Article: A trigonotarbid arachnid from the Upper Silurian of Shropshire
Jason A. Dunlop
A trigonotarbid (Arachnida: Trigonotarbida) from the oldest known terrestrial ecosystem (Silurian, Pridoli Series) of Ludford Lane, Shropshire, UK is described as Eotarbus jerami gen. et sp. nov., and is the earliest known non-scorpion arachnid. This specimen predates Rhyme Chert and Gilboa trigonotarbids which show more plesiomorphic characters, and is similar to some Early Devonian trigonotarbids from Alken an der Mosel and other German localities of similar age. Eotarbus jerami is too poorly preserved to be assigned unequivocally to a family, but most closely resembles the Trigonotarbidae. Eotarbus is interpreted as a plesion and is probably a sister group to all trigonotarbids with triangular carapaces lacking lateral eyes.