Which period large mammal first appeared

The period between the extinction of the dinosaurs and the present day is called the Age of Mammals or Cenozoic. Mammals appeared on the earth long before the extinction of the dinosaurs; in fact, dinosaurs and mammals originated within 10 million years of each other, in the late Triassic about 200 million years ago.

Late Triassic Period

Earliest-known Mammals: Some of the earliest-known mammals include Eozostrodon, Deltatheridium, Jeholodens, Megazostrodon, Triconodon, and Zalambdalestes. Eozostrodon was one of the first true mammals; it lived during the late Triassic period and early Jurassic period, about 210 million years ago.

answer; ///i believe that the correct answer is (the worksheet);

as the gila monster consumes the eggs or young of the desert cottontail and gambel's quail, thus its main food supply is only accessible for a restricted time duration every year. however, for this, the gila monsters exhibit three adaptations, which elevate their survival rate in the desert condition.  

first, is that they possess huge bodies, and can consume greater concentrations of food during a small period. secondly, they require to feed infrequently as they can accumulate fat in their tails. ultimately, their rate of metabolism is very low, so that they can burn their reservoirs of fat gradually.