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Achilleodinium biformoides

Achilleodinium biformoides, (Eisenack, 1954b, p. 68), Eaton, 1976, p. 234.

Originally Hystrichosphaeridium, subsequently Baltisphaeridium (acritarch genus), thirdly Hystrichokolpoma, fourthly (and now) Achilleodinium, fifthly Florentinia.
Lentin and Williams (1981, p.2) retained this species in Achilleodinium.

Holotype: Eisenack, 1954b, pl.11, fig.18.
Age: late Eocene–early Oligocene.
Locus typicus: Palmnicken, Samland, E Prussia, Russia

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Original description as Hystrichosphaeridium biformoides: [Eisenack 1954, p. 68-69] (Translation: LPP):

Diagnosis:
central shell spherical to slightly oval with dispersedly standing broad and short appendices with accessory tips, and between them irregularly arranged thin, partly pointed, partly furcate or frilled processes of about the same length as the former. Mostly equipped with pylomes.

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Emended description:

Eaton, 1976, p. 235:

Diagnosis:
Cyst body spherical or subspherical with a smooth or finely granular surface.
Processes intratabular, variable in size and shape, with a striated or finely fibrous appearance. Apical processes relatively narrow, typically open distally. Precingular processes 1''-5'', and postcingular processes 2'''-5''', are large, broad, circular to polygonal in cross-section, and usually distally expanded and closed. Processes 6'' and 1''' are relatively reduced. Cingular processes are slender, hollow, distally open, usually two, but sometimes one per reflected plate area. Sulcal processes similar to those on the cingular and apical zones. Antapical process usually longer than the other large processes.
Reflected tabulation 4', 6'', 6c, 5''', 1p, 1'''';
archaeopyle precingular, formed by displacement of plate 3''.

Dimensions:
Holotype: overall diameter 70 µm; diameter of cyst body 50 µm.
Observed range: diameter of cyst body 42-63 µm; large processes, length up to 22 µm, breadth up to 28 µm; length of slender processes up to 17 µm. (n = 14).

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Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.

Achilleodinium biformoides (Eisenack, 1954b) Eaton, 1976. According to Eaton (1976, p.235), has a smooth to finely granulate wall and intratabular processes with a striate or finely fibrous appearance. Apical processes narrow, typically open. Precingular processes 1"-5" and postcingular processes 2"'-5"' are large, broad, circular to polygonal in cross-section and usually closed distally. Processes 6" and 1"' relatively reduced. Cingular processes are slender, hollow, distally open, one or usually two per paraplate. Some slender sulcal processes. Antapical process the longest. Body diameter 42-63 µm, total diameter (from Eisenack), 70-100 µm.
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