Ferdina mena, Mah, Christopher L., 2017

Mah, Christopher L., 2017, Overview of the Ferdina - like Goniasteridae (Echinodermata: Asteroidea) including a new subfamily, three new genera and fourteen new species, Zootaxa 4271 (1), pp. 1-72 : 18

Ferdina in the Goniasteridae

Observations of Ferdina specimens identify several characters that support placement within the Goniasteridae . These include the presence of goniasterid-like abactinal plates arranged into a flattened surface framed by a distinct marginal plate arrangement in juveniles of Ferdina mena n. sp. ( Fig. 6 ). As outlined in the introduction, the placement of Ferdina in the Goniasteridae was first considered by Viguier (1878, 1879) with some agreement by Fisher (1919). The placement of Neoferdina within the Goniasteridae by Mah and Foltz (2011) supported by molecular data, suggests that a closely related genus with shared characters (e.g., furrow spination, granulate tegument covering adambulacrals) such as Ferdina can also be plausibly classified within the Goniasteridae . Blake and Reid (1998) also noted goniasterid affinities when comparing members of the “ Ferdina group”, including Ferdina , Paraferdina Neoferdina and Sinoferdina with the Cretaceous Denebia .

Relatively small individuals of Ferdina mena n.sp. (e.g. MNHN-IE-2007-4941 at R= 1.2 cm) show a welldeveloped marginal series with a more quadrate and blocky morphology forming a distinct frame around the abactinal plates ( Figs. 6 A–C). Although the marginal plate morphology and arrangement appear to vary more in larger individuals, these smaller specimens suggest synapomorphies for placement in the Goniasteridae . These specimens also show the arm as quadrate in cross-section as opposed to larger individuals with a more rounded or convex abactinal surface. Although juveniles of the other two Ferdina spp. were unavailable, those of F. mena would suggest that there is a transformation in the shape/convexity of the abactinal surface and arm shape as this species increases in size.

Figures

FIGURE 6. Ferdina mena n. sp. Small goniasterid-like specimens. MNHN-IE- 2007 - 4941. Scale Bar = 1.5 mm A. Abactinal surface. B. A bactinal surface detail. C. Lateral view showing paired bare regions in each interradius. D. Actinal surface.