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Odontochitina singhii
Odontochitina singhii Morgan, 1980
Holotype: Morgan, 1980, pl.20, figs.12-13
Locus typicus: Eromanga Basin, Australia
Stratum typicum: Albian
Original description: Morgan, 1980, p.29
Pericyst ambitus strongly fusiform, drawn out into a long narTow apical horn and one long narrow antapical horn of approximately equal length with or without a short pointed second antaplcal hom; large horns located on the midline, second small antapical horn, when developed located at base of large antapical horn; endocyst ambitus ovoidal, closely appressed to pericyst except at apex and antapex, in the vicinity of the horns; long pericoels therefore only developed inside the two or three horns; compression random. Penphragm thin, psilate, but the large horns may have one or two long rows of perforations 2-3 µm across, extending most of the length of the horns, in the same manner as Odontochitina costata Alberti; endophragm thin, psilate. Paratabulation not visible, except perhaps along the archeopyle margin; archeopyle apparently apical, type A, wall layers closely appressed; operculum slightly smaller than cyst following archeopyle formation; suture margin not straight, but showing apparent broad sulcal notch, equal in width to one-quarter of the archeopyle margin, no accessory archeopyle sutures developed; corresponding apparent sulcal "tab" present on operculum.
Holotype: 188 µm long and 35 µm broad, without operculum.
Affinties:
Morgan, 1980, p.30: One very small, and two large subequal horns, the consequent filsiform ambitus, and presence or absence of periphragm perforations, are characteristic of O. singhii. All other species of Odontochitina have three subequal horns and a consequent three-rayed ambitus. O. operculata lacks periphragm perforation: O. costata has a few rows of perforations (2-3 µm wide) in the periphragm along the horns; O. striatoperforata has a few rows of perforations (2-5 µm wide) and parasutural ridges (1 µm high), on the horns: O. porifera has many rows of perforations (4-6 µm wide), entlrely covenng the periphragm horns.
Holotype: Morgan, 1980, pl.20, figs.12-13
Locus typicus: Eromanga Basin, Australia
Stratum typicum: Albian
Original description: Morgan, 1980, p.29
Pericyst ambitus strongly fusiform, drawn out into a long narTow apical horn and one long narrow antapical horn of approximately equal length with or without a short pointed second antaplcal hom; large horns located on the midline, second small antapical horn, when developed located at base of large antapical horn; endocyst ambitus ovoidal, closely appressed to pericyst except at apex and antapex, in the vicinity of the horns; long pericoels therefore only developed inside the two or three horns; compression random. Penphragm thin, psilate, but the large horns may have one or two long rows of perforations 2-3 µm across, extending most of the length of the horns, in the same manner as Odontochitina costata Alberti; endophragm thin, psilate. Paratabulation not visible, except perhaps along the archeopyle margin; archeopyle apparently apical, type A, wall layers closely appressed; operculum slightly smaller than cyst following archeopyle formation; suture margin not straight, but showing apparent broad sulcal notch, equal in width to one-quarter of the archeopyle margin, no accessory archeopyle sutures developed; corresponding apparent sulcal "tab" present on operculum.
Holotype: 188 µm long and 35 µm broad, without operculum.
Affinties:
Morgan, 1980, p.30: One very small, and two large subequal horns, the consequent filsiform ambitus, and presence or absence of periphragm perforations, are characteristic of O. singhii. All other species of Odontochitina have three subequal horns and a consequent three-rayed ambitus. O. operculata lacks periphragm perforation: O. costata has a few rows of perforations (2-3 µm wide) in the periphragm along the horns; O. striatoperforata has a few rows of perforations (2-5 µm wide) and parasutural ridges (1 µm high), on the horns: O. porifera has many rows of perforations (4-6 µm wide), entlrely covenng the periphragm horns.