Alex Hyde / Human Head Louse (Pediculus humanus capitis) macro shot of claw, that allows the louse to grip onto the hairs of their human host, False-colour scanning electron micrograph (SEM).

Steve Nicholls / Skeleton of a Python (Python sp)

Juan Manuel Borrero / Illustration of different feather types, including flight feathers, filoplumes, down, and semiplume feathers. Pencil and watercolor painting.

Juan Manuel Borrero / Illustration of gills of an Elasmobranch (Sharks and skates). Pencil, watercolor and pastel illustration

Juan Manuel Borrero / Illustration of detail of the mouthparts of Myxine hagfish, (Myxine sp) Pencil, watercolor and pastel illustration

Juan Manuel Borrero / Illustration of diagram of ammocoetes or lamprey larvae (Petromyzontiformes) and Myxine hagfish (Myxine sp). Pencil and watercolor painting.

Juan Manuel Borrero / Illustration of internal Nautilus anatomy. Pencil and watercolor painting.

Juan Manuel Borrero / Illustration of generalized mollusc anatomy. Pencil and watercolor painting.

Anup Shah / Celebes / Black crested macaque (Macaca nigra) female with swelling of sexual skin to indicate she is in estrus, Tangkoko National Park, Sulawesi, Indonesia.

Anup Shah / Celebes / Black crested macaque (Macaca nigra) close-up of rears, one female in estrus and one male, Tangkoko National Park, Sulawesi, Indonesia.

Alex Hyde / Smooth Newt tadpole (Triturus vulgaris) overhead view photographed on a white backgrond. Derbyshire, UK. August.

Tony Phelps / Boomslang (Dispholidus typus) male showing hemipenes, deHoop Nature reserve, Western Cape, South Africa

Pete Oxford / Eastern diamondback rattlesnake (Crotalus adamanteus) close up of cloaca, belly and tail scales, captive

Bryan and Cherry Alexander / Muktuk, a traditional Inuit and Chukchi meal made from the skin, gristle and blubber of Narwhal (Monodon monoceros).

Edwin Giesbers / Tufted Duck (Aythya fuligula) male on water with open gape showing serrations to the beak. The Netherlands, June.

Stephen Dalton / Ventral view of Nymph of Hawker Dragonfly (Aeshna sp.), showing "mask", an extendable lower mandible used for catching prey. UK, November.

Jane Burton / Gills of Bass {Morone labrax} exposed, Europe

Mike Read / Detail of the scent gland on hind leg of a Sika deer (Cervus nippon) UK

Paul D Stewart / Illustartion of series of primate skeletons, the frontis engraving by Waterhouse Hawkins from the first edition of Huxley's 1863 'Evidences as to Man's Place in Nature'. In this book Huxley presented...

Paul D Stewart / Three toed sloth (Bradypus tridactylus). Skeleton of a three toed sloth, or 'Ai', copperplate engraving from Cuvier's 'Ossamens Fossiles' 1812. Cuvier saw that the key to understanding fossils was to...

Paul D Stewart / 'Grand Mastodon' engraving in Cuvier's 'Ossamens Fossiles' (1812). Mammut americanum is a late pliocene/pleistocene relative of the elephants whose fossils are found only in North America. First disco...

Paul D Stewart / Illustration of skeleton of a hippopotamus, (Hippopotamus amphibius) skelton, copperplate engraving from Cuvier's 'Ossamens Fossiles'. Cuvier saw that the key to understanding fossils was to relate th...

Paul D Stewart / Elephant skeleton engraving in Cuvier's 'Ossamens Fossiles' (1812). Cuvier, the master of comparative anatomy, referenced modern species with extinct fossils to reveal their affinities and differences...

Chris Shields / Illustration of Dragonfly (Aeshnidae sp.) nymph - showing clasping mouthparts in extended and retracted positions.

Martin Camm / Carwardine / Illustration of Sperm Whale (Physeter macrocephalus), cross-section of head showing spermaceti organ (purple) and spermaceti (pink) (Wildlife Art Company).