Anatomy of an Elephant
Dane Aleksander, animator at Animat Habitat.
This article is continued from A History of Elephants.
A parable of three blind men, or women, and an elephant. Three people are each touching a different part of an elephant without seeing the elephant. The first person touches the trunk of the elephant, and says, “An elephant is like a snake.” The second person touches a leg of the elephant, and says, “No, an elephant is like a tree.” The third person touches the side of the elephant, and says, “Incorrect on both accounts, an elephant is like a wall.” Each one of them thinks that the two other statements are incorrect, when in fact they are all describing different parts of the same elephant.
Here we step back to look at the anatomy of an elephant, including notes taken in the making of Ella.
Elephant skeleton © Museum of Natural History, Marseille [recolored]
Teeth and Tusks
An elephant only has four molars at any one time, with two on top and two on bottom. These molars are located along both sides of the upper and lower jaw. Each molar is the size of a brick, and weighs up to about twenty pounds. An elephant can only grow six sets of these molars in a lifetime. These molars grind away from use all day, everyday. When the sixth set of molars is worn down from forever chewing fodder, the elephant is soon to starve, unable to supplement a diet with tree bark and so on. 
The life expectancy of an elephant in the wild is sixty to seventy years. 
Old elephant bulls have often died near marshlands where the vegetation is easier to eat. So goes the legend of elephant graveyards. 
Elephant tusks are teeth, too. Elephant tusks are in fact incisors, which begin to grow after a calf has reached about a year of age. Then, for the rest of the life of an elephant, elephant tusks do not stop growing. 
Much of the tusk is made up of a hard, dense, bone tissue called dentin. This is wrapped in enamel, which is the hardest animal tissue, and which is the part of the tusk that manages the most wear. Elephant tusks are of course also classified as ivory.
The tusks of an elephant bull will grow much larger than the elephant cow. An elephant bull with at least one tusk weighing in excess of 100 pounds is classified as a super-tusker. Each tusk can grow to two metres in length and, for some super-tuskers, up to about 200 pounds in weight in the course of a lifetime. Today, there are little more than twenty super-tuskers left on Earth, and their tusks do not exceed 150 pounds. 
For elephants, tusks are more than an indication of social stature. Elephants need their tusks to survive: to dig for roots and water and so on, to strip bark from trees, to clear pathways, and to defend themselves. Elephants are either left-tusked or right-tusked. The tusk that an elephant uses most will appear a bit more worn down. 
No one needs a tusk other than an elephant.
“An elephant's appetite is prodigious. They eat roughly four percent of their body weight each day, so a five tonne elephant will eat some 200 kilograms of vegetation. A natural consequence of this is the production of copious quantities of dung – on average each elephant produces roughly one tonne of natural organic manure every week, packed with nutrients, that feeds countless insects and enriches the soil of their habitat. When they have been feeding on fruits or pods, their dung is also packed with seeds, all deposited miles from the parent plant and protected from weevils and other seed predators. in so doing, elephants effectively sow the next generation of trees, each seedling getting a good start in life growing in rich compost. Trees with small seeds can also have them dispersed by fruit-eating birds, primates and antelopes, but those species with big seeds need big seed-dispersal agents. Elephants disperse more seeds and more species, over longer distances, than any other animal. This is why ecologists have dubbed them the ‘mega-gardeners of the forest’.”
— Ian Redmond OBE, Ambassador for UNEP Convention on Migratory Species, Consultant for Born Free Foundation, Remembering Elephants (book, 2016), Envisage Books
What's in the Trunk?
An elephant trunk is an extension of the upper lip and nose. This highly adapted olfactory organ has nostrils at the tip through which the elephant can breath, has a highly developed sense of smell and sense of touch, and gives the elephants a flexibility to manipulate the world around them. 
Elephants have six times as many facial nerve cells as humans, half of which control their complex trunk muscles. Elephants have more than forty
up to 150 thousand muscles in their trunk. An elephant trunk, or proboscis, for which the order of the elephantidae family genus – proboscidea – is named, contains sixteen larger muscles for major movements, such as raising the trunk. Thousands of smaller muscle fascicles, or bundles of muscle fibres, allow for finer movements of the trunk. African elephants have two finger-like projections at the tip of the trunk, which they can use to pick grass, leaves and fruit. 
Elephants use their trunk to skim water holes for the clearer water settled at the surface. Elephants can contain about six to twelve litres – more than a gallon – of water in their trunk at a time, then spout the water into their mouths or otherwise. Elephants also reserve water in a pharyngeal pouch in their throat for a sunny day. 
Elephants use their trunk to shower themselves with dust and mud and so on. This provides an effective sun-block that protects from ultraviolet rays and from parasites. 
Elephants use their trunk to collect vegetation and to uproot trees, as well as to interact and to communicate with others through smell, sound and touch. 
“The trunk is a masterpiece, a complex fusion of hand, lip and nose with a multitude of functions. It can fell trees, lift heavy logs, blow torrents of water, trumpet loudly, or delicately pick up a single seed. A super-sensitive, telescopic antenna, it rises high into the air to smell for danger, and can also be used as an effective weapon. A trunk can reach seemingly impossible places, remove grit from the eye, and be used to caress and give comfort.”
— Steve Bloom, Elephants, ‘Body and Mind’ (book, 2006), Chronicle Books LLC
Elephants use their trunk to test unsteady or unfamiliar terrain, by using the outside of the trunk to beat the ground to determine if it is firm enough to walk on. Once determined to be safe, the elephant will step with a front foot onto the tested area. A rear foot follows and is carefully placed in exactly the same footprint. Elephants will also beat the ground with their trunk to signal anger or displeasure. 
Despite their mass and the massive size of their feet, studies of elephant walking patterns have shown that an elephant walks on his or her toes without making much noise at all, putting the most pressure on the outer toes of the front feet and the least amount of pressure on the heels. Elephant leg bones have no cavity for marrow, instead they are solid bone, which helps to bear the weight of an elephant. Their large round feet spread out as they take a step, which helps to prevent elephants from sinking into the ground and sticking into the mud. 
Research has shown that elephants can communicate more than five
up to twenty miles apart using an infrasonic rumble, which travels through the ground faster than sound through the air. Elephants detect these vibrations with a sponge-like digital cushion in the soles of their feet, and sense the direction based on the signal difference between feet. Elephants have been known to detect a thunderstorm from miles away and head toward the rain. 
Close-up-of elephants feet disturbing Cape Turtle Doves © Steve Bloom [stevebloomphoto.com]
Skin, Skull, Ears and Eyes
African elephant skin is gray and wrinkled, is over an inch thick in places, and has no sweat glands. The wrinkled skin helps to store moisture and keep an elephant cooler for longer after dusting and wallowing and so on. The wrinkled skin also increases the surface area of the skin in contact with the air, allowing more blood that flows close to the surface to expel heat before recycling to the core. 
Elephant skin is covered with papillae, with hairs of varying color, length, thickness and all of which makes elephant skin highly sensitive. Elephants of the same herd will often greet each other with touch. 
The hair of elephant calves has a lighter, red-brown color with a softer texture, then grows darker and more coarse. Elephant hair that grows along the back and tail is flattened and can grow to almost a metre in length. Eyelashes that grow up to five inches long help to shade the eyes from dirt and sand swirling in the desert. Elephants also have three eyelids: upper, lower and one that moves vertically. The vertical eyelid is clear, and protects the eyes while allowing them to see. 
Elephant skin is soft and thin in places as well, in particular over top of a network of veins in the ears. An elephant fanning his or her ears against the air acts to radiate heat from blood in the ears before returning to the body. As the temperature of the day increases, so does the tempo of the elephant ears. When there is wind, elephants will conserve energy by standing with their rear to the breeze and spreading out their ears to catch the moving air. 
“She gazed down at me. Her ears splayed open in the shape of Africa. Her eyes, kind and concerned.”
— Daphne Sheldrick, Love, Life and Elephants: An African Love Story (book, 2012), Farrar, Straus and Giroux
Daphne Sheldrick, Tsavo © SWT [sheldrickwildlifetrust.org]
African elephant ears appear to resemble the shape of the African continent. This is different from Asian elephant ears which resemble the shape of India in Southwest Asia where they are found. Of course all elephants use their ears to hear. Elephants make – and listen for – a range of vocalizations, from high-pitched trumpets to infrasonic rumbles that resonate from miles away. Digital cushions on the soles of their feet indeed sense these distant rumbles, and then the skeletal structures of elephant forelegs and scapulae conduct these as vibrations to the inner ear. 
Elephants will also display their big ears to communicate aggression and submission and so on. 
Elephants display a range of emotions, including demonstrating grief at the loss of herd members. Elephants have visited and revisited the bones of past herd members long after she has passed on, even when the sites happen to fall out of the way. An elephant has a spot on the sides of his or her head, behind each eye, which is at times darkened by the secretion of glands near the temporal lobe. These temporal glands are activated when an elephant is subject to highly charged situational stress or enters into hormonal responses, such as “musth”. 
“Periodically adult male elephants enter a state of heightened aggression, brought about by a condition known as musth, the result of a massive hormone surge. Musth is easily recognized by the dark oily secretion that oozes from the temporal glands on the sides of the head. The glands swell to the size of footballs, and press hard against the back of the eyes, causing considerable pain. The elephants will force their tusks into the ground to relieve pressure, and can sometimes be driven into a frenzy from the pain […]. Body temperatures rise, and they flap their ears frequently to keep cool. Ketones flood the brain, altering their states of mind, which results in repetitive behavior. Extra testosterone makes them more aggressive than usual, and limits their ability to function normally. They appear to want to dominate everything in sight […]. In the wild, musth helps the elephant to maintain his dominant position and meet with females who are in season.”
— Steve Bloom, Elephants, ‘Body and Mind’ (book, 2006), Chronicle Books LLC
Charging bull elephant, Savuti, Botswana © Steve Bloom [stevebloomphoto.com]
An elephant brain is about three times the size of a human brain, with three times the neurons, found mostly in the cerebellum. This relatively large part of the brain, one-fifth, allows for elephants to have advanced sensorimotor abilities. That elephantine cerebellum is attributed to complex facial abilities, in particular, the elephant musculatur multitool—the trunk. Elephants are kind of like a big deal.