Brisingida

Fau, Marine & Villier, Loïc, 2020, Comparative anatomy and phylogeny of the Forcipulatacea (Echinodermata: Asteroidea): insights from ossicle morphology, Zoological Journal of the Linnean Society 189 (3), pp. 921-952 : 925

Clade Brisingida

*3. Partial fusion of the oral frame ossicles (orals, first ambulacrals and odontophores) forming a rigid ring ( Figs 4A, B , 8C, D ).

*6. The odontophore is longer than wide ( Fig. 4B, E ; see Supporting Information, Fig. S1G, J ).

11. The ratio between the length and the height of the distal process of the first ambulacral is between 0.9 and 1.7 (convergent with the Asteriidae and the Stichasteridae ; Fig. 5H ).

12. The ratio between the length and the height of the proximal process of the first ambulacral is between 4 and 6 (convergent with Sclerasterias ; Fig. 5H ).

*20. The articulation iioa is in abactinal position compare to the muscle insertion aciim ( Fig. 6F ; see Supporting Information, Figs S3 , S 4 ).

25. Presence of four or more enlarged spine bases on the orals.

28. Ambulacral with strongly arched abactinal profile (convergent with the Asteriidae ; Fig. 7I).

32. Furrow on ambulacrals present, but irregular ( Fig. 7H).

43. Muscles insertions dadam and padam (on adambulacrals) are approximately of equal sizes (convergent with some asteriids; Fig. 7T).

46. Crest between the muscles insertions dadam and padam (on adambulacrals) present (convergent with the Zoroasteridae ; Fig. 7O, T).

54. Actinals absent or reduced and loose in the dermal tissues (convergent with Labidiaster annulatus and Pycnopodia helianthoides ).

62. Presence of only one row of marginals (convergent with the Zoroasteridae ).

*100. Straight pedicellariae absent.

Figures

Figure 1. Summary of the most recent phylogenetic hypothesis of the Forcipulatacea derived from molecular data by Mah & Foltz (2011a) and Mah et al. (2015). Both studies used the same genes data set (mitochondrial 16S rDNA, 12S rDNA and nuclear early stage histone H3) and were performed using maximum likelihood. One species was added in Mah et al., 2015. The reconstructed tree of Mah & Foltz (2011a) is the strict consensus of the two phylogenetic trees published. The clades ‘six-rayed Pedicellasteridae’ and Paulasteriidae refer to the same taxa, two species of Paulasteriidae were described in Mah et al. (2015) and were, therefore, not yet named in Mah & Foltz (2011). The family Pedicellasteridae is polyphyletic in both analyses, because it includes the clade Pedicellasteridae and the ‘Ampheraster clade’.

Figure 3. Strict consensus tree with selected synapomorphies mapped on the nodes. See Appendix 1 for full descriptions of characters. Characters in green are non-ambiguous synapomorphies (i.e. they occur only once in the tree), and red characters are ambiguous synapomorphies, (i.e. they occur at least two times independently in the tree).

Figure 4. Oral ring in abactinal view (A) and scanning electron microscopy (SEM) images of odontophores in abactinal view (B, G) and actinal view (C–F, H). A, photography of the oral ring of Freyella elegans (MNHN-IE-2013–12862); B, part of the oral ring of Brisingaster robillardi (MNHN-IE-2009–7198); C, Myxoderma sp. (MNHN-IE-2013–16033); D, Zoroaster carinatus philippinensis (MNHN-IE-2013–16031); E, Odinella nutrix (MNHN-IE-2009–7198); F, Sclerasterias tanneri (YPM No 87684); G, Diplasterias brucei (MNHN-IE-2013–16032); H, Labidiaster annulatus (MNHN-IE-2013–12850). Coloured areas indicate the presence of a differentiated stereom. In blue: insertion of the muscle odom; in green: articulation poda and doda. See Table 2 for abbreviations. Scale bars: 5 mm (A), 1 mm (B), 500 µm (C–H).

Figure 5. Scanning electron microscopy (SEM) images of first ambulacrals in actinal view (A, C, E–H) and abactinal view (B, D). A, B, Notasterias armata (MNHN-IE-2009–7163); C, D, Smilasterias scalprifera (MNHN-IE-2013–12860); E, Pycnopodia helianthoides (YPM No 87689); F, Labidiaster annulatus (MNHN-IE-2013–12850); G, Zoroaster carinatus philippinensis (MNHN-IE-2013–16031); H, Freyella elegans (MNHN-IE-2013–12862). Measurements used in characters 11, 12 and 13 are in red dashed lines on the actinal views: teeth length (tl), proximal process height (pph) and distal process height (dph). Coloured areas indicate the presence of a differentiated stereom. In red: insertion of the muscle actam; in purple: insertion of the muscle abtam; in dark blue: insertion of the muscle lim; in brown: insertion of the muscle procoam; in orange: articulation procoa. in light blue: articulation lia; in green: articulation doda. Actinal to the bottom. See Table 2 for abbreviations. Scale bars: 500 µm.

Figure 6. Scanning electron microscopy (SEM) images of oral ossicles in interradial view. A, Sclerasterias tanneri (YPM No 87684); B, Pycnopodia helianthoides (YPM No 87689); C, Notasterias armata (MNHN-IE-2009–7163); D, Smilasterias scalprifera (MNHN-IE-2013–16029); E, Heliaster cumingi (YPM No 87688); F, Freyella elegans (MNHN-IE-2013–12862); G, Zoroaster fulgens (MNHN-IE-2013–12861); H, Plutonaster bifrons (MNHN-IE-2013–10677). Coloured areas indicate the presence of a differentiated stereom. In purple: insertion of the muscle abiim; in yellow: insertion of the muscle aciim; in blue: insertion of the muscle odom; in pink: articulation iioa; in green: articulation poda and doda. Actinal to the bottom. See Table 2 for abbreviations. Scale bars: 500 µm.

Figure 8. Oral frame of: A, Urasterias linckii (YPM No 87685); B, Myxoderma sp. (MNHN-IE-2013–16033); C, Odinella nutrix (MNHN-IE-2009–7198); and D, Freyella elegans (MNHN-IE-2013–12862). See Table 2 for abbreviations. Scale bars: 1 mm (A), 2 mm (B–D).