Definition: A paleotherian is a type of paleontologist who studies the fossil record to understand the evolution and diversity of life forms. They study the different stages of life, from the earliest known organisms to modern species. Paleotherians are interested in understanding how these ancient organisms evolved into their current form, as well as the changes that have occurred over time due to environmental conditions such as climate change. This research helps us understand how the Earth has changed and what it will look like in the future.