These were, at their maxima, among the most extensive glaciations in the Earth's history.
In the mesothermal class some regimes resemble those of tropical and equatorial areas, with single or double summer maxima corresponding to heavy seasonal rainfall, while others include sustained flow with slight warm-season minima.
Temperatures are high; the warmest months generally average about 27 °C 811 °F), with mean daily maxima from 30 °C to 38 °C (86 °F to 100 °F) and warm, oppressive nights.
When these two fields are operating synchronously in time, they are said to be in time phase; i.e., both reach their maxima and minima together and both go through zero together.
In the region of central Europe, the Saale is represented by three glacial maxima separated by two periods, or interstades, of moderating climatic conditions.
Temperature maxima are even higher inland, but along the coast of the Indian Ocean temperatures are considerably lower because of a cold offshore current.
Winters are mild and sunny, with July maxima from 68 °F (20 °C) in the south to 79 °F (26 °C) in the north.
Extinctions at the Middle Permian Late Permian boundary were even more severe bordering on catastrophic with a reduction of 70 percent to 80 percent from the Middle Permian generic maxima.
The sensitivity of thermoreceptors extends across a continuum of thresholds and response maxima.
Extinctions at the boundary between the Guadalupian and Lopingian epochs (259.8 million to 252.2 million years ago) were even more severe bordering on catastrophic with a reduction of 70 to 80 percent from the Guadalupian generic maxima.
Disruptive ecological changes eventually reduced marine invertebrates to crisis levels (about 5 percent of their Guadalupian maxima)—their lowest diversity since the end of the Ordovician Period.
