This study on a fossil of 500 million years old questions everything that we thought about their origin

A paleontological discovery upsets our traditional vision of spiders. Moreover, A fossil of Soften symmetrical515 million years old, reveals a brain structure very close to that of modern arachnids. Meanwhile, This find suggests a much more aquatic origin than expected.

What Mollisonia’s fossilized brain changes in our vision of evolution – This study fossil 500 million – This study fossil 500 million new

Spiders have long symbolized earthly life. Their respiratory system, hunting behavior and adaptation to dry environments seemed to support this idea. For decades, scientists have thought that their ancestors had left the ocean about 400 million years agolike the first amphibians.

However, this scenario is mainly based on external morphological clues, such as the presence of cherries, a segmented exoskeleton or articulated legs. However, in paleontology, appearances are sometimes misleading. It is precisely the interior of the head of Soften symmetrical which questions everything.

Mollisonia’s fossilized brain reveals an organization close to modern spiders

This fossil. discovered in Canadian shales, belonged to a marine creature in the average Cambrian. Thanks to advanced optical imaging, the researchers were able to reconstruct the architecture of its nervous system. They then identified a brain configuration in a fanwith a reversal of lobes and nerves connected to the legs. This structure strongly resembles that observed in current spiders.

This discovery is all the more striking as this study fossil 500 million new it is based on internal data rarely preserved this study fossil. 500 million in such old fossils. In addition, Nicholas Strausfeld, neurobiologist at the University of Arizona, led this study. He insists that this brain structure gives spiders their agility and precision. According to him, Soften could not be a simple cousin, but a real aquatic parent of spiders.

In order to validate this hypothesis, the researchers conducted an in -depth phylogenetic study, based on 115 brain and morphological lines. Consequently, the results confirm a close link between Soften And the arachnids, eliminating the idea of a simple evolutionary coincidence.

This fossil could upset our understanding of the evolution of arthropods

If this hypothesis is confirmed. it would redraw an entire branch of evolution. Thus. spiders would no longer be solely terrestrial animalsbut the descendants of a this study fossil 500 million new navy line who developed advanced neurological capacities. very early on.

In addition, this this study fossil 500 million revelation also relaunches the debate on the emergence of complex brains. She suggests that traits deemed recent already existed in the first forms of multicellular life. Therefore, it modifies our chronology on neurological specialization in the animal kingdom.

Sources :

• Current Biology
• University of Arizona
• National Geographic