Systematic revision of the Savignia genus group (Araneae: Linyphiidae: Erigoninae) with notes on their cephalic lobe evolution

We use 269 morphological characters (175 newly defined) and 70 taxa (59 ingroup taxa) to reconstruct the relationships and evolutionary trends of cephalic lobes in this lineage. Our findings show that cephalic lobes with varying shapes and sizes appear in several Savignia genus group lineages, highlighting that it is not a good diagnostic character. The high support in several clades allows the redefinition of the genera Savignia, Diplocephalus, Araeoncus, Erigonella Dahl, 1901, Dicymbium Menge, 1868 and Glyphesis Simon, 1926 based on synapomorphies and leads to new species assignments.

Our results also show that while genera are well supported, their interrelationships are not, suggesting that genera closely related with the Savignia genus group may need further revision. Simplified, the generic relationships of the Savignia genus group are Glyphesis (Dicymbium (( Erigonella (Hemistajus resurrected rank, Savignia )) (Diastanillus (Diplocephalus, Araeoncus ))).