How much can late Permian ecosystems tell us about modern Earth? A lot.
(PHYSorg.com Archaeology & Fossils)

A whopping two hundred and fifty-two million years ago, Earth was crawling with bizarre animals, including dinosaur cousins resembling Komodo dragons and bulky early mammal-relatives, millions of years before dinosaurs even existed. New research shows us that the Permian equator was both a literal and figurative hotspot: it was, for the most part, a scorching hot desert, on top of having a concentration of unique animals. Here, you could find ancient crocodile-sized amphibians right next to newly evolved dinosaur and croc relatives. Many of these species were wiped out after an extinction which changed life on the planet forever.