Reniporella reniformis ( Guha & Gopikrishna, 2004 ) Sonar & Pawar & Wayal, 2022

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 : 269

Reniporella reniformis ( Guha & Gopikrishna, 2004) n. comb.

( Fig. 17 , Table 14)

Thalamoporella reniformis Guha & Gopikrishna, 2004: 14 , figs 8–10.

Material examined. GIS/B 0363–0368. Gypseous shales Harudi, Harudi Formation, middle Eocene (Lutetian), 23 ° 31’25” N, 68 ° 41’07” E, elevation 6 m, 12 January 2011, DST project, New Delhi . GIS/B 0369–0373. Fulra argillaceous clay section, southern flank of Babia hill, about 1.7 km of Fulra village, upper Eocene (Priabonian), 23 ° 42’30” N, 68 ° 47’12” E, elevation 19 m, 17 January 2011, DST project, New Delhi .

Description. Colony erect, multiserial, stems dichotomously branching. Autozooids arranged quincuncially, small, roundly subhexagonal with convex lateral margins, these well developed, thick, raised and granular ( Fig. 17A, D ). Orifice-opesia proportionally large, c. 30% of zooid length, transversely D-shaped with rounded lateral margins; arcuate distal margin raised, proximal margin straight ( Fig. 17B, E ). Opesiules large, longitudinally elongate and somewhat bean-shaped, unequal in size, one comprising c. 50% of zooid length, the other shorter ( Fig. 17E ). Cryptocyst depressed, smooth, imperforate ( Fig. 17B ). Avicularia and ovicells not observed.

Remarks. Guha & Gopikrishna (2004, p. 14, figs 8–10) placed this species in Thalamoporella . However, its slit-like, unequal opesiules, short autozooids and absence of avicularia are exceptional characters that distinguish it from all other species of the genus. Considering these characters, it is conceivable that it belongs to Reniporella . It resembles Reniporella gordoni Guha & Gopikrishna, 2004 in having semicircular opesia, smooth depressed cryptocyst, and large kidney-shaped opesiules. The placement of Reniporella in Steginoporellidae seems doubtful. Given the position of the opesiules, Reniporella is here re-assigned to Thalamoporellidae .

Figures

FIGURE 17. Reniporella reniformis (Guha & Gopikrishna, 2004) n. comb. (GIS/B 0363). A. General view of the colony showing rectangular autozooids. B. Enlargement of the autozooids, cryptocyst, orifices and large unequal opesiules. C. Back view of the colony. D, E. (GIS/B 0369). D. Cylindrical colony showing autozooids. E. Enlargement of the colony showing orifices, slit-like opesiules and cryptocyst. Scale bars: A, 500 µm; B, 200 µm; C, 1 mm; D, 1 mm; E, 500 µm.