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Do Mammals Lay Eggs? Rare Egg Laying Mammal Species You Didn't Know

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Eggs are synonymous with birds, however, some mammals can lay eggs.

Mammals who lay eggs rather than giving birth to live young are called monotremes. Monotreme means a multi-purpose aperture in their back end that is used for both waste and reproduction.

Monotremes are a select group of creatures. There is only one species of platypus left on the planet today. Monotremes are found only in New Guinea and Australia. Monotremes aren't like the majority of the mammalian world, even if they're warm-blooded and have hair. Many animal groups, including amphibians, fish, and some mammals, include species that produce eggs and others that give birth to live young.

Egg-laying allows for better mobility for the mother, who isn't 'encumbered with huge eggs or embryos for a protracted period,' according to Gibbons, as well as a larger possibility of genetic variation if numerous mating partners and clutches are used. In addition, the mother may better protect her growing embryo until it becomes ready to be born if she bears live young.

Read all about it right here, and make sure you check out other articles like do locusts bite and do male cats spray after being neutered.

What are mammals?

Any member of the vertebrate animal group whose young are fed milk from the mother's particular mammary glands is referred to as a mammal.

Warm-blooded creatures, including humans, have internal temperature regulation systems. Monotremes, marsupials, and placental mammals are the three groups of the class Mammalia. Only animals that lay eggs are monotremes. There are just two animals on the globe that lay eggs.

According to fossil evidence, their final common ancestor was poisonous. Other mammals that are venomous include the slow loris and various rodent species. Monotremes have a unique shoulder girdle in comparison to other mammals. Young echidnas, like marsupials, spend some time in a protective pouch.

Do mammals lay eggs?

Only two types of mammals, the duck-billed platypus as well as the echidna, lay eggs. However, living young have been observed in both marsupial and placental mammals since the divergence of the two families of mammals roughly 160 million years ago.

Monotremes are primitive mammals because, like birds and reptiles, they give birth to eggs rather than live birth. Birds, tortoises, and crocodilians are the only animals that do not have any live young. Fish live birth is also uncommon in fish, accounting for only 2% of all known species, such as guppies and sharks. In addition, nipples are not present in egg-laying mammals. Instead, milk is excreted through mammary glands on the epidermis. This monotreme milk contains very high quantities of antimicrobial protein not present in other animals. 

Mammals laying eggs is a very rare phenomenon, but not completely unheard of!

List Of Mammals That Lay Eggs

The duck-billed platypus, short-beaked echidna, eastern long-beaked echidna, western long-beaked echidna, and Sir David's long-beaked echidna are the only five species of mammals who lay eggs.

In addition, spurs can be found on the hind limbs of the echidna and platypus species. The duck-billed platypus is a unique creature that may be found in Tasmania and parts of eastern Australia. Surprisingly, the spurs on their legs can produce venom. It may injure smaller animals, but it will not affect humans. The female platypus lays her eggs in a burrow dug in the earth. When a baby platypus, called a puggle, is born, it is bald and about the size of the human hand.

For a few months, it will nurse alongside its mother in a protective pouch. By emitting a potent toxin, the male platypus fulfills the task of safeguarding the mother and the infant platypus. Platypus venom is not 'reptilian,' but rather an acquired feature similar to reptile venom.

Echidnas come in four species. A spiny coat, clawed feet, rudimentary tail, toothless jaws, small legs, sticky tongue, and a long snout distinguish these animals. In her pouch, the female echidna deposits a leathery-shelled egg, which emerges after 11 days. The hatchling is about the size of a coin and feeds on the mother's milk for several weeks in the pouch.

The short-beaked  Echidna is also known as the 'spiny anteater.' They utilize their sticky tongue to capture termite insects and smash them within their jaws because they don't have teeth. Then, the hatchling will nurse for several weeks in a tiny pouch concealed in its mother's feathers.

Why do Monotremes lay eggs?

Scientists now believe that the unusual, egg-laying mammals that still survive today, did so because their forebears took to the ocean.

Monotremes in all of their extant species are active parents. The eggs are kept in the mother's womb for a lengthy time, absorbing nutrition. Monotremes get a single lower jaw bone, a fast metabolism, three middle ear bones, fur, and produce milk to feed their young. Aside from laying eggs, they have other characteristics that make them seem like reptiles than humans.

Before their pouch-bearing relatives, the marsupials conquered the continent down under 71-54 million years ago, and the strange monotremes controlled Australia over millions of years. Zaglossus hacketti and Obdurodon tharalkooschild are two extinct monotremes. Although they are categorized as mammals, they have non-mammalian traits. For example, they have a somewhat lower body temperature than normal mammals; a trait shared with reptiles.

Long ago, monotremes were allegedly more common. According to fossil records, egg-laying mammals split between marsupials and placental animals (all other mammals, including cats, dogs, and humans) as long ago as the Triassic period. Unfortunately, mammalian fossils aren't particularly well preserved that far ago. Obsolete egg-laying animals were more varied and diverse than the few species that exist now. Primitive egg-laying mammals were found in South America, in addition to New Guinea and Australia. Live birth has developed over 100 times among species like boa snakes and blue-tongued skinks, even though most reptiles lay eggs. 

How do egg-laying mammals nurse their young? Females use milk to feed their young. These are a subset of the Australosphenida, which includes other similar extinct animals from South America, Madagascar, and Australia from the Jurassic to Cretaceous periods.

Here at Kidadl, we have carefully created lots of interesting family-friendly facts for everyone to enjoy! If you liked our suggestions for do mammals lay eggs then why not take a look at do lizards have teeth, or llama facts.

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