"Plate atrophy ('plate crushing') giving rise to interambulacral plates analogous to demi-plates immediately above the ambitus is described in the Miocene spatangoid Lovenia woodsi, from Beaumaris, Victoria. It appears to be caused by the development of large primary tubercles on the aboral surface, which causes the expansion of the lowest tubercle-bearing platesduring ontogeny, so that the more ventral interambulacral plates are squeezed against the ambitus."

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