Dark coats may have helped the earliest mammals hide from hungry dinosaurs. The spots and stripes familiar to us today didn't arise until later in mammalian evolution https://www.sciencenews.org/article/dark-coats-earliest-mammals-dinosaurs

#Mesozoic mammaliaforms illuminate the origins of pelage coloration https://www.science.org/doi/10.1126/science.ads9734

"Zebra stripes? Leopard print? Neither were in vogue among the earliest #mammals during the Age of #Dinosaurs. Early mammals and their close relatives probably sported dark, drab coats from snout to tail."