When we think about it, it is obvious it would have been impossible for humans like us to have lived very long among the huge predatory animals which roamed the earth millions of years ago. There is an exception to this of course and that is if we were advanced enough to protect ourselves. Giants were everywhere. I see now where scientists found the remains of a giant fresh water shark which lived about 300 million years ago. This beast was 10 feet long and had double rows of ripping teeth. The shark was called Orthacanthus and was considered to be the top predator of its day. There has been quite a few artifacts found which seem to indicate there were giant humans. Hammers too heavy for people our size to wield, axes far too large and heavy and other things. On the other hand there is a theory which states there were advanced civilizations around on this planet which ultimately went to the stars or were destroyed, perhaps by fighting each other or by an alien race.

One does have to wonder about those monsters however. Why did such huge beasts roam the earth in the first place and how come we have nothing on land that big anymore? We can control the size of some fish just by putting them in a larger tank, but the earth is the same size as it was, more or less. Did you know this is not a simple question to answer? Even the experts in the field are split on several theories when they try and explain the size of these animals and it could even turn out none of the theories are correct.

The first theory states the temperatures were hotter and there was far more carbon dioxide in the atmosphere. It goes on to say this led to a lot more vegetation and a great abundance of food for animals. The easiest way to explain this theory is the animals grew into dinosaurs, because they ate so well. The plant eaters got so large the carnivores had to develop into huge sizes so they could hunt and eat the plant eaters.

The next theory seems to say growing into a giant is not necessarily a benefit for eating. The bigger you are the more you have to eat. Yet these animals got bigger, much bigger. Some paleontologists believe the reason dinosaurs got so big was simply because it gave them some type of advantage over other animals. This does seem a little simplistic.

Moving on there is a theory that states not all dinosaurs were of the same type. Some were either warm blooded or cold blooded. They say there were both types depending on the species.  Supposedly sauropods became so large, because they had to, to maintain their body temperature. The reason for this was a cold blooded animal of huge size would warm up slowly in the sun and cool down slowly at night giving it a pretty even temperature. A smaller cold blooded animal would have problems. Wait, doesn’t science tell us all dinosaurs had a common ancestor? Yes it does, which hurts this theory and would mean again the warm blooded dinosaurs would have become giants to be able to eat the big plant eating dinosaurs.

Everyone loves dinosaurs, but we wouldn’t have loved them if we would have had to live among them. We would probably have been at their mercy. Can you imagine trying to kill a 12 ton animal with a stone spear? Anyway which theory looks correct to you? When I look at these theories it seems to me they all have serious problems. Why did giant sized animals only develop during the Mesozoic Era which lasted about one hundred million years? They did not seem to exist before this time and we know they didn’t exist on land after it.

While dinosaurs do not exist any longer, there is a living creature which is the largest animal to have ever lived on this planet and it is the Blue Whale. They are so big their tongues weigh as much as an elephant. This creature proves something to us about large creatures and this is this giant creature eats some of the smallest things in the ocean. They are called krill and are tiny shrimp like animals. The Blue Whale has to eat about 8,000 pounds of krill a day. Why did these giant creatures of the sea develop when dinosaurs were extinct? It seemed like the time for giant animals was over and yet these whales exist and are mammals like us.

Someone asked an interesting question and it was why aren’t whales getting bigger, why did they stop at the size they are at? It seems you can only get to a certain size, because your internal organs such as you lungs will not keep up with your outside size at some point. At least this is what scientists believe. I believe there is really no explanation which is satisfactory as to why whales have gotten so big. There are other mammals in the ocean which are not giants. One might say evolution has its secrets. Scientists say whales could never have gotten as big as they are if they developed on land and were only able to get this big, because the water supports part of their weight. We know the size of a whale protects them from most predators. In many instances the larger the animal the longer the life span. This is not true in every case however.

I think we have to admit we really don’t know why animals are the size they are. I can even take this a step further and say we really don’t know why we are the size we are. Things might not go the way we think when it comes to size. One would believe the bigger the planet the larger the life on it, but that may not be true. We have seen this with our planet. We have had giant animals and we have had the animals we have now. Things seem to change, but we don’t know if this will be true for other worlds which may have life on them. Size could have more to do with the period of time life is living on a planet and what is the composition of the atmosphere and conditions on a planet. Yes, it does seem nature works in mysterious ways.