Mammals That Lay Eggs

Mammals are warm-blooded animals that give birth to live young. Cats, dogs, elephants, giraffes, whales, dolphins, porpoises and obviously Homo sapiens are all mammals. Mother nature loves to experiment and has created a creature that has captured the imagination of humans. This creature is a mammal that lays eggs. Shocking and surprising thing to note is that there are mammals that lay eggs. Once upon a time, this fact was a scandalous issue, and people believed it to be the biggest hoax of all time. However, when one of the species of mammals that lays eggs was brought to Europe in 1799 from Australia, many scientists were called in to give their expert advice. Dr. George Shaw, with careful examination, recognized this strange species with a duck-bill, beaver tail, otter footed mammal as a new member of the animal species kingdom. People thought of this strange creature to be a result of clever stitching, but it was in fact a platypus.

What Mammals Lay Eggs

The mammals that lay eggs are called monotremes. The word monotremes is derived from the Greek word monos meaning single and trema that means hole. Hole in this context refers to cloaca. These mammals do not give birth to live young like the marsupials and placental mammals. These monotremes are warm-blooded animals with a high metabolic rate. Similar to their counterparts, they too have hair on their body, females produce milk for their young ones, have three middle ear bones and a single bone in their lower jaw.

What Kind of Mammals Lay Eggs

As mentioned above in what mammals lay eggs, monotremes have a combination of mammal characteristics and therapsid ancestral characteristics. The traits that are an answer to the question what kind of mammals lay eggs are:

• Cloaca: A single opening for passing urine, feces and eggs where they are deposited before expelled out of the body.
• Leather Bill: A leather bill is present to help detect prey.
• Nipple: They do not have a true nipple for milk secretion. Instead, milk is secreted through skin of the abdomen.
• Spur: Males have a spur on their hind limbs. Platypus uses this spur to secrete venom.
• Ear: These mammals have a primitive inner bone that has fewer coils.
• Teeth: These monotremes have no teeth instead have horny pads.
• Gait: These animals have a reptilian gait with limbs that are aligned laterally to the body.

Mammals Reproduce By Laying Eggs

There are three living species of monotremes recognized scientifically. These three species includes the duck-billed platypus, the long-beaked echidna and short-beaked echidna. The following paragraphs will cover some information related to each species of mammals that lay eggs.

Duck Billed Platypus

Scientific Classification

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Mammalia
Order:	Monotremata
Family:	Orthorhynchidae
Genus:	Ornithorhynchus
Species:	Ornithorhynchus anatinus

Information on Platypus

The Ornithorhynchus anatinus or platypus has a streamlined body that looks like an otter. The tail looks like a beaver's tail, with a duck like bill to detect prey. It also have webbed feet. An adult platypus is about 47.5 to 60 cm in length. The platypus habitat includes the freshwater regions of eastern Australia.

Long Billed Echidna

Scientific Classification

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Mammalia
Order:	Monotremata
Family:	Tachyglossidae
Genus:	Zaglossus
Species:	Zaglossus bruijni

Information on Long Beaked Echidna

The long-beaked echidna is the smaller species of the two echidnas. These mammals have their bodies covered in spines that are yellow in color with black tips. Below these spines, they have fur. They have snout that is about the half the length of their head. The males have a spur on their hind legs that lacks venom. The adult long-billed echidna has a length of 53 cm and a tail, that is, 6 cm in length. The long-beaked echnida is found in Papua New Guinea.

Short Beaked Echidna

Scientific Classification

Kingdom:	Animalia
Phylum:	Chordata
Subphylum:	Vertebrata
Class:	Mammalia
Order:	Monotremata
Family:	Tachyglossidae
Genus:	Tachyglossus
Species:	Tachyglossus aculeatus

Information on Short Beaked Echidna
The short beaked echnida is covered in fur and spines. It has a distinctive snout and specialized tongue that is used to catch prey at great speed. The short-beaked echidna is found throughout Australia and in the southwestern regions of New Guinea. It is commonly called Spiny Anteater in old texts and this term is now rarely used. The adult short-beaked echidna is about 45 to 77.5 cm in length.

So of you had a question, do mammals lay eggs, then the answer is yes. Monotremes are mammals that lay eggs that have smaller brains than the placental mammals and marsupials. I hope this article has helped you discover the marvels of nature and a distinct class in the kingdom Animalia.