Spiders may have originated in the ocean before adapting to life on land, according to new research. Fossil analysis reveals that an ancient creature called Mollisonia symmetrica, which lived 500 million years ago, had a brain organization similar to modern spiders and their relatives.
The study challenges widely held beliefs about when spiders adapted to land, suggesting that they may have transitioned from sea-dwelling ancestors to terrestrial predators. The fossil’s neural arrangements showed a unique pattern of segmental ganglia controlling movement, as well as a reverse front-to-back brain organization, characteristic of modern arachnids.
The discovery is significant, as it provides evidence for the evolutionary development of arachnid brains and may have helped spiders hunt stealthily and spin webs with precision. This finding supports the idea that spiders and scorpions, which have remained largely unchanged for 400 million years, are among the most successful groups of arthropod predators.
The research suggests that early arachnids on land may have contributed to the evolution of insect wings as a critical defense mechanism. The Mollisonia lineage is believed to have given rise to various spider species, including spiders, scorpions, sun spiders, vinegarroons, and whip scorpions.
Source: https://abcnews.go.com/US/spiders-evolved-ocean-adapting-land-preserved-fossil-reveals/story?id=123996141