Podocyrtis (Lampterium) goetheana (Haeckel)

Cycladophora goetheana Haeckel, 1887, p.1376, pl.65, fig.5

Podocyrtis (Lampterium) goetheana (Haeckel), Riedel and Sanfilippo, 1970, p.535

DESCRIPTION

Large, three-segmented pterocorythid. Cephalis irregularly hemispherical with few to many small pores and bearing a stubby, sometimes expanded distally, bladed horn. Thorax, approximately hemispherical, short (30-50 microns), thick-walled with rough surface. The abdomen, which varies considerably in length, is made up of a series of very large, elongated pores separated by long straight bars. Between the lumbar stricture and the large elongated pores, is a single row of smaller pores (diameter 38-62 m). Some specimens terminate with a distal row of smaller pores. Prior to its extinction rare P. goetheana morphotypes exhibit a tendency to extreme reduction in abdominal size, by eliminating the large elongated pores (Sanfilippo, unpubl. data).

DIMENSIONS

Based on 35 specimens. Total length (excluding horn) 230-465 m; length of cephalothorax 75-90 m. Width of thorax 70-90 m; of abdomen 120-190 m (Sanfilippo, unpubl. data).

DISTINGUISHING CHARACTERS

P. (L.) goetheana is distinguished from P. (L.) chalara by the abdomen having a series of very large, elongated pores separated by long, straight bars (Sanfilippo et al., 1985).

VARIABILITY

Through its brief stratigraphic range the thorax is constantly short (30-50 m), the most variable features being the length of the long abdominal pores (120-260 m) and the presence or absence of another row of pores distal to them. The horn in some specimens is expanded distally (Sanfilippo et al., 1985).

DISTRIBUTION

The few latest middle to early late Eocene samples in which this species has been found are all from the tropics. Its morphotypic first appearance defines the base of the Podocyrtis goetheana Zone. Its morphotypic last appearance is in the early part of the Calocyclas bandyca Zone.

PHYLOGENY

This species evolved directly from P. (L.) chalara, and terminates the Lampterium lineage.

REMARKS

Additional illustrations can be found in Riedel and Sanfilippo, 1978a, pl.8, fig.6.

For generic level taxonomy see Sanfilippo and Riedel, 1992.

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