Conochitina, EISENACK, 1931 emend. PARIS, GRAHN, NESTOR et LAKOVA, 1999

Morávek, Radek, 2009, Lower Wenlock Chitinozoa From The Bykoš Locality (Silurian, Prague Basin, Barrandian Area, Czech Republic), Acta Musei Nationalis Pragae Series B 65 (1 - 2), pp. 37-60 : 43

Conochitina tuba EISENACK, 1932

Pl. 6, figs. 4-7.

D e s c r i p t i o n: Conochitina with tubular vesicle. The flexure is inconspicious, flanks are straight to convex. Base is flat to convex and the basal edge is rounded. The mucron is sunken. The neck is tubular and clearly diferentiated from the chamber.

D i s c u s s i o n: C. tuba differs from C. proboscifera f. truncata by a clearly differentiated neck and a lower ratio of length to width of the vesicle. However, these ratios can be excceded. C. tuba occurs in the upper part of the profile only.

O c c u r r e n c e: Lower Silurian of the Prague Basin ( Dufka, 1990): Homerian (zone: C. lundgreni) .

Gotland ( Laufeld, 1974): From the Slite Beds to the Hemse beds (upper Sheinwoodian to the Ludfordian).

Mehaigne area (Brabant Massif, Belgium; Verniers, 1981, 1982): From the formation MB7 to the formation MB8, middle to late Wenlock.

Estonia and North Latvia ( Nestor, 1994): Jaani stage to the Rootsiküla stage, chitinozoan biozone 15 to 22; middle Sheinwoodian to upper Homerian.

Southwestern Estonia and northernmost Latvia ( Nestor et Nestor, 2002): Staicele ( Estonia) drill core: upper part of the Tõlla Member to the Sõrve Formation, chitinozoan biozone numbers 5-11; Ikla ( Estonia) drill core: from the Paramaja Member to the Jamaja Formation, chitinozoan biozone numbers 5-8.