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Hapsocysta fenestrata

Hapsocysta fenestrata (Versteegh and Zevenboom in Versteegh, 1995, p.91–92, pl.4, figs.1–7) Heilmann-Clausen and Van Simaeys, 2005, p.166.

Originally Piccoladinium, subsequently (and now) Hapsocysta.

Holotype: Versteegh, 1995, pl.4, figs.1,4.
Paratype: Versteegh and Zevenboom, 1995, Pl. IV, fig. 5
Type Locality: Punta Piccola Section, Sicily, Italy
Age: early Chattian–mid Piacenzian.

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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP
Piccoladinium fenestratum Versteegh and Zevenboom in Versteegh, 1995. Diagnosis from Versteegh and Zevenboom in Versteegh (1995, p.91-92). Gonyaulacoid, S-type, camocavate cysts of which the endo- and periphragm are connected only dorsally. The subspherical smooth to finely granular endophragm reflects no tabulation and is about half the diameter of the periphragm. All septa on the subspherical smooth periphragm are sutural. The maximally reflected tabulation is ap, 4', 6", as, ras/sulcal pore, rs, ls, ps, 6c, 6"’,1p, 1"”. Each of the plates 1", 2", 4", 5", and 2"’-6"’ has a large penitabular hole. Consequently only small strands of plate material are present apart from the septa. Size: endophragm height 17-27 µm, periphragm height 33-49 µm, periphragm width 44-52 µm.
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Original diagnosis: Versteegh and Zevenboom, 1995, p. 225
Gonyaulacoid, S-type, camocavate cysts of which the endo- and periphragm are connected only dorsally. The subspherical smooth to finely granular endophragm reflects no tabulation and is about half the diameter of the periphragm. All septa on the subspherical smooth periphragm are sutural. The maximally reflected tabulation is ap, 4', 6'', as, ras/sulcal pore, rs, ls, ps, 6c, 6''', 1p, 1 ''''. Each of the plates 1'', 2'', 4'', 5'' and 2'''- 6''' has a large penitabular hole. Consequently only small strands of plate material are present aside the septa.

Description: Versteegh and Zevenboom, 1995, p. 225
This species of Picoladinium may lack the sutural septa between plates 1' and 4' as well as part of the sutural septa between plates as, ras, rs, ls and 1'''. Additional penitabular holes may be present in the other plates than 1'', 2'', 4'', 5'' and 2'''- 6''', excluding the dorsal area where the endophragm and periphragm are connected. The archaeopyle is formed by the loss of plate 3''. Dimensions: Holotype: endophragm height: 26 µm; maximum width: 27 µm; periphragm height: 39 µm; maximum width: 44 µm. Paratype: endophragm height: 27 µm; maximum width: 22 µm; periphragm height: 46 µm; maximum width: 51 µm. Range: endophragm height: 17-27 µm; periphragm height: 33-49 µm; periphragm width 44-52 µm; specimens measured: 6.

Affinities:
Versteegh and Zevenboom, 1995, p. 225
P. fenestratum differs from Hapsocysta peridictya (Eisenack and Cookson, 1960) Davey, 1979 in having apical plates and in having only a part of the pericystal plates perforate. The tabulation of Hapsidaulax margarethae Sarjeant, 1975 differs from that of P. fenestratum in several aspects, of these the absence of singular plates for H. margarethae is most evident.

Stratigraphy:
Early Chattian (Manum et al., 1987) to Middle Piacenzian, NN16/17 (Zevenboom and Versteegh, in prep.)
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