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Freboldinium serrulata
Freboldinium serrulatum (Davies, 1983) Below, 1990
Contrary to the opinion of Lentin and Williams (1993, p.227), this combination is validly published, since the generic name Freboldinium is validly published.
Originally Lithodinia, subsequently (and now) Freboldinium.
Holotype: Davies, 1983, pl.9, figs.3-4; text-figs.21A-B
Age: Toarcian-Early Bajocian
Original diagnosis: Davies, 1983, p.26
Oblate, proximate dinoflagellate cysts. Autophragm thin, smooth to punctate or slightly granulate, otten possessing remnants of a kalyptra. Tabulation marked by low, otten indistinct, finely serrulated sutural crests. Tabulation: ?4", 6", 6c, 6""", 1p, 1"""". Archeopyle: ("?4A). Size: length - 30(38)52 µm; breadth - 29(35)46 µm.
Original description: Davies, 1983, p.26
Sutural crests are up to 1.5 µm high. The sulcus is well defined and bordered by two crests with serrulated margins. The laevo-rotary cingulum is bordered by cingular crests up to 2 µm high and tabulated by low non-serrulated ridges (approx. 0.5 µm high) . The apex is terminated by a thickening. Tabulation within the apical series is poorly defined and not often visible: however, by the shape of the operculum four apical plates are suggested. The operculum is sometimes attached ventrally, or completely removed. The kalyptra when present gives the cyst a spongy appearance.
Affinities:
Davies, 1983, p. 26: This species is distinguished from other species of Lithodinia by its thin, low, hyaline serrulated crests, frequent possession of a kalyptra, the very thin transparent autophragm and its small size.
Contrary to the opinion of Lentin and Williams (1993, p.227), this combination is validly published, since the generic name Freboldinium is validly published.
Originally Lithodinia, subsequently (and now) Freboldinium.
Holotype: Davies, 1983, pl.9, figs.3-4; text-figs.21A-B
Age: Toarcian-Early Bajocian
Original diagnosis: Davies, 1983, p.26
Oblate, proximate dinoflagellate cysts. Autophragm thin, smooth to punctate or slightly granulate, otten possessing remnants of a kalyptra. Tabulation marked by low, otten indistinct, finely serrulated sutural crests. Tabulation: ?4", 6", 6c, 6""", 1p, 1"""". Archeopyle: ("?4A). Size: length - 30(38)52 µm; breadth - 29(35)46 µm.
Original description: Davies, 1983, p.26
Sutural crests are up to 1.5 µm high. The sulcus is well defined and bordered by two crests with serrulated margins. The laevo-rotary cingulum is bordered by cingular crests up to 2 µm high and tabulated by low non-serrulated ridges (approx. 0.5 µm high) . The apex is terminated by a thickening. Tabulation within the apical series is poorly defined and not often visible: however, by the shape of the operculum four apical plates are suggested. The operculum is sometimes attached ventrally, or completely removed. The kalyptra when present gives the cyst a spongy appearance.
Affinities:
Davies, 1983, p. 26: This species is distinguished from other species of Lithodinia by its thin, low, hyaline serrulated crests, frequent possession of a kalyptra, the very thin transparent autophragm and its small size.