After the Boom
By Shanuka Kadupitiyage Ceylon Today Features
Last week, we learnt that life on Earth exploded after the Cambrian period, where a massive number of new species were seen. We don’t exactly know how or why, but maybe one day we can find out. You might be wondering what happened after it all though.
Life kept evolving and hundreds of new species very different to life on our planet today existed. In a way, you could say that after the boom in Cambrian Earth, life continued to ‘branch out’ and in the process, new species of animals evolved. This era was called the Ordovician period.
The Earth was very different from what it looks like today during this time. Most of the continents were part of a bigger ‘supercontinent’ known as Gondwana. By the way, this was long before Pangaea existed. This is many millions of years before to be honest.
Most life was found only in the ocean according to what we know during this time period. The reptiles, birds and mammals we see today didn’t exist during this time period. Instead, it was the invertebrates (In-ver-ter-brates) that ruled the Earth in this period; yes, the shellfish, trilobites and plenty of other creatures you will never see today. Fish might have existed during this time period, but we still don’t know enough to be sure.
A collection of creatures
Some of the species that lived during this time period had really freaky, cool features to them. Most of them were shellfish, including some of the early Brachiopods (Brak-ee-ohpods). We don’t know much, but we do know some sort of fish with teeth did exist.
That’s because we found fossils of teeth, but no actual fish. Scientists called these creatures Conodonts, a type of ancient fish that did not have jaws. There was also a group of creatures we call Graptolites, which lived in colonies, either attached to the ocean bed, or free floating in the sea. You would have also been able to see plenty of corals during this period, although they would have been quite different from what we see today.
Ended with a freeze
Although there was plenty of life on Earth, the world had to face a mass extinction event somewhere during this time period. A huge number of species were completely wiped out. But, many of their cousins survived to tell the tale. We’re talking about the OrdovicianSilurian extinction event, which was probably the second largest mass extinction event.
Number one is ‘The great dying,’ which we talked about a few weeks before. Unlike the great dying, this mass extinction event happened in stages, which we call waves and most likely would have happened because of the whole Earth getting colder, and freezing most of the ocean water, leading into an ice age.
When the ice age ended and the world suddenly increased in temperature, the second stage of mass extinction happened in this period. Of course, all this happened during a very long period of time, with many species going extinct. Some brachiopod, trilobite and coral species survived but other species like graptolites were almost completely wiped out.
We do know some of what happened during this ancient time period, but we still don’t know the full picture, which is why more research is needed to solve the many mysteries we do know, and discover other mysteries we don’t know about that happened during this time. Of course, it’s up to you to find out more about these.