Grobben 1908: bilaterian split based on blastopore fate; protostome (mouth-first: arthropod / mollusc / annelid) vs deuterostome (anus-first: echinoderm / chordate); supported by 18S-rRNA + Hox cluster.
Grobben 1908: bilaterian split based on blastopore fate; protostome (mouth-first: arthropod / mollusc / annelid) vs deuterostome (anus-first: echinoderm / chordate); supported by 18S-rRNA + Hox cluster.