Belongs within: Ambuloasteroidea.
Contains: Solasteridae, Pterasteridae.
The Spinulosacea are a lineage of asteroids potentially supported by the absence of a mouth and a rudimentary gut in the larva, more or less asymmetrical coelomic sac formation in early development, and terminals that originate from the fusion of many calcification centres (Blake 1987). Adult forms have large, spade- or ploughshare-shaped mouth-angle plates and wide ambulacral furrows in the Velatida, whereas the Echinasteridae have small mouth-angle plates and narrow ambulacral furrows (Spencer & Wright 1966, as Eugnathina and Leptognathina). Velatida other than Solasteridae have delicate, elongate ambulacral plates with a distal articular flange on the head (Blake 1987).
Characters (Blake 1987): Body shape thickened, with discs large or small, arms columnar or tapering, interbrachial angles often acute; area about mouth not depressed. Marginals, abactinals, actinals differentiated or not, ossicles generally relatively small; encrusting ossicles in form of spinelets, reduced in some taxa; pedicellariae always lacking. Madreporite near disc centre, usually small. Abactinals generally closely spaced, paxilliform or flattened; in early ontogeny, abactinals large in number without calycinal ring, in adults, calycinals range from undifferentiated to clearly defined. Terminals small. Marginals commonly in two series but only one or neither series differentiated in various taxa; almost always cryptozonate where differentiated. If multiple actinal rows present, longest row adjacent to adambulacrals. Oral frame, ambulacral column protected by thickened dermal tissues or not, not unusually protected by skeletal armour; oral frame dominated by oral ossicles. Ambulacral column rarely compressed, adoral carina lacking. Superambulacrals lacking, interbrachial septa reinforced with ossicles. Papulae generally widely distributed; tube feet almost always in two rows, suckered discs present but lacking spicules. In development, bipinnaria not known to occur alone, coelomic sac formation more or less asymmetrical with left somatocoel forming from posterior part of archenteron; larval mouth absent, larval gut rudimentary; terminals arising by fusion of many calcification centres.
<==Spinulosacea
|--Echinasteridae [Leptognathina, Spinulosa, Spinulosida]BH03
| |--Metrodira Gray 1840MG-H11, SW66 [incl. Scaphaster de Loriol 1899SW66; Metrodiridae, Metrodirinae]
| | `--*M. subulata Gray 1840SW66
| |--Cribraster Perrier 1891SW66
| | `--*C. sladeni Perrier 1891SW66
| |--Dictyaster Wood-Mason & Alcock 1891SW66
| | `--*D. xenophilus Wood-Mason & Alcock 1891SW66
| |--Plectaster Sladen 1889SW66
| | `--*P. decanus (Müller & Troschel 1843) [=Echinaster decanus]SW66
| |--Poraniopsis Perrier 1891 [incl. Alexandraster Ludwig 1905, Lahillea de Loriol 1904, Ortmannia de Loriol 1906]SW66
| | `--*P. echinaster Perrier 1891SW66
| |--Rhopiella Fisher 1940SW66
| | `--*R. koehleri Fisher 1940SW66
| |--Thyraster Ives 1890SW66
| | `--*T. serpentarius (Müller & Troschel 1842) [=Echinaster serpentarius]SW66
| |--Henricia Gray 1840B02 (see below for synonymy)
| | |--*H. sanguinolenta (Müller 1776)SW66 (see below for synonymy)
| | |--H. compacta (Sladen 1889)MG-H11
| | |--H. oculataB87
| | `--H. scabriorBK77
| `--Echinaster Müller & Troschel 1840 [incl. Henricides Verrill 1914, Othilia Gray 1840, Rhopia Gray 1840]SW66
| |--E. sagenus (Retzius 1805) (see below for synonymy)SW66
| |--E. callosus Marenzeller 1895BM09
| |--E. jacobseniSG93
| |--E. luzonicus (Gray 1840)BM09
| |--E. purpureusF67
| |--E. stereosomus Fisher 1913MG-H11
| |--E. superbus Clark 1916SM15
| `--E. varicolor Clark 1938SM15
`--Velatida [Eugnathina, Velata]BH03
| i. s.: Lepyriactis Spencer 1927 [Lepyriactinidae]SW66
| `--*L. nudus Spencer 1927SW66
| HelianthasteridaeSW66
| |--Helianthaster Roemer 1863SW66
| | `--*H. rhenanus Roemer 1863SW66
| |--Echinasterella Stürtz 1890SW66
| | `--*E. sladeni Stürtz 1890SW66
| `--Hystrigaster Lehmann 1957SW66
| `--*H. horridus Lehmann 1957SW66
| TaeniactinidaeSW66
| |--Taeniactis Spencer 1927SW66
| | `--*T. wenlocki Spencer 1927SW66
| |--Lepidasterella Schuchert 1914SW66
| | `--L. gyalum (Clarke 1908) [=Helianthaster gyalum; incl. *L. babcocki Schuchert 1914]SW66
| `--Baliactis Spencer 1922 [incl. Leioactis Lehmann 1957, Palaeactis Lehmann 1957]SW66
| |--*B. ordovicus Spencer 1922SW66
| `--B. devonicusSW66
| Pythonaster Sladen 1889 [Pythonasteridae, Pythonasterinae]SW66
| `--*P. murrayi Sladen 1889SW66
|--SolasteridaeB87
`--+--+--Caymanostella [Caymanostellidae]B87
| `--KorethrasteridaeB87
| |--Korethraster Thomson 1873SW66
| | `--*K. hispidus Thomson 1873SW66
| |--Anareaster Fell & Clark 1959SW66
| | `--*A. ganymede Fell & Clark 1959SW66
| |--Peribolaster Sladen 1889SW66
| | `--*P. folliculatus Sladen 1889SW66
| `--Remaster Perrier 1894SW66
| `--*R. palmatus (Perrier 1894) [=Korethraster (*Remaster) palmatus]SW66
`--+--TropidasteridaeB87
| |--Tropidaster Forbes 1850SW66
| | `--*T. pectinatus Forbes 1850SW66
| `--Plumaster Wright 1861SW66
| `--*P. ophiuroides Wright 1861SW66
`--+--PterasteridaeB87
`--Myxasteridae [Myxasterinae]B87
|--Myxaster Perrier 1885SW66
| `--*M. sol Perrier 1885SW66
`--Asthenactis Fisher 1906SW66
`--*A. papyraceus Fisher 1906SW66
Echinaster sagenus (Retzius 1805) [=Asterias sagena; incl. A. seposita Lamarck 1816 non Retzius 1783, *Echinaster sepositus]SW66
Henricia Gray 1840B02 [incl. Cribella Forbes 1841 non Agassiz 1835SW66, Cribrella Lütken 1857 non Agassiz 1835SW66, Cyllaster Clark 1916SW66, Spinohenricia Heding 1936SW66]
*Henricia sanguinolenta (Müller 1776)SW66 [=Asterias sanguinolentaSW66, Cribrella sanguinolentaBK77, Echinaster sanguinolentusBK77, Echinus sanguinolentusBK77]
*Type species of generic name indicated
References
[BK77] Barel, C. D. N., & P. G. N. Kramers. 1977. A survey of the echinoderm associates of the north-east Atlantic area. Zoologische Verhandelingen 156: 1–159.
[B87] Blake, D. B. 1987. A classification and phylogeny of post-Palaeozoic sea stars (Asteroidea: Echinodermata). Journal of Natural History 21 (2): 481–528.
[B02] Blake, D. B. 2002. Compsaster formosus Worthen & Miller (Asteroidea; Echinodermata): a Carboniferous homeomorph of the post-Paleozoic Asteriidae. Paläontologische Zeitschrift 76 (2): 357–367.
[BH03] Blake, D. B., & H. Hagdorn. 2003. The Asteroidea (Echniodermata) of the Muschelkalk (Middle Triassic of Germany). Paläontologische Zeitschrift 77 (1): 23–58.
[BM09] Bryce, C., & L. Marsh. 2009. Echinodermata (Asteroidea, Echinoidea and Holothuroidea) of Mermaid (Rowley Shoals), Scott and Seringapatam Reefs, Western Australia. Records of the Western Australian Museum Supplement 77: 209–220.
[F67] Fell, H. B. 1967. Echinoderm ontogeny. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt S. Echinodermata 1. General characters. Homalozoa–Crinozoa (except Crinoidea) vol. 1 pp. S60–S85. The Geological Society of America, Inc., and The University of Kansas: Lawrence (Kansas).
[MG-H11] McEnnulty, F. R., K. L. Gowlett-Holmes, A. Williams, F. Althaus, J. Fromont, G. C. B. Poore, T. D. O’Hara, L. Marsh, P. Kott, S. Slack-Smith, P. Alderslade & M. V. Kitahara. 2011. The deepwater megabenthic invertebrates on the western continental margin of Australia (100–1100 m depths): composition, distribution and novelty. Records of the Western Australian Museum Supplement 80: 1–191.
[SM15] Sampey, A., & L. M. Marsh. 2015. Kimberley marine biota. Historical data: echinoderms. Records of the Western Australian Museum Supplement 84: 207–246.
[SG93] Simms, M. J., A. S. Gale, P. Gilliland, E. P. F. Rose & G. D. Sevastopulo. 1993. Echinodermata. In: Benton, M. J. (ed.) The Fossil Record 2 pp. 491–528. Chapman & Hall: London.
[SW66] Spencer, W. K., & C. W. Wright. 1966. Asterozoans. In: Moore, R. C. (ed.) Treatise on Invertebrate Paleontology pt U. Echinodermata 3 vol. 1 pp. U4–U107. The Geological Society of America, Inc., and The University of Kansas Press.