Table of Contents
- 1 What are monotremes most closely related to?
- 2 What are monotremes related to?
- 3 What mammals are more closely related?
- 4 How are monotremes different from other mammals?
- 5 What other animals are monotremes?
- 6 How do monotremes differ from other mammals?
- 7 Are reptiles or amphibians more closely related to mammals?
- 8 What are our closest animal relatives?
- 9 What are the characteristics of monotremes?
- 10 What is the fossil record for monotremes?
- 11 How did monotremes acquire the molar tooth?
Certain features of the skull appear to link monotremes to the extinct early mammal groups. Other evidence, particularly genetic data, places Monotremata close to more-advanced mammals, namely marsupials.
Monotremes are a subgroup of the Australosphenida, a clade which contains other related extinct mammals from the Jurassic and Cretaceous of Madagascar, South America and Australia.
Are monotremes more closely related to reptiles or mammals?
Monotremes are a derivative of an ancient mammal stock but there is no direct evidence of what it might have been. Monotremes are not closely related to marsupials or placental mammals, but rather they evolved from a distinct group of reptilian ancestors.
Mammals are more closely related to birds than they are to amphibians. Both mammals and birds evolved from reptiles, a group of vertebrates that…
How are monotremes different from other mammals?
Monotremes are different from other mammals because they lay eggs and have no teats. Monotremes are different from other mammals because they lay eggs and have no teats. The milk is provided for their young by being secreted by many pores on the female’s belly.
Why are monotremes classified as mammals?
Why then are they considered mammals you may be wondering? Like other mammals, monotremes are warm-blooded. They have hair on their bodies and produce milk to feed their young. Although they have mammary glands, monotremes do not have nipples like other mammals.
What other animals are monotremes?
The monotremes are a group of highly specialised egg-laying predatory mammals, containing the platypus and echidnas. There are only five living species of monotreme, contained within two families: Family Ornithorhynchidae: the platypus, a single species in a single genus, Ornithorhynchus anatinus.
How do monotremes differ from other mammals?
How are monotremes similar to reptiles?
The word “monotreme” literally means “one opening,” which is a characteristic feature: similar to birds and reptiles, they have the same opening for fecal matter, urine, and reproduction, called a cloaca. Also like birds and reptiles, monotremes lay eggs, although their eggs are uniquely rubbery and rather small.
We now think of this way of organizing reptiles and amphibians as inaccurate because more rigorous analyses of anatomy and genetics revealed that reptiles are more closely related to mammals than to amphibians.
What are our closest animal relatives?
DNA: Comparing Humans and Chimps. Part of Hall of Human Origins. The chimpanzee and bonobo are humans’ closest living relatives. These three species look alike in many ways, both in body and behavior.
Why are some mammals classified as monotremes?
What are the characteristics of monotremes?
Monotremes lay eggs and like other mammals lactate (produce milk) but instead of having nipples like other mammals, monotremes secrete milk through mammary gland openings in the skin. Adult monotremes do not have any teeth. Monotremes are long-lived mammals. They exhibit a low rate of reproduction.
What is the fossil record for monotremes?
The fossil record for monotremes is rather sparse but it is thought that monotremes diverged from other mammals early on, before marsupials and placental mammals evolved. A few monotreme fossils from the Miocene are known. Fossil monotremes from the Mesozoic include Teinolophos, Kollikodon, and Steropodon.
What is the only mammal that lays eggs?
Updated June 05, 2019. Monotremes (monotremata) are a unique group of mammals that lay eggs, unlike placental mammals and marsupials, who give birth to live young. Monotremes include several species of echidnas and the platypus.
How did monotremes acquire the molar tooth?
Some recent work suggests that monotremes acquired this form of molar independently of placental mammals and marsupials, although this hypothesis remains disputed. Tooth loss in modern monotremes might be related to their development of electrolocation.