The most general characteristic of molluscs is they are unsegmented and bilaterally symmetrical .
Molluscs have developed such a varied range of body structures , it is difficult to find synapomorphies ( defining characteristics ) to apply to all modern groups .
The most general characteristic of molluscs is Molluscs are unsegmented and bilaterally symmetrical .
Molluscs have developed such a varied range of body structures , it is difficult to find synapomorphies ( defining characteristics ) to apply to all modern groups .