Carboniferous ammonoids of the family Goniatitidae and its descendants frequently possess
 subquadrate conch cross seetions with flattened venters and low apertures, where the whorl width
 has approximately the same values as the conch diameter.  They occur in an increasing number in
 time md are most common near the Viséan-Namurian boundary.  Statistical analysis leads to the
 conclusion that the ammonoids with this conch morphology can be attributed to intraspecific
 variability.  Therefore, the subspecies Goniatites (Goniatites) stenumbilicatus globiformis KULLMANN,
 1961 md Goniatites crenifalcatus sphaeroides BOGOSLOVSKAYA, 1966 are treated as synonyms.