. You start at the front of the mouth and work backwards, so listing incisors, canines, premolars and finally, molars. This is called the 'dentition formula'.

Squirrels have 1 incisor, 0 canines, 3 premolars and 2 molars in their top jaw. They have just 2 premolars in the lower jaw. So their dentition formula is: I 1/1, C 0/0, P 3/2 and M 3/3. You multiply the numbers by two, for the two sides of the jaw and see that in total, squirrels have 22 teeth. Humans, as adults, have 32 teeth.

Rats, mice and voles have 1 incisor and 3 molars on each side of the mouth, top and bottom. They have no canines or premolars. Their dentition formula is I 1/1, C 0/0, P 0/0 and M 3/3. So they have just 16 teeth.

Insectivores

Insectivores are animals which eat insects. It is not only mammals which are insectivores. Many species of bird, fish, reptile and amphibian are insectivores, too. Large numbers of insects, such as ladybirds and dragonflies, also eat insects.

Hedgehogs, moles and shrews are mammal insectivores. Bats are also mammals, which eat insects. (They are classified in a group of their own.)

See how similar insectivore skulls are!

Mole skull

This is 3.5cm long x 0.8cm high. Less than 1cm high!

Hedgehog Skull

This is larger and much more solid, at 4.3cm long x 2cm high

These animals are insectivores.

Mole and Hedgehog

See The Mammal Society website for more photos and information about other insectivores, such as the different shrew species.

Mole skull, 3.5cm long x 0.8cm high

Insectivore Skulls

Insectivores have a long, narrow skull. This has adapted to a life of grubbing around in the soil and dead leaves to find food. Moles live in underground tunnels and shrews create tunnels just above the ground, through the leaf litter and plant roots or they live in burrows abandoned by other small mammals. The narrow, pointed skull is adapted for tunnel-life, too.

These mammals do not rely on sight or hearing. They have small eyes, with eye sockets low down on the skull and relatively small ear holes. Moles are not blind as many people think.

Insectivores have a long, pointed snout. They sniff out their prey in the soil and leaf litter. The bones of the skull do not go to the very tip of the nose. Cartilage is at the end. Inside the nose are thin folds of bone, where the scent cells lie.

The jaw bone is very long and narrow, with a small area at the back for the chewing muscles to attach onto. Insectivores do not need to chew and grind up plant matter, like rabbits and deer do.

Mole, jaw bone, 2.4cm long x 0.7cm high

Shrews have a very high metabolism and need to feed every 2-3 hours to stay alive, even through the night. It is particularly hard for them to find food in winter. Amazingly their body has adapted to this by shrinking over the winter months, which means they use less energy to move and need less food. Even their skull and brain shrinks!

Hedgehog skull, just 2cm high but fearsome to a worm!
Hedgehog at The British Wildlife Centre

Insectivores: Teeth and Diet

The main photo shows molars in a hedgehog skull.

Insectivores eat mainly insects. Hedgehogs and shrews also eat worms, slugs and snails. Moles eat mainly earthworms.

Insectivores need to eat a lot of insects to survive each day. Insects are small and often hard to catch, so it takes a large amount of energy for these mammals to collect their food.

Insects are difficult to eat because they have a hard exoskeleton on the outside of the body. This needs to be crunched and broken up, to reach the nutritious soft body inside.

Stag beetle, with a tough exoskeleton.

Insectivores have a large number of small, pointed teeth which have evolved to suit the task of catching and chewing up their insect prey.

Dentition Formula

Moles have 3 small pairs of incisors at the front, which they use to catch slippery worms! Then 1 pair of canines and 7 pairs of sharp, jagged premolars/molars. Their dentition formula is I 3/3, C 1/1, P 4/4, M 3/3. They have 44 teeth in all.

Mole skull, from the front!

Hedgehogs have similar teeth, with 36 teeth in all. They have fewer teeth in the lower jaw. Their dentition formula is I 3/2, C 1/1, P 3/2, M 3/3.

Shrews have 32 teeth in all, with fewer teeth in the lower jaw.

Shrews have a red layer on the tips of their teeth. This shows there is iron in the enamel, which strengthens the points. Their skulls and jaws are so small and fragile, they need reinforcements to break up the insect cases. Plus, the iron helps prevent the teeth wearing down. Shrews' teeth do not keep growing throughout their life.

Shrews have tiny, red-tipped teeth. The jaw bone is about 1cm long!

Carnivores

Carnivores are predators which eat mostly meat, or the flesh of other animals. Foxes, badgers, stoats, weasels, polecats, pine martins, mink and otters are all carnivores which live in the UK.

Carnivores are usually strong, fast hunters. They have sharp claws and teeth for killing their prey.

See how similar carnivore skulls are.

Fox Skull

This is 15cm long x 6cm high.

Badger Skull

This is 13cm long x 6cm high.

Stoat Skull

This is 5cm long x 2cm high.

These animals are all British carnivores: Fox, Badger, Otter, Weasel, Stoat, Pine marten, Polecat, Wildcat and American mink.

Fox
Badger
Otter
Weasel
Polecat, American mink ,Wild cat, Stoat and Pine marten

The photos were taken at The British Wildlife Centre.

Fox skull, 15cm long x 6cm high

Carnivore Skulls

Carnivores have heavy, solid skulls. They need to be strong to crunch up the bones and tear up prey. Large jaw muscles attach to the skulls. The skulls are long but not very high.

Carnivores are predators. Their eyes are close together and face forwards, not out to the sides. They have excellent vision immediately in front of them, which is where they need to be able to pinpoint and pounce on their prey. They can see the area in front of them, with good binocular vision, looking at the object with both eyes.

These animals have a long, pointed nose/snout. They can sniff out their prey. They also have whiskers to feel their way and sense movement in the dark.

Foxes have large, upright ears but the ears of the other carnivores are relatively small. Their ear holes are small, compared to rodents, rabbits and deer.

Carnivores: Teeth and Diet

Carnivores eat mainly the flesh of other animals which they hunt. They eat smaller mammals, especially rodents, small birds, birds' eggs, frogs and lizards. Badgers even eat hedgehogs!

Most carnivores also eat insects, earthworms and berries.

Carnivores have 3 pairs of small incisors at the front of the mouth. These are used to tear off the flesh and skin.

The long, pointed canine teeth are next to the incisors. There is a pair on each side. These are used to kill prey, and for display and defence.

The premolars and molars have sharp, jagged points. These are good for killing prey, slicing through the meat and crunching the bones.

Dentition Formula

Foxes have 42 teeth: on each side in the top jaw, they have 3 incisors, 1 canine, 4 premolars and 2 molars. They have 3 molars in the bottom jaw. The dentition formula is I 3/3, C 1/1, P 4/4, M2/3.

Badgers have 36 teeth: on each side in the top jaw, there are 3 incisors, 1 canine and 4 premolars and 1 molar. They have 3 premolars and 2 molars, at the bottom. The formula is I 3/3, C 1/1, P 4/3, M 1/2.

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Deer

Deer are large animals with two hooves on each foot. They are herbivores and feed on grass and plants. Male deer usually have antlers.

Deer are 'ruminants'. This describes the way they digest their food. When deer first pull up clumps of grass or plants, they chew it very little and send it down to the stomach. When they have filled their stomach with large amounts of grass, they lie down in a quiet place and bring the grass back up into their mouths, to chew again. This is called 'chewing the cud'. Cows and sheep do it, too. You will see deer have very different teeth, to the other groups of animals.

There are six species of deer living in the UK. These are Red deer, Fallow deer, Muntjac deer, Roe deer, Chines water deer and Sika deer. Wild boar are also classified in their group.

See how similar the deer skulls are!

Fallow deer, skull, female

This is 26cm long x 13cm high.

Roe deer, skull, female

This is 21cm long x 10.5cm high.

Muntjac deer, skull, female

This is 16cm long x 6cm high.

Male deer skulls are much more dramatic, with antlers growing out of the back of the skull. I will add some photos, soon!

Fallow Deer, often kept in parks.
Roe Deer, common in the countryside
Muntjac Deer, the smallest species.
Fallow deer skull, 26cm long x 13cm high

Deer Skulls

These are the largest skulls in this presentation. They look solid and are heavy but inside there are delicate folds of bone, which reduce the weight. The skulls are tall, with a long, narrow snout.

Eye Sockets. Deer are prey animals. Their large eyes face out to the side, so they can keep watch for danger even when they are grazing.

Fallow deer, growing new antlers. This happens every year.

Nose. Deer have a long, pointed snout. This helps them reach into the undergrowth to pull up clumps of grass or up through the tree branches, to grasp fresh leaves.

Ear Holes. Deer have large, upright ears to catch sounds but the ear holes on the skull are relatively small.

Deer have a large, solid jaw bone, with a large area for the chewing muscles.

Fallow deer, jaw bones. 22.5cm long x 10cm high
Fallow deer. See how high up, the eye sockets are on the skull. They face out to the side.
Fallow deer, close up of the eye socket. Note the 'lacy' delicate layers of bone inside, not solid.

Deer Teeth & Diet

Deer are 'herbivores'. They eat grass, plant shoots, acorns, nuts, heather, leaves and tree bark.

It looks as if deer have 4 pairs of incisors on the lower jaw, at the front of the mouth. In fact, these are 3 pairs of incisors and 1 pair of canines. The canines have moved and evolved to act like extra incisors.

The incisors are for collecting food: pulling up grass and tearing off leaves or berries.

Fallow deer, lower incisors

Deer have a rough pad on the top of the mouth instead of teeth. They use this to grasp the grass and leaves. If they had incisor teeth on the top, they would cut through the vegetation and not be able to pull up clumps.

There is a gap between the incisors and premolars. Rodents have this 'diastema', too. For deer, they can suck in their cheeks while they are grazing to close off the back of their mouth. This prevents them choking on the plants before they have been swallowed.

Fallow deer skull and jaw bone

The premolars/molars at the back, are for chewing and grinding up the food. The surface of the molars consists of hard enamel and soft dentine, which wear down at different rates. This makes sharp, cutting ridges across the surface of the teeth. These make the molars more effective at breaking down the tough plant matter.

Fallow deer molars, ridged surface

Remember that rodents have a layer of tough enamel on the front of their incisors, which creates a sharp cutting edge for gnawing bark. Different adaptations for different methods of feeding.

Dentition Formula

Deer have just 6 premolars/molars on each side in the top jaw and 3 incisors, 1 canine and 6 premolars/molars in the bottom jaw. So, they have 32 teeth, in all. The dentition formula is I 0/3, C 0/1, P 3/3, M 3/3.

The photo shows the lower jaw of a Fallow deer

Rabbits

Rabbits are classified in the same group as hares. They are medium-sized mammals, with long ears and long back legs. They are prey animals and can both move quickly, especially hares!

Rabbits live in underground tunnels and hares live above the ground.

In Britain, there is just 1 species of rabbit and 3 species of hare.

Adult Rabbit, Skull

This is 8.5cm long x 3.5cm high.

Young Rabbit, Skull

This is 6cm long x 3.4cm high.

Rabbits are herbivores.

Rabbits do not 'chew the cud' like deer but instead they eat their droppings, so the food passes through their digestive system twice. This is the way this group of mammals has adapted to deal with the fact that plant matter is hard to break down and digest.

See The Mammal Society website, to find out more about rabbits and the different hare species.

Rabbit skull, 8.5cm long x 3.5cm high

Rabbit Skulls

Rabbits are prey animals. They need to be able to move quickly and watch out for danger on all sides, even when their heads are down to feed.

Rabbit skulls are light and delicate. In several sections of the skull, particularly at the back and in the nasal cavity, the bones are not solid but a delicate latticework of thin struts. These are strong but lightweight.

Back of a Rabbit skull. See the delicate lattice of bone and the large tunnels leading to the middle and inner ear!

Eye Sockets. Rabbits have eyes which are proportionally large and high up on the head. As prey animals, the eye sockets face out to the side. This positioning enables the rabbit to look in all directions, not just focus immediately in front of them, like predators do.

Ear Holes. Rabbits have an excellent sense of hearing. They have very large ear holes, which point upwards, high up on the head. They can twist their long ears around to pick up sounds and the noises are then funnelled down into these tubes, to the middle and inner ear.

Large, upright ears and huge eyes looking to the side!

Rabbits have long noses so they can sniff out danger. The folds of bone inside the nasal cavity are covered in scent cells. They also use their whiskers to sense what is around them, especially underground.

Rabbit Skull

Rabbits have a large, flat area at the back of the jaw bone. This is where the chewing muscles attach.

Rabbit, jaw bone, 6.2cm long x 3.5cm high

Rabbit Teeth & Diet

Rabbits are herbivores. They eat grass, crops, vegetables, berries, leaves and buds. In autumn and winter, they also eat twigs and tree bark.

Rabbits have a pair of large incisors at the front of the mouth. They also have second pair, called 'peg teeth', growing behind these. Their teeth do not have roots and keep growing throughout their life.

See the peg teeth, behind the front incisors.

Rabbits have a 'diastema' or gap in between their incisors and premolars, like deer and rodents. This is they can shut off the back of the mouth while they are gnawing and nibbling away at hard plant matter, before it is ready to swallow.

At the back of their mouth, Rabbits have 3 premolars and 3 molars in their top jaw. These are to chew and grind up the fresh food and soft droppings, which they eat for a second time around.

Dentition Formula

Rabbits have 2 incisors on each side of the mouth at the top, 3 premolars and 3 molars. (No canines.) At the bottom, they have only 1 incisor, 2 premolars and 3 molars. The dentition formula is I 2/1, C 0/0, P 3/2, M 3/3. In total, they have 28 teeth.

The photo shows a Rabbit's premolars/molars in the upper jaw.

The Collector, Photographer and Author

I am Susanna Ramsey and I have a unique collection of natural history objects relating to British Wildlife. Over the last ten years, I have assembled an extensive range of skulls, skeletons, bones, skins, feathers, wings, antlers, insect specimens and taxidermy, all from animals in the UK.

During 2010-2018, I took my Nature Collection into local primary schools to display and run workshops for the children, linking the exhibition to science topics in the National Curriculum such as Adaptations, Bones, Classification, Food Webs, Habitats, Life Cycles and Local Wildlife.

In 2018-2020, I worked with the leading schools' catalogue, TTS ,to create a range of Educational Resources for primary schools, nurseries, after school clubs and families. To find out more about these products, click here or see below.

So much still to discover!

The above photo shows some of the 40 photo cards in the Classification: Natural History set. (See below.)

Exhibits and Thanks

Almost all of the animals in my collection were either found by myself, Susanna Ramsey, or donated by friends and family to The Nature Collection, as an educational resource. Huge thanks for all the tiny, carefully-wrapped bundles of feathers and bones, to Steve and Sam Read, John Lock, Chris Matcham, Franko Maroevic, Tim Howard, Jan Wilczur, Simon Richards, Peter Veniard, Paula Redmond, Phil Davis, Bob & Sally Black, Jo & Frank Sheppard and Katie Ramsey. Many of these people are naturalists and experts in their field; I am indebted to them too, for all that they have taught me about our local wildlife.

Over the years, I have been lucky enough to be a regular visitor to the Angela Marmont Centre for UK Biodiversity at the Natural History Museum, London. The unimaginably-vast collection of British insect specimens, stored in row upon row, of metal, floor-to-ceiling cabinets has been a massive inspiration to me. There is something infinitely satisfying about the way every species has its own box, within a drawer, within a cabinet and that each can be found within minutes, by the care and expertise of the staff. To witness the incredible number of UK species of moth, beetle, butterfly, fly, grasshopper etc, is simply mind blowing and I feel so privileged to be able to visit and photograph some of the specimens!

I have used the photo stacking equipment at the Angela Marmont Centre to take highly-detailed photos of some of the specimens to put into slideshows for my primary school workshops. When I was young, I always wanted to be an archaeologist and it was my ambition to work in a museum; to sit in the Centre, using the equipment and handling the specimens, listening to the chatter of the experts at work, has been a dream come true. I am so grateful to the staff at the Centre for their encouragement and for always making me feel so welcome.

The delicate skeletons were cleaned to perfection by a colony of flesh-eating, dermestid beetles, skilfully managed by Edward de Geer.

Thanks also to Tonja Grung, of Made from the Dead Taxidermy, for sharing her incredible knowledge, patience and skill. I will never forget our amazing sessions on animal taxidermy.

Sources of Information / Further Reading:

BRITISH WILDLIFE PRODUCTS

Explore the whole range of British Wildlife products created by the leading schools' catalogue, TTS and The Nature Collection. The products are perfect for use in primary schools, nurseries, after school clubs, forest schools or at home with friends and family.

Look & Learn Cards: British Birds, Mammals, Minibeasts

Food Webs Activity Pack

Classification: British Wildlife & Natural History

Identification Wheels: British Birds, Mammals & Minibeasts

Discovery Bags: British Birds, Mammals, Minibeasts

Playground Signboards: Birds, Mammals, Minibeasts

Created By
Susanna Ramsey
Appreciate

Credits:

Susanna Ramsey