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 Lutites plicatus Korn & Hairapetian gen. et sp. nov. urn:lsid:zoobank.org:act: 1713B70A-3C3C-4FCD-9827-BBBA6F989797 Fig. 55 ; Table 29 Diagnosis Species of Lutites gen. nov. with conch reaching 120 mm dm. Subadult stage with oval, compressed whorl profile (ww/wh=0.75) and rounded venter; about 12 radial plications per volution. Adult stage with subtrapezoidal, compressed whorl profile (ww/wh =0.72), weakly concave flanks, flattened venter and subangular ventrolateral shoulder; numerous weak and densely arranged plications and small ventrolateral nodes. Prongs of external lobe multiply serrated; altogether 20 notches of E, A and L lobes. Etymology From the Latin ‘ plicatus ’, meaning ‘corrugated’, referring to the dense ribbing. Material examined Holotype IRAN • Esfahan Province , Baghuk Mountain E section ; Hambast Formation; illustrated in Fig. 55A ; MB.C.30018 . Description Holotype MB.C.30018 is a specimen with 84 mm diameter, of which the last 120 degrees belong to the body chamber ( Fig. 55A ). Nearly one volution of the phragmocone can be studied; at this stage the whorl profile is oval and compressed with a rounded venter. The ornament consists of nearly 20 faint radial plications, which are coarsest near the umbilicus and in the ventrolateral area, where they form weak nodes. The ornament is weaker on the body chamber, where the plications are more numerous. The whorl profile is subtrapezoidal and compressed (ww/wh=0.72) in the adult stage with a rounded umbilical margin, weakly concave flanks and a flattened venter. Fig. 55. Lutites plicatus Korn & Hairapetian gen. et sp. nov. A . Lateral and dorsal view, holotype MB.C.30018, section E, float. B . Suture line, holotype MB.C.30018, 13.7 mm ww, 18.6 mm wh. Abbreviations: see Material and methods. Scale bar units=1 mm. Table 29. Conch dimensions (partly estimated) and ratios of the holotype of Lutites plicatus Korn & Hairapetian gen. et sp. nov. from Baghuk Mountain.

Specimen	dm	ww	wh	uw	ah	ww/dm	ww/wh	uw/dm	WER	IZR
MB.C.30018	84.3	20.7	28.7	34.5	26.7	0.25	0.72	0.41	2.14	0.07
MB.C.30018	59.7	15.3	20.5	23.2	–	0.26	0.75	0.39	–	–

The suture line of the holotype has a narrow external lobe with asymmetric, multiply serrated prongs (four and six small notches), an asymmetric and inflated ventrolateral saddle and multiply serrated adventive and lateral lobes ( Fig. 55B ). Both lobes show notches of various size. Remarks Lutites plicatus gen. et sp. nov. differs in the shape of the flattened, but convex venter from most of the other species of the genus ( L. lyriformis gen. et sp. nov. , L. profundus gen. et sp. nov. , L. alius gen. et sp. nov. ), which possess a completely flat or even concave venter. Stratigraphic range Upper part of the Hambast Formation; horizon unknown.