Only two kinds of egg-laying mammals are left on the planet today—the duck-billed platypus and the echidna, or spiny anteater. These odd “monotremes” once dominated Australia, until their pouch-bearing cousins, the marsupials, invaded the land down under 71 million to 54 million years ago and swept them away.
The series that began the franchise, Mighty Morphin Power Rangers (an American adaptation of the 1992 Japanese Super Sentai Series, Kyōryū Sentai Zyuranger), began broadcasting as part of the Fox Kids block of programing that aired on the Fox network. It lasted for three seasons (from 1993 to 1996).
Although the actual atmospheric lapse rate varies, under normal atmospheric conditions the average atmospheric lapse rate results in a temperature decrease of 6.4C°/km (3.5F°/1,000 ft) of altitude above ground level. The measurable lapse rate is affected by the moisture content of the air (humidity).