What Are Elephant Tusks Made Of? (Also, Know About Its Structure & Composition & More Info About It)
What are Elephant tusks made of?
Elephant tusks are composed of Enamel, Cementum, Dentin, and Pulp tissue. These tusks are made up of Ivory which is actually a variety of dentin composed of many microscopic tubules.
This dentin lies beneath the upper enamel and peripheral cementum layer just in the core portion of the elephant tusk. Both enamel and cementum are outer protective layers.
The inner pulp lies just inward to the dentin layer at the central portion of the tusk. And this is composed of nerves, a few blood vessels, and a soft non-calcified connective tissue.
It has been seen that the growth in elephant’s tusk can be seen in layers, with the inside layer being the last produced.
It is also to be noted that about one-third portion of the tusk is embedded in the bony sockets of the elephant’s skull while emerging on the sides of the base of the trunk.
From the inside, if you see you will find that the end portion of the tusk is hollow with having a hollow cavity that runs half the length of the trunk along with its interior.
This hollow cavity contains nerve sub-branches, nerve endings, and a bit of blood vessels. It is also where the pulp is located.
While the tip portion of the trunk is very hard and solid in composition. It does not contain any hollow cavity with only having a single thin narrow nerve channel running through its centre to the tip of the tusk.
Note that the tusks are highly made up of dentin, and the outer surface is covered with shiny white enamel at the tip of the tusk.
The tusks continuously grow during the lifetime of the elephant from the outside layer to the inside.
Let’s Know: Interesting Things About Elephant Tusks
Elephant Tusks look very elongated front teeth that extend well beyond the mouth while emerging on the sides of the base of the trunk.
In the case of elephants, there are total 26 teeth, that includes 2 incisors teeth, 12 deciduous premolars teeth, and 12 molars teeth. The 2 incisors teeth are also known as the tusks.
The tusks of an elephant are also referred to as the modified second incisors teeth that come out of the upper jaw with about one-third portion of the tusk being embedded in the elephant’s skull itself.
Their tusks are formed when the 6–12 months old baby elephant’s deciduous milk teeth get replaced with a new set of teeth that starts to grow continuously at the rate of about 17 cm in a year.
Their tusks continuously grow throughout their lifetime. Also note that their tusks evolved from teeth that we people have, giving the species an evolutionary advantage.
It is also to be noted that the tusks of African elephants can get so enormous that each of the tusks can reach a length of about 1.5 to 2.5 meters with a weight of around 23 to 45 kg each.
Also, you must know that both male and female African elephants are characterized by having a pair of tusk each.
Female African elephants have tusks that are significantly small, thin, and often with a uniform thickness.
While, female Asian elephants do not have tusks but male Asian elephants do have.
Female Asian elephants do not have true tusks. They have tushes that are even harder than the tusks and are seen to seldom extend beyond their upper lip.
In the wild, you will also find some male Asian elephants that do not have tusks because of their various genetic disorders. These tuskless male Asian elephants are known as ‘Makhnas’.
While a very few elephants are there that are with extra-long tusks. They are better known as ‘Big Tuskers’ and they do look astonishingly beautiful.
Male elephants grow significantly larger tusks than their female counterparts. In fact, Elephant tusks never stop growing during their lifetime so some old bulls display enormous examples.
Also learn that the external appearance of tusks varies with almost all elephants. Their tusks act as a sign of their identity, dominance, health, and are a result of having the best dominant genes in their community.
Tusk size and shape are inherited. This also indicates the genetic well-being, hierarchy, and dominancy in a lot of elephants from generation after generation.
Let’s Know: Structure & Compostition of Elephant Tusks
Elephant tusks are made up of four layers: Enamel, Cementum, Dentin, and the inner Pulp.
Let’s known and understand the structure and composition of each of these four layers along with some important points to note, just in order to, know about the structure of the tusk overall.
1. Enamel – Outer layer that is thickest at the tip and gets thinnest around half the length of the tusk
The enamel layer is the protective covering of the tusk and consists of hard calcified tissues covering the dentin layer.
This enamel layer runs from the tip to at least half the length of the tusk. In the tip it’s concentration is the highest.
Enamel is the hardest tissue in the body of the elephants that contains no living cells and highly consists predominantly of 95% to 98% apatite crystals containing calcium and phosphate.
2. Cementum – Thin Outer Layer
Then comes the cementum layer. This a thin layer that comes just inner to the enamal.
And in that portion of the tusk where enamel isn’t present the cementum becomes the top layer.
Cementum is nothing but a fibrous bone-like mineralized tissue that lines the dentin of the tusk’s root.
It functions to protect the tusk root and also to anchor the tusk to the bony socket of the upper jaw of the skull along with the help of many fibrous joints.
Cementum is slightly softer than dentin. By weight, it consists of about 45% to 50% Hydroxylapatite [Ca10(PO4)6(OH)2] inorganic mineral and about 50% to 55% organic matter composed primarily of collagen and proteoglycans along with water.
3. Dentin – Thick Mid-Layer
Then comes the ivory layer which is actually a variety of dentin in the tusks. This dentin is the second hardest tissue in the elephant’s body next after the enamel.
It is a very thick layer that is present all throughout the length of the tusk wrapping around the pulp cavity.
Dentin is composed of mineralized connective tissues and tubules with an organic matrix of collagenous proteins.
In the dentin layer of the tusk, there is approximately 45% of dentin that consists of the mineral Hydroxyapatite, 33% is the organic materials, and 22% is water.
Dentin is a bit softer than Enamel because the crystals of the mineral Hydroxyapatite in the dentin are about 30 times smaller thus making dentin somewhat softer than the enamel.
4. Pulp – Cone-Shaped Inner Layer
Pulp is the inner layer of the tusk and is only present in one-third the length of the tusk just at the base portion of the tusk.
Actually, the main portion of the cone-shaped pulp is situated at the base of the tusk while the peripheral tip portion of the cone-shaped pulp lies a few centimeters far from the base towards the one-third length of the tusk.
In the pulp, there are various nerve endings equipped with many blood vessels and a lot of fibrous tissues as well along with numerous densely packed randomly orientated collagen fibres.
It is also to be noted that Elastin fibres are not present within the pulp tissue. The base part of the cone-shaped pulp is highly concentrated by large vessels (arteries and veins) running parallel to the longitudinal axis of the tusk.
✱ Some Important Points To Note
Enamel is incapable of self-repairing, whereas dentin and cememtum can regenerate with limited capacity.
Dentin is light-yellow in color. While Enamel is pure white in color, and Cementum is light-yellow in color being slightly lighter than dentin.
The enamel and the dentin meet at an area known as the DEJ or Dento-Enamel Junction.
Enamel is the hardest, Detin is the harder material, and Cementum is just hard in the tusks. The pulp is relatively softer and fibrous in nature.
The presence of microtubules in the dentin part of the tusk allows the various nerve branches and sub-branches to pass through it. This gives the sensation of pain and sensitivity in exposure to thermal, chemical, or osmotic stimuli.
Ameloblasts cells are responsible for the formation of enamel by secreting the enamel proteins: enamelin and amelogenin. Ameloblast cells are lost after the enamel process is complete.
Odontoblastic cells are the tall columnar cells that are located just between the soft dental pulp and hard dentin. They are highly responsible for the production of dentin.
Cementoblasts cells secrete cementum within the root of the tusks. These cells are of the mesenchymal origin that functions in the deposition of an irregular collagenous matrix with an interfibrillar matrix termed cementoid that makes the cementum.
Fibroblasts are the prominent cells, along with other cells like odontoblasts, defence cells like histiocytes, macrophage, granulocytes, mast cells, and plasma cells that are present in the pulp portion altogether.
Are elephant tusks made up of the same material as fingernails?
Not at all! Elephants tusks are not made up of the same material as fingernails. In fact, it is the horns of rhinos, cows, buffaloes, deer, etc. that are all made up of the same material as fingernails.
Actually, it is to be noted that the tusks are made up of ivory (dentin) which is a characteristic feature of teeth.
While the fingernails are made up of keratin and other proteins in very small amounts.
Keratin is actually a type of fibrous structural protein called scleroproteins that can be found in higher vertebrates like humans, rhinos, deers, etc.
α-Keratin is a type of keratin that can be found in hairs, scales, nails, feathers, horns, claws, and also in the outer layer of skin.
To clearly understand this just look and compare your teeth and nails. You will see that the teeth are harder and white. While the nails are soft, light-white in color, and flexible as compared to the teeth.
Ivory (a variety of dentin) that makes the tusks is totally different from keratin protein that makes up the fingernails and horns.
These two biological materials are structurally and compositionally totally different from each other.
Ivory contains a lot of minerals and other things like mostly calcium phosphates and magnesium along with water.
On the other hand, fingernails are actually made of a protein called keratin which forms the cytoskeletal structures within the body cells and epidermal derivatives of hairs, fingernails, and horns.
Also, there’s another notable difference between the two materials. As, if the fingernails break off in animals then a new one regenerates as soon as possible.
While Elephants’ tusks don’t have the ability to regenerate and if, once it gets broken then its a loss for the lifetime.
The structure and composition of tusks contain enamel, cementum, dentin, and pulp. In no way, it contains the keratin protein.
So, we can conclude that the elephants’ tusks are not made up of the same material as fingernails.
Do elephants feel pain when their tusks are cut off?
Yes, if the tusks of an alive elephant are cut off or get broken or decayed then it will give severe sensitivity and pain to the elephant.
The tusks contain blood vessels (both arteries and veins), and nerves that pass from the pulp to the tip of the tusk.
So, alive elephants do feel pain when their tusks are cut off due to the presence of nerve endings.
Also, that one-third portion of each elephant’s tusk remains embedded in the bony sockets within the skull of the animal just in the upper jaw part.
This embedded part contains the base of the inner cone-shaped pulp portion which has the highest concentration of nerves, tissues, and also blood vessels.
So, cutting off the tusk can lead to the breakage of the various fibrous tissues from the skull of the elephant which may altogether lead to a high loss of blood and very painful sensitivity making the animal very ill.
Such extreme pain can even cause trauma or death for the animal.
And, if the elephant shed the tusk of its own, naturally due to tooth decay or accidental breakage then there won’t be any severe pain in cutting off the tusk.
However, during the time of shedding off the tusk due to some natural tooth decay or accidental breakage can be extremely painful for the animal.
However, if it is a dead elephant then there are no chances of feeling pain at all while cutting the tusk off, and we all know that, right? It’s simple logic and biology!