Lituites applanatus Remelé, 1880: 438 Cyclolituites applanatus Remelé 1886: 467 Lituites applanatus Remelé 1890: 30. Cyclolituites applanatum Holm 1891: 33 Cyclolituites applanata Neben & Krueger 1971 : pl. 32 figs 19–20. Taxonomy and ontogeny of the Lituitida (Cephalopoda) from Orthoceratite Limestone erratics (Middle Ordovician) Aubrechtová, Martina Korn, Dieter European Journal of Taxonomy 2022 2022-03-08 799 1 1 108 (Remele, 1880) Remele 1880 [554,1034,1730,1757] Cephalopoda Lituitidae Cyclolituites GBIF Animalia Orthocerida 95 96 Mollusca species applanatus   Fig. 72      Lituites applanatus Remelé, 1880: 438.    Cyclolituites applanatus–  Remelé 1886: 467; 1890: 101, pl. 1 fig. 6a–b.    Lituites applanatus– Remelé 1890: 30.    Cyclolituites applanatum–  Holm 1891: 33.    Cyclolituites applanata–  Neben & Krueger 1971: pl. 32 figs 19–20.    Diagnosis Species of the genus  Cyclolituiteswith tightly coiled conch, only last whorl detached near mature aperture; whorl profile compressed (WWI = 0.60). Shell surface with narrow annuli/raised lirae, adorally 0.5–1 mmapart, marked ventral sinus; lateral sinus weakly developed in inner whorls of the conch, shallow and asymmetric towards the aperture.    Type material    Lectotype(designated herein) GERMANY• Brandenburg, Eberswalde; Ordovician, Upper Grey Orthoceratite Limestone; Kgl. Forstakademie EberswaldeColl.; illustrated by Remelé (1880: pl. 1 fig. 6; 1890: pl. 1 fig. 6), re-illustrated here in Fig. 72B; MB.C.11671.2.   Additional material   GERMANY• 1 spec.; Brandenburg, Oderberg; Ordovician, Upper Grey Orthoceratite Limestone; MB.C.30560.    Description  LectotypeMB.C.11671.2 ( Fig. 72B) consists of a part of the coiled conch (dm = 20 mm; one and a half tightly coiled whorls; WWI = 0.60; WER = 2.40) with an incomplete body chamber. The shell ornament consists of narrow annuli/raised lirae (up to 0.5 mmapart) separated by very fine growth lines. The ornament elements form a deep ventral sinus and a shallow lateral sinus. The slightly flattened venter of the last whorl is raised and separated from the flanks by subangular ridges. The last quarter of the last whorl belongs to the body chamber. Specimen MB.C.30560 ( Fig. 72A) consists of the coiled part (dm = 33 mm; one and a half tightly coiled whorls; WWI = 0.60; WER dm = 3.40) with an almost complete body chamber. The shell is ornamented by narrow annuli/raised lirae (up to 0.50–1 mmapart) and very fine growth lines in between. The ornament elements form a ventral sinus and a lateral sinus. The lateral sinus is weakly developed and shallow, the point of its maximum backward curvature is located in the ventrolateral area. As in the lectotype, the ventral side of the last whorl is slightly raised and flattened and forms a subangular ridge. The body chamber has half the length of the last whorl.    Remarks The lectotypeof  C. applanatusdiffers from the below described specimens of  C. lynceusbecause it has a smaller diameter of the conch ( 20 mm), a less compressed whorl profile (WWI = 0.60), a lower whorl expansion rate (WER 2.40) and a coarser ornament. Specimen MB.C.30560 (also figured by Neben & Krueger 1971: pl. 32 figs 19–20) differs from the lectotypein the larger size and higher whorl expansion rate (WER = 3.40 vs 2.40 inthe lectotype) and is thus similar to  Cyclolituites lynnensis(late Middle or early Late Ordovician of Norway). It is possible, however, that the differences have the reason in an earlier ontogenetic growth stage of the lectotype. Since specimen MB.C.30560 has the same type of ornament and whorl profile shape (whorls are not impressed dorsally and lack a conspicuous keel ventrally) as the lectotype, it is retained in  C. applanatushere.    Geographic and stratigraphic occurrence Northern Germany(in erratics within Pleistocene gravels); Upper Grey Orthoceratite Limestone, late Lasnamägi Regional Stage, late Darriwilian, Middle Ordovician. 3700114312 MB Forstakademie Eberswalde Germany Eberswalde Eberswalde Ordovician 96 97 MB.C.11671.2 1 Brandenburg lectotype 3700114326 MB Germany Oderberg Oderberg Ordovician 96 97 MB.C.30560 1 Brandenburg