NOMEN: Cryptopneustida Boudreaux 1979 (I) [H.B. Boudreaux. Significance of intersegmental tendon system in arthropod phylogeny and monophyletic classification of Arthropoda. – pp. 551-586. In.: Gupta A.P. (ed.). Arthropod Phylogeny. Van Nostrand Reinhold Company, N.Y., 1979: 1-762]
ORIGINAL LISTED MEMBERSHIP (Boudreaux
1979):
Eurypterida + Arachnida 
JUNIOR CIRCUMSCRIPTIONAL SYNONYM:
= Metastomata Weygoldt & Paulus 1979 (IX)
= Sclerophorata Kamenz & Staude & Dunlop 2011
TYPIFIED NAME IN BASIC FORMAT: Araneus/fg (sine Limulus; incl. Eurypterus)
TYPIFIED NAMES IN USE: -
MODERN STATUS: the valid, the oldest name of a probably holophyletic taxon.