In the book wonderful life, the famous paleontologist Stephen Jay Gould described the infinite variety of species that inhabited the oceans makes 530 million years ago. Their study was based on the fossil of a place known as the Burguess Shale, a geological formation that is located in Canada and that has been very important to know the biological history of the planet. Their abundant remains are relics of the past that testify to how they were the first beings that were in more than one cell and have served to expand and understand the current theories of evolution.
These first forms of life lacked the cartilages or bones, so that their remnants, which contain soft structures, have come down to us from a fossil record incomplete. The scientists added new discoveries every year, and with this knowledge we launched new hypotheses about their appearance, their relationships of kinship or how was the environment in which they lived. The appearance of the first vertebrates (animals with backbone) makes 525 million years ago and, from them, the development of the first fish, assumes, however, one of the great paradoxes of paleontology. What is preserved of this fauna is, in principle, more resistant and, therefore, more easy to become a fossil and arrive to our days, is weak and his pieces are very fragmented. This makes it difficult the knowledge that we have about the beings that dominated a period of time known as the Paleozoic environment. This lack limits what we know of our ancestors, more distant, in other words, what we know of our own origin.
class=”icon-foto_16_g”> A fish that makes 430 million years ago in tropical waters in what is today the canadian Arctic.. SCIENCE
The step from shallow water to the depths clarifies Ivan Sansom, a paleontologist at the University of Birmingham and co-author of the study. “Some fish that had armor skin very heavy and they remained on the coast nearby, with casual travel to fresh water. Others were more flexible and found it easier to expand into deeper waters, but also occupied the coast and the fresh water,” says Sansom.
on the other hand, in another article also published by the journal Science the paleobióloga Catalina Pimiento, from the University of Swansea (Uk), highlights another aspect of the study. Given the large volume of data that Sallan and his team have reviewed and the relationships that have been found among many species of fish and their habitats, Pepper, stresses the importance of the work to understand not only the origin of the vertebrates, but the life of the marine ecosystems in danger, as is the case of coral reefs today, which could help to combat its disappearance.
“The use of large databases of data will help to describe the pattern that extends over 500 million years of evolution. This is particularly important if we consider that we may lose the tropical reefs or environments close to the coast due to climate change”, concludes Ivan Sansom.
A placodermo, similar to the current manta, in the Devonian period. SCIENCE
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