A fossil from a sea creature named Mollisonia, discovered over 500 million years ago, has revealed an arachnid brain structure previously thought to be unique to spiders. The analysis of the ancient fossil’s brain found that its chelicerae – pincer-like mouthparts used for tearing small prey – were connected to two neural areas located at the front margin of the nervous system, unlike other crustaceans and insects.
According to researchers, this reversed brain structure is characteristic of arachnids, suggesting that they may not have evolved on land as previously believed. The finding has sparked debate about the origins of spider-like creatures and their unique abilities, such as extraordinary dexterity and speed.
Source: https://www.newscientist.com/article/2489181-ancient-animals-fossilised-brain-prompts-rethink-of-spider-evolution