Fossil Thalamoporellidae (Bryozoa) from Paleogene-Neogene sediments of western Kachchh, Gujarat, India
Author
Sonar, Mohan A.
Department of Geology, Government Institute of Science, Aurangabad, Maharashtra, India.
Author
Pawar, Ravi V.
Department of Geology, Government Institute of Science, Aurangabad, Maharashtra, India.
Author
Wayal, Dyaneshwar V.
Department of Geology, Government Institute of Science, Aurangabad, Maharashtra, India.
text
Zootaxa
2022
2022-02-25
5104
2
251
274
journal article
20446
10.11646/zootaxa.5104.2.5
dc85c0df-79ee-4aab-b21d-2df3a61d8ac0
1175-5326
6280839
DE993A29-98B4-4DA0-85CF-9B8D4868A454
Thalamoporella rhombifera
Guha & Gopikrishna, 2004
(
Fig. 13
,
Table 10
)
Thalamoporella rhombifera
Guha & Gopikrishna, 2004: 25
, figs 22, 23.
Material examined.
GIS/B 0300–0325. Argillaceous limestone in Waior-Charopadi stream near Waghot, Chhasra Formation,
lower Miocene
(Burdigalian),
23°25’55’’ N
,
68°42’40’’ E
,
elevation
28 m
,
16 January 2011
, DST project, New
Delhi
.
Description.
Colonies erect, cylindrical, with dichotomously branching stems, circular in cross-section. Autozooids arranged in quincunx, rectangular, each separated from neighbours by thick, raised granular boundaries; arranged in series of alternating rows (
Fig. 13A
). Orifice transversely D-shaped, distally arched, proximal margin straight.Two small adoral tubercles, one on each side of orifice. Two small equal-sized opesiules, oval or subrounded, below the slanting edge of orifices away from the lateral walls of the autozooid. Frontal cryptocyst well developed, sunken below level of autozooidal margin, granular, coarsely perforated by relatively large pores (
Fig. 13B
). Avicularia at bifurcation of rows, narrowly elongate, symmetrical, almost 75% of autozooid length; torqued towards sibling zooid (
Fig. 13C, D
); rostrum tapering distally with acute tip, rounded proximally, foramen drop-shaped,
c.
80% of avicularian length, the proximal part bordered by smooth cryptocyst. Ovicells not observed.
Remarks.
This species has an avicularium shape similar to that in the
Thalamoporella hamata
–
T. falcifera
–
T. winstonae
group illustrated by
Soule
et al.
(1999
, pp. 7–11, figs 4, 5, 6a, c, 7, 8), but in these species the avicularium is torqued away from the sibling zooid.