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Lithodinia serrulata

Lithodinia?"serrulata" Davies, 1983, p.26, pl.9, figs.1-6; text-figs.21A-B.
Holotype: Davies, 1983, pl.9, figs.3-4; text-figs.21A-B.
NOW Freboldinium. Originally Lithodinia, subsequently (and now) Freboldinium.
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.
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