During Mesozoic era, the age of reptiles (dinosaurs), mammals were small, generalised and rare. By the end of Mesozoic or beginning of Coenozoic, the dinosaurs vanished and mammals suddenly expanded into varied evolutionary patterns. Early in Cretaceous period, placental mammals became distinct from marsupials. During Eocene and Oligocene, most of the orders of mammals originated moving into habitats and ecological [...]
The following points highlight the three main types of teeth found in mammals. The types are: 1. Incisors 2. Canines 3. Cheek Teeth (Premolars and Molars). Type # 1. Incisors: These are the front teeth borne by the premaxillae in upper jaw and tips of dentaris in lower jaw They are single-rooted, monocuspid and long, curved and sharp-edged. They are [...]
Many mammals, specially living in forest areas, have become modified to live on trees. Their mode of living is named as arboreal. Arboreal mammals are able to climb the trees and use their branches as the highways. There are three possible modes of aerial locomotion or flight-gliding, soaring and flapping. Gliding is the rudimentary flight displayed by certain fishes (Exocoetus), [...]