taxonID	type	description	language	source
03D587D79670FFA8F300FA88FB5AF832.taxon	type_taxon	Type species Rhagasostoma hexagonum Koschinsky, 1885, by subsequent designation (Canu & Bassler 1917: 31). Eocene, Lutetian, Gosaumergel von Götzreuth (= Gerhartsreiter Schichten), graben near Siegsdorf-Gerhartsreit, Traunstein, Bavaria, Germany. A neotype was chosen and figured by Taylor et al. (2018 b).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79670FFA8F300FA88FB5AF832.taxon	diagnosis	Amended diagnosis Colony encrusting or erect, vincularian and dichotomously branching. Autozooids subhexagonal; zooidal boundaries raised. Cryptocyst extensive, granular, sometimes peripheral caverns present. Gymnocyst lacking or minutely present. Opesia terminal or subterminal, occupying about one-third of the frontal surface, longitudinally elliptical, with deep opesiular indentations at the proximolateral corners, sometimes with occlusor lamina. Ovicells endozooidal or immersed. Avicularia vicarious and about the same size as autozooids, or interzooidal; opesia roundish or longitudinally elliptical, located centrally, usually with thin articular ridges bearing two short teeth proximally and a short or long, slit-like opesiular indentation between the teeth; sometimes wedge-like structures present. Kenozooids rounded or oval bifoliated and located at edges of colonies with opesia roundish, small.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79671FFA2F330FED8FCB7FECF.taxon	description	Figs 3 – 4, Table 1	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79671FFA2F330FED8FCB7FECF.taxon	materials_examined	Material studied Lectotype (here designated) UNITED KINGDOM • England; Chalk (? Santonian) of Sussex; NHMUK D 2967 (Fig. 3 A – C; figured by Lonsdale 1850: pl. 18. B, fig. 9). Paralectotype (here designated) UNITED KINGDOM • same data as for lectotype; NHMUK D 2959 (Fig. 3 D; figured by Lonsdale 1850: pl. 18. B, fig. 11). Additional figured material UNITED KINGDOM • England, Sussex coast; late Santonian (Marsupites testudinarius Zone); SM B 36881 (Fig. 3 E – G; figured by Brydone 1936: pl. 35, fig. 8) • England, Hampshire, near Winchester, Owslebury, Hensting Farm; early Campanian (Goniotheutis quadrata Zone); SM B 36669 (Fig. 3 H – J; figured by Brydone 1930: pl. 26, figs 2 – 3). GERMANY • Lower Saxony, Sehnde-Höver, Alemannia quarry; early Campanian; SMF 24564 (Fig. 4 A – B; figured by Voigt 1975: pl. 5, figs 1, 3 – 4 as coll. Voigt no. 7381) • Same data as for preceding; SMF 29915 (Fig. 4 C). BELARUS • 2 specs; Grodno Region, quarry near Hrodna / Grodno (Гродна / Гродно); erratic block of? late Campanian age; PIN 2922 / 219 (Fig. 4 D), 2922 / 273 (Fig. 4 E – F). Other material GERMANY • Lower Saxony, Sehnde-Höver, Alemannia quarry; early Campanian; SMF 29916. BELARUS • 2 specs; Grodno Region, quarry near Hrodna / Grodno (Гродна / Гродно); erratic block of? late Campanian age; PIN 2922 / 217, 2922 / 250. Description	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79671FFA2F330FED8FCB7FECF.taxon	description	Colony usually erect, with flattened bifoliate branches, fragments 2.0 – 7.0 mm long by 2.5 – 5.5 mm wide; encrusting sheet-like colonies, measuring up to 5.0 – 7.0 mm long by 3.5 – 7.0 mm wide. Ancestrula and early astogeny not observed. Autozooids variable in shape, often broad, 6 - sided and rhomboidal with rounded distal ends, zooidal boundaries raised. Gymnocyst lacking. Cryptocyst extensive, finely pustulose, depressed or slightly convex centrally, sometimes with proximal or proximolateral peripheral caverns, up to 0.17 mm long (Fig. 3 D – G; and Taylor 1991, 2002). Opesiae terminal, rarely subterminal, semielliptical with narrow shelf in the distal part, formed by two walls, a thin inner wall delimiting the distolateral part and a salient, thickened outer wall delimiting the proximolateral part (Fig. 3 J). Proximal edge of opesia straight, smooth, thickened, with outgrowths near the two proximolateral corners delimiting, small round opesiules (outgrowths are often broken, thus giving the opesiules the appearance of opesiular indentations or they may be obscured by sediment infills of the opesia). Septula not observed. Ovicells endozooidal, brooding cavity located within the proximal part of the distal zooid (Figs 3 C, I, 4 A – D); ooecium is formed by the distal zooid, well-recognizable, with cryptocyst-like surface and arch-like proximal edge with elongated proximolateral processes extending along the cryptocyst of the maternal zooid. Avicularia interzooidal, longer than autozooids, elongate (Figs 3 C, I – J, 4 F). Rostrum channelled, with elevated wing-like walls and pointed apex, conical in outline, asymmetrical, dextral or sinistral. Proximal part rounded, shorter and wider than rostrum. Cryptocyst pustulose, concave, sometimes with proximal peripheral caverns (Fig. 3 E). Opesia large, usually roundish, rarely oval, with thickened distolateral edge and with thin articular ridges bearing two short teeth in the proximal margin and a slit-like opesiular indentation between the teeth; opesiules lacking. Kenozooids round, located at edges of colonies (Fig. 4 A, C – D). Cryptocyst finely pustulose, peripheral caverns not observed. Opesia roundish, small. Intramural reparative budding of autozooids and avicularia sometimes observed (Fig. 4 C, F), all with the same polarity as the host zooid. Closure plates and reparative budding kenozooids not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79671FFA2F330FED8FCB7FECF.taxon	discussion	Remarks We have restudied Lonsdale’s syntypes in the NHMUK collection, choosing a lectotype (the bifoliate specimen figured by Lonsdale 1850: pl. 18. B, fig. 9), as well as material from the collections of R. M. Brydone, E. Voigt, and T. A. Favorskaya. One specimen identified by Brydone as O. inelegans (Brydone 1930: pl. 26, figs 2, 3) does indeed belong to this species, while another (Brydone 1930: pl. 25, figs 11, 12) is regarded as a new species, Rhagasostoma brydonei sp. nov. The specimen figured by Brydone (1930: pl. 26, fig. 1) was not restudied. The specimen described by Brydone (1936: pl. 35, fig. 8) as belonging to the subspecies O. inelegans angliae (Brydone, 1936) is conspecific with Lonsdale’s encrusting sheet-like colony of R. inelegans. Favorskaya (1992, 1996) mentioned three specimens of this species from Campanian deposits in Uzbekistan and Turkmenistan, which according to our studies comprise two species: R. aralense sp. nov. (Favorskaya 1992: 125, pl. 64, fig. 6, pl. 65, fig. 1) and R. operculatum sp. nov. (Favorskaya 1992: pl. 64, fig. 7; 1996: pl. 3, fig. 4). Rhagasostoma inelegans can be easily distinguished from R. brydonei sp. nov., R. minuens Brydone, 1936 and R. operculatum sp. nov. in having an avicularian rostrum conical in outline rather than spade-shaped or falciform. It further differs from R. brydonei sp. nov. by having endozooidal ovicells instead of immersed ovicells. Rhagasostoma inelegans differs from R. angliae in that the avicularian cryptocyst has a large roundish or oval opesia lacking opesiules, instead of a small subcircular opesia with two opesiules. It differs from R. aralense sp. nov., which also has an avicularian rostrum conical in outline, by the rostrum being asymmetrical instead of symmetrical, and the avicularian opesia roundish rather than egg-shaped.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79671FFA2F330FED8FCB7FECF.taxon	distribution	Distribution Late Santonian United Kingdom: Coast of Sussex, England. Early Campanian Germany: Alemannia quarry, Sehnde-Höver, Lower Saxony; Lahstedt-Oberg, Lower Saxony (according to Voigt 1949, 1975). United Kingdom: Hensting Farm, Owslebury, Hampshire, England. Late Campanian Belarus: Quarry near Hrodna / Grodno (Гродна / Гродно), Grodno Region.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7967AFFA1F37CFEA3FD5BFCE2.taxon	description	urn: lsid: zoobank. org: act: B 229 DB 57 - 799 E- 494 C- 95 EF- 7 F 117080 B 3 E 9 Fig. 5, Table 2	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7967AFFA1F37CFEA3FD5BFCE2.taxon	diagnosis	Diagnosis Colony erect, bifoliate. Autozooids rectangular, zooidal boundaries raised; gymnocyst lacking; cryptocyst extensive with peripheral caverns; opesia terminal, rarely subterminal, semielliptical with shelf in the distal part, proximal edge with small roundish opesiules; ovicells immersed, ooecia vestigial. Avicularia interzooidal, longer than autozooids; rostrum channeled with pointed tip, spade-shaped, symmetrical or asymmetrical; proximal part rounded, shorter and wider than rostrum; opesia oval or roundish with thickened articular ridges bearing two very short teeth proximally and a long, slit-like opesiular indentation between the teeth; opesiules lacking. Kenozooids rare, rounded or oval.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7967AFFA1F37CFEA3FD5BFCE2.taxon	etymology	Etymology In honour of Reginald Marr Brydone (1873 – 1943), a prolific author of bryozoan species from the English Chalk and collector of the type material of the new species.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7967AFFA1F37CFEA3FD5BFCE2.taxon	materials_examined	Material studied Holotype UNITED KINGDOM • England, Hampshire, south of Alton, Froxfield, Kings Lane; latest Turonian (Sternotaxis plana Zone); SM B 36666 (Fig. 5 A – B; figured by Brydone 1930: pl. 25, figs 11 – 12). Paratypes UNITED KINGDOM • Same data as for holotype; SM B 36667 (Fig. 5 C – D) • 3 specs; England, Kent; Coniacian of Chatham; SMF 29939 (Fig. 5 F), 29940 (Fig. 5 E), 29941 (Fig. 5 G – H).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7967AFFA1F37CFEA3FD5BFCE2.taxon	description	Description Colony usually erect, with flattened bifoliate branches, fragments 3.5 – 6.0 mm long by 2.0 – 6.5 mm wide. Ancestrula and early astogeny not observed. Autozooids variable in shape, often broad and roughly rectangular with rounded distal ends; zooidal boundaries raised. Gymnocyst lacking. Cryptocyst extensive, finely pustulose, depressed or slightly convex centrally, with peripheral caverns surrounding the cryptocyst (Fig. 5 B, D, F – H) or rarely developed in proximal or proximolateral part of cryptocyst (Fig. 5 E). Opesia terminal, rarely subterminal, semielliptical, with shelf in the distal part, formed by two walls, a thin inner wall delimiting the distolateral part and a salient, thickened outer wall delimiting the proximolateral part (Fig. 5 H). Proximal edge of opesia straight, smooth, thickened, with outgrowths near the two proximolateral corners delimiting small, roundish opesiules (outgrowths are often broken thus giving the opesiules the appearance of opesiular indentations or they may be obscured by sediment infills of the opesia). Septula not observed. Ovicells immersed, ooecium formed by the distal zooid, vestigial, vizor-like, brooding cavity located in the distal part of the maternal zooid and below the colony surface (Fig. 5 H). Avicularia interzooidal, elongate, longer than autozooids. Rostrum channelled, with elevated wing-like walls and pointed tip, spade-shaped, symmetrical or asymmetrical, dextral or sinistral. Proximal part rounded, shorter and wider than rostrum. Cryptocyst pustulose, concave, peripheral caverns rare. Opesia large, usually oval, rarely roundish, with thickened articular ridges bearing two very short teeth proximally and a long, slit-like opesiular indentation between teeth; opesiules lacking. Kenozooids rounded or oval, located usually at edges of colony (Fig. 5 B). Cryptocyst finely pustulose with proximal peripheral caverns. Opesia roundish, small. Closure plates, intramural reparative budding of zooids not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7967AFFA1F37CFEA3FD5BFCE2.taxon	discussion	Remarks We have restudied Brydone’s examples of Rhagasostoma inelegans in the SM collection. The specimen identified by Brydone as this species (Brydone 1930: pl. 25, figs 11, 12) does not belong to Lonsdale’s species and is here regarded as a new species, R. brydonei sp. nov. The new species differs from the closely related species Rhagasostoma inelegans, R. minuens, R. angliae and R. aralense sp. nov. in the avicularian rostrum being spade-shaped rather than having a conical outline shape or falciform. Moreover, the ovicells of R. brydonei sp. nov. are immersed. Rhagasostoma brydonei sp. nov. differs from R. angliae in having an avicularian cryptocyst with large oval or roundish opesia lacking opesiules, instead of a small subcircular opesia and two opesiules. The new species differs from R. operculatum sp. nov., which has a similar spade-shaped avicularian rostrum, by the rostrum being narrowed at the base, enlarged centrally and with a pointed tip, instead of being the same width along almost its entire length and having a pointed or rounded tip.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7967AFFA1F37CFEA3FD5BFCE2.taxon	distribution	Distribution Late Turonian United Kingdom: Kings Lane, Froxfield, south of Alton, Hampshire, England. Coniacian United Kingdom: Chatham, Kent, England.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79679FFBDF305FC70FADBFA7A.taxon	description	Figs 6 – 7, Table 3	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79679FFBDF305FC70FADBFA7A.taxon	materials_examined	Material studied Lectotype (here designated) UNITED KINGDOM • England, East Sussex, between Brighton and Roedean; late Santonian (Uintacrinus socialis Zone / lower Marsupites testudinarius Zone); SM B 36883 (Fig. 6 A – D; figured by Brydone 1936: pl. 35, fig. 10). Paralectotype (here designated) UNITED KINGDOM • England, Norfolk, Trimingham; early Maastrichtian (Ostrea lunata Zone, Porosphaera Beds); SM B 36882 (Fig. 6 E – F; figured by Brydone 1936: pl. 35, fig. 9). Additional figured material UNITED KINGDOM • 2 specs; England, Kent; Coniacian of Chatham; SMF 29921 (Fig. 7 A – B), 29922 (Fig. 7 C) • England, Wiltshire, SW of Salisbury, Harnham; early Campanian; SMF 29920 (Fig. 7 D) • England, Norfolk, Trimingham; early Maastrichtian (Ostrea lunata Zone) [middle Campanian (Belemnitella mucronata Zone), Weybourne, Norfolk, in SM database]; SM B 36678, specimen (a) (Fig. 7 H) • 2 specs; England, East Sussex, Newhaven, Meeching Quarry; early Campanian; SMF 29943 (Fig. 7 E), 29944 (Fig. 7 F). FRANCE • Hanches; Campanian; SMF 29918 (Fig. 7 G). Other material UNITED KINGDOM • 3 specs; England, East Sussex, Newhaven, Meeching Quarry; early Campanian; SMF 29919, 29942, 29945. GERMANY • Schleswig-Holstein, Lägerdorf; early Campanian; SMF 29917.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79679FFBDF305FC70FADBFA7A.taxon	description	Description Colony encrusting sheet-like, fragments about 10 mm in diameter, or erect with flattened bifoliate branches, fragments up to 2.0 – 10.0 mm long by 2.0 – 5.0 mm wide. Ancestrula (Fig. 6 C) about 0.27 mm in diameter, rounded rhombic. Autozooids variable in shape, often broad and subrectangular with rounded distal ends; zooidal boundaries raised. Gymnocyst lacking. Cryptocyst extensive, finely pustulose, depressed or slightly convex centrally, sometimes with proximolateral peripheral caverns, up to 0.22 mm long (Fig. 7 B – F), rarely peripheral caverns surrounding the cryptocyst (Fig. 7 H). Opesia terminal, rarely subterminal, semielliptical with slight shelf in the distal part (Fig. 6 D, F), formed by two walls, a thin inner wall delimiting the distolateral part and a salient, thickened outer wall delimiting the proximolateral part. Proximal edge of opesia straight, smooth, thickened, with outgrowths near the two proximolateral corners delimiting, small roundish opesiules (outgrowths are often broken thus giving the opesiules the appearance of opesiular indentations, or they may be obscured by sediment infills of the opesia). Septula not observed. Ovicells endozooidal, ooecium is formed by the distal zooid, recognizable as a small swelling of its proximal cryptocyst (Figs 6 D, 7 C, E – F). Avicularia interzooidal, elongate, longer than autozooids. Rostrum channeled with elevated wing-like walls and pointed tip, falciform (almost the same width along the whole length of the rostrum or slightly expanding near apex, and pointed tip curved, sickleshaped), asymmetrical, dextral or sinistral. Proximal part rounded, shorter and wider than the rostrum. Cryptocyst pustulose, concave, without peripheral caverns. Opesia large, roundish or oval, with thickened articular ridges bearing two short teeth proximally and a long, slit-like opesiular indentation between the teeth; opesiules lacking. Kenozooids rounded, rare, located at the margins of a colony. Cryptocyst finely pustulose. Opesia round. Intramural reparative budding of avicularia within host avicularia sometimes observed (Fig. 7 B), all with the same polarity as the host zooid. Intramural reparative kenozooidal buds sometimes observed within host autozooids and avicularia (Fig. 7 D – E). Closure plates not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79679FFBDF305FC70FADBFA7A.taxon	discussion	Remarks Brydone (1936) introduced the subspecies Rhagasostoma inelegans minuens for unilaminar colonies lacking ovicells. We have restudied Brydone’s syntypes in the SM collection, choosing a lectotype (the specimen figured by Brydone 1936: pl. 35, fig. 10); endozooidal ovicells are present in this colony. Voigt (1949) mentioned one specimen of “ Onychocella cf. inelegans ” from the early Campanian of Lägerdorf, Schleswig-Holstein of Germany but this belongs to Rhagasostoma minuens. Rhagasostoma minuens can easily be distinguished from R. inelegans, R. brydonei sp. nov., R. aralense sp. nov. and R. operculatum sp. nov. in having a falciform avicularian rostrum. The species differs from R. angliae, specimens of which may have similar falciform avicularian rostra, in the avicularian cryptocyst having large roundish or oval opesia without opesiules instead of small subcircular opesia and two opesiules.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79679FFBDF305FC70FADBFA7A.taxon	distribution	Distribution Coniacian United Kingdom: Chatham, Kent, England. Late Santonian United Kingdom: between Brighton and Roedean, East Sussex, England. Early Campanian United Kingdom, England: Harnham, SW of Salisbury, Wiltshire; Meeching Quarry, Newhaven, East Sussex. Germany: Lägerdorf, Schleswig-Holstein. Campanian France: Hanches. Early Maastrichtian United Kingdom: Trimingham, Norfolk, England.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79665FFB6F31DF9F7FD57FCFA.taxon	description	Figs 8 – 9, Table 4	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79665FFB6F31DF9F7FD57FCFA.taxon	materials_examined	Material studied Lectotype (here designated) UNITED KINGDOM • England, Norfolk, Norwich; Middle Campanian (Belemnitella mucronata Zone) of Hartford; SM B 36877 (Fig. 8 A – E; figured by Brydone 1936: pl. 35, fig. 4). Paralectotype (here designated) UNITED KINGDOM • England, Norfolk; early Maastrichtian (Ostrea lunata Zone) of Trimingham; SM B 36879 (Fig. 8 F – H; figured by Brydone 1936: pl. 35, figs 6 – 7). Additional figured material UNITED KINGDOM • England, Norfolk; middle Campanian (Belemnitella mucronata Zone) of Weybourne; SM B 36671 (Fig. 9 A – C). FRANCE • Île-de-France; late Campanian of Vigny; SMF 29914 (Fig. 9 D – E). GERMANY • Early Maastrichtian of Hemmoor; SMF 26288 (Fig. 9 F – G; figured by Voigt 1949: pl. 8, fig. 3).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79665FFB6F31DF9F7FD57FCFA.taxon	description	Description Colony encrusting, sheet-like, fragments up to 10 mm in diameter, or erect with flattened, bifoliate branches, fragments up to 6.0 – 7.0 mm long by 3.0 – 5.0 mm wide. Ancestrula (Fig. 8 B) about 0.33 mm in diameter, rounded rhombic, surrounded by six periancestrular zooids, five zooids possibly budded directly from the ancestrula. Autozooids variable in shape, often broad and roughly rectangular with rounded distal ends; zooidal boundaries raised. Gymnocyst lacking. Cryptocyst extensive, finely pustulose, depressed or slightly convex centrally, sometimes with peripheral cavern surrounding the cryptocyst (Fig. 8 C). Opesia terminal or subterminal, semielliptical with shelf distally, formed by two walls, a thin inner wall delimiting the distolateral part and a salient, thickened outer wall delimiting the proximolateral part (Figs 8 E, H, 9 C). Proximal edge of opesiae straight, smooth, thickened, with outgrowths near the two proximolateral corners delimiting small, roundish opesiules (outgrowths are often broken, giving the opesiules the appearance of opesiular indentations, or they may be obscured by sediment fillings inside the opesia). Septula not observed. Ovicells endozooidal, ooecium is formed by the distal zooid, ill-recognizable, with cryptocyst-like surface (Fig. 9 E). Avicularia interzooidal, longer than autozooids, elongate. Rostrum channeled with elevated wing-like walls and pointed tip, conical in outline or sometimes falciform, asymmetrical, dextral or sinistral. Proximal part rounded, shorter and slightly wider than the rostrum. Cryptocyst pustulose, concave with depression centrally, sometimes with peripheral cavern surrounding the cryptocyst (Fig. 8 C, E, H), having three openings: a distal small subcircular opesia; two lateral and parallel slit-like opesiules formed by long teeth of articular ridges, which grow together with proximal edge of opesia; a long and slit-like opesiular indentation proximally between the teeth (Figs 8 E, H, 9 C, E, G). Cryptocyst between openings frequently destroyed, causing the openings to coalesce into a single opening of variable outline that is sometimes tulip-shaped. Kenozooids rounded, very rare, located at the margins of a colony or between zooids (Fig. 9 D). Cryptocyst finely pustulose. Opesia roundish, small. Closure plates, intramural reparative budding in autozooids and avicularia not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79665FFB6F31DF9F7FD57FCFA.taxon	discussion	Remarks Brydone (1936) introduced the subspecies Rhagasostoma inelegans angliae for unilaminar colonies lacking ovicells. We have restudied Brydone’s syntypes in the SM collection, choosing a lectotype (the specimen figured by Brydone 1936: pl. 35, fig. 4). The specimen figured by Brydone (1930: pl. 26, fig. 5) was not restudied. Brydone (1936) compared his specimens of Rhagasostoma inelegans angliae from the Trimingham Chalk with the bilaminar, ovicellate Onychocella dichotoma sensu Levinsen (1925) from the early Maastrichtian white Chalk of southeastern Denmark and northern Jylland. However, Levinsen’s drawing shows that his species has an avicularian opesiae similar to Rhagasostoma inelegans incarcerata sensu Brydone (1930). The avicularia of this subspecies apparently contain two pairs of lateral, parallel, slit-like opesiules in the central part of the cryptocyst, whereas angliae has only one pair of lateral, parallel, slit-like opesiules. Voigt (1949: 26) mentioned one specimen from the late Campanian (Belemnitella lanceolata Zone) of Hemmoor. Our study shows that the avicularian opesia in this specimen are similar to angliae, while Voigt (1949) described it as Onychocella dichotoma Goldfuss, 1826 and classified O. inelegans incarcerata as a junior synonym of O. dichotoma. Rhagasostoma angliae can easily be distinguished from R. inelegans, R. brydonei sp. nov., R. minuens, R. aralense sp. nov. and R. operculatum sp. nov. as the avicularian cryptocysts have small, subcircular opesia and two opesiules instead of large, roundish or oval opesia without opesiules. Rhagasostoma rowei (Brydone, 1906) and R. mimosa (Brydone, 1930) also have avicularian cryptocysts with small subcircular opesia and opesiules, but R. angliae differs from these species in having articular ridges bearing teeth with proximal opesiular indentation between the teeth and interzooidal, and elongate avicularia with asymmetrical rostra instead of vicarious, rhomboidal avicularia with symmetrical rostra.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79665FFB6F31DF9F7FD57FCFA.taxon	distribution	Distribution Middle Campanian United Kingdom: Norwich and Weybourne, Norfolk, England (Brydone 1936). Late Campanian France: Vigny, Île-de-France. Early Maastrichtian Germany: Hemmor (Voigt 1949). United Kingdom: Trimingham, Norfolk, England.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966EFFB5F372FC77FD60FA77.taxon	description	urn: lsid: zoobank. org: act: BA 58 BA 06 - 3 D 7 D- 4 C 8 C- 8125 - 3490 AE 0 A 37 E 7 Fig. 10, Table 5	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966EFFB5F372FC77FD60FA77.taxon	diagnosis	Diagnosis Colonies erect, bifoliate. Autozooids subrectangular; gymnocyst lacking; cryptocyst extensive with proximolateral peripheral caverns; opesiae terminal, semielliptical without shelf in the distal part, proximal edge crenulated with small, roundish opesiules; ovicells endozooidal. Avicularia interzooidal, larger than autozooids; rostrum channeled with pointed top, conical in outline, almost symmetrical; proximal part rounded, shorter and wider than rostrum; opesia egg-shaped with thin articular ridges bearing two short teeth proximally and an opesiular indentation between the teeth; opesiules lacking. Kenozooids at the margins of a colony, roundish, with small opesia.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966EFFB5F372FC77FD60FA77.taxon	etymology	Etymology The species is named after its type locality, the region south of the former Aral Sea in the Republic of Karakalpakstan, Uzbekistan.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966EFFB5F372FC77FD60FA77.taxon	materials_examined	Material studied Holotype UZBEKISTAN • Republic of Karakalpakstan; early Campanian (Cibicidoides temirensis / Bolivinoides decoratus decoratus Zone; LS 13) of the southern Aral Sea Region; TsNIGR Museum 26 / 12582 (Fig. 10 A – F; figured by Favorskaya 1992: pl. 64, fig. 6). Paratypes UZBEKISTAN • Same data as for holotype; middle Campanian (Brotzenella monterelensis Zone; LS 14) of the southern Aral Sea Region; TsNIGR Museum 28 / 12582 (Fig. 10 G; figured by Favorskaya 1992: pl. 65, fig. 1). Type locality and horizon Uzbekistan, Republic of Karakalpakstan; southern Aral Sea Region; Cibicidoides temirensis / Bolivinoides decoratus decoratus Zone (LS 13), early Campanian.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966EFFB5F372FC77FD60FA77.taxon	description	Description Colony erect, flattened, bifoliate, fragments 3.0 – 5.0 mm long by 2.0 – 3.0 mm wide. Ancestrula and early astogeny not observed. Autozooids variable in shape, often broad and subrectangular with rounded distal ends; zooidal boundaries raised. Gymnocyst lacking. Cryptocyst extensive, finely pustulose, convex centrally, slightly depressed around edges, with proximolateral peripheral caverns; lateral wall of some caverns ribbed (Fig. 10 B, E – G). Opesia terminal, semielliptical without shelf in the distal part, formed by two walls, a thin inner wall delimiting the distolateral part and a salient, thickened outer wall delimiting the proximolateral part (Fig. 10 C, F). Proximal edge of opesia straight, crenulated, thickened, with outgrowths near the two proximolateral corners delimiting small, roundish opesiules (outgrowths are often broken thus giving the opesiules the appearance of opesiular indentations, or they may be obscured by sediment infilling the opesiae). Septula not observed. Ovicells endozooidal, ooecium is formed by the distal zooid, seen as a low swelling of its proximal cryptocyst (Fig. 10 G). Avicularia interzooidal, larger than autozooids, elongate. Rostrum channeled with elevated wing-like walls and a pointed tip, conical in outline, almost symmetrical. Proximal part rounded, shorter and wider than rostrum. Cryptocyst pustulose, concave, without peripheral caverns. Opesia egg-shaped with the narrow end pointing upwards and with thin articular ridges bearing two short teeth proximally and a short or long, slit-like opesiular indentation between the teeth; opesiules lacking. Kenozooids rounded, located at the margins of a colony. Cryptocyst finely pustulose. Opesia roundish, very small. Closure plates, intramural reparative budding of autozooids, avicularia and kenozooids not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966EFFB5F372FC77FD60FA77.taxon	discussion	Remarks Rhagasostoma aralense sp. nov. differs from R. brydonei sp. nov., R. minuens and R. operculatum sp. nov. in having avicularian rostra that are a conical in outline rather than spade-shaped or falciform. The new species differs from R. inelegans and R. angliae, which also have avicularian rostra conical in outline, in the rostrum being almost symmetrical and the avicularian opesia egg-shaped. The crenulated proximal edge of the autozooidal opesia is clearly another important character distinguishing this species from others. However, it is possible that the ribs are sediment particles or diagenetic crystals.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966EFFB5F372FC77FD60FA77.taxon	distribution	Distribution Early to middle Campanian Uzbekistan: between Chimboy / Shımbay (Чимбой / Шымбай) and the Aral Sea in the Republic of Karakalpakstan.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966DFFB0F36BF9C4FBF9FBD0.taxon	description	urn: lsid: zoobank. org: act: 23 F 08 F 8 D- 29 DB- 4470 - B 8 FA-B 176256858 F 8 Fig. 11, Table 6	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966DFFB0F36BF9C4FBF9FBD0.taxon	diagnosis	Diagnosis Colony erect, bifoliate. Autozooids subrectangular, zooidal boundaries raised; gymnocyst lacking; cryptocyst extensive; opesia terminal, semielliptical; putative calcified opercula rounded trapezoidal. Avicularia interzooidal; rostrum channeled with rounded tip, between conical in outline and spade-shaped, asymmetrical; proximal part rounded, shorter and wider than rostrum; opesia egg-shaped with thin articular ridges bearing two short teeth proximally and a short opesiular indentation between the teeth; opesiules lacking.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966DFFB0F36BF9C4FBF9FBD0.taxon	etymology	Etymology The species is named from the Latin ‘ operculum ’ because the opesiae of autozooids are presumably closed by calcified opercula.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966DFFB0F36BF9C4FBF9FBD0.taxon	materials_examined	Material studied Holotype TURKMENISTAN • Western Kopetdag, Kara-Kala; boundary layers of the early Campanian (Cibicidoides temirensis / Bolivinoides decoratus decoratus Zone; LS 13) to middle Campanian (Brotzenella monterelensis Zone; LS 14) of the western Kopetdag; TsNIGR Museum 27 / 12582 (Fig. 11 A – C; figured by Favorskaya 1992: pl. 64, fig. 7). Type locality and horizon Turkmenistan, Western Kopetdag; boundary layers of the early to middle Campanian.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966DFFB0F36BF9C4FBF9FBD0.taxon	description	Description Colony erect, flattened, bifoliate; fragments 6.0 mm long by 2 mm wide. Ancestrula and early astogeny not observed. Autozooids variable in shape, often broad and subrectangular with rounded distal ends; zooidal boundaries raised. Gymnocyst lacking. Cryptocyst extensive, finely pustulose, slightly depressed centrally, without peripheral caverns. Opesia terminal, semielliptical, presumably closed by calcified opercula. Putative opercula rounded trapezoidal and slightly concave, tubercular externally (Fig. 11 C), proximal edge slightly arched and with ‘ ears’ at the ends, which are 0.03 – 0.05 mm wide, ‘ ears’ projecting 0.01 – 0.02 mm below the proximal edge. Septula not observed. Ovicells not observed. Avicularia interzooidal, longer than autozooids, elongate. Rostrum channeled with elevated walls and often rounded top, between conical in outline and spade-shaped, asymmetrical, dextral or sinistral. Proximal part rounded, shorter and wider than rostrum, cryptocyst pustulose, concave. Opesia egg-shaped with the narrow end pointing upwards and with thin articular ridges bearing two short teeth proximally and short opesiular indentation between the teeth; opesiules lacking. Kenozooids, closure plates, intramural reparative budding autozooids, kenozooids, and avicularia not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966DFFB0F36BF9C4FBF9FBD0.taxon	discussion	Remarks Rhagasostoma operculatum sp. nov. differs from R. brydonei sp. nov., another species with a spade-shaped avicularian rostrum, in the rostrum having almost the same width along the whole of their length and having a pointed or rounded rostral tip instead of the rostrum being narrowed at the base, enlarged centrally and with a pointed tip. The new species differs from the other species described herein in having a spade-shaped avicularian rostrum instead of one that is conical in outline or falciform. Moreover, opesiae of autozooids of R. operculatum sp. nov. are presumably closed by calcified opercula. Rhagasostoma operculatum sp. nov. is the earliest known species in cryptocystidean anascan cheilostomes that has putative calcified opercula. Late Cretaceous cheilostomes with calcified opercula from the family Onychocellidae include Inversaria flabellula (von Hagenow, 1846) from the late Campanian of Scania, Sweden,? Inversaria sp. from the late Campanian to Maastrichtian of United Arab Emirates, and Inversaria tubiporacea (Goldfuss, 1826) and Onychocella exilis Koromyslova & Shcherbinina, 2015 from the Maastrichtian of NW Europe and Uzbekistan, respectively (Voigt & Williams 1973; Voigt 1974; Di Martino & Taylor 2013; Koromyslova 2014 b; Koromyslova & Shcherbinina 2015). Calcified opercula have also been observed in several species belonging to the family Cribrilinidae Hincks, 1879 including Castanopora lambi Turner, 1975 from the Maastrichtian of USA (Turner 1975; McKinney et al. 2003; Taylor & McKinney 2006).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7966DFFB0F36BF9C4FBF9FBD0.taxon	distribution	Distribution Early to middle Campanian Turkmenistan: western Kopetdag, Kara-Kala.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79668FF8CF335FBADFDA9F90C.taxon	description	Figs 12 – 13, Table 7	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79668FF8CF335FBADFDA9F90C.taxon	materials_examined	Material studied Figured material GERMANY • 2 specs; Schleswig-Holstein, Saturn quarry near Kronsmoor; early Maastrichtian; SMF 29906 (Fig. 12 A – E), 29907 (Fig. 12 F). UNITED KINGDOM • England, Norfolk; early Maastrichtian (Ostrea lunata Zone) of Trimingham; SM B 36679 (Fig. 12 G; figured by Brydone 1930: pl. 26, fig. 15). BELARUS • 3 specs; Grodno Region; erratic block of? late Campanian age in a quarry near Hrodna / Grodno (Гродна / Гродно); PIN 2922 / 216 (Fig. 13 B), 2922 / 218 (Fig. 13 A), 2922 / 275 (Fig. 13 C). KAZAKHSTAN • 2 specs; Emba River; late Campanian (Belemnitella lanceolata Zone); PIN 5502 / 3058 (Fig. 13 D), 5502 / 3059 (Fig. 13 E). Other material BELARUS • Grodno Region; erratic block of? late Campanian age in a quarry near Hrodna / Grodno (Гродна / Гродно); PIN 2922 / 274.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79668FF8CF335FBADFDA9F90C.taxon	description	Description Colony erect, with flattened bifoliate branches (3 – 4 mm wide). Ancestrula and early astogeny not observed. Autozooids variable in shape, often broad and subrectangular with rounded distal ends; zooidal boundaries raised. Gymnocyst sometimes observed (Figs 12 G, 13 E). Cryptocyst extensive, finely pustulose, slightly depressed or slightly convex centrally, sometimes with proximal peripheral caverns (Fig. 13 B, C). Opesia terminal, rarely subterminal, semielliptical with distal shelf, a thin inner wall delimiting the distolateral part of the opesia and a thickened, projecting outer wall delimiting the proximolateral part (Figs 12 C, 13 C). Proximal edge of opesia straight, smooth, thickened, with proximolateral outgrowths defining small opesiules at the corners; outgrowths often destroyed, giving opesiules the appearance of opesiular indentations. Septula not observed. Ovicells endozooidal, ooecium is formed by the distal zooid, wellrecognizable, with cryptocyst-like surface and arch-like proximal edge with elongated proximolateral processes extending along the cryptocyst of the maternal zooid (Figs 12 B, D, G, 13 B, D – E). Avicularia interzooidal, smaller than autozooids, elongate. Rostrum channeled, symmetrical, with elevated winglike walls and a pointed tip, rising above the surface of the colony and tilted to the right or left, rostral tip not reaching the opesia of the distal autozooid. Rostrum tilted over the proximal part of the distal autozooid or the ooecium of a maternal autozooid. Wedge-like structures present (Fig. 12 B – D), extending from the base to the middle of the rostrum and partially covering the opesia, but often these structures are broken (Fig. 12 E). Proximal part rounded, shorter and wider than rostrum, cryptocyst pustulose, concave, without peripheral caverns. Opesia roundish, with two short teeth proximally, opesiules lacking (Fig. 12 E). Kenozooids subcircular, located along the branch margins (Fig. 12 A). Cryptocyst finely pustulose, opesia roundish (Figs 12 C, 13 A, D – E). Intramural reparative kenozooidal buds sometimes observed within host autozooids and avicularia (Fig. 13 D – E), all with the same polarity as the host zooid. Closure plates, intramural reparative budding autozooids and avicularia not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79668FF8CF335FBADFDA9F90C.taxon	discussion	Remarks The type material of Rhagasostoma gibbosum (Marsson, 1887) could not be found, although part of the Marsson Collection has recently been recovered (Martha 2014). From the similar species R. tchvanovi (Favorskaya, 1992), R. gibbosum differs in having a rostrum that is short and tilted to the right or left instead of being long and almost straight. Rhagasostoma gibbosum can be distinguished from R. gibbosulum by the slightly convex border of the cryptocyst and the very rare presence of a gymnocystal portion.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79668FF8CF335FBADFDA9F90C.taxon	distribution	Distribution Late Campanian Belarus: Quarry near Hrodna / Grodno (Гродна / Гродно), Grodno Region. Kazakhstan: Emba River. Early Maastrichtian United Kingdom: Trimingham, Norfolk, England. Germany: Saturn quarry near Kronsmoor, Schleswig-Holstein, Island of Rügen, Mecklenburg-Vorpommern. Maastrichtian: unspecified localities in Denmark.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79654FF8BF330F961FD36F929.taxon	description	Fig. 14, Table 8	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79654FF8BF330F961FD36F929.taxon	materials_examined	Material studied Holotype UNITED KINGDOM • England, High Down; middle Campanian (Belemnitella mucronata Zone) of Isle of Wight; SM B 36887 (Fig. 14 A – D; figured by Brydone 1936: pl. 36, fig. 1). Additional figured material BELARUS • Grodno Region; erratic block of? late Campanian age in a quarry near Hrodna / Grodno (Гродна / Гродно); PIN 2922 / 242 (Fig. 14 E – F). GERMANY • 4 specs; Schleswig-Holstein, Saturn quarry near Kronsmoor; early Maastrichtian; SMF 29908 (Fig. 14 G), 29909 (Fig. 14 H), 29911 (Fig. 14 I), 29912 (Fig. 14 J). Other material GERMANY • 2 specs; same data as for preceding; SMF 29910, 29913.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79654FF8BF330F961FD36F929.taxon	description	Description Colony erect, with flattened bifoliate branches (1 – 6 mm wide). Ancestrula and early astogeny not observed. Autozooids variable in shape, often broad and roundish; zooidal boundaries raised. Gymnocyst? present proximolaterally, smooth (Fig. 14 B, G, I), but usually not visible. Cryptocyst extensive, finely pustulose, usually slightly convex centrally. Opesia terminal or subterminal, semielliptical, delineated by two walls, a thin inner wall forming the distolateral rim and a projecting and thickened outer wall forming the proximolateral rim. Proximal edge of opesia straight, smooth, with outgrowths at the two proximolateral corners delineating small opesiules; outgrowths often destroyed, giving the opesiules the appearance of opesiular indentations (Fig. 14 C, I – J). Septula not observed. Ovicells endozooidal, ooecium is formed by the distal zooid, well-recognizable, with cryptocyst-like surface and arch-like proximal edge with elongated proximolateral processes extending along the cryptocyst of the maternal zooid (Fig. 14 I). Avicularia interzooidal, smaller than autozooids, elongate. Rostrum channeled, asymmetrical, rarely symmetrical, with elevated wing-like walls and a pointed tip, rising above the surface of the colony and tilted to the right or left, rostral tip not reaching the opesia of distal autozooid. Rostrum tilted over gymnocyst of the distal autozooid or ooecium. Wedge-like structures present (Fig. 14 I – J), extending from the base to the middle of the rostrum and partially covering the opesia, but often these structures are broken (Fig. 14 D). Proximal part of avicularium rounded, shorter and wider than rostrum, cryptocyst pustulose, concave, but often not visible. Opesia round with two short teeth proximally, opesiules lacking (Fig. 14 J). Kenozooids sometimes numerous, located along edges of branches, roundish (Fig. 14 H). Cryptocyst finely pustulose. Opesia round. Intramural reparative kenozooidal buds in host autozooids sometimes observed (Fig. 14 B), all with the same polarity as the host zooid. Closure plates and intramural reparative budding of autozooids and avicularia not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79654FF8BF330F961FD36F929.taxon	discussion	Remarks Rhagasostoma gibbosulum can be distinguished from R. gibbosum by the convex border of the cryptocyst and the inferred, well-developed gymnocyst.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79654FF8BF330F961FD36F929.taxon	distribution	Distribution Middle Campanian United Kingdom: High Down, Isle of Wight, England. Late Campanian Belarus: Quarry near Hrodna / Grodno (Гродна / Гродно), Grodno Region. Early Maastrichtian Germany: Saturn quarry, near Kronsmoor, Schleswig-Holstein.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79653FF86F326F906FD0DF91C.taxon	description	Fig. 15, Table 9	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79653FF86F326F906FD0DF91C.taxon	description	30 – 70 (8) 53.75 ± 11.88	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79653FF86F326F906FD0DF91C.taxon	materials_examined	Material studied Holotype UZBEKISTAN • Republic of Karakalpakstan; late Campanian (Cibicidoides voltzianus Zone; LS 15) of the southern Aral Sea Region; TsNIGR Museum 33 / 12582 (Fig. 15 A – C; figured by Favorskaya 1992: pl. 68, fig. 6). Additional figured material UZBEKISTAN • Same data as for holotype; TsNIGR Museum 34 / 12582 (Fig. 15 D – E; figured by Favorskaya 1992: pl. 68, fig. 7) • Republic of Karakalpakstan; middle Campanian (Brotzenella monterelensis Zone; LS 14) of the southern Aral Sea Region; TsNIGR Museum 32 / 12582 (Fig. 15 F).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79653FF86F326F906FD0DF91C.taxon	description	Description Colony erect with flattened bifoliate branches (3 – 4 mm wide). Ancestrula and early astogeny not observed. Autozooids variable in shape, often broad and subrectangular with rounded distal ends; zooidal boundaries raised. Gymnocyst lacking. Cryptocyst extensive, finely pustulose, slightly depressed centrally, sometimes with proximolateral peripheral caverns (Fig. 15 F). Opesia terminal, semielliptical, formed by two walls, a thin inner wall forms the distolateral part of the opesia, and a projecting thickened outer wall forms the proximolateral part (Fig. 15 C, E). Proximal edge of opesia straight, smooth, with outgrowths at the two proximolateral corners which delineate small opesiules; outgrowths often destroyed giving the opesiules the appearance of opesiular indentations. Septula not observed. Ovicells endozooidal, ooecium is formed by the distal zooid, well-recognizable, with cryptocyst-like surface and arch-like proximal edge with elongated proximolateral processes extending along the cryptocyst of the maternal zooid (Fig. 15 A – B). Avicularia interzooidal, smaller than autozooids, elongate. Rostrum channeled with elevated wing-like walls and pointed tip, narrow, almost straight, asymmetrical, dextral or sinistral. Top of rostrum reaches opesia of distal autozooid. Wedge-like structures not observed. Proximal part rounded, shorter and wider than rostrum, cryptocyst pustulose, concave. Opesia round with short slit proximally, opesiules lacking (Fig. 15 C). Closure plates, kenozooids, intramural reparative budding of autozooids and avicularia not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79653FF86F326F906FD0DF91C.taxon	discussion	Remarks Rhagasostoma tchvanovi differs from the closely related species R. gibbosum in the avicularian rostrum being long and almost straight instead of short and tilted to the right or left. The specimen described by Brydone (1930: pl. 26, fig. 12) as Onychocella gibbosum weybournensis differs from R. gibbosum (Marsson, 1887) in having a long and straight avicularian rostrum and is conspecific with R. tchvanovi. Specimen 32 / 12582 in the collections of the TsNIGR Museum and labelled as “ O. subgibbosum Brydone, 1930 ” is not the one that was depicted by Favorskaya (1992: pl. 67, fig. 3) and belongs to R. tchvanovi.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79653FF86F326F906FD0DF91C.taxon	distribution	Distribution Middle to late Campanian Republic of Karakalpakstan, Uzbekistan: six localities between Chimboy / Shımbay (Чимбой / Шымбай) and the Aral Sea.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7965EFF9FF31CF911FB61FA2C.taxon	description	Figs 16 – 18, Table 10	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7965EFF9FF31CF911FB61FA2C.taxon	materials_examined	Material studied Holotype UNITED KINGDOM • England, Norfolk, Trimingham; early Maastrichtian (Ostrea lunata Zone); SM B 36113 (Fig. 16 C; not figured by Brydone 1906). Additional figured material RUSSIAN FEDERATION • 2 specs; Ulyanovsk Region; Late Cretaceous; PSM PSU 2 / 187 (Fig. 16 A; figured by Eichwald 1868: pl. 8, fig. 9), MMI 15 / 49 (Fig. 16 B; figured by Lahusen 1873: pl. 4, fig. 4). UNITED KINGDOM • 2 specs; same data as for holotype; SM B 36260 (Fig. 16 D – E; figured by Brydone 1913: pl. 8, fig. 12), B 36697 (Fig. 16 F – G; labeled as O. mimosa in the Brydone Collection). BELARUS • Grodno Region; erratic block of? late Campanian age in a quarry near Hrodna / Grodno (Гродна / Гродно); PIN 2922 / 204 (Fig. 16 H; figured by Koromyslova 2014 a: pl. 9, fig. 6). BELGIUM • Harmignies near Mons; late Campanian; SMF 29924 (Fig. 17 A – B). UZBEKISTAN • Southern Aral Sea Region; late Campanian, Cibicidoides voltzianus Zone; TsNIGR Museum 26 / 12939 (Fig. 17 C; figured by Favorskaya 1996: pl. 4, fig. 1). TURKMENISTAN • Western Kopetdag; late Campanian; TsNIGR Museum 35 / 9757 (Fig. 17 D – E; figured by Voigt 1967: pl. 18, fig. 3) • Tuarkyr; late Maastrichtian; TsNIGR Museum 36 / 9757 (Fig. 18 E; figured byVoigt 1967: pl. 18, fig. 2) • Western Kopetdag; late Maastrichtian; TsNIGR Museum 32 / 9757 (Fig. 18 I; figured by Voigt 1967: pl. 18, fig. 4). KAZAKHSTAN • Emba River; late Campanian (Belemnitella lanceolata Zone); PIN 5502 / 3051 (Fig. 17 F – G) • 2 specs; Mangyshlak Peninsula; Maastrichtian; PIN 3421 / 1009 (Fig. 18 F – G), 3421 / 1008 (Fig. 18 H) • Northern Aral Sea Region; Maastrichtian; PIN 5502 / 3050 (Fig. 18 J). GERMANY • 2 specs; Rügen; early Maastrichtian; SMF 29931 (Fig. 17 H – I), 29932 (Fig. 18 A) • Hamburg-Hummelsbüttel; former brick factory; late Maastrichtian; SMF 29933 (Fig. 18 D). DENMARK • Island of Møn; early Maastrichtian; SMF 29925 (Fig. 18 B – C). Other material BELARUS • 15 specs; Grodno Region; erratic block of? late Campanian age in a quarry near Hrodna / Grodno (Гродна / Гродно); PIN 2922 / 200 (figured by Koromyslova 2014 a: pl. 9, fig. 1), 2922 / 201 (figured by Koromyslova 2014 a: text-fig. 1 c), 2922 / 208 (figured by Koromyslova 2014 a: pl. 9, fig. 7), 2922 / 210 (figured by Koromyslova 2014 a: pl. 9, fig. 3, text-figs 1 a, b, 2), 2922 / 223 (figured by Koromyslova 2014 a: pl. 9, fig. 5, text-figs 1 g, 3 a), 2922 / 224 (figured by Koromyslova 2014 a: pl. 9, fig. 4, text-fig. 4 e), 2922 / 226 (figured by Koromyslova 2014 a: text-fig. 4 d), 2922 / 227, 2922 / 234 (figured by Koromyslova 2014 a: text-fig. 1 d), 2922 / 231, 2922 / 255 (figured by Koromyslova 2014 a: text-fig. 4 ac), 2922 / 256 (figured by Koromyslova 2014 a: text-fig. 4 h), 2922 / 257 (figured by Koromyslova 2014 a: text-fig. 4 f), 2922 / 268, 2922 / 279 (figured by Koromyslova 2014 a: pl. 9, fig. 2). KAZAHKSTAN • 4 specs; Emba River; late Campanian (Belemnitella lanceolata Zone); PIN 5502 / 3052 to 3055 • Mangyshlak Peninsula; Maastrichtian; PIN 3421 / 1006. GERMANY • 5 specs; Rügen; early Maastrichtian; SMF 29926 to 29930 • 4 specs; Tornesch; late Maastrichtian; SMF 29935 to 29938 • Hamburg-Hummelsbüttel; former brick factory; late Maastrichtian; SMF 29934.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7965EFF9FF31CF911FB61FA2C.taxon	description	Description Colony rigidly erect, bifoliate, multiserial, branches 2.0 – 10.0 mm wide. Ancestrula and early astogeny not observed. Colony formed by pyriform and ovate autozooids and vicarious avicularia. Autozooids subrectangular with rounded distal ends; zooidal boundaries raised. Pyriform autozooids with a narrow proximal end, widening distally, the widening usually starting from the proximal margin of the opesia. In ovate autozooids, the proximal end is partly overlapped by the avicularian rostrum and the autozooid begins to widen considerably below the proximal margin of the opesia, usually at the boundary with an avicularium. Gymnocyst lacking. Cryptocyst slightly granulated, slightly depressed centrally and occupying half or more of the frontal surface of the autozooid, peripheral caverns lacking. Opesia terminal or subterminal. Opesial rim elevated, formed by projecting cryptocyst, bell-shaped due to small lateral projections (occlusor lamina) and opesiular indentations, between which there is a short or long, tongue-like projection of cryptocyst (Figs 16 A, C, E, 17 G, 18 H – I), often broken, in which case the opesiular indentations are poorly defined and the proximal edge of the opesia is almost straight. In the complete absence of lateral projections and tongue the opesiae are subcircular (Figs 17 C – E, H, 18 A – B, D – G). Distal walls with two septula (Fig. 16 H); septula in lateral walls not observed. Ovicells immersed, ooecia vestigial formed by the distal zooid, vizor-like, with slightly granulated surface, not protruding above colony surface (Figs 16 G, 17 C, E, G, 18 G, I). Avicularia vicarious, rhomboidal. Rostrum conical in outline and symmetrical, usually with straight lateral walls; indentations or projections present at the rostral base. Three types of avicularia differing mainly in the length of the rostrum and rostral apex which partly overlaps the proximal end of the distal autozooid: avicularia with long rostra and long trough-like apices (130 – 210 µm); avicularia with short rostra and short trough-like apices (0 – 130 µm); and avicularia with rostra without projecting apices. Proximal part short, narrowing downwards, with convex lateral sides. Entire frontal surface of avicularium occupied by a fragile, slightly granulated cryptocyst containing five openings: two small, subcircular openings, distally and proximally, in between three slit-like, parallel openings (Figs 17 I, 18 G). Cryptocyst between openings frequently destroyed causing them to coalesce into a single opening of variable outline. Intramural reparative budding of autozooids and closure plates not observed. Intramural reparative budding of avicularia may be present in some or all avicularia depending on the colony (see Koromyslova 2014 a), they are observed within host avicularia, numbering as many as three intramural buds, all apparently having the same polarity as the host avicularium. Kenozooids not observed. Both the inner and outer sides of branches of colonies show concentrations of autozooids in which the opesiae are subcircular and the proximal part is shortened or completely absent, and deformed avicularia that are irregularly ovate to rhomboidal in shape and possess an elongated opening at the centre.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7965EFF9FF31CF911FB61FA2C.taxon	discussion	Remarks Eschara volgensis Eichwald, 1865 from the Late Cretaceous of Simbirsk (now Ulyanovsk, Russian Federation) was regarded as possibly conspecific with Rhagasostoma rowei by Voigt (1967). Voigt, who examined the Eichwald Collection housed at the Palaeontological and Stratigraphical Museum at the Faculty of Geology, St Petersburg State University, found that the original material of this species from Simbirsk, Ulyanovsk Oblast, Russia differs from R. rowei only in the opesia being smaller and having a slightly visible tongue-like projection of the cryptocyst. Unfortunately, the specimen of E. volgensis (PSM PSU 2 / 187 and PSM PSU 2 / 188) could not be found during our visit to the collections. However, a photograph of the specimen made by Prof. E. Voigt in 1963 is reproduced here (Fig. 16 A). This species was redescribed by I. I. Lahusen (1873) whose collection is stored in the Museum of the Mining Institute, St Petersburg. The specimen of E. volgensis (MMI 15 / 49) could not be examined using SEM, but a microphotograph is shown instead (Fig. 16 B). The Lahusen material of E. volgensis is from the vicinity of Yazykov village in Simbirsk Province, Ulyanovsk Oblast. He stated that the sample described by Eichwald (1865) was not completely identical with his samples. Our findings show that the sample described by Lahusen is conspecific with Rhagasostoma rowei. In a monograph on the development of different species of Woodipora Jullien, 1888 from the Coniacian to the Maastrichtian, Schubert (1986) transferred Brydone’s species rowei to the genus Woodipora. He did not regard the presence of opesiules or opesiular indentations as being diagnostic for species and concluded that rowei and mimosa were synonymous, differing simply in the preservation of the opesiules (for a more detailed summary regarding a possible synonymy of rowei and mimosa, see the remarks for R. mimosa). Rhagasostoma rowei has bell-shaped autozooidal opesia because of the small lateral projections and opesiular indentations separated by a short projecting tongue of cryptocyst. Opesia with a straight or rounded proximal edges are formed when the lateral projections and cryptocystal tongue become broken-off. When the cryptocyst located between the opesiules in autozooids of R. mimosa is destroyed, the opesia takes a shape similar to that of R. rowei. Thus, this similarity is related to the state of preservation and it is evident that pristine colonies of R. rowei have opesiular indentations whereas those of R. mimosa have opesiules. We have restudied the type material from the collections of R. M. Brydone and also material from the collections of I. I. Lahusen, E. Voigt and T. A. Favorskaya. The specimens labelled as O. mimosa (SM B 36697) from the Brydone Collection and (TsNIGR Museum 32 / 9757) from the Voigt Collection belong to R. rowei because the autozooids lack opesiules. Usually R. rowei is characterized by colonies that widen distally with numerous avicularia. The large number of avicularia is due to the fact that avicularia occur at the start of the new zooidal rows needed to widen the branches. From these avicularia, ovate autozooids are budded distally, from which in turn pyriform autozooids are budded (Koromyslova 2014 a). However, there is one specimen of R. rowei from the Maastrichtian of Turkmenistan (Fig. 18 E; figured by Voigt 1967: pl. 18, fig. 2) that differs from the holotype and many other specimens in having almost parallel-sided branches and rare avicularia. Additionally, some large colonies are almost parallel-sided at the base with rare avicularia but widen distally where numerous avicularia are present (Figs 17 A – B, 18 F – G). It can be assumed that the samples described by Voigt (1967) and other similar specimens (Fig. 18 D) were broken-off from the bases of such colonies and hence have few avicularia. Ovate autozooids, which are budded from avicularia, are also rare and often poorly expressed. Obviously, R. rowei was usually characterized by stem-like colonies, which are almost parallel-sided at the base and have few avicularia, but become fan-like distally where numerous avicularia are present. Furthermore, colonies of this species can occasionally have bifurcating branches (Figs 16 B – C, F, 18 A – B, F). Entire colonies are rare and usually we can see only a small part of colonies, which were broken-off. Schubert (1986) mentioned the presence of R. rowei in his distribution list from Royan in southwest France. However, it would be rather surprising to find this species in the Aquitaine Basin, as the bryofauna described so far from the Aquitaine Basin differs considerably from the northern Chalk Sea bryofauna. In his synonymy list and in his remarks, Schubert (1986) placed, following Voigt (1930), Marsson’s (1887) Eschara Delarueana (non d’Orbigny, 1851) and Voigt’s (1925) Onychocella cf. delarueana in synonymy with R. rowei. However, this material is derived from the early Maastrichtian of Rügen (Marsson 1887) and the late Maastrichtian of the ‘ Blue Hills’ (Blaue Berge) in eastern Germany (Voigt 1925). The true Rhagasostoma delarueana (d’Orbigny, 1851) from Royan, however, is not conspecific with R. rowei. Since no samples of R. rowei were found among the material studied by Schubert (1986) labelled “ Royan ”, this locality has to be deleted from the distribution list of R. rowei. Schubert (1986) erroneously considered all material from Møns Klint in eastern Denmark as late Maastrichtian. However, no sediments from the late Maastrichtian crop out at Møns Klint (cf. Mutterlose et al. 1998) and the samples studied by Schubert (1986) are in fact labelled as early Maastrichtian. A specimen comparable to R. rowei has recently been described as ‘ Onychocella ’ sp. in Koromyslova et al. (2018 a) from the early Maastrichtian of the Aktolagay Plateau, western Kazakhstan. The Aktoalagay species, however, is encrusting and only very poorly preserved.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D7965EFF9FF31CF911FB61FA2C.taxon	distribution	Distribution Late Santonian France: Vasterival near Sainte-Marguerite-sur-Mer, Normandy (Schubert 1986). Late Campanian Belgium: Harmignies near Mons. Belarus: Quarry near Hrodna / Grodno (Гродна / Гродно), Grodno Region (Koromyslova 2014 a). Turkmenistan: “ Kredin ” gorge in the Kopet Dag Mountains NW of Aşgabat (Voigt 1967). Uzbekistan: southern Aral Sea Region, Republic of Karakalpakstan (Favorskaya 1996). Kazakhstan: Emba River. Early Maastrichtian Denmark: Møns Klint, Sjaelland (Schubert 1986). Germany: Hemmoor and Lüneburg, Lower Saxony (Voigt 1967); Saturn quarry near Kronsmoor, Schleswig-Holstein (Schubert 1986); Island of Rügen, Mecklenburg-Vorpommern (von Hagenow 1839; Voigt 1930). Kazakhstan: Along the Chobda river, and Kenderlyshor, Mangystau Region (Voigt 1967). United Kingdom: Trimingham, Norfolk, England (Brydone 1906). Late Maastrichtian Denmark: Kongsted (Faxe Kommune; Schubert 1986). France: Chef-du-Pont, Normandy (Schubert 1986). Germany: Blaue Berge near Dessau-Rosslau, Saxony-Anhalt (Voigt 1925), Tornesch, Hamburg-Hummelsbüttel. Turkmenistan: Koimat gorge and a gorge W of the “ Kamyschli ” gorge in the Kopet Dag Mountains NW of Aşgabat, Tuarkyr (Voigt 1967). Maastrichtian Kazakhstan: northern Aral Sea Region, Mangyshlak Peninsula.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79647FF99F302FA01FE02FDC8.taxon	description	Fig. 19, Table 11	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79647FF99F302FA01FE02FDC8.taxon	materials_examined	Material studied Lectotype (here designated) UNITED KINGDOM • England, Norfolk; Porosphaera Beds of Trimingham; early Maastrichtian (Ostrea lunata Zone); SM B 36696 (Fig. 19 AB; figured by Brydone 1930: pl. 28, figs 1 – 2). Additional figured material DENMARK • Island of Møn; early Maastrichtian; SMF 29923 (Fig. 19 C). KAZAKHSTAN • 2 specs; Mangystau Region;? early Maastrichtian of Hanga-Baba (урочиЩе Хангабаба) on the Mangyshlak Peninsula; PIN 5502 / 3056 (Fig. 19 F), 5502 / 3057 (Fig. 19 D – E). Other material BELARUS • 2 specs; Grodno Region; erratic block of? late Campanian age in a quarry near Hrodna / Grodno (Гродна / Гродно); PIN 2922 / 203, 2922 / 207 (imaged in Koromyslova 2014 a: pl. 10, figs 1 – 2).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79647FF99F302FA01FE02FDC8.taxon	description	Description Colony rigidly erect, bifoliate, multiserial, branches 2.0 – 10.0 mm wide. Ancestrula and early astogeny not observed. Colony formed by pyriform and ovate autozooids and vicarious avicularia. Autozooids subrectangular with rounded distal ends; zooidal boundaries raised. Pyriform autozooids with a narrow proximal end but widening distally, the widening usually starting from the proximal margin of the opesia. In ovate autozooids, the proximal end is partly overlapped by the avicularian rostra and the autozooid begins to widen considerably below the proximal margin of the opesia, usually at the boundary with an avicularium. Gymnocyst lacking. Cryptocyst slightly granulated, slightly depressed centrally and occupying half or more of the autozooidal frontal surface, peripheral caverns lacking. Opesia terminal or subterminal. Opesial rim elevated, formed by a projecting, thickened cryptocyst, subcircular, a pair of opesiules located 70 – 90 µm proximallateral of opesia and divided from the latter by a cryptocystal tongue. Fusion of cryptocyst distal of opesiules and tongue of cryptocyst incomplete. Septula in walls not observed. Ovicells immersed, ooecium is formed by the distal zooid, triangular, vestigial, with slightly granulated surface, not protruding above the colony surface (Fig. 19 A – B, D – F). Avicularia vicarious, rhomboidal. Rostrum conical in outline and symmetrical, usually with straight lateral walls; indentations or projections present at base of rostrum. Usually two types of avicularia differing mainly in the length of the rostrum and rostral apex, which partly overlaps the proximal end of the distal autozooids: avicularia with short rostra and short, trough-like apices (0 – 130 µm), and avicularia with long rostra without projecting apices. Proximal part short, narrowing downwards, with convex lateral sides. Entire frontal surface of avicularium occupied by a fragile, slightly granulated cryptocyst containing five openings: two small, subcircular openings, distally and proximally, in between three slit-like, parallel openings. Cryptocyst between openings frequently destroyed causing them to coalesce into a single opening of variable outline. Closure plates, kenozooids and intramural reparative budding in autozooids and avicularia not observed.	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79647FF99F302FA01FE02FDC8.taxon	discussion	Remarks Rhagasostoma mimosa was introduced by Brydone (1930) for species from the Porosphaera beds of Trimingham very much resembling R. rowei (Brydone, 1906) but differing from the latter in having two opesiules. He considered the possibility that colonies of R. rowei were badly preserved samples of R. mimosa but concluded that the two must be different species because colonies of R. rowei are more slender and fragile, avicularia of R. mimosa have a central cavity enclosed by a marked wall, and R. rowei and R. mimosa never co-occur in the Chalk of England. Voigt (1967) re-examined R. rowei and R. mimosa from Central Asia and rejected the morphological arguments used by Brydone (1930) to separate the two species. He concluded that except for R. mimosa having opesiules, the two species are completely identical, but as no intermediate stages occur, he regarded a separation of R. rowei and R. mimosa as justified. He argued that calcification of the frontal wall of R. rowei during the Late Cretaceous resulted over time in the formation of two opesiules completely separated from the opesia as passages for the bundles of parietal muscles. A similar development has also been observed in Rhagasostoma disparile (d’Orbigny, 1851) and Rhagasostoma strumulosum Marsson, 1887 (cf. Schubert 1986: fig. 12), which are indeed closely related to R. rowei and R. mimosa. Furthermore, Voigt (1967) assigned mimosa to the genus Woodipora Jullien, 1888 because of the opesiules, but kept rowei in Onychocella. In his Woodipora monograph, Schubert (1986) regarded rowei and mimosa as two different phenotypes of the same species, which he assigned to Woodipora. The length and width measurements that he conducted on autozooids and avicularia and their opesiae revealed no significant distinction between rowei and mimosa. Furthermore, he argued that colonies in the mimosa stage often have autozooids with and also without opesiules (cf. Schubert 1986: pl. 8, fig. 3). As the zooids without opesiules are of primary origin and cannot have been destroyed during preparation or other processes, he concluded that the occurrence of opesiules is not species-specific and cannot be considered an argument for the existence of mimosa as an independent species. He regarded the mimosa stage as an ‘ end-member’ of a parallel development by progressive calcification of the cryptocyst from the Coniacian to the Maastrichtian resulting in the formation of two opesiules. Zooids with advanced calcification of the cryptocyst, however, did not completely replace the rowei stage, the two stages thus co-occurring in single colonies. Voigt (1991) again regarded mimosa and rowei (and also R. disparile and R. strumulosum) as separate species. He saw the four species as an example of an intermediate status between onychocellid pseudomalacostegans and microporid or thalamoporellid coilostegans, placing disparile and rowei in Onychocella and strumulosum and mimosa in Woodipora. Thus, the microporid or thalamoporellid genus Woodipora would have originated several times by convergent evolution. Without description or figures, Favorskaya (1992) mentioned Onychocella mimosa from the Maastrichtian of the southern Aral Sea Region in Uzbekistan and from Hanga-Baba (урочиЩе Ханга-баба), 30 km east of Fort Shevchenko (Форт-Шевченко) in the Mangystau Region, Kazakhstan. A comprehensive description of morphological differences between R. rowei and R. mimosa from the Grodno quarry in Belarus was undertaken by Koromyslova (2014 a). As she showed, the two species are not conspecific and differ in the shape of the autozooidal opesia and in the cryptocyst that develops opesiular indentations in R. rowei and opesiules in R. mimosa. Furthermore, specimens of R. rowei show intramural reparative budding in avicularia, which has not been observed in colonies of R. mimosa. Based on the length of the rostrum and the apex, three different types of avicularia have been observed in R. rowei, while R. mimosa shows only avicularia with short rostra and short trough-like apices (Koromyslova 2014 a). Avicularia of R. rowei and R. mimosa are indeed very distinct from most other species within the genus Rhagasostoma. Centrally located, there is an opesia and three opesiules in the avicularian cryptocyst. We have restudied Brydone’s syntypes in the SM collection, choosing a lectotype (figured by Brydone 1930: pl. 28, figs 1 – 2), as well as the material from the collection of E. Voigt (Fig. 18 I, 19 C) and T. A. Favorskaya (Fig. 19 D – F). The specimens labelled as Onychocella mimosa (SM B 36697) from the Brydone Collection and (TsNIGR Museum 32 / 9757) from the Voigt Collection belong to R. rowei because the autozooids lack opesiules. As already discussed by Brydone (1930) and Voigt (1967), R. mimosa and R. rowei are very similar, differing only in R. mimosa having opesiae that are round instead of bell-shaped and opesiules instead of opesiular indentions. The presence of autozooids with opesiular indentations in colonies of R. mimosa in most cases can be explained by post-mortem destruction of the cryptocystal tongue that separated the opesiules from the opesia, or by the fact that the opesiae and opesiules of these autozooids were not formed fully and they were in the rowei stage (cf. Schubert 1986: pl. 8, fig. 3).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
03D587D79647FF99F302FA01FE02FDC8.taxon	distribution	Distribution Late Campanian Belarus: Quarry near Hrodna / Grodno (Гродна / Гродно), Grodno Region (Koromyslova 2014 a). Early Maastrichtian Germany: Saturn quarry near Kronsmoor, Schleswig-Holstein (Schubert 1986); glacial drift deposits in northern Germany (Voigt 1967). Kazakhstan: unknown locality on the Mangyshlak Peninsula, Mangystau Region (Favorskaya 1992). United Kingdom: Trimingham, Norfolk, England (Brydone 1930). Uzbekistan: southern Aral Sea Region, Republic of Karakalpakstan (Favorskaya 1992). Late Maastrichtian Denmark: Møns Klint, Sjaelland (Schubert 1986). Turkmenistan: Gorge W of the “ Kamyschli ” gorge in the Kopet Dag Mountains NW of Aşgabat (Voigt 1967).	en	Koromyslova, Anna V., Taylor, Paul D., Martha, Silviu O., Riley, Matthew (2018): Rhagasostoma (Bryozoa) from the Late Cretaceous of Eurasia: taxonomic revision, stratigraphy and palaeobiogeography. European Journal of Taxonomy 490: 1-66, DOI: 10.5852/ejt.2018.490
