taxonID	type	description	language	source
66120869FFB1FFDEBDFDE006FD74FE1E.taxon	type_taxon	Type species: Orthoceras sociale Hall in Miller, 1877, from the Katian Stage, Upper Ordovician Series, Maquoketa Shale, Iowa, USA.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB1FFDEBDFDE006FD74FE1E.taxon	diagnosis	Diagnosis: Smooth or cancellate orthocones with subcircular transverse section. Siphuncle subcentral; early segments barrel-shaped and slender, expanding abruptly at septal foramina with cyrtochoanitic to suborthochoanitic septal necks; during ontogeny, later segments become subcylindrical with suborthochoanitic to orthochoanitic septal necks. Endosiphuncular annuli grow forward and backward, joining those of adjacent segments to form continuous parietal lining of nearly uniform thickness throughout segments (after Ghavidel-Syooki et al., 2015).	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB1FFDEBDFDE006FD74FE1E.taxon	discussion	Remarks: Typical specimens of Isorthoceras display a cancellate sculpture, and longitudinal lirae on the conch surface (Ghavidel-Syooki et al., 2015; Kröger et al., 2009, 2011). According to the spatial and temporal distribution of Isorthoceras, Niko (2008) suggested that the taxa should arise from Laurentia and spread around Baltica during the Boda Event. However, Ghavidel-Syooki et al. (2015) compiled all the occurrences and records of Isorthoceras around the world, e. g., Sandbian and Katian of Laurentia, Sandbian of Avalonia and Baltica, and Katian of Arabia and Baltica (Iran and Bohemia). Te latter authors accordingly suggested that this genus might have originated from Baltica, or it might be Laurentia. Te distribution pattern agrees with the habit of Isorthoceras (Kröger et al., 2009). Isorthoceras sp. Figure 3 Locality and horizon: Tanout el Fecht, northeastern Anti-Atlas region, Morocco. Upper Tiouririne Formation, Katian Stage, Upper Ordovician Series.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB1FFDEBDFDE006FD74FE1E.taxon	materials_examined	Material: Two specimens, NIGP 207332 and NIGP 207333, at Tanout el Fecht, northeastern Anti-Atlas, the Upper Tiouririne Formation, Katian Stage, Upper Ordovician Series.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB1FFDEBDFDE006FD74FE1E.taxon	description	Description: One specimen, NIGP 207332 (Fig. 3 A, B), comprises portions of the phragmocone and part of the body chamber, 55 mm in maximum diameter and 195 mm in length. Te apical angle slightly exceeds 7 °. Te shell ornament cannot be studied due to the poor preservation of the shell surface. Te conch cross-section is circular. Te cameral height varies from 6.3 to 13.1 mm (0.18 – 0.25 of the corresponding conch diameter). Te siphuncle is subcentral at the dorsal – ventral median section. Te siphuncle is barrel-shaped and expands abruptly at the septal foramen, with a diameter at the septal foramen of 0.07 of the corresponding phragmocone diameter. Septal necks are suborthochoanitic. Siphuncular and cameral deposits are not presented. The other specimen, NIGP 207333 (Fig. 3 C, D), comprises portions of a phragmocone 41 mm in maximum diameter and 114 mm in length. The apical angle could not be determined due to the poor preservation of the specimen. The surface of the conch is unknown. The conch cross-section is circular. The cameral height varies between 6.1 and 10.6 mm (0.16 – 0.27 of the corresponding conch diameter). The siphuncle is subcentral, barrel-shaped, and expands abruptly immediately after the septal foramen, with a diameter at the septal foramen of 0.06 of the phragmocone diameter (Fig. 3 D). Septal necks are suborthochoanitic. Connecting rings are adnate at the episeptal surface of the septa. Endosiphuncular and cameral deposits are visible and more developed on the ventral side of the siphuncle and camerae.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB1FFDEBDFDE006FD74FE1E.taxon	discussion	Remarks: Te material described above does not appear to differ significantly from other specimens of Isorthoceras in most internal characters measured, i. e., the large size and abrupt expansion of the siphuncular segments. Although the present specimens share many characters with the genus Isorthoceras, we assign it only in open nomenclature. Furthermore, the species and have been suggested to need revision (Ghavidel-Syooki et al., 2015; Kröger et al., 2011).	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDEBDFDE6E8FF12FA9E.taxon	type_taxon	Type species: Tafadnatoceras tiouririnense Ebbestad et al., 2022 from the Katian Stage, Upper Ordovician Series, Upper Tiouririne Formation at Tafilalt, eastern Anti-Atlas, Morocco. Included species: Tafadnatoceras tiouririnense Ebbestad et al., 2022; Tafadnatoceras elfechtense sp. nov. (this work).	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDEBDFDE6E8FF12FA9E.taxon	diagnosis	Diagnosis: Slightly curved orthocones with central siphuncle; siphuncle expanded within chambers with adnate area at septa and small septal perforation; septal necks cyrtochoanitic; connecting rings adnate during late growth stages; with siphuncular lining composed of stacked layers of parietal deposits; with cameral deposits (modified after Ebbestad et al., 2022).	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDEBDFDE6E8FF12FA9E.taxon	discussion	Remarks: Ebbestad et al. (2022) proposed that the genus Tafadnatoceras is similar to Adnatoceras Flower, 1939 and Paradnatoceras Chen & Liu, 1974 but differs in having a continuous lining inside the siphuncle. Moreover, the species of Tafadnatoceras resemble Isorthoceras bisignatum (Barrande, 1877) from Bohemia, Zagros of Iran (Ghavidel-Syooki et al., 2015) and the Moroccan material presented here, but differ in lacking the Isorthoceras - like reticulate ornamentation (Ebbestad et al., 2022).	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDDBE47E7ADFDC0F81E.taxon	description	Figures 4, 5, 6, 7 urn: lsid: zoobank. org: act: 33 F 0 B 118 - CC 6 D- 4 AB 1 - 90 CF- 83 D 09871 B 323	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDDBE47E7ADFDC0F81E.taxon	etymology	Etymology: Referring to the type locality, Tanout el Fecht, Morocco.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDDBE47E7ADFDC0F81E.taxon	materials_examined	Holotype: Body chamber with a rather long part of the phragmocone, NIGP 207336 (Figs. 5 C, 6 B, C, 7). Paratype: NIGP 207334 (Figs. 5 A, 6 E), NIGP 207337 (Figs. 5 D, 6 A), NIGP 207338 (Figs. 5 E, 6 D), NIGP 207343 (Figs. 5 J, 6 F). Type locality and horizon: Tanout el Fecht, northeastern Anti-Atlas. Upper Tiouririne Formation, Katian Stage, Upper Ordovician Series. Material: Twelve specimens, NIGP 207334 – NIGP 207345 at Tanout el Fecht, northeastern Anti-Atlas region, Morocco, the Upper Tiouririne Formation, Katian Stage, Upper Ordovician Series.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDDBE47E7ADFDC0F81E.taxon	diagnosis	Diagnosis: Orthoconic phragmocone, with an angle of expansion of ca. 10 °; conch cross-section circular; siphuncle central with septal perforation diameter ca. 0.05 of the corresponding conch diameter; siphuncular segments expanded, barrel-shaped; connecting rings adnate to septa, adnation wide; septal necks cyrtochoanitic and brim length equal to adnation length; parietal siphuncular deposits form continuous linings; massive episeptal and hyposeptal deposits.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDDBE47E7ADFDC0F81E.taxon	description	Description: Te holotype NIGP 207336 is a portion of a phragmocone with a length of 47.9 mm and a diameter of 10.9 – 16.7 mm (angle of expansion ca. 9.6 °; Fig. 5 C). Te conch cross-section is circular. Te cameral height varies between 3.1 and 3.7 mm (0.20 – 0.34 of the corresponding conch diameter). Te conch surface is nearly smooth, probably due to poor preservation. Te siphuncle is almost central with narrow septal perforation (minimum 0.05 of the corresponding conch diameter). Te septal necks are cyrtochoanitic with a brim ca. 0.22 mm in length and ca. 0.45 mm in width. Te connecting rings are barrel-shaped in the median section (Fig. 6 B, C, 7). Te expansion of the siphuncular segment at its mid-length has a diameter of 0.18 of the corresponding conch diameter. In this specimen, the connecting ring is adnate to the episeptal surface of the septum for a width of 0.45 mm, equal to the length of corresponding septal necks. Parietal siphuncular deposits form continuous linings. Massive, irregular episeptal and hyposeptal deposits occur. Other specimens, paratypes NIGP 207334, NIGP 207337, NIGP 207338 and NIGP 207343, reveal siphuncular deposits similar to those of the holotype, containing parietal continuous linings with calcite and argillaceous layers (Fig. 6 A, D – F). Te calcite layers become thinner or are absent at the septal foramen. Te septal necks in NIGP 207334 and NIGP 207343 are cyrtochoanitic, with an equal width between brim and area of adnation (Fig. 6 E, F). Te connecting rings expand abruptly and bend anteriorly (Fig. 6 E).	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
66120869FFB7FFDDBE47E7ADFDC0F81E.taxon	discussion	Remarks: Te ornament of the present material is unknown. Te specimens described above are similar to Tafadnatoceras tiouririnense, in general features such as the angle of conch expansion, the siphuncular shape and position and with respect to the parietal siphuncular deposits with continuous linings. However, the specimens of T. elfechtense sp. nov. possess a wider septal neck brim and connecting ring adnation compared to the type species T. tiouririnense. Moreover, the new species differs in having cameral deposits and anteriorly bent connecting rings.	en	Fang, Xiang, Kröger, Björn, Liang, Kun, Chen, Qing, Song, Jiaqi, Jiang, Lan, He, Yaoyan, Wang, Chenggang, Zeng, Xiongwei, Liu, Hao, Wei, Kai, Wu, Fafu, Qie, Wenkun (2025): Late Ordovician cephalopods from Morocco and their implications. Swiss Journal of Palaeontology (37) 144 (1): 1-11, DOI: 10.1186/s13358-025-00374-5, URL: https://doi.org/10.1186/s13358-025-00374-5
