Search results
Results from the WOW.Com Content Network
The origins and early evolution of primates is shrouded in mystery due to lack of fossil evidence. They are believed to have split from plesiadapiforms in Eurasia around the early Eocene or earlier. The first true primates so far found in the fossil record are fragmentary and already demonstrate the major split between strepsirrhines and ...
The traditional hypothesis of cetacean evolution, first proposed by Van Valen in 1966, [9] was that whales were related to the mesonychians, an extinct order of carnivorous ungulates (hoofed animals) that resembled wolves with hooves and were a sister group of the artiodactyls (even-toed ungulates). This hypothesis was proposed due to ...
Whales evolved from land-living mammals, and must regularly surface to breathe air, although they can remain underwater for long periods of time. Some species, such as the sperm whale, can stay underwater for up to 90 minutes. [2] They have blowholes (modified nostrils) located on top of their heads, through which air is taken in and expelled.
The first fully terrestrial vertebrates were reptilian amniotes — their eggs had internal membranes that allowed the developing embryo to breathe but kept water in. This allowed amniotes to lay eggs on dry land, while amphibians generally need to lay their eggs in water (a few amphibians, such as the common Suriname toad, have evolved other ways of getting around this limitation).
The larynx evolved when the first land vertebrates started breathing air and needed to separate food from air to prevent choking. Whales evolved from land mammals roughly 50 million years ago.
The whale was first mentioned in ancient Greece by Homer. There, it is called Ketos, a term that initially included all large marine animals. From this was derived the Roman word for whale, Cetus. Other names were phálaina (Aristotle, Latin form of ballaena) for the female and, with an ironic characteristic style, musculus (Mouse) for the male.
A baby monkey struggles and squirms as it tries to escape the man holding it by the neck over a concrete cistern, repeatedly dousing it with water. In another video clip, a person plays with the ...
Sir Wilfrid Le Gros Clark was one of the primatologists who developed the idea of trends in primate evolution and the methodology of arranging the living members of an order into an "ascending series" leading to humans. [7] Commonly used names for groups of primates such as prosimians, monkeys, lesser apes, and great apes reflect this methodology.