Heliodiscus asteriscus |
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Heliodiscus echiniscus separated from H. asteriscus of Benson, 1966 Richard N. Benson (19/09/2003) |
Benson, 1966, pl. 9, fig. 4 is Heliodiscus echiniscus on the basis of the presence of additional spines arising from the surface of the disc in addition to the marginal spines.
From Benson, 1966:
Margin of shell with 5-30 or more, relatively long, broad, conical to three-bladed spines, generally lying in a single plane, not continuous inwards as beams; in one specimen 20-30 smaller, less robust marginal spines present in addition to the heavier spines [pl. 9, fig. 4 = H. echiniscus]; |
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