| Home> Miocene>

List species

Amphispyris roggentheni Goll, 1980

Description - Add description

With the exception of the composition and size of the lattice shell, this species is very similar to Amphispyris reticulata (Ehrenberg 1872). Goll (1969) emended the description of A. reticulata (Liriospyris reticulata), and two specimens are illustrated here for comparison (pl. 6, figs. 2 and 5). The dimension of the sagittal ring and lattice shell are identical for both morphs. Lattice shells are apico-basally flattened and inflated, oblate in the front-to-back and lateral directions. When viewed from the apical or basal sides, the gross outline of the lattice shell is kidney-shaped, with an indentation near the vertical spine. There is no basal ring or basal aperture; the lattice shell encloses the base of the sagittal ring, and the short primary lateral spines are joined to the lattice shell (333-440mm) is far greater than the thickess on specimens of A. roggentheni, and the lattice shell may be constricted at both the front and back.
Lattice shells of both species are composed of lattice bars of two distinct sizes. Six pairs of massive lattice bars are joined to the sagittal ring, and smaller lattice bars proliferate from them to produce a delicate lattice. A few specimens of A. roggentheni have a fine lattice similar to A. reticulata, but most specimens have a coarser lattice with pores 10-25mm in diameter framed by thick lattice bars.
Almost certainly, A. roggentheni does not represent an isolated breeding population , and consequently it does not merit full species rank. This morph probably will be designated as a subspecies when its evolution is better understood.
Goll 1980











Discussion / Comments


Web links