Let's hear some theories.
I propose the following theories on the extinction of the dinosaurs:
1. A metabolic disorder relate to thinning of egg shells during incubation due to variations in certain hormones. The embryos would die, as the shells would be unable to protect them from predation and dehydration. Therefore within a very short space of time all the dinosaurs could have died out if no infants survived. Also related to shell defects, is the idea that multi-layer egg shells formed, with two or three shells on individual eggs, which would suffocate any embryo. This idea is based on studies of French and Spanish dinosaur eggs found in the Pyrenees.
2. Mental disorders, including a decrease in brain size resulting in stupidity. There is evidence that many of the large dinosaurs, must have had very small brains in comparison to their total body size, possibly as small as a kitten's brain. With such small brain capacity responses to the surrounding environment would have been so slow that they could not compete with faster thinking animals.
3. With the increase and diversification of plants that lose their leaves seasonally, such as deciduous trees, there would have been less food available throughout the year for the herbivore dinosaurs. If the herbivores died out, the carnivores would also have nothing to eat, resulting in their death also.
4. Wobbling of the galactic plane. If the angle of this plane varies, dust and meteorites can be swept into our Universe, and there are more impact events than usual. There is some evidence that extinction events occur approximately every 26 million years. Wobbling of the galactic plane occurs on a similar frequency, and therefore the two events have been linked together with limited success.
