Rats are known to be of varying sizes. It has been established from the fossil records of the giant rats. It has been determined from the study of these fossils which have been excavated from various locations and places around the world that the size of a rat can even rah up to that of a small sized dog. This is really a disturbing size especially for a rat. This fossil study has made many scientists suspicious and even worrying about the evolution in their sizes. Another alarming statement has also been claimed by the scientists and according to this claim, if the rats are grown under the right circumstances, then they can even grow up to the size of a cow. However no such evidence has been found so far in reality. The study of ancient animals has shown that it was about millions of years ago when there was giant rodents found prowling all over the Earth. Some fossil studies have also shown the size of a fossil rat to be ten times bigger than the present day rats. These giant rats were supposed to be herbivores and the reason for their failure to survive has not been found yet.
Size and weight dimensions
As far as the size and weight dimensions of this mega fauna are concerned, it has been found that the biggest of these fossils was estimated to be of 5 kilograms or 11 pounds which is approximately equal to that of a small dog. Even some exceptions are also found. For example the largest fossil of a rodent was having the weight of about more than a ton and its size was equal to that of a bull. This rodent is now extinct and it was named as Josephoartegasia monesi. In the modern days the equivalent of this animal is capybara which has got the size approximately equal to that of a sheep.
Reason for such huge sizes
Presently, a normal rat has got the weight of about a pound but the weight of giant rats could reach up to about 175 pounds. This success rate in growth shoes that the rodents can be the most successfully evolved species on earth if they are given a proper chance. This is possible when the rats are given enough ecospace and there is no large animal to hinder their growth or survival. Another alarming thing is that the rats are nowadays growing immune to many pesticides and poisons as well.
How big do rats get?