A relatively diverse chelicerate fauna has been detected in Early Devonian, Siegenian strata of the Westerwald area, Rhineland-Palatinate, Germany. The arachnids, comprising trigonotarbids and the oldest phalangiotarbids, are described and figured here along with the chasmataspidids. To accomodate the phalangiotarbid a new genus and species in the family Architarbidae, Devonotarbus hombachensis, is raised. Devonotarbus n. gen. is characterized by an approximately straight posterior carapace margin, abbreviated and undivided anterior tergites, a large sixth tergite, and fused posterior tergites. The chasmataspidid closely resembles Diploaspis casteri from the Emsian assemblage of Alken an der Mosel, but is readily discernible as a new species, D. muelleri, by a strong tuberculation of its dorsal integument. With only fragmentary opisthosomal remains available, the trigonotarbids cannot be placed in known taxa with any certainty at this time.