The evolution of the arachnida

Abstract

This paper is a critical review of the principal problems in the taxonomy of the Chelicerata athigher levels. Of systems proposed, most are highly opinable and based on second-hand, uncontrolled information. A cladistic methodology has rarely beenused.The only point generally accepted is the validity of most recent orders; the only progressmade in the last fifty years appears to be thedefinitive solution of the problem of the positionof the Xiphosura. Remarkable also is the lumpingtogether of the two “classes” of the Merostomataand the Arachnida. © 1980 Taylor & Francis Group, LLC.