mrs.oroblanco said:
Lamar,
Where did you get the idea that dinosaurs could not breath in an oxygen rich environment?
If you are talking about the old theory that was touted for a long time, that fact has been pretty much denounced by the studies done with alligators and birds. The newest theory being that they had one-way air flow capacity, so that they could utilize air very highly concentrated, and that birds, being a descendent of dinosaur birds, actually needed the extra-rich oxygen, for flights that demanded high oxygen (like when they migrate), and alligators have the same capacity. Or am I not understanding what you saying?
http://www.newscientist.com/article...ird-breath-may-explain-dinosaurs-triumph.html
http://news.nationalgeographic.com/news/2010/01/100114-alligators-dinosaurs-birds-lungs-breathing/
http://www.sciencentral.com/video/2009/03/25/dinosaur-bird-bones/
B
Dear mrs.oroblanco;
TO explain in a bit more depth, recent research has proven that the Earth's atomosphere was much thinner in the beginning than it is now. This had been theorized for quite some time, because it seemed to be a long shot that oxygen was introduced to our planet from beyond our own atomosphere.
The first bacteria and plankton started giving off oxygen. This much is known because they can be reproduced in labratories at will. In fact, most liology students culture these examples because they are so easy to produce and there is so little which can go wrong with their experiments.
We now understand that during the proto-earths's formation there was less than 10% oxygen in the atomosphere and very likely much less than that rather high number. As bacterias grew into multi-cellular proto-plant life, they started consuming the huge amounts of carbon dioxide and carbon monoxide in the atomosphere and excreted oxygen as a result.
As dinosaurs evolved, the earth was a seething mass of plant life, because of the rising oxygen content, and as a result of the rising oxygen content, water was also being produced from the remaining hydrogen in the atomosphere. By this time, mutli-cellular life forms were literally THRIVING on their environments and multi-celled animals were soon evolving to counteract the sharp rise in plant life.
A large number of dinosaurs were very small, however there were also very large herds of herbivores and it was these dinosaurs which consumed huge quantities of plant life, all the while excreting huge amounts of poorly eaten and poorly digested plant life. By this point, the oxygen content was on the rise, but it was still not to the point where modern types of mammals could hope to survive, therefore they did not evolve until much later in the timeline.
Evolution is an extremely odd characteristic of Earth-born life forms and it is also VERY exacting. In short, the evolutionary process will not produce a life form which is not adapted to the environment in which it lives. For instance, we know that the largest mammals are the ones which lived in areas with the largest food sources. During the age of the wooly mammoth, we know that even though it was mostly a cold weather mammal, there must have also been great amounts of plant life in order to sustain large herds of these creatures, and in fact, most of Russia had just tthe right amount of flora for them to eat.
Dinosaurs therefore ate the plant matter which was producing oxygen and the dinosaurs were also expelling huge amounts of carbon dioxide at the same time. This is natures' check and balances in motion. We also know that during the age of the dinosaurs, the oxygen content was stil very low.
By this, we can also ascertain that even if dinosaurs were capable of high speeds over long distances, this was probably not possible because of the reduced oxygen content of the era. It has been surmised that DNA scientists can reverse-engineer all animals thus far known, including extinct species such as dinosaurs, yet one of the primary concerns would be the animals' ability to survive in a modern Earth environment without genetic alterations.
The odds of actually hatching a triceratops and having it live are close to nil, simply because of a large number of factors involved, with one of those being the animals' ability to adapt to an now oxygen rich environment. Most scientists feel that it is simply not possible to do so, because of the vast environmental differences.
Your friend;
LAMAR