Dinosaurs dominated the earth for over 150 million years and it was not until about 66 million years ago that they ceased to exist. Whether this extinction was a gradual process or an abrupt catastrophic end has been subject for scientific and geological discussion for many years. In search for these answers, scientists research beyond fossils. Countless research papers and geological evidence have contributed to several hypotheses and working explanations of how the extinction of dinosaurs may have occurred. Knowledge on the mysterious extinction of dinosaurs is thoroughly complicated by multiple interpretations of the same evidence and lack of clear pointers to uphold one hypothesis and dispel with all the rest. This mystery is far much complicated than the simple whodunnit hypothesis. All hypotheses and theories are based on substantial scientific evidence and observation. While different hypotheses may be supported by the same observations, more evidence is sought to disprove the unsubstantiated once.
Was It An Asteroid?
Probably the most reviewed hypothesis about the extinction of the dinosaurs is an asteroid impact that is backed by the evidence of a huge crater at Chicxulub along the coast of Mexico. However new insight suggests that this may only have been final blow as opposed to the main cause. High precision dating of tektites from Haiti have shown that the impact may have occurred slightly over 66 million years ago which is almost at the exact time of the dinosaurs demise. The two events are shown to be simultaneous to a very high confidence level. However this evidence does point to the fact that this was the sole cause of the extinction.
Or Maybe Volcanic Eruptions
More evidence shows that volcanic eruptions may have played a major part both in predating the asteroid strike and causing climatic and weather changes that were gradually killing off all types of dinosaurs. Those in support of this explanation try to give it more weight by emphasis on the lack of evidence of non avian dinosaur fossils at the impact layer. This suggests that they may have died off before the impact actually occurred. The idea that this volcanism caused the extinction fits in well with other mass extinction events from the face of the earth. Pale-oceanographers agree with this hypothesis as mass extinctions are known to co-occur with large-scale volcanic activity.
Was It A Combination Of These Two Theories?
A more plausible theory is that the volcanic eruptions in India were already killing off the dinosaurs before the falling asteroid dealt the final blow. These lava flows may have killed off the dinosaurs directly or through weather and climatic changes that gradually became unconducive for their existence. These changes, from excessive heat to extreme cold snaps may have been killing off the dinosaurs before the chicxulub impact that saw the death of most avian dinosaurs and acted as the final straw.
Some Less Plausible Theories
Other theories which however do not have supporting evidence include:
- The sun might have become too hot for the dinosaurs existence.
- Most dinosaurs drowned after a monstrous asteroid fell in the sea causing destructive tidal waves.
- The Earth’s magnetic field reversed thereby killing of the dinosaurs.
- Another outrageous explanation is that they may have been eaten off by other bigger dinosaurs, which needless to say fails to explain the disappearance of those bigger dinosaurs.
All of these less plausible theories should be approached with much skepticism. While some of them have fervent backers, they all lack the all important evidence that would make any of them scientifically valid.
As you can see, there are quite a few possible explanations as to the disappearance of the dinosaurs. Currently, the scientific community seems to be largely behind the combination theory as the likely cause of their demise. As more evidence is gathered, it is possible that even this solid theory could be dethroned for another.