The first appearance of nonplacental mammals on Urantia failed. [1] Mammals possess immense survival advantages due to basic instincts manifested in primitive types. [2]
45 million years ago, small egg-laying reptilian mammals flourished as continental backbones were elevated and coastlines sank, leading to rapid mammalian evolution. [3] The placental mammals sprang from an agile little dinosaur, evolving rapidly into various forms including marine and air navigators. [4]