Professor Nick Strausfeld from the University of Arizona and Greg Edgecombe from the London Natural History Museum published their discovery and analysis of the earliest known complete nervous system of a new fossil that is the first known relative of spiders in the Oct. 16, 2013, issue of the journal Nature.
The fossil resembles spiders in having a segmented body, twenty-four appendages, and a pair of appendages attached to the head that were probably used for grasping prey. The early arthropod could swim and travel on land. The joints of the appendages and fangs of the fossil are very similar to those of present day spiders.
The researchers use CT scans and scanning laser techniques to reconstruct the nervous system of the fossil. This was possible due to the iron content of the sediments the fossil was found in that preserved the neural connections between the fossil’s brain and appendages.
Comparison of the nervous system to that of present day scorpions, spiders, and horseshoe crabs identified this 520-million-year-old Alalcomenaeus as the earliest known spider relative. Over 150 individual points of the fossil’s nervous system and physiology were compared to modern samples and proved the analysis to be accurate.