Search results
Results From The WOW.Com Content Network
Eutheria (from Greek εὐ-, eú-'good, right' and θηρίον, thēríon 'beast'; lit. ' true beasts '), also called Pan-Placentalia, is the clade consisting of placentals and all therian mammals that are more closely related to placentals than to marsupials.
2.3.3 Order Dasyuromorphia (marsupial carnivores) 2.3.4 Order Peramelemorphia (bandicoots and bilbies) 2.3.5 Order Diprotodontia (diprotodont marsupials)
Previously, it was thought that these mammals died out in the face of competition from "more competitive" placental carnivorans during the Pliocene Great American Interchange, but more recent research has showed that sparassodonts died out long before eutherian carnivores arrived in South America (aside from procyonids, which sparassodonts ...
The class Mammalia is divided into two subclasses based on reproductive techniques: monotremes, which lay eggs, and therians, mammals which give live birth, which has two infraclasses: marsupials/metatherians and placentals/eutherians.
Paranyctoides is an extinct genus of early eutherian mammal from the Late Cretaceous of North America and possibly Asia. It was named in 1979 by Fox for tooth and jaw material from the Dinosaur Park Formation of Alberta, which he named Paranyctoides sternbergi.
Later on, the eutherian and metatherian lineages separated; the metatherians are the animals more closely related to the marsupials, while the eutherians are those more closely related to the placentals. Since Juramaia, the earliest known eutherian, lived 160 million years ago in the Jurassic, this divergence must have occurred in the same period.
Expansion in Laurasia was dominated by Boreoeutheria, which includes primates and rodents, insectivores, carnivores, perissodactyls and artiodactyls. These groups expanded beyond a single continent when land bridges formed linking Africa to Eurasia and South America to North America.
This was South America's first eutherian carnivore. South American procyonids then diversified into forms now extinct (e.g. the "dog-coati" Cyonasua, which evolved into the bear-like Chapalmalania). However, all extant procyonid genera appear to have originated in North America. [70]