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Odontochitina
From Williams et al., 2017:
[Odontochitina, Deflandre, 1937b, p. 94. Emendations: Davey, 1970, p. 354; Bint, 1986, p. 138; El Mehdawi, 1998, p. 174; Núñez-Betelu and Hills, 1998, p. 925–926, 928
This name was not validly published in Deflandre (1935, p.234) since no type was designated, a requirement under the I.C.Z.N. at that time
Type species: originally as Odontochitina silicorum, Deflandre, 1937b (pl.18 (al. pl.15), fig.8)] ; Odontochitina operculata, (Wetzel, 1933), Deflandre and Cookson, 1955
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Original description: [Deflandre, 1935]: (Translation: Stover and Evitt, 1978, p. 67):
Diagnosis:
A curious, apparently chitinous cell, already larger (150µm) than the preceding ones, but for me not suggesting any relationship, even approximately, with a known creature.
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Deflandre, 1937, p. 94:
The chitonoid theca is formed of two parts, one bearing a single horn, considered as upper, the other globular, provided with two more or less divergent horns.
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Emended descriptions:
Davey, 1970:
Diagnosis:
Cavate cysts consisting of spherical inner body and outer membrane. Outer membrane extended into long tapering apical horn and two shorter tapering antapical horns. Very rarely, short, branching precingular and postcingular processes are present.
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Bint, 1986:
Description:
Large cysts with ceratioid outline and three prominent horns, apical, antapical, and right lateral, which may be pointed or blunted distally. Right lateral horn is postcingular and may be straight or recurved with a cingular notch at the point of recurvation.
Cornucavate; endocyst subspherical or produced slightly into the horn bases, with circular equatorial section. periphragm separated from endophragm at horns, but hypocystal pericoels may be enlarged beyond horn bases. Antapical pericoel may have an elongate extension up the left ventral surface as far as the cingulum.
Archaeopyle apical, type (tA), operculum free. Archaeopyle suture rounded to weakly angular; sulcal notch, where discernible, mid-ventral or offset slightly to the left.
Paratabulation usually not expressed, cingulum may be indicated by faint transverse lines, sulcus not indicated.
Affinities:
Odontochitina is most similar to Xenascus, from which it differs in lacking an ornamentation of spines on the periphragm. Pseudoceratium and Endoceratium differ in having a dorso-ventrally compressed body and a strongly offset sulcal notch. Pseudoceratium is usually single-walled but when it has two walls they are linked by numerous connecting structures and Endoceratium is circumcavate, whereas Odontochitina is cornucavate.
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Supplemental diagnosis:
Pocock, 1972, p. 78:
Diagnosis:
Dinoflagellata with an unplaced chitinous theca formed of two parts, one (the epitheca) carrying a single horn, the other (hypotheca) carrying two.
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Modified description:
Stover and Evitt 1978, p. 67-68:
Synopsis:
Cysts cavate, ceratioid, with single long, apical, antapical, and probably postcingular horns; endophragm and periphragm appressed except at the base of the horns (cornucavate); archeopyle apical, Type tA.
Description:
Shape: Ceratoid with three long horns - an apical, an antapical, and a third probably postcingular horn - tips of the horns generally pointed.
Wall relationships: Endophragm and periphragm appressed between the horns, or an antapical pericoel may be present.
Wall features: No parasutural features. Endophragm smooth; periphragm of the body smooth or scabrate; perforations and/or longitudinal striae may be present on the horns of some species.
Paratabulation: Not normally indicated; archeopyle may show angulation.
Archeopyle: Apical, Type tA, principal archeopyle suture smooth to weakly angular; perioperculum includes the apical horn; endoperculum with or without slight protrusion into horn; operculum free.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Size: Large.
Affinities:
Odontochitina differs from Pseudoceratium in being cavate and in having typically longer horns, an uncompressed body, and in lacking projections on the periphragm. On Pseudoceratium the postcingular horn in particular is much shorter than its counterpart on Odontochitina.
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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.
Odontochitina Deflandre, 1937b, emend. Davey, 1970, emend. Bint, 1986. Odontochitina was emended by Bint (1986, p.138) as follows, Large cysts with ceratioid outline and three prominent horns, apical, antapical, and right lateral, which may be pointed or blunted distally. Right lateral horn is postcingular and may be straight or recurved with a cingular notch at the point of recurvature. Cornucavate; endocyst subspherical or produced slightly into the horn bases, with circular equatorial section. Periphragm separated from endophragm at horns, but hypocystal pericoels may be enlarged beyond horn bases. Antapical pericoel may have an elongate extension up the left ventral surface as far as the cingulum. Archeopyle apical, type (tA), operculum free. Archeopyle suture rounded to weakly angular; sulcal notch, where discernible, mid-ventral or offset slightly to the left. Paratabulation usually not expressed, cingulum may be indicated by faint transverse lines, sulcus not indicated.
[Odontochitina, Deflandre, 1937b, p. 94. Emendations: Davey, 1970, p. 354; Bint, 1986, p. 138; El Mehdawi, 1998, p. 174; Núñez-Betelu and Hills, 1998, p. 925–926, 928
This name was not validly published in Deflandre (1935, p.234) since no type was designated, a requirement under the I.C.Z.N. at that time
Type species: originally as Odontochitina silicorum, Deflandre, 1937b (pl.18 (al. pl.15), fig.8)] ; Odontochitina operculata, (Wetzel, 1933), Deflandre and Cookson, 1955
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Deflandre, 1935]: (Translation: Stover and Evitt, 1978, p. 67):
Diagnosis:
A curious, apparently chitinous cell, already larger (150µm) than the preceding ones, but for me not suggesting any relationship, even approximately, with a known creature.
-----------------------------------------------------------------------------------------------------
Deflandre, 1937, p. 94:
The chitonoid theca is formed of two parts, one bearing a single horn, considered as upper, the other globular, provided with two more or less divergent horns.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Emended descriptions:
Davey, 1970:
Diagnosis:
Cavate cysts consisting of spherical inner body and outer membrane. Outer membrane extended into long tapering apical horn and two shorter tapering antapical horns. Very rarely, short, branching precingular and postcingular processes are present.
----------------------------------------
Bint, 1986:
Description:
Large cysts with ceratioid outline and three prominent horns, apical, antapical, and right lateral, which may be pointed or blunted distally. Right lateral horn is postcingular and may be straight or recurved with a cingular notch at the point of recurvation.
Cornucavate; endocyst subspherical or produced slightly into the horn bases, with circular equatorial section. periphragm separated from endophragm at horns, but hypocystal pericoels may be enlarged beyond horn bases. Antapical pericoel may have an elongate extension up the left ventral surface as far as the cingulum.
Archaeopyle apical, type (tA), operculum free. Archaeopyle suture rounded to weakly angular; sulcal notch, where discernible, mid-ventral or offset slightly to the left.
Paratabulation usually not expressed, cingulum may be indicated by faint transverse lines, sulcus not indicated.
Affinities:
Odontochitina is most similar to Xenascus, from which it differs in lacking an ornamentation of spines on the periphragm. Pseudoceratium and Endoceratium differ in having a dorso-ventrally compressed body and a strongly offset sulcal notch. Pseudoceratium is usually single-walled but when it has two walls they are linked by numerous connecting structures and Endoceratium is circumcavate, whereas Odontochitina is cornucavate.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Supplemental diagnosis:
Pocock, 1972, p. 78:
Diagnosis:
Dinoflagellata with an unplaced chitinous theca formed of two parts, one (the epitheca) carrying a single horn, the other (hypotheca) carrying two.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Modified description:
Stover and Evitt 1978, p. 67-68:
Synopsis:
Cysts cavate, ceratioid, with single long, apical, antapical, and probably postcingular horns; endophragm and periphragm appressed except at the base of the horns (cornucavate); archeopyle apical, Type tA.
Description:
Shape: Ceratoid with three long horns - an apical, an antapical, and a third probably postcingular horn - tips of the horns generally pointed.
Wall relationships: Endophragm and periphragm appressed between the horns, or an antapical pericoel may be present.
Wall features: No parasutural features. Endophragm smooth; periphragm of the body smooth or scabrate; perforations and/or longitudinal striae may be present on the horns of some species.
Paratabulation: Not normally indicated; archeopyle may show angulation.
Archeopyle: Apical, Type tA, principal archeopyle suture smooth to weakly angular; perioperculum includes the apical horn; endoperculum with or without slight protrusion into horn; operculum free.
Paracingulum: Not indicated.
Parasulcus: Not indicated.
Size: Large.
Affinities:
Odontochitina differs from Pseudoceratium in being cavate and in having typically longer horns, an uncompressed body, and in lacking projections on the periphragm. On Pseudoceratium the postcingular horn in particular is much shorter than its counterpart on Odontochitina.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Notes:
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Odontochitina Deflandre, 1937b, emend. Davey, 1970, emend. Bint, 1986. Odontochitina was emended by Bint (1986, p.138) as follows, Large cysts with ceratioid outline and three prominent horns, apical, antapical, and right lateral, which may be pointed or blunted distally. Right lateral horn is postcingular and may be straight or recurved with a cingular notch at the point of recurvature. Cornucavate; endocyst subspherical or produced slightly into the horn bases, with circular equatorial section. Periphragm separated from endophragm at horns, but hypocystal pericoels may be enlarged beyond horn bases. Antapical pericoel may have an elongate extension up the left ventral surface as far as the cingulum. Archeopyle apical, type (tA), operculum free. Archeopyle suture rounded to weakly angular; sulcal notch, where discernible, mid-ventral or offset slightly to the left. Paratabulation usually not expressed, cingulum may be indicated by faint transverse lines, sulcus not indicated.