Molecular evidence has led taxonomists to group bilaterally symmetrical animals in one of three clades: Deuterostomia, Lophototrochozoa, or Ecydysozoa. Give one distinguishing characteristic of these of these groups other than molecular differences.

One distinguishing characteristicof all three clades i.e Deuterostomia, Lophototrochozoa, or Ecydysozoa are  balstopore development, internal body cavity and exoskeleton respectively

Explanation:

Apart from molecular difference, there exist structural differences between the three clades, which are as follows –  

Deuterostomia – The development of embryo is different from the protostomes as the first opening in this clade is anus and the blastopores develops into the anus.

Lophototrochozoa – They do not have ant distinguished internal body cavity. Organs with in coelom can move freely. For example - flatworm

Ecydysozoa – have the ability to shed their tough and flexible exoskeleton i.e cuticle , several times throughout their life span