eutherian mammal
Học thuậtThân thiện
Definition
- Noun:
- A mammal that gives birth to relatively mature, live young after a long gestation period, during which the embryo is nourished by a placenta: This term refers to all placental mammals, which constitute the vast majority of living mammal species. It excludes monotremes (egg-laying mammals) and marsupials (mammals whose young complete development in an external pouch).
Usage Examples
- Noun:
- Humans, dogs, and whales are all examples of a eutherian mammal.
- The fossil record shows that the eutherian mammal diversified after the extinction of the dinosaurs.
- Unlike a kangaroo, a cat is a eutherian mammal whose offspring are born in a more developed state.
Advanced Usage
- In evolutionary biology, the term eutherian is often used as a noun to refer to the group itself.
- The divergence between eutherians and marsupials occurred millions of years ago.
- The adjective form eutherian describes characteristics of this group.
- The eutherian reproductive strategy involves a complex placenta.
Variants and Related Words
- Eutherian (adj/n): Pertaining to placental mammals; also used as a synonym for "eutherian mammal."
- Eutherian embryos develop differently from marsupial embryos.
- Placental mammal (n): A direct synonym for eutherian mammal.
- Placentalia (n): The scientific infraclass name for this group.
Synonyms
- Placental mammal: The most common direct synonym.
- Placental: A shortened, informal form used in scientific contexts.
Related Terms (Conceptual)
- Metatheria: The infraclass containing marsupials.
- Prototheria: The subclass containing monotremes (egg-laying mammals like the platypus).
- Placenta: The organ that nourishes the developing fetus, defining this group.
Noun
- mammals having a placenta; all mammals except monotremes and marsupials