Paleontologists have made a groundbreaking discovery that challenges long-held beliefs about the evolution of arachnids. The fossilized features of the brain and central nervous system of Mollisonia symmetrica, an extinct animal from the mid-Cambrian seas, reveal a surprising connection to modern spiders and scorpions.
The study, led by Professor Nicholas Strausfeld, found that Mollisonia symmetrica’s nervous system corresponds to that of living arachnids, despite its previously thought to be an ancestral member of chelicerates. This discovery suggests that the diversification of arachnids occurred earlier than previously believed.
The researchers analyzed the brain’s organization and found a unique pattern that is reversed in modern crustaceans, insects, and centipedes. This arrangement is similar to that found in modern spiders, which may be an evolutionary development that provides shortcuts for movement control.
“This finding is a major step in evolution, which appears to be exclusive to arachnids,” said Professor Strausfeld. The study’s results also suggest that the arachnid brain has computational speed and motor action control abilities.
The discovery sheds light on the early history of arachnids and their potential role in shaping the evolution of insects and millipedes. It also highlights the advantages of flying, which gave spiders an edge in hunting and defense.
Source: https://www.sci.news/paleontology/mollisonia-symmetrica-14088.html