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 : 41

Conochitina cf. emmastensis NESTOR, 1982

Pl. 4, figs. 1-5; pl. 9, figs. 11-14.

cf. 1982 Conochitina emmastensis NESTOR, p. 108, pl. 1, figs. 1-3, text-fig. 1.

cf. 1990 Conochitina emmastensis NESTOR, Dufka, p. 65, pl. 36, figs. 1-5.

cf. 1993 Conochitina emmastensis NESTOR, Nestor, pl. 2, figs. 3-4.

cf. 1994 Conochitina emmastensis NESTOR, Nestor p. 28-29, pl. 13, figs. 1-4.

cf. 1995 Conochitina emmastensis NESTOR, Grahn, fig. 7A.

cf. 2005 Conochitina emmastensis NESTOR, Nestor, pl. 2, fig. 2.

D e s c r i p t i o n: The chamber constitutes two thirds of the total length of the vesicle, it is conical, with straight or convex flanks. The maximal diameter of the vesicle is above the basal edge. The neck is tubular with a short colarette. A wide mucron occurs on the flate base. The basal edge is rounded.

D i s c u s s i o n: C. emmastensis is longer, with a narrower neck, which can hardly be distinguished from the chamber.

O c c u r r e n c e: Lower Silurian of the Prague Basin ( Dufka, 1990): upper Aeronian to the lower Sheinwoodian (zones: M. sedgwickii,? M. riccartonensis) .

Estonia ( Nestor, 1982): Adavere Formation to the Jaani Formation (M. sedgwickii to C. murchisoni), Aeronian to Sheinwoodian.

Jaagarahu Core, Estonia ( Nestor, 1993): Velisa Formation of the Adavere Stage (Llandovery) to the lower part of Mustjala Member of the Jaani Stage (Wenlock).

Estonia and North Latvia ( Nestor, 1994): Raikküla Stage to the Jaani Stage, chitinozoan biozones 7-10 (middle Aeronian to middle Telychian) and 12 (lower Sheinwoodian).

Subsurface of Gotland ( Grahn, 1995): from the Aeronian (zone M. sedgwickii) to the lower Sheinwoodian (zone C. centrifugus).

Southwestern Estonia and northernmost Latvia ( Nestor et Nestor, 2002): Staicele drill core ( Latvia): upper part of the Rumba Formation (Adavere stage), chitinozoan biozone number 2; Ikla ( Estonia) drill core: from Rumba Formation to the Tõlla Member, chitinozoan biozones number 1-4.

West Estonian drill cores – Margachitina margaritana Biozone ( Nestor, 2005): In Viki core and Kaugatuma core C. emmastensis appears in the Velise Formation (Llandovery), in Ohesaare core and Ruhnu core C. emmastensis was found in the Velise and Riga Formation close to the Llandovery – Wenlock boundary (the precise boundary is not known) .