Hyporosopora sp.

Zatoń, Michał & Taylor, Paul D., 2009, Middle Jurassic cyclostome bryozoans from the Polish Jura, Acta Palaeontologica Polonica 54 (2), pp. 267-288 : 284

Hyporosopora sp.

Fig. 14 .

Material.—One colony GIUS 8−3509−23.

Measurements.—FWL, 566–700 µm; FWW, 150–166 µm; LAM, 58–116 µm; TAM, 66–116 µm; LPM, 100–133 µm; TPM, 100–133 µm; GTL, 816 µm; GDL, 183 µm; GW, 500 µm; PL, 8.8–10 µm; PW, 8.8–10 µm.

Description.—Colony encrusting, sheet−like, multiserial, bereniciform, unilamellar.

Autozooids elongate, frontal walls flat to convex, zooidal boundaries indistinct in some places. Apertures subcircular, some closed by terminal diaphragms. Preserved peristomes short, tapering distally. Pseudopores poorly preserved due to worn frontal walls, large, as wide as long, drop−shaped, pointed distally ( Fig. 14B ).

One broken gonozooid preserved. Brood chamber small, broader than long, bulbous, sharply delineated from proximal frontal wall, subtriangular in outline with distally extending two lateral lobes; roof densely pseudoporous ( Fig. 14A ). Ooeciopore not visible.

Remarks.—This species is characterized by a small brood chamber differing in shape and size from the other species of Hyporosopora described here. While it may represent a new species, more material is required to justify such distinction.

Stratigraphic and geographic range.—Upper Bathonian of Żarki, Polish Jura.

Figures

Fig. 14. Plagioeciid cyclostome bryozoan Hyporosopora sp. from the Middle Jurassic ore−bearing clays of the Polish Jura, GIUS 8−3509−23. A. Autozooids and partly crushed gonozooid. B. Pseudopores, Upper Bathonian, Żarki (Żar1). Scale bars: 200 µm (A), 20 µm (B). BSE SEM images of uncoated specimens.