Eocrinoids were a
paraphyletic group that are seen as the basal stock from which all other blastozoan groups evolved.
Early evolution The following cladogram, after Nardin et al. 2017 with slight modifications, shows the progression of early eocrinoid families, with all other eocrinoid families (including representatives
Trachelocrinus and
Ridersia) grouped with "derived Blastozoans" as their relationships with each other and with other blastozoans are not addressed.
Relationships to other groups Relationships among the eocrinidae and other blastozoan clades are an area of ongoing study. Below are two of many cladograms showing some aspect of eocrinoid
paraphyly or
polyphyly. }} }} ==References==