Congruence between nuclear and mitochondrial genes in Demospongiae: A new hypothesis for relationships within the G4 clade (Porifera: Demospongiae)

► Classification of Demospongiae G4 group was tested using rRNA and CO1 sequences. ► This is the most comprehensive study of the Demospongiae G4 clade. ► The LSU and CO1 genetrees conflict with the current morphological classification. ► A new hypothesis for relationships of G4 taxa is proposed. ► The order Axinellida Lévi, 1973 is resurrected and two new families are created.