Lituites Bertrand, 1763

Aubrechtová, Martina & Korn, Dieter, 2022, Taxonomy and ontogeny of the Lituitida (Cephalopoda) from Orthoceratite Limestone erratics (Middle Ordovician), European Journal of Taxonomy 799 (1), pp. 1-108 : 46-47

Genus Lituites Bertrand, 1763

Type species

Lituites lituus de Montfort, 1808 ; by original designation.

Diagnosis

Genus of the family Lituitidae with tightly or loosely coiled apical part of the conch; uncoiled part straight or variably curved; expansion angle up to ca 8°. Whorl profile compressed in the coiled and backcoiled part and circular in the straight part of the conch. Shell surface with sinuous annuli and/or lirae. Siphuncle position changes from subdorsal to subcentral during ontogeny. Fully mature aperture

with a pair of pronounced ventrolateral lappets, similar but shorter dorsolateral lappets and a low dorsal projection (after Furnish & Glenister 1964, emended).

Species included

Lituites anguinus Angelin, 1880 ; Lituites anhuiense Qi, 1980 ; Lituites baculus sp. nov.; Lituites bottkei sp. nov.; Lituites clavis sp. nov.; Lituites dewitzi sp. nov.; Lituites evolutus Fang, Chen & Zhang in Fang et al., 2017; Lituites fallax Remelé, 1890 ; Lituites hengshanensis Qi, 1980 ; Lituites kruegeri sp. nov.; Lituites lii Yü, 1930 ; Lituites Lasaulxii Remelé, 1890 ; Lituites lituus de Montfort, 1808 ; Lituites nebeni sp. nov., Lituites ningkiangense Lai, 1965 ; Lituites perfectus Wahlenberg, 1818 ; Lituites procerus Remelé, 1890 ; Lituites tenuicaulis Remelé, 1890 ; Lituites Törnquisti Holm, 1891 ; Lituites wuweiense Qi, 1980 (synonym of L. ningkiangense Lai, 1965 ); Lituites xizangense Lai, 1982 .

Remarks

Most species of the genus Lituites known from Baltoscandia and erratics in north central and eastern Europe were described already in the 19 th century. Differences between the species concern mainly the mode of coiling, the shape of the whorl profile, the degree of curvature of the backcoiled part, the expansion angle and the shell ornament ( Aubrechtová & Meidla 2020: 278, table 2). However, the apparently high intraspecific variation and common morphological transitions between the species make it often difficult to distinguish between them. An additional problem is that the species were originally defined based on the coiled and backcoiled parts of the conch. The straight part and mature aperture are not known in most of the species, which makes it impossible to taxonomically determine specimens consisting only of the uncoiled part ( Holm 1891).

Geographic and stratigraphic occurrence

Argentina, Baltoscandia, northern Germany, northern Poland, Kaliningrad Region of Russia, Bohemia, Lhasa Terrane (North Tibet), North and South China; Middle to Late Ordovician.