Atalantria, Cordey & Carter, 2007

Tekin, Kagan, Krystyn, Leopold, Okuyucu, Cengiz, Bedi, Yavuz & Sayit, Kaan, 2020, Late Triassic to Early Jurassic radiolarian, conodont and ammonite assemblages from the Tavuscayiri block, Mersin Mélange, southern Turkey: Time constraints for the T / J boundary and sedimentary evolution of the southern margin of the northern Neotethys, Geodiversitas 42 (27), pp. 493-537 : 525

Atalantria sp. A

( Fig. 12O )

OCCURRENCE. — Lower Jurassic, lower Sinemurian of Mersin Mélange, NW of Mersin city, southern Turkey.

DESCRIPTION

Test multicyrtid, increasing in width distally except the last segment. Last segment decreasing in width. Cephalis hemisphaerical, poreless with small, rudimentary, needle-like horn. Thorax to rest of segments, except the last one, subtrapezoidal. Last segment inverse subtrapezoidal in outline. Segments have two transverse rows of pores with hexagonal pore frames.

REMARKS

This specimen differs from Atalantria emmela ( Cordey & Carter 1996: 67, pl. 24, fig. 13) by having a distally constricted test. It can be differentiated also from Atalantria epaphrodita ( Cordey & Carter 1996: 446, pl. 1, figs 6, 7, 10, 11) by having a shorter test and cephalis with unbranched, needle-like horn.

Figures

FIG. 12. — Photomicrographs of the radiolarians from the Orbuklukeli section; A, B, Canoptum rhaeticum Kozur & Mostler,1981, Orbuk-15;C, Canoptum striatum (Kozur & Mostler, 1990), Orbuk-27; D-J, Laxtorum breve Tekin, n. sp.; D, Holotype, Orbuk-32; E-J, Paratypes, Orbuk-32; K-L, Laxtorum obscurum Tekin, n. sp., K, Holotype, Orbuk-27; L, Paratype, Orbuk-27; M-N, Atalantria emmela (Cordey & Carter, 1996), Orbuk-32; O, Atalantria sp. A, Orbuk-27; P-Q, Pseudoeucyrtis