The silurian period occurred                a.  during the hadean eon.      b.  before the neogene period.      c.  during the mesozoic era.      d.  after the permian era.

We know that the Silurian period gave way to the Devonian period, which is when the Neogene era started, therefore:

The answer is B. before the Neogene era.

Hope it helped,

BioTeacher101

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.