The Evolution of Massive "Thunder Beasts" and Their Survival Tactics.

Researchers have explored the pathways that led to the evolution of huge multi-tonne bodies in Cenozoic mammals by studying brontotheres, mammals that look like modern-day rhinos but are more closely related to horses. The team suggests that the ecological niches in which the herbivorous brontotheres lived became saturated, explaining the diverse range of sizes within these ancient mammals. The smaller brontotheres that lived in these highly competitive niches evolved to be bigger to combat the higher extinction risk they experienced. The study is published in Science.