The Sporadoceratidae are amongst the most widespread and longest-ranging ammonoid families of the Devonian. However, many forms are still poorly known.  A critical review of literature and new records indicate that a range of new genera should be distinguished, based on the iterative introduction of spiral ornament and open umbilicate whorls. The oldest genus, Maeneceras, had its acme in Upper Devonian II (UD II) but rare members ranged into the upper Famennian (UD V), Goniatites biferus PHILLIPS (1841 ) is regarded as a subjective synonym of Goniatites ungeri MÜNSTER  (1840). Therefore, the Maene. biferum Zone (UD II-G) has to be renamed as Maene. subvaricatum Zone.The morphometric analysis of a population from the lower Famennian (UD II-G) of Hassi Nebech (S-Tafilalt, Morocco) is used as a case study to evaluate the significance of shell and sutural teatures as well as the intraspecific variability in the group. Results are used for taxonomic revisions.
 Internal shell thickenings change throughout ontogeny and cannot be used easily to distinguish species in Maeneceras. Growth of the conchs continued throughout life without reaching a fixed maximum size. An analysis of the depths of A2  lobes showed the presence of three morphotypes but there was no clear species separation as known from younger strata.  This is either based on too strong condensation and mixture of individuals of different geological age, or the population documents a case of initial but not yet completed speciation.