Alphabetical Listing of Families within this Taxa Group:

family     Aeropsidae		T4023400
family     Brissidae		T4009661
family     Eurypatagidae		T4023642
family     Hemiasteridae		T4023405
family     Loveniidae		T4015835
family     Macropneustidae		T4023650
family     Maretiidae		T4023651
family     Micrasteridae		T4023652
family     Palaeostomatidae		T4023657
family     Palaeotropidae		T4023658
family     Paleopneustidae		T4023660
family     Paleopneustina incertae sedis A		T4023661
family     Paleopneustina incertae sedis B		T4023662
family     Pericosmidae		T4023501
family     Prenasteridae		T4023663
family     Schizasteridae		T4023412
family     Spatangidae		T4015802