Canoptum productum Tekin, 2020

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 : 522-524

Canoptum productum Tekin , n. sp.

( Fig. 11 R-U)

urn:lsid:zoobank.org:act:4E402E3A-79F5-405C-AB7F-EB5F656496A0

HOLOTYPE. — Sample Orbuk-15, HU.JMB.0150 ( Fig. 11R ).

PARATYPES. — HU.JMB.0151 ( Fig. 11S ), HU.JMB52 ( Fig. 11T ), HU.JMB.0153 ( Fig. 11U ).

TYPE LOCALITY. — Orbuklukeli section, Mersin Mélange, NW of Mersin city, southern Turkey.

ETYMOLOGY. — From the Latin productum , lengthened, long, due its long test.

OCCURRENCE. — Late Triassic, Rhaetian, Orbuklukeli section, Mersin Mélange, NW of Mersin city, southern Turkey.

DIMENSIONS (based on four specimens, in µm). — Maximum length of test: 170-220 (holotype: 220, average: 190); Maximum width of test: 80-100 (holotype: 100, average: 89.3).

DESCRIPTION

Test long, slender, very slowly incerasing in width and height distally with six post-abdominal segments. Cephalothorax dome-shaped, probably without horn, poreless, collar stricture indistinct. Lumbar stricture and other strictures prominent, marked by relatively deep depressions and mainly poreless. Abdomen to post-abdominal segments hoop-like, mainly covered by veneer of thick, microgranular silica with scattered, small, subcircular pores. Two rows of pores (15-16 pores at one row on half a circumference) can be seen just above and below septa located at strictures when silica accumulation is not prominent. REMARKS

This species differs from Canoptum merum ( Pessagno &Whalen 1982: 124, pl. 1, figs 1, 15, 16, 20; pl. 12, fig. 11) by a having a more slender test covered by prominent silica accumulation, fewer scattered pores and abdomen to last post-abdominal segments hoop-like instead of trapezoidal in outline.

Figures

FIG. 11. — Photomicrographs of the radiolarians from the Orbuklukeli section; A, B, Droltus sp. aff. D. eurasiaticus Kozur & Mostler, 1990, Orbuk-32; C, Droltus hecatensis Pessagno & Whalen, 1982, Orbuk-32; D-F, Droltus laseekensis Pessagno & Whalen, 1982, Orbuk-27; G-J, Trexus dodgensis Whalen & Carter in Carter, Whalen & Guex, 1998; G-H, Orbuk-27; I, J, Orbuk-32; K-O, Canoptum cephalobulbosum Tekin, n. sp.; K, Holotype, Orbuk-15; L-O, Paratypes, Orbuk-15; P, Canoptum columbiaense Whalen & Carter in Carter, Whalen & Guex, 1998, Orbuk-27; Q, Canoptum merum Pessagno & Whalen, 1982, Orbuk-15; R-U, Canoptum productum Tekin, n. sp.; R, Holotype, Orbuk-15; S-U, Paratypes, Orbuk-15; V-X, Canoptum rarum Tekin, n. sp.; V, Holotype, Orbuk-15; W-X, Paratypes, Orbuk-15. Scale bar: A, B, 200 µm; C, P, 120 µm; D-J, 100 µm; K-O, R-X, 80 µm.