Menucoestheria, Gallego and Covacevich, 1998

Olempska, Ewa, 2004, Late Triassic spinicaudatan crustaceans from southwestern Poland, Acta Palaeontologica Polonica 49 (3), pp. 429-442 : 439-440

Menucoestheria ? sp.

Figs. 5B , 10 .

Material.—Two valves poorly preserved.

Description.—Carapace of moderate size, elliptical in outline, up to 5.8 mm long and up to 2.0 mm high; anterior and posterior margin rounded; umbo situated close to anterior end of dorsal margin; ventral margin slightly convex; more than 20 growth bands, ornamented by reticulate pattern in dorsal region and gradually changed into radial striae in lower part of each growth bands near ventral part of carapace.

Remarks.— Menucoestheria ? sp. is morphologically similar to Menucoestheria bocki , but differs mainly in the presence of radial striae ornamentation occurring only in the lower part of the each growth band in ventral part.

Occurrence.—Late Carnian, Krasiejów, Poland.

?Family Palaeolimnadiidae Tasch, 1956

Genus Krasiestheria nov.

Type species: Krasiestheria parvula gen. et sp. nov.

Derivation of name: The name is derived from Krasiejów— type locality, and the genus name Estheria .

Type horizon and locality: Late Triassic , late Carnian, Krasiejów,southwestern Poland .

Diagnosis.—A small spinicaudatan genus with subcircular outline; relatively large umbonal area; growth bands with ornamentation of minute punctae pattern in upper part of each growth band and radial striae in lower part of each growth band.

Remarks.— Krasiestheria shows certain resemblances to Palaeolimnadia Raymond, 1946 , and to Bilimnadia Novojilov, 1960, in comparatively large umbonal region, but differs from them in its surface ornament pattern.

Figures

Fig. 5. A. Laxitextella laxitexta (Jones, 1890). Left valve ZPAL Cr. 6/2 in oblique dorsal view (A1), and details of shell structure showing layers of cuticle (A2–A4). B. Menucoestheria? sp. Right valve ZPAL Cr. 6/3 with details showing layers of cuticle in mid−dorsal area. C, D. Menucoestheria bocki sp. nov. C. Specimen ZPAL Cr. 6/28, showing growth bands ornamentation (C1), and details of shell structure showing layers of cuticle in median area (C2). D. Specimen ZPAL Cr. 6/15, showing growth band reticulate ornamentation in mid−dorsal part (D1), and details of cuticle layers in mid−dorsal area (D2).

Fig. 10. Menucoestheria? sp. Right valve ZPAL Cr. 6/3 in lateral−ventral view (A), and oblique anterior view (B); the same showing details of growth bands ornamentation in dorsal area (C); the same with details of growth bands ornamentation in mid−ventral area (D); details of shell structure showing layers of cuticle in dorsal area (E, F); details showing gradually changed growth bands ornamentation during the successive growth stages (G).