United States or New Zealand ? Vote for the TOP Country of the Week !
All these remarkable reptilian characters must have been possessed by the stem-form of the whole mammal class, the Promammal of the Triassic period, and have been inherited from the Proreptiles. During the Triassic and Jurassic periods the sub-class of the Monotremes was represented by a number of different stem-mammals.
Word Of The Day