satan differs from this genus in having a more developed squamosal lamina, wider and shallower orbital margin of the maxilla, dorsoventrally taller and transverselly compressed proximal end of urostyle, and medially tilted dorsal margin of ilium (CASAMIQUELA, 1958, 1961; Appendix 3; see below).
The genus Gigantobatrachus was recovered in the present analysis as the sister group of Calyptocephalella, both conforming a clade sustained by three synapomorphies: 1-presence of very well-developed dorsal iliac crest, 2- urostyle as long as presacral column, and 3- short and curved clavicle (see Appendix 3).
Moreover, these specimens belong to the genus Gigantobatrachus because of its gigantic size (the largest known taxon within the family), external ornamentation composed by very deep and wide pits separated by strong osseous ridges (see CASAMIQUELA, 1958), proximal articular end of urostyle strongly dorsoventrally compressed and transversally expanded (unambiguous synapomorphy of Gigantobatrachus; Appendix 3), and very small and deeply concave orbital margins of the maxilla (unambiguous synapomorphy of Gigantobatrachus; Appendix 3).
Sacral vertebra and urostyle: 0--articulated; 1--fused.
Urostyle length compared to total presacral length: 0--lower; 1--subequal (REIG, 1960a,b).