eutherian
Physiology
Biology
(adjective)
the mammals more closely related to animals like humans and rodents than to marsupials
Examples of eutherian in the following topics:
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Living Mammals
- Living mammals can be classified in three subclasses: eutherian, metatherians and monotremes.
- Living mammals can be classified into three major classes: eutherians, monotremes, and metatherians.
- The eutherians, or placental mammals, and the metatherians, or marsupials, together comprise the clade of therian mammals.
- Marsupials differ from eutherians in that there is a less complex placental connection.
- Eutherians are the most widespread of the mammals, occurring throughout the world.
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Evolution of Mammals
- Later, the eutherian and metatherian lineages separated.
- Metatherians are the animals more closely related to the marsupials, while eutherians are those more closely related to the placentals.
- Eutherians are distinguished from noneutherians by various features of the feet, ankles, jaws, and teeth.
- One of the major differences between placental and nonplacental eutherians is that placentals lack epipubic bones, which are present in all other fossil and living mammals (marsupials and monotremes).
- Since Juramaia, the earliest-known eutherian, lived 160 million years ago in the Jurassic, this divergence must have occurred in the same period.
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Blastocyst Formation
- The trophoblast combines with the maternal endometrium to form the placenta in eutherian mammals.
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Characteristics of Mammals
- While male monotremes and eutherians possess mammary glands, male marsupials do not.
- Eutherian mammals also possess a specialized structure that links the two cerebral hemispheres, called the corpus callosum.
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White Matter of the Cerebrum
- The corpus callosum (Latin: "tough body"), also known as the colossal commissure, is a wide, flat bundle of neural fibers beneath the cortex in the eutherian brain at the longitudinal fissure.