Obolinae King, 1846

Holmer, Lars E. & Biernat, Gertruda, 2002, Urban and Peri-urban small and medium-size Enterprise Development for sustainable Vegetable Production and Marketing Systems, Acta Palaeontologica Polonica 47 (1), pp. 141-156 : 142

publication ID	https://doi.org/ 10.13140/rg.2.1.3543.9120
persistent identifier	https://treatment.plazi.org/id/FB5C1130-FFBA-5930-FFFE-D0400E29FD5E
treatment provided by	Felipe
scientific name	Obolinae King, 1846
status

Treatment

Subfamily Obolinae King, 1846 Genus Leptembolon Mickwitz, 1896

Type species: Obolus (Leptembolon) lingulaeformis Mickwitz, 1896 ;

Ordovician Leetse beds (late Tremadoc–early Arenig Hunneberg

Stage); northern Estonia.

Leptembolon cf. lingulaeformis ( Mickwitz, 1896) Fig. 1A–L View Fig .

Leptembolon lingulaeformis Mickwitz ; Kozłowski 1948: 5. Lingulella zejszneri sp. nov.; Bednarczyk 1964: 46, pl. 7: 1–14, 8: 1–4. Lingulella cf. zeuschneri Bednarczyk ; Biernat 1973: 56, pl. 2: 1–2. cf. Leptembolon lingulaeformis (Mickwitz) ; Popov and Holmer 1994: 48, figs 48, 49. [full synonymy]

Material.—Total of 4 dorsal and 4 ventral valves. Figured dorsal valves: RM Br133755 (L = 1.39, W = 1.67, LI = 0.56, ML = 0.25, WI = 1.09, WG = 0.70), RM Br133758, RM Br133760; ventral valves: RM Br133756, RM Br133757 (L = 2.00, W = 1.40, LI = 0.46, ML = 0.21, WI = 0.60, WG = 0.07).

Description.—Shell evenly and subequally biconvex, slightly inequivalved, elongate, subtriangular, with maximum width at about mid−length. Ventral valve slightly longer than the dorsal, 140% as long as wide (N = 1). Ventral pseudointerarea not elevated above valve floor; occupying 65% of maximum valve width (N = 1). Pedicle groove deep, narrowly triangular. Propareas bisected by widely divergent flexure lines. Ventral internal characters poorly impressed.

Dorsal valve 140% as long as wide (N = 1). Dorsal pseudointerarea crescent−shape, occupying 43% of total valve width (N = 1). Median groove wide and poorly defined with reduced propareas. Dorsal internal characters poorly impressed.

Remarks.— Biernat (1973) found only the ventral valves of this species, and the new valves are identical to those in all aspects of morphology. Popov and Holmer (1994) questionably referred this taxon to Leptembolon lingulaeformis , and this view is maintained here. However, the scant available material is represented only by juveniles. As noted by Popov and Holmer (1994), it is possible that Lingulella sanctacrucensis ( Bednarczyk 1964) is also synonymous with L. lingulaeformis , but its exact relationship to the type species still remains unclear. These authors also gave a more detailed comparative discussion of Leptembolon lingulaeformis , as well as a review of its geographic distribution.