Basyaylella elsae, Zágoršek & Gordon, 2013

Zágoršek, Kamil & Gordon, Dennis P., 2013, Late Tortonian bryozoans from Mut Basin, Central Anatolian Plateau, southern Turkey, Acta Palaeontologica Polonica 58 (3), pp. 595-607 : 600-602

Basyaylella elsae sp. nov.

Figs. 2, 3 .

Etymolog y: In honour of Professor Elsa Gliozzi, who provided us with the samples and who has been studying the Başyayla section in detail for many years.

Type material: Holotype: PM2 − T1217 ( Fig. 2B), sample BAS 4 . Paratypes: PM2 − T1218 to T1229 , 12 specimens , samples BAS 4 , 6 , 7 , and 19 ( Figs. 2, 3 ).

Type locality: Başyayla section, Turkey .

Type horizon: Upper Tortonian , Miocene .

Referred material.— 22 additional colonies (two of them illustrated ( Fig. 3B, F ) PM2 − T1159 and PM2 − T1160 ) were studied from samples BAS 7 , 13 , 14 , and 19 under the SEM, but not included into the type collection .

Diagnosis.—As for the genus.

Description.—Colony erect, rigid, branches bifurcating ( Fig. 2A) with autozooecia opening on three sides. Branch cross section circular, no median lamella developed. Attachment point wide, rigid ( Fig. 2F). Frontal part of branch with up to five rows of autozooecia ( Fig. 2A, B), abfrontal side with sinuous, slightly zigzag pattern of attachment of lateral walls ( Fig. 2C–E).

In external view, autozooecia elongated, separated by narrow furrows. Frontal shield of less−calcified autozooecia apparently with areolar pores only ( Fig. 2G) and large central nonporous area. Later, the nonporous area becomes reduced, with the rest of frontal wall strongly perforated. ( Fig. 2B–D, I). Primary orifice circular, semi−oval, with thick, wide but short peristome ( Fig. 2B). A few secondary orifices develop a pseudosinus, perhaps during intramural budding, similar that those described by Berning (2008) ( Fig. 2B, D, H).

Adventitious (interzooidal?) avicularia situated on frontal ( Fig. 2B) and abfrontal sides ( Fig. 2C) of branch, occupying proximal part of autozooecial frontal wall ( Fig. 2B, H). Pivot bar well developed, rounded rostrum palate tapering proximally ( Fig. 2B, C). Ovicells not observed on branch exteriors. Kenozooecia often present in branch bifurcations ( Fig. 2I) or on abfrontal side ( Fig. 2F).

In internal views autozooecia clearly separated by furrows with mixed (umbonuloid and lepralioid) frontal shield. The umbonuloid part elongated semicircular, small with characteristic microstructure ( Fig. 3B, E ) and ring scar ( Fig. 3A, B, D–F ). The lepralioid part perforated by very large pores ( Fig. 3B–F ). Marginal areolar pores visible only near orifice (Fig.

http://dx.doi.org/10.4202/app.2011.0100

3B, F). Primary orifice circular with slightly straight proximal margin ( Fig. 3A, D ) and sometimes with median ridge ( Fig. 3B, E ). Peristome long, smooth ( Fig. 3B, C ). Parallel longitudinal furrows evident in sides of separated adjacent frontal shields ( Fig. 3B, C ). Internal walls thin ( Fig. 3E ).

Ovicells deeply immersed in distal autozooecia ( Fig. 3A, D–F ), not pronounced on external surface; ovicells globular ( Fig. 3F ), visible only when zooids are fractured and viewed from interior ( Fig. 3E ); entooecium perforated by pores of same size as frontal pseudopores ( Fig. 3A, F ), ectooecium not observable. A narrow wall developed between autozooecial orifice and ovicell chamber ( Fig. 3A, F ).

Measurements.—Given in µm, average value in brackets:

– width of colony branch: 519–886 (682) in bifurcation up to 1270

– width of autozooecium (external): 218–399 (310)

– length of autozooecium (external): 503–914 (744)

– width of autozooecium (internal): 170–209 (191)

– length of autozooecium (internal): 633–778 (678)

– width of avicularium: 101–124 (116)

– length of avicularium: 238–319 (267)

– width of kenozooecium: 150–252 (201)

– length of kenozooecium: 160–378 (269)

– diameter of orifice (external): 122–167 (150)

– diameter of orifice (internal): 99–133 (117)

– diameter of pseudopores (external): 29–41 (36)

– diameter of pores (internal): 21–28 (23)

– diameter of peristome in section: 160–167 (164)

– width of ovicell (internal): 151–164 (147)

– width of umbonuloid shield: 87–139 (113)

– length of umbonuloid shield: 109–170 (139) Remarks.—As noted above, there are some similarities with two North American species attributed to Enoplostomella but which are unlikely to belong to that genus.

The type of substrate colonized by Basyaylella elsae sp. nov. has not been observed.

Figures

Fig. 3. Interior view of an ascophoran bryozoan Basyaylella elsae gen. et sp. nov. from the Miocene of Turkey. A. PM2−T126, detail showing part of a concealed ovicell chamber (broken) and the reduced umbonuloid part of the frontal shield. B. PM2−T1159, autozooecial profiles with clearly observable umbonuloid part of the frontal shield, smooth peristome, large pseudopores and laminations in frontal shield. C. PM2−T1227, detail of a laterally broken specimen with well pronounced laminations in frontal shield and a smooth peristome. D. PM2−T1228, interior view showing broken, concealed ovicellular chambers, deeply immersed in distal autozooecia. E. PM2−T1229a, similar view to D and also showing the umbonuloid part of the frontal shield. F. PM2−T1160, detail of ovicell interior with entooecial perforations. A, C, D, E sample BAS 4; B, F sample BAS 7. Scale bars 100 µm.