Costatheca striata ( Dijkstra 1949 ) Hall, 1967

Heřmanová, Zuzana, Kvaček, Jiří, Dašková, Jiřina & Halamski, Adam T., 2020, Plant reproductive structures and other mesofossils from Coniacian / Santonian of Lower Silesia, Poland, Palaeontologia Electronica (a 61) 23 (3), pp. 1-23 : 15-16

Costatheca striata ( Dijkstra 1949) Hall, 1967

Figure 10D, E

1949 Chrysotheca striata Dijkstra , p. 26, pl. 2, fig. 7.

1967 Costatheca striata (Dijkstra) Hall , p. 1298

1983 Costatheca striata (Dijkstra) Hall, Binda and Nambudiri , p. 2721, figs. 10, 12 (emended diagnosis).

For a more extensive synonymy see ( Batten and Zavattieri, 1996, 1995).

Lectotype. Sample/slide 738-9. Maurits State Mine selected by Batten (1988, pl. 19, fig. 30).

Description. Elongate bodies, 2.2–2.5 mm long and 0.6–0.8 mm broad ( Figure 10D, E ); ends slightly S-shape curved. A more complete specimen shows a scar ( Figure 10E ) that may represent the structure termed “operculum” by Batten and Zavattieri (1995). About ten ribs running parallel to the longitudinal axis, and less pronounced perpendicular structures resembling striation caused by thickly cutinised cells.

Remarks. According to Knobloch (1981), C. diskoensis shows a large variability in terms of size, shape and number of ribs. This opinion was questioned by Batten (1988), who studied the type material from Greenland, and who distinguished the specimens grouped by Knobloch into a separate species of Costatheca . Following Batten (1988), we assigned the studied material to C. striata (Dijkstra) Hall from the Santonian of Limburg ( Dijkstra, 1949). C. striata was described from the Santonian of Limburg. This species differs from most species of Costatheca in having perpendicular striations. C. lata (Vangerov) Hall from the Santonian of Aachen ( Vangerow, 1954) differs from C. striata in having relatively low length/width ratio ( Kovach and Dilcher, 1988). It is not clear what Costatheca represents. It could be an insect egg as suggested by Tiffney (1983) and Batten and Zavattieri (1995), whereas Binda and Nambudiri (1983) assumed that Costatheca could be related to the seeds of angiosperms of the Butomaceae family.

Range. Late Coniacian or early Santonian age.

Occurrence. Żeliszów locality.

Material studied. K 3010, K 3011; the material is housed in the National Museum Prague.

Figures

FIGURE 10. Insect remains (A) insect coprolite no. K2768 (A) coprolithes lateral view, no. K2768, scale bar 0.1 mm, Rakowice Małe locality (B) coprolite apical view, hexagonal in outline, no. K2768, scale bar 0.1 mm, Rakowice Małe locality (C) X-ray image, cross section, no. K2768, scale bar 0.1 mm, Rakowice Małe locality. (D) Costatheca striata no. K3010 scale bar 1 mm, Żeliszów locality (E) Costatheca striata showing “operculum” no. K3011 scale bar 1 mm. Żeliszów locality.