Podoliapora doroshivi, Olempska, 2012

Olempska, Ewa, 2012, Exceptional soft-tissue preservation in boring ctenostome bryozoans and associated “ fungal ” borings from the Early Devonian of Podolia, Ukraine, Acta Palaeontologica Polonica 57 (4), pp. 925-940 : 934-936

Podoliapora doroshivi sp. nov.

Figs. 2–8 .

Etymology: After the type locality.

Holotype: ZPAl Br XIV/009, phosphatized colony ( Fig. 3B ).

Type horizon: Early Devonian, Lochkovian, Chortkiv Formation of the Tyver Group.

Type locality: Doroshiv, Podolia, Ukraine. Material.—More than 150 fragments of colonies.

Diagnosis.—A Podoliapora which characterized by cylindrical or irregularly developed autozooids, aperture rounded−ovate disposed symmetrically along “stolon”, with the dimension ranging from 58 to 64 µm, covered inside by the mem−

http://dx.doi.org/10.4202/app.2011.0200

brane with narrow slit−like orifice in its middle part. Two rows of accessory tubules occur along both sides of main “stolon” on autozooids. Up to four lateral stolon−like tubules are located on both sides of the autozooid. “Heterozooids” are numerous, mostly cylindrical in shape, rarely ovate or more irregular; connected to two or three autozooids by “stolons”. Fossilized setigerous collar and cuticular body sac are preserved.

Discussion.— P. doroshivi differs from similar species of Orbignyopora Pohowsky, 1978 in the presence of numerous lateral stolon−like tubules and the presence of specialized heterozooids, presumed to function as store−rooms. Further study is required to determine its family and superfamily range (see discussion in Todd 2000).

Stratigraphic and geographic range.— Type locality only.

Figures

Fig. 2. Early Devonian bryozoan Podoliapora doroshivi gen. et sp. nov., from the Doroshiv section, Podolia, Ukraine.A. Lateral view of a single autozooid showing external morphological features, ZPAL Br XIV/102. B. Reconstruction in transverse section.C. Reconstruction in longitudinal section.

Fig. 3. Early Devonian bryozoan Podoliapora doroshivi gen. et sp. nov., from the Doroshiv section, Podolia, Ukraine.Stereo−pairs of phosphatized colonies in basal view; frontal parts of the colonies and orifices are not visible as they opened onto the surface of the host shell. A–C. Internal views of partly preserved zooids with basal walls collapsed, soft−tissue preserved inside autozooids, and orifices visible at the distal ends of autozooids. A. ZPAL Br XIV/008. B. ZPAL Br XIV/009. C. ZPAL Br XIV/015. D–F. Basal views of the colonies with zooid completely preserved. D. ZPAL Br XIV/002. E. ZPAL Br XIV/155. F. ZPAL Br XIV/157.

Fig. 4. Early Devonian bryozoan Podoliapora doroshivi gen. et sp. nov., from the Doroshiv section, Podolia, Ukraine. SEM photographs showing phosphatized soft−tissue preserved inside autozooids. ZPAL Br XIV/009. A. Internal view (A1) showing wrinkling frontal (arrow) and lateral cystid walls, setigerous collar twisted within the vestibulum, entrance of the main stolon into the autozood is preserved below the vestibulum, secondary−order “stolons” partly preserved in both sides of the autozooid, oblique lateral view (A2) showing accessory tubules and imprints of the host shell microstructure preserved on the surface of the coating layer. B. Internal view of autozooid (B1) and close−up showing longitudinal parietal muscles and irregular shape of autozooids occurring in dense colonies (B2). C. Internal view showing setigerous collar twisted within vestibulum.

Fig. 6. Early Devonian bryozoan Podoliapora doroshivi gen. et sp. nov., from the Doroshiv section, Podolia, Ukraine. SEM photographs showing imprints of the molluscan host shell microstructures preserved on the surface of the coating layer (internal mould of the interstitial space). A. Basal part of the autozooid specimen, ZPAL Br XIV/155. B. Oblique lateral view showing the coating layer with host shell microstructure preserved; the external surface of cuticle is visible only in places where the coating layer have been damaged; arrow shows poorly visible micro−pore on the surface of cuticle, ZPAL Br XIV/002. H

Fig. 7. Early Devonian bryozoan Podoliapora doroshivi gen. et sp. nov., from the Doroshiv section, Podolia, Ukraine. SEM photographs of zooids coated by micro−fibrils of host shell microstructure. A. ZPAL Br XIV/008. Basal view of partly preserved autozooid, cylindrical−heterozooid and “stolons” (A1). Lateral view of proximal part of autozooid showing partly preserved main tunnel−like stolon (A2). B. ZPAL Br XIV/009. Lateral view of side wall of autozooid (B1). Partly preserved autozooid with accessory tubules and internal view showing cuticle layer preserved inside the zooid and external coated layer with imprint of host shell microstructure (B2). Obliquely internal view of autozooid (vestibular part not preserved) showing cuticle with folds of longitudinal parietal muscles preserved (B3). Internal view of autozooid showing folds of circular and longitudinal muscles (B4).

Fig. 8. Early Devonian bryozoan Podoliapora doroshivi gen. et sp. nov., from the Doroshiv section, Podolia, Ukraine. A. ZPAL Br XIV/009. Lateral view of cylindrical−shaped heterozooid cavity, basal wall collapsed (A1). Close−up showing external coating layer and internal lamellae, basal wall collapsed (A2). B. ZPAL Br XIV/011. Oblique view of the partly preserved colony showing cylindrical heterozooids, basal wall collapsed. C. ZPAL Br XIV/112; Lateral view showing autozooids and ovate−shaped heterozooids (C1), lateral views of heterozooids showing layers infilling the interior of the cavity, visible in places where the coating layer has not been preserved (C2, C3), basal walls collapsed. D. ZPAL Br XIV/071. Fragmentary preserved colony in oblique view showing heterozooid cavity with basal wall preserved. E. ZPAL Br XIV/137. Oblique view of cylindrical heterozooid with basal wall collapsed (E1), close−up showing host shell microstructure preserved on the surface of the coating layer (E2).