Subgenus Macroderus CROISSANDEAU, 1894 Macroderus previously included a single species, the type species C. divergens REITTER, 1884 from Aragón (Northeast Spain). Species of this well-defined subgenus are characterized by the following character combination: body broad and robust, strongly convex (cross-section); colouration reddish to reddish-brown; antennae slender, antennomeres VI and VIII not transverse, VII only indistinctly longer and larger than VI and VIII at most, and IX and X weakly transverse, less than 1.5 times as broad as long; eyes composed of approximately five to seven large ommatidia; pronotum strongly transverse, at least 1.25 times as broad as long, very shiny; punctation sparse and extremely fine, barely noticeable even at high magnification (100 x); pubescence long and suberect to depressed; elytra broad, strongly convex in cross-section, anteriorly with a lateral humeral carina only and with a pronounced sulcus originating from the anterior impression; hind wings reduced; metaventrite practically impunctate and very glossy; legs without appreciable sexual dimorphism; all tibiae more or less distinctly clavate, i.e., very narrow in basal half and distinctly dilated in apical half; male metaventrite more or less distinctly impressed; aedeagus with bulbous capsule, short and often broad ventral ventral process, and with internal structures partly composed of clusters of filaments; parameres thin, reaching apex of median lobe, or nearly so, and with moderately long apical seta. Several of these characters (shape and punctation of pronotum; pronotum strongly transverse; elytra with prounced lateral humeral carina, without supra-humeral carina, and with a pronounced sulcus extending from anterior impression; metaventrite practically impunctate; all tibiae without sexual dimorphism; derived morphology of the aedeagus) are unique in the genus and partly evidently synapomorphic. For this reason, the subgeneric status Macroderus is retained for the purpose of the present paper.

Published as part of Assing, Volker, 2021, On the Cephennium fauna of the Iberian Peninsula and the Atlantic Islands (Coleoptera, Staphylinidae, Scydmaeninae), pp. 891-931 in Linzer biologische Beiträge 52 (2) on pages 924-925, DOI: 10.5281/zenodo.5039032