Thalamoporella kharinadiensis Guha & Gopikrishna, 2004

Sonar, Mohan A., Pawar, Ravi V. & Wayal, Dyaneshwar V., 2022, Fossil Thalamoporellidae (Bryozoa) from Paleogene-Neogene sediments of western Kachchh, Gujarat, India, Zootaxa 5104 (2), pp. 251-274 : 264

Thalamoporella kharinadiensis Guha & Gopikrishna, 2004

( Fig. 11 , Table 8)

Thalamoporella kharinadiensis Guha & Gopikrishna, 2004: 23 , figs 20, 21.

Material examined. GIS/B 0231–0270. Yellowish limestone west of Haripar, Kharinadi Formation , lower Miocene (Aquitanian), 23°22’08’’ N, 68° 49’40’’ E, elevation 20 m, 14 January 2011, DST project, New Delhi .

Description. Colony erect, bilaminar. Autozooids arranged quincuncially in alternating longitudinal series, rectangular, bordered by indistinct, raised, smooth autozooidal borders. Orifices subcircular, a little wider than long, strongly arched distally with a concave proximal margin ( Fig. 11A, B ). Cryptocyst shallow, smooth, gently sloping towards opesiular region. Adoral area narrow lacking tubercles. Opesiules large, rounded, unequal, deeply sunken, adjacent to lateral walls proximal to orifice. Avicularia at bifurcation of rows, c. 75% of autozooidal length, vicarious, elongate, straight, with rounded rostrum directed distally; foramen somewhat elongate-pyriform in eroded present material, c. 80% of avicularian length, cryptocyst little preserved proximally, smooth ( Fig. 11B ). Ovicells not observed.

Remarks. The present material agrees with T. kharinadiensis Guha & Gopikrishna, 2004 , but the preservation is poor, reflected in the details of the avicularium and apparent absence of pores in the cryptocyst. Additionally, most of the autozooids in a colony show anomalous growth, i.e. incomplete cryptocysts, that might reflect growth in a low pH setting.

Figures

FIGURE 11. Thalamoporella kharinadiensis Guha & Gopikrishna, 2004 (GIS/B 0231). A. General view of colony showing autozooids, orifices and avicularia. B. Detail of an avicularium, autozooids, orifices, opesiules and cryptocyst. Scale bars: A, 500 µm; B, 200 µm.