After Shackleton, 2005, with species from the “Paleobiology Database”:
<==o †Palasteriscidae Gregory, 1900 [incl. Urasterellidae Schuchert, 1914] |--o †Urasterellinae Schuchert, 1914 | |?- †Bohemaster Jaekel 1923 | |?-o †Salteraster Stürtz, 1893 | | |-- †S. biradialis | | |-- †S. coronella | | |-- †S. imbricatus | | `-- †S. selwyni | |?-o †Ulrichaster Spencer, 1950 | | |-- †U. macrodentatus | | `-- †U. ulrichi | |--o †Cnemidactis Spencer, 1918 | | |-- †C. girvanensis (Schuchert, 1914) | | |-- †C. macroadambulacralatas | | `-- †C. osloensis | `--o †Urasterella McCoy, 1851 | |-- †U. asperula [Roemeraster asperula] | |-- †U. asperrimus (Salter, 1857) | |-- †U. constellata | |-- †U. creswelli | |-- †U. grandis | |-- †U. gutterfordensis | |-- †U. huxleyi | |-- †U. montana | |-- †U. pulchella | |-- †U. ruthveni | |-- †U. thraivensis | `-- †U. verruculosa `--o †Palasteriscinae Gregory, 1900 |-- †Lanthanaster cruciformis Branstrator, 1972 `--+-- †Platanaster ordovicus Spencer, 1919 `--o †Baliactis Spencer, 1927 |-- †B. ordovicus Spencer, 1922 |-- †B. devonicus |-- †B. scutatus `-- †B. tuberatus
Reference(s):
- Shackleton, J. D., 2005: Skeletal homologies, phylogeny and classification of the earliest Asterozoan echinoderms.
–Journal of Systematic Palaeontology: Vol. 3, #1, pp. 29-114