The ilia is round and hypoplastic with a very flat acetabular roof and a very unusual medial projection of bone that is said to resemble the head of a snail. Figure 4 of PMID:3799723 illustrates this feature.
Comment:
This feature was first observed in a condition that was termed Schneckenbecken dysplasia, Schneckenbecken is a German word that means snail-like pelvis.