Cavernella praecavifera
Creators: name: Ernst, Andrej
name: Claussen, Anna Lene
name: Seuss, Barbara
name: Wyse Jackson, Patrick N.
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Bryozoa
Stenolaemata
Fenestrida
Fenestellidae
Cavernella
Cavernella praecavifera

description: Cavernella praecavifera (Schulga-Nesterenko, 1951)
Figures 12H, 13 A-F, 14A-D; Appendix
1951 Fenestella praecavifera Schulga-Nesterenko, p. 44-45, pl. 9, fig. 4, text-fig. 9.
1951 Fenestella dvinensis Schulga-Nesterenko, p. 45-48, pl. 9, figs. 2, 5, text-fig. 10.
non 1983 Fenestella dvinensis Schulga-Nesterenko, 1951; Yang and Lu, p. 273-274, pl. 5, figs. 11-14.
2001 Cavernella dvinensis (Schulga-Nesterenko, 1951); Morozova, pl. 7, fig. 2.
Material. SNSB-BSPG 2020 XCI 69, SNSB-BSPG 2020 XCI 71, SNSB-BSPG 2020 XCI 73, SNSB-BSPG 2020 XCI 78, SNSB-BSPG 2020 XCI 79, SNSB-BSPG 2020 XCI 112, SNSB-BSPG 2020 XCI126, SNSB-BSPG 2020 XCI 127, SNSB-BSPG 2020 XCI 128.
Exterior description. Reticulate colonies formed by straight branches joined by relatively narrow dissepiments. Fenestrules oval to rectangular. Autozooecia arranged in two rows on branches. Autozooecial apertures circular, with low peristome and stellate structure; two to four apertures spaced per fenestrule length. Rounded nodes on the low keel, regularly spaced. Reverse side finely striated containing rounded nodes 0.025 –0.040 mm in diameter.
Interior description. Autozooecia relatively long, roughly pentagonal to triangular in mid-tangential section; with short to moderately long vestibule in longitudinal section. Axial wall between autozooecial rows strongly undulating; aperture positioned at distal end of chamber. Superior hemisepta long; inferior hemisepta indistinct. External laminated skeleton well-developed on both obverse and reverse sides traversed by microstylets. Microstylets 0.008 –0.010 mm in diameter. Heterozooecia are cavernozooecia in form of elongated chambers, arranged in pairs on the reverse side of branches or on dissepiments, opening into the fenestrule, 0.06–0.10 mm in width and with rounded openings 0.04–0.05 mm in diameter.
Remarks. Differences between Cavernella dvinensis (Schulga-Nesterenko, 1951) and C. praecavifera (Schulga-Nesterenko, 1951) are minimal, therefore, C. dvinensis is regarded as being junior synonym of C. praecavifera. As far as Morozova (1974, p. 65) designated Fenestella dvinensis Schulga-Nesterenko, 1951, as the type species of the genus Cavernella, this name is retained for the type species of the genus, despite its junior status (Code of Zoological Nomenclature, Article 67.1.2).
The species identified as Fenestella dvinensis Schulga-Nesterenko, 1951, from the Kankerin Formation of Kalpin of western Xinjiang, China (Yang and Lu, 1983) does not belong to this species because it lacks cavernozooecia. It differs also in some other morphological characters. This bryozoan has stellate nodes instead of rounded ones in C. dvinensis. Furthermore, the Chinese material has significantly smaller fenestrules (fenestrule length 0.40–0.45 mm vs. 0.60–0.65 mm in the material from the Russian Platform and 0.53–0.71 mm in the studied material from the Finis Shale).
Cavernella praecavifera (Schulga-Nesterenko, 1951) differs from Cavernella supercarbonica (Schulga-Nesterenko, 1951) from the Pennsylvanian (Gzhelian) of the Russian Platform in having smaller fenestrules (fenestrule width 0.19–0.39 mm vs. 0.27–0.40 mm in C. supercarbonica; fenestrule length 0.53–0.71 mm vs. 0.50– 0.75 mm in C. supercarbonica).
Occurrence. Pennsylvanian (Upper Carboniferous, Kasimovian); Russia. Graham Formation, Pennsylvanian (Virgilian); TXV-200 (“Spillway section at Lost Creek Lake”), Texas, USA.
description: Published as part of Ernst, Andrej, Claussen, Anna Lene, Seuss, Barbara & Wyse Jackson, Patrick N., 2022, Stenolaemate bryozoans from the Graham Formation, Pennsylvanian (Virgilian) at Lost Creek Lake, Texas, USA, pp. 1-56 in Palaeontologia Electronica (a 15) (a 15) 25 (2) on page 24, DOI: 10.26879/1174, http://zenodo.org/record/11032471