Tubucella mammillaris (Milne Edwards, 1836)

Zágoršek, Kamil & Gordon, Dennis P., 2014, Revision of the Oligocene bryozoan taxa described by Stoliczka (1862), with the description of a new genus of Bryocryptellidae, Geodiversitas 36 (4), pp. 541-564 : 556

Tubucella mammillaris

( Milne Edwards, 1836)

( Fig. 6I, J )

Eschara mammillaris Milne Edwards, 1836: 336 , pl. 11, fig. 10.

Eschara ( Porina ) porulosa Stoliczka, 1862: 89, pl. 3, fig. 3.

Tubucella mammillaris – Zágoršek 2001: 67, pl. 28, figs 2, 3, 5; 2003: 176 (cum syn.).

MATERIAL EXAMINED. — Ŋree syntypes of Eschara porulosa, registered as 2010/0259/0009. Ŋe chosen lectotype (designated here) corresponds with Stoliczka’s illustration (1862: pl. 3, fig. 3) and is depicted as Figure 6I herein.

DIAGNOSIS. — Colony large, bilamellar, with lensoidal cross section and well-developed median lamella. Autozooecia hexagonal to circular, arranged in c. 12-15 longitudinal series around branch. Each autozooecium comprising two regions of about equal length, a distal peristomial part and a proximofrontal part, the former strongly convex, sometimes hexagonal, the latter weakly convex, not clearly delimited from that neighbours, the frontal shield coarsely pseudoporous. Aperture circular to oval, surrounded by thick, low peristome. Ascopore of similar size to pseudopores, situated in distal half of autozooecia. Ooecia and avicularia lacking.

REMARKS

Ŋe separation of autozooecia into two parts as described by Zágoršek (2003) and also illustrated by Bock (2013a) is not evident in the syntype specimens (the thin threads of calcification normally separating these parts are not observable). Other features, however (flat colonies, presence of median lamella and ascopore situated in the distal half of the autozooecium), clearly identify this species.

Tubucella mammillaris differs from Tubucella papillosa (Reuss, 1848) in having flatter branch profiles ( T. papillosa has more-rounded branches), shorter autozooecia (more elongate in T. papil- losa) and the ascopore situated closer to the aperture (near the centre of the frontal shield in T. papillosa ).

Figures

FIG. 6. – A-D, Anarthropora macropora (Stoliczka, 1862), n. comb.; A, general view of lectotype; B, autozooecium showing frontal foramina and suboral avicularium; C, syntype showing quincuncial arrangement of autozooecia; D, frontal-shield foramen showing well-preserved radial denticulation;E, F, Escharella grotriani (Stoliczka,1862);E, lectotype showing arrangement of autozooecia; F, zooecium with ooecium and oral spines; G, H, Myriapora? beyrichi (Stoliczka, 1862), n. comb.; G, lectotype showing smooth outlines of autozooecia; H, detail of aperture with condyles typical of myriaporids; I, J, syntype of Eschara porulosa identified as Tubucella mammillaris (Milne Edwards, 1836); I, general view of chosen lectotype of synonymous Eschara porulosa Stoliczka, 1862; J, lateral view of colony showing autozooecia with large apertures. Scale bars: 100 μm.