by New studies suggest that spiders and other Arachnids may come in the sea, based on the analysis of a 500 million year old fossil.
The “exquisite preserved” copy supports the idea that these creatures go to the study published on Tuesday in the study published on Tuesday before adapting to life ashore Current biology.
Researchers at the University of Arizona analyzed the petrified brain of Mollisonia Symmetrica, a extinct species in the Cambrian period, which was once regarded as an ancestor of horseshoe crabs. However, the study showed that its neuronal structure is more like that of modern spiders and their relatives, which indicates a closer evolutionary connection to Arachnids than previously assumed.
The front part of Mollisonia’s body, referred to as a prosoma, has a radiant pattern of nerve clusters that control five pairs of tags. In addition, his non-segmented brain sends short nerves to two pliers-like “claws”, which resemble the Zäfern in spiders and other arachnids.
Researchers at the University of Arizona examined the petrified brain of Mollisonia Symmetrica, an extinct Kambrische way, of which it was previously assumed that it is an ancestor of horseshoe crabs. (Nick Strausfeld/Department of Neurosciences, University of Arizona)
The most important feature that the fossil identifies as an early arachnide is the unique organization of his brain, which represents the back of the arrangement from front to back in modern crabs, insects, centipedes and horseshoe crabs, said researchers.
In an explanation, Nick Strausfeld, senior author and professor at the University of Arizona, said the brain of the fossil appears “backwards”, similar to modern spiders.
This back-to-front brain arrangement can be an important evolutionary adaptation that provides neural abbreviations that improve movement control.
According to the study, this discovery questions the common conviction that the diversification only passes to land after the transition of a common ancestor. Earlier fossil evidence indicates that Arachnids only lived on land and developed.
The prosoma or the front section of Mollisonia’s body have a radiant arrangement of nerve clusters that manage five pairs. (Nick Strausfeld/Department of Neurosciences, University of Arizona)
“It is still vigorously discussed where and when Arachnids first appeared and what kind of chelizeraten their ancestors were and whether it was marine or half -sized like horseshoe crabs,” said Strausfeld.
When they had adapted to life on land, Mollisonia-like Arachnids probably fed early insects and millipedes. These early Arachnids may also have influenced the development of insect wings, an important defense mechanism.
Researchers say that the origin of the Mollisonia probably led to spinning, scorpions, sun spiders, vinegar and whip spiders.
