These “horses” were small with paws rather than hooves. Eohippus, one of the earliest horses, was about the size of a collie dog, for example, and had five toes. Occasionally a foal today is born with more than one hoof at the end of each leg. Julius Ceasar, before he became a Senator, owned such a horse; it was named Toes.
The small stature of these creatures may, in fact, be due to the scarcity of food rather than due to global temperature.
A very good description of what happened planet-wide after the Cretaceous-Tertiary extinction event (Chicxulub) can be found in John & Mary Gribbons book, Fire On Earth. When a bolide that large smacked into the earth, it sent powerful ground shock waves around that earth that met and possibly cracked open the crust, leading to a horrific volcanic event (Deccan Traps - India). It may well have taken millions of years for the earth’s geologic structure and climates to stabilize.
High temperatures themselves wouldn’t normally cause smaller sizes among animals, scarcity of food, however, would have done so. Many animals in equatorial Africa are large as long as they have ample food sources. In a hot place such as the Sahara, little food equals smaller animals or no animals.
I meant the sickness of having to link CO2 and warming to every article.
having to explain “correlation is not causation” to people who obviously know better - is just sick.