Antropora ramaniaensis, Sonar & Pawar & Wayal, 2022

Sonar, Mohan A., Pawar, Ravi V. & Wayal, Dnyaneshwar V., 2022, Newly discovered species of cheilostomatid Bryozoa from the Miocene of western Kachchh, Gujarat, India, European Journal of Taxonomy 821, pp. 16-39 : 22-24

Antropora ramaniaensis sp. nov.

urn:lsid:zoobank.org:act:24CED4FE-BFAA-4443-A52B-9A2A97D58DB7

Fig. 4 ; Table 3

Diagnosis

Unilaminar encrusting colonies with rhomboidal to oval autozooids; opesia oval to subtriangular, extensive finely granular cryptocyst, small elongate avicularia placed on raised cystid randomly located in the narrow interzooecial space. Ovicells endozooecial, cap like.

Etymology

The species is named after the locality ‘Ramania’ in Kachchh, Gujarat.

Material examined

Holotype INDIA • fossiliferous limestone of cliff section exposed 1.5 km southeast of Waghot Village in Waior-Charopadi stream; Burdigalian, lower Miocene, Chhasra Formation; 23°25′49″ N, 68°42′35″ E; Jan.– Feb. 2012; Sonar leg.; GIS/B 0440 .

Paratypes INDIA • 20 specs; same collection data as for holotype; GIS/B 0441 to 0460 .

Description

Colony unilaminar, encrusting. Autozooids oval to lozenge-shaped, separated by shallow, thin grooves ( Fig. 4A ). Gymnocyst vestigial; cryptocyst extensive, finely granular, gently sloping into opesia. Opesia roughly oval to bell shaped given the later constrictions, narrowing distally, occupying ½ of frontal area ( Fig. 4B–C ). Distal zooidal margins arched, raised. Small interzooecial avicularia elongate, with rounded rostrum, mostly distally directed, without crossbar, avicularium raised on small cystid seated randomly in narrow interzooidal space. Ovicells endozooecial, cap like, observed in fertile zooids ( Fig. 4C–D ).

Remarks

The circum-tropical Recent species Antropora minor ( Hincks, 1880) is similar to the Kachchh species in the shape of autozooids and opesia but differs in having a coarsely granular cryptocyst, the presence of small kenozooidal papillae at the proximal end of the autozooid and the occurrence of large vicarious avicularia (see Tilbrook 1998: 34, fig 2a–f). Antropora typica Canu & Bassler, 1928 has a superficial resemblance with the Kachchh species in its general morphology; however, the former species is characterized by smoothly calcified gymnocysts, interzooecial avicularia with an acutely triangular rostrum, and sporadic large vicarious avicularia (see Tilbrook 1998: 37, figs 1f, 3a). Antropora leucocypha Marcus, 1937 also resembles the new Kachchh species in the shape of the autozooid (see Winston 1982: 123, figs 36–37). However, the former has a beaded and crenulated cryptocyst and autozooids surrounded by numerous kenozooids. The Recent cosmopolitan warm-water species A. granulifera Hincks, 1880 differs in the crenulated, raised mural rim and shows a similarity in the shape of the autozooids. The Indonesian late Burdigalian species A. cf. subvespertilio ( Canu & Bassler, 1929) differs in having a trifoliate opesia and differently shaped autozooids (see Di Martino & Taylor 2014: 43, pl. 15, fig. 2a–e). Antropora gadhavii Guha & Gopikrishna, 2005 differs from A. ramaniaensis sp. nov. in having a much less developed cryptocyst steeply sloping into the opesia, distal zooidal margins broad and subrectangular, indistinct autozooidal boundaries and oval avicularia with an acute rostrum.

Figures

Fig. 4. Antropora ramaniaensis sp. nov., holotype (GIS/B 0440). A. General view of the colony showing rhomboidal to oval autozooids. B. Enlargement of the colony showing autozooids with extensive cryptocyst and interzooecial avicularia. C. Close-up of autozooids with cap like, endozooecial ovicells (arrow) and interzooecial avicularia. D. Close-up of autozooids with the endozooecial ovicells.