Atelostomata (apical system)
Description The two extant orders differ in the plate scheme of the apical system: Left: Holasteroida: The arrangement is elongated, the ocular plates OII and OIV toch each other and separate the anterior (G2/G3) and the posterior (G4/G1) genital plates. The ocular plates OI and OV form the posterior end (Corystus relictus; modified after Mooi & David 1996). Right: Spatangida: The apical system is more compact, the enlarged genital plate G2 (madreporite) expands to the posterior, separating G1 and G4 and the ocular plates O I and O V (Brissus; after Mortensen 1951).
Scale 2 mm.
Author Schultz, Heinke
JPG file - 138.41 kB - 2 332 x 1 032 pixels
added on 2009-02-233 090 viewsBeRMS taxaScan of drawing Spatangoidachecked Kroh, Andreas 2021-02-24Scan of drawing Atelostomatachecked Kroh, Andreas 2021-02-24From reference Schultz, H. (2009). Sea urchins II: Worldwide irregular d...
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© 2009 Schultz, Heinke