Fig. 4

Arrangement of marginals and related ossicles. Scale bars, a, d–h 5 mm; b, c, i–k 10 mm. a, b, Goniaster tessellatus (Lamarck 1816), USNM Division Echinoderms E06716, a, uncleared arm and interbrachium, marginals edged by granules, superomarginals bear tubercles, abactinals with spines; b, interbrachial arc, granules cleared, intermarginals (arrows); c, Kionaster petersonae n. gen., holotype, UF 148379, interbrachium, tubercles forming prominences; d, e, Paulia horrida Gray, 1840, USNM Div. Ech. 38087, partially cleared; d, distal lateral view of arm and interbrachium shows both larger and smaller marginals, IM ossicles more numerous, intercalated intermarginals, a few granules remain; e, dorsal–lateral with enlarged distal SM ossicles; f, Amphiaster insignis Verrill, 1868, USNM Div. Ech. 39862, partially cleared; lateral view of arm and interbrachium, marginal ossicles are robust and closely spaced, some granules remain; g, Pauliella aenigma Ludwig 1905, USNM Div. Ech. 102006, lateral view of disk and interbrachium, marginal ossicles are robust and closely spaced, granules obscure ossicular boundaries; h–k, Asterodiscides truncatus (Coleman, 1911), USNM Div. Ech. E10144, partially cleared arm, h, arrow identifies row of marginals below enlarged distal SM, i, k, arrows identify two marginals from different perspectives; dark boundary above marginals is the edge of the abactinal papulate field, see text for discussion