They did not. Mammals evolved independently of birds.
Australia had no placental mammals, so marsupials diversified. New Zealand had neither placental mammals or marsupials (with the exception of bats), so birds diversified and took on many of the ecological roles usually played by mammals.
in the womb, jaguars are placental mammals.
No. Periods are seen only in placental mammals. Birds do not have them.
Placental mammals and marsupials develop in a placenta within the uterus before being delivered. Monotremes develop in an egg.
In the uterus -- like all placental mammals.
fluuckck you science
Terrestrial placental mammals do have fur or hair. Marine placental mammals do not.
True
No. Primates are a group of placental mammals, but there are many placental mammals that are not primates.
placental mammals are the most famous mammals
Most mammals are placental...marsupial mammals and monotremes are not placental.
Yes. Shrews are placental mammals.