Complex sentence: Within the "" spondiogenys "group" the gradual clinal variation over geographic range and extensive intergradation means that the geographical limits and acceptance of the various subspecies varies between authorities.
Split into simpler sentences: Within the "" spondiogenys "group" the features of the subspecies vary clinally. The gradual variation over geographic range and extensive intergradation means that the geographical limits and acceptance of the various subspecies varies between authorities.