A large percentage of schoolchildren are likely to know the answer to the question, “What happened 66 million years ago?” The answer will come back, “An asteroid killed the dinosaurs.” And they would be correct. The asteroid which has been calculated to have been around 8 miles across, crashed into the Yucatan Peninsula in Mexico. It was a mass extinction event which wiped out 75% of all living creatures upon the planet. There have been five mass extinction events for different reasons in Earth’s history. Some scientists fear that we are at the start of the sixth due to global warming.
Of course, the blast, although huge, did not wipe everything out straightaway. But the effects of the blast would have plunged the Earth into a darker and colder climate which had devastating effects over a period of years. It would be assumed that those in greatest peril would be creatures, especially vertebrates living in the region of Mexico and the surrounding areas. But there was one species of night lizard who would have been in sight of the explosion and not only survived the initial blast, but continued to live in that region to the present day.
They were the only land based vertebrates to have survived. The dinosaurs survive today as birds as they descended from them. By how did the night lizards survive? It was probably a combinations of factors. They are very small, just a few inches in length and they choose to live in their own microhabitats, such as in rock crevices. They also have a very slow metabolism which means they do not have to eat that often. All of these factors would have helped them to survive the deadly conditions which followed the initial impact.
This might sound an interesting story, but it has a very serious side to it. As far as we know, if all vertebrates had been wiped out, there is a good chance that humans would not have evolved. So, you could also say that these could be called the “Lizards who saved the human race.”
John Pullen 