Marsupials have evolved, along with placental mammals, from Therian mammals. Molecular data suggests that Marsupials separated from Eutherian (placental) mammals approximately 90 million years ago. Australia is the main habitat for marsupials, however there are some in South and North America. As Australia separated from …show more content…
Evidence from the differences in teeth structure has provided evidence for the differentiation of marsupial and placental mammals. Fossil records have a general consensus that with maturation, marsupial’s third premolars and post canine check teeth are the only teeth to be replaced. This feature is observed in fossils dating back 95-100 million years ago. The analysis of morphological evidence has established a stronger relationship between marsupials and placental mammals than monotremes (Zhe-Xi et al.