The Changhsingian (Late Permian) ammonoids from Baghuk Mountain (Central Iran) Author Korn, Dieter 286CA4F3-7EBC-4AEF-A66A-B2508D001367 Museum für Naturkunde, Leibniz Institut for Research on Evolution and Biodiversity, Invalidenstrasse 43, 10115 Berlin, Germany. dieter.korn@mfn.berlin Author Hairapetian, Vachik 1AB10F8F-4576-481B-9270-5DCD25110DBB Department of Geology, Esfahan (Khorasgan) Branch, Islamic Azad University, Esfahan, Iran. vhairap@gmail.com Author Ghaderi, Abbas 925F2B42-7326-4461-B2A6-83CB83ECCC63 Department of Geology, Faculty of Science, Ferdowsi University of Mashhad, Azadi Square, 9177948974, Mashhad, Iran. aghaderi@um.ac.ir Author Leda, Lucyna 81481AFA-C8EE-4E90-A954-FD0E7987621E Museum für Naturkunde, Leibniz Institut for Research on Evolution and Biodiversity, Invalidenstrasse 43, 10115 Berlin, Germany. lucyna.skorpion3@wp.pl Author Schobben, Martin 44C2A45A-B16C-434F-8F22-FC9C0FCA2551 Utrecht University, Department of Earth Sciences, Princetonlaan 8 A, 3584 CB Utrecht, The Netherlands. & Department of Geology, Esfahan (Khorasgan) Branch, Islamic Azad University, Esfahan, Iran. schobbenmartin@gmail.com Author Akbari, Amir 3C9DB6F9-2034-418F-876C-49359D07D29F Department of Geology, Esfahan (Khorasgan) Branch, Islamic Azad University, Esfahan, Iran amakbari80@yahoo.com text European Journal of Taxonomy 2021 2021-10-27 776 1 106 journal article 3782 10.5852/ejt.2021.776.1559 453c885c-f427-4a38-ab97-dc14b686e126 2118-9773 5604715 226B6C59-8620-4A29-9BEF-359BE67A1A2C Shevyrevites shevyrevi Teichert & Kummel in Teichert et al. , 1973 Fig. 17 ; Table 2 Shevyrevites shevyrevi Teichert & Kummel in Teichert et al. , 1973: 410 , pl. 3 figs 1–3, 6. Bernhardites radiosus – Shevyrev 1965: 171 , pl. 21 fig. 7 ; 1968: 86, pl. 1 fig. 7, pl. 2 fig. 1. Shevyrevites shevyrevi – Bando 1979: 133 , pl. 5 figs 1, 5, pl. 8 figs 6–7. — Korn et al. 2019: 46, text- figs 11–12 . non Shevyrevites shevyrevi – Zhao et al. 1978: 107 , pl. 11 figs 2–4, 6–7. Diagnosis Species of Shevyrevites with conch reaching 70 mm dm. Subadult stage with oval, compressed whorl profile (ww/wh= 0.70–0.90) and rounded venter; 30 coarse ribs per volution.Adult stage with rectangular and compressed whorl profile (ww/wh =0.70–0.80), flattened flanks, flattened venter and subangular ventrolateral shoulder; coarse and sharp ribs on the flank, venter smooth. Prongs of external lobe usually bifid; altogether 20–25 notches of E, A and L lobes. Type material Holotype IRAN • East Azerbaijan , Ali Bashi Mountains ; Ali Bashi Formation ; illustrated by Teichert & Kummel in Teichert et al. (1973 : pl. 3 figs 1–2); MCZ 9678 . Material examined IRAN • 30 specimens ; Esfahan Province , Baghuk Mountain 1 section; Hambast Formation ; MB.C.29664 to MB.C.29669 • 4 specimens ; Esfahan Province , Baghuk Mountain B section ; Hambast Formation ; MB.C.29670 to MB.C.29673 • 12 specimens ; Esfahan Province , Baghuk Mountain E section ; Hambast Formation ; MB.C.29674 to MB.C.29678 • 2 specimens ; Esfahan Province , Baghuk Mountain G section ; Hambast Formation ; MB.C.29679 • 33 specimens ; Esfahan Province , Baghuk Mountain H section ; Hambast Formation ; MB.C.29680 to MB.C.29687 • 92 specimens ; Esfahan Province , Baghuk Mountain ; Hambast Formation ; MB.C.29688 to MB.C.29712 . Description There is little morphological variation in the material when the conch proportions are regarded. specimen MB.C.29674 is an incomplete but comparatively well-preserved specimen with 52 mm diameter ( Fig. 17A ). It is extremely discoidal (ww/wh =0.24) and evolute (uw/dm =0.48) with a compressed, parallel-sided whorl profile with flat venter and an angular ventrolateral shoulder. The sculpture consists, on the last volution of the phragmocone as well as the body chamber, of sharp and slightly sigmoidal ribs on the flanks; on half a volution around 20 of such ribs can be counted. The suture line of specimen MB.C.29674 has a short external lobe with concave flanks and bifid prongs ( Fig. 17D ). The ventrolateral saddle is asymmetric and appears dorsally inclined. The adventive lobe is semicircular in shape with twelve small notches of equal size. In contrast to this is the lateral lobe almost flat at its base; it is also serrated by numerous small notches. There is some variation in the shape of the venter. In contrast to specimen MB.C.29674, the other two figured specimens MB.C.29672 ( Fig. 17B ) and MB.C.29670 ( Fig. 17C ) show a less flattened or even a rounded venter. These two specimens do not show as sharp ribs as specimen MB.C.29674. Remarks Shevyrevites shevyrevi differs from S. nodosus in the lack of the coarse nodes of the subadult stage and from S. corrugatus sp. nov. in the much coarser and less numerous ribs. Table 2. Conch dimensions (partly estimated) and ratios of selected specimens of Shevyrevites shevyrevi Teichert & Kummel in Teichert et al. (1973) from Baghuk Mountain.

Specimen	dm	ww	wh	uw	ah	ww/dm	ww/wh	uw/dm	WER	IZR
MB.C.29674	52.1	12.3	15.4	24.8	15.2	0.24	0.80	0.48	1.99	0.01
MB.C.29670	45.4	9.9	14.4	18.9	14.1	0.22	0.69	0.42	2.10	0.02
MB.C.29672	43.8	11.2	13.4	20.9	13.0	0.26	0.84	0.48	2.02	0.03
MB.C.29705.5	56.8	12.5	16.8	26.4	16.0	0.22	0.74	0.46	1.94	0.05
MB.C.29676.2	54.3	12.8	17.2	25.3	16.6	0.24	0.74	0.47	2.07	0.03
MB.C.29676.3	50.1	11.2	16.2	22.2	15.6	0.22	0.69	0.44	2.11	0.04
MB.C.29676.1	48.8	12.5	15.5	23.3	15.0	0.26	0.81	0.48	2.08	0.03
MB.C.29705.4	47.7	11.7	13.9	21.5	13.4	0.25	0.84	0.45	1.93	0.04
MB.C.29693.1	46.8	10.7	13.2	22.2	12.5	0.23	0.81	0.47	1.86	0.05
MB.C.29705.7	45.2	11.4	13.7	20.1	13.4	0.25	0.83	0.44	2.02	0.02
MB.C.29676.4	45.0	11.7	12.9	22.4	12.3	0.26	0.91	0.50	1.89	0.05
MB.C.29704.1	35.6	9.2	9.5	17.9	9.2	0.26	0.97	0.50	1.82	0.03

Fig. 17. Shevyrevites shevyrevi Teichert & Kummel in Teichert et al. , 1973 . A . Lateral and dorsal view, specimen MB.C.29674, section E, float. B . Lateral and dorsal view, specimen MB.C.29672, section B, float. C . Lateral and dorsal view, specimen MB.C.29670, section B, float. D . Suture line, specimen MB.C.29674, at 10.8 mm ww, 13.0 mm wh. E . Whorl profile proportions. Abbreviations: see Material and methods. Scale bar units =1 mm. Stratigraphic range Upper part of the Hambast Formation; 5.20 to 4.70 m below the extinction horizon ( Shevyrevites shevyrevi Zone ).