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Odontochitina tabulata
From Fensome et al., 2019:
Odontochitina tabulata El Mehdawi, 1998, p.174,177–178, pl.1, figs.1–8; pl.2, figs.1–6; text-figs.2A–D. Holotype: El Mehdawi, 1998, pl.1, fig.2; text-fig.2B. Age: late Santonian–early Campanian.
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Original description El-Mehdawi 1998:
Holotype. Well C3-65, core # 4, 8520-8523 feet; slide OX).
England Finder reference P34/0. P1. 1, fig. 2; Fig. 2b.
Paratype. Well C3-65, core # 4, 8520-8523 feet; slide OX).
England Finder reference P44/4. PI. I , fig. 1.
Type locality. AGOCO Well C3-65, core # 4, 8520-8523 feet.
Diagnosis. Ceratioid cyst, cornucavate to occasionally epicavate; endocyst ovoidal to subspherical, lenticular in shape with apical, antapical and lateral horns of unequal size. Distal extremities are pointed, closed or open. The lateral horn is dagger-shaped. The cyst has a paratabulation reflected by the paracingulum and well developed pandasutural and parasutural ridges. Ridges low, smooth and thin, with smooth or serrate margins. Apical archeopyle, type [tA], operculum free; paracingulum and parasulcus are indicated by parasutural ridges.
Paratabulation formula, 4 , 6” 5-6c, 6 ” , Ip, I ” ” , Xs.
Description.
Cyst type. Ceratioid, cornucavate, occasionally epicavate.
Shape. Pericyst ceratioidal in outline; ventro-dorsally or laterally compressed. Endocyst ovoidal to subspherical, lenticular, with straight or convex sides but the right lateral margin below the lateral horn is usually convex. Three pointed or truncated (probably by mechanical breakage), short ( < 50 pm) to long ( > 50 pm) horns are present. The lateral horn is postcingular and dagger-shaped being recurved to some degree towards the antapex. It possesses a paracingular notch at the point of recurvature. Both the apical and antapical horns are straight or slightly recurved to a small degree. This recurvature is more prominent at the mid-length of the antapical horn.
Wall relationships. Cornucavate to epicavate, with thick, smooth endophragm and thin, smooth to scabrate periphragm, separated from each other at the bases of the three horns. Antapical and lateral pericoels do occur, sometimes in connection with each other.
Wall features. Periphragm thin, smooth, with continuous narrow pandasutural and parasutural ridges with low relief and smooth to serrate crests; accessory parallel ridges are developed across the apical, antapical and lateral horns. The endophragm is smooth, sometimes with a small rounded nipple- like protrusion which is due to the protrusion of the endophragm into the base of the apical and antapical horns (PI. 1, fig. I; PI. 2, fig. 6). The periphragm is smooth to scabrate. About 2/3 of the distal part of the apical, antapical and lateral horns are ornamented with numerous perforations which are aligned alongside the ridges on the horns. These perforations are subcircular to subrectangular and < 0.5 m to > 3 m in diameter.
Paratabulation. Gonyaulacacean, normally indicated by parasutural ridges, archeopyle and paracingulum. The derived paratabulation formula is 4, 6 , 5-6c, 6 ” , Ip, l””, Xs.
Archeopyle. Apical, type [tA], principal archeopyle parasuture smooth or zigzag with slightly offset parasulcal notch; operculum free.
Paracingulum. Distinct and delineated by shallow transverse depression and two parallel parasutural ridges which may also indicate the presence of 5 4 paraplates. Paracingular notch is always present at the point of re-curvature of the lateral horn.
Parasulcus. Delimited by parasutural features and shallow longitudinal depression on the mid-ventral surface of the hypocyst and on the anterior part of the epicyst by the parasulcal notch.
Dimensions. Overall length (without apical horn) 210 (265) 320pm; endocyst length 54 (64) 74pm, width 42 (54) 74pm; apical horn length 100 (104) 108pm; antapical horn length 40 (62) 82pm; lateral horn length 34 (57) 80pm; specimens measured 19. Dimensions of holotype; overall length (without apical horn) 250pm; endocyst length 74pm, width 72pm; antapical horn length 76 pm; lateral horn length 60 pm.
Dimension of paratype; overall length (without apical horn) 21 0 pm; endocyst length 64 pm, width 70 pm; antapical horn length 62 pm; lateral horn length p34 m.
Remarks. Odontochitina tabuluta sp. nov. a species of Odontochitina Deflandre, 1935 emend., is characterized by possessing pandasutural and parasutural ridges reflecting clear gonyaulacacean paratabulation. Odonrochitina tabulata sp. nov. is similar to O. cribropoda Deflandre & Cookson, 1955 and O. porifera Cookson, 1956 in the general morphology, but the former differs from the two latter species in having paratabulation reflected by panda- and parasutural features, which the latter species are lacking. The new species also differs from 0. p o r f e r a in that the perforations are restricted to the 2/3 of the distal part of the apical, lateral and antapical horns.
Stratigraphic occurrence. Late Cretaceous (Late Santonian- Early Campanian), Well C3-65, core # 4, sample numbers 34, 35 & 36 (depths 8517-8521 feet, 852g8523 feet, 8524-8527 feet).
Odontochitina tabulata El Mehdawi, 1998, p.174,177–178, pl.1, figs.1–8; pl.2, figs.1–6; text-figs.2A–D. Holotype: El Mehdawi, 1998, pl.1, fig.2; text-fig.2B. Age: late Santonian–early Campanian.
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Original description El-Mehdawi 1998:
Holotype. Well C3-65, core # 4, 8520-8523 feet; slide OX).
England Finder reference P34/0. P1. 1, fig. 2; Fig. 2b.
Paratype. Well C3-65, core # 4, 8520-8523 feet; slide OX).
England Finder reference P44/4. PI. I , fig. 1.
Type locality. AGOCO Well C3-65, core # 4, 8520-8523 feet.
Diagnosis. Ceratioid cyst, cornucavate to occasionally epicavate; endocyst ovoidal to subspherical, lenticular in shape with apical, antapical and lateral horns of unequal size. Distal extremities are pointed, closed or open. The lateral horn is dagger-shaped. The cyst has a paratabulation reflected by the paracingulum and well developed pandasutural and parasutural ridges. Ridges low, smooth and thin, with smooth or serrate margins. Apical archeopyle, type [tA], operculum free; paracingulum and parasulcus are indicated by parasutural ridges.
Paratabulation formula, 4 , 6” 5-6c, 6 ” , Ip, I ” ” , Xs.
Description.
Cyst type. Ceratioid, cornucavate, occasionally epicavate.
Shape. Pericyst ceratioidal in outline; ventro-dorsally or laterally compressed. Endocyst ovoidal to subspherical, lenticular, with straight or convex sides but the right lateral margin below the lateral horn is usually convex. Three pointed or truncated (probably by mechanical breakage), short ( < 50 pm) to long ( > 50 pm) horns are present. The lateral horn is postcingular and dagger-shaped being recurved to some degree towards the antapex. It possesses a paracingular notch at the point of recurvature. Both the apical and antapical horns are straight or slightly recurved to a small degree. This recurvature is more prominent at the mid-length of the antapical horn.
Wall relationships. Cornucavate to epicavate, with thick, smooth endophragm and thin, smooth to scabrate periphragm, separated from each other at the bases of the three horns. Antapical and lateral pericoels do occur, sometimes in connection with each other.
Wall features. Periphragm thin, smooth, with continuous narrow pandasutural and parasutural ridges with low relief and smooth to serrate crests; accessory parallel ridges are developed across the apical, antapical and lateral horns. The endophragm is smooth, sometimes with a small rounded nipple- like protrusion which is due to the protrusion of the endophragm into the base of the apical and antapical horns (PI. 1, fig. I; PI. 2, fig. 6). The periphragm is smooth to scabrate. About 2/3 of the distal part of the apical, antapical and lateral horns are ornamented with numerous perforations which are aligned alongside the ridges on the horns. These perforations are subcircular to subrectangular and < 0.5 m to > 3 m in diameter.
Paratabulation. Gonyaulacacean, normally indicated by parasutural ridges, archeopyle and paracingulum. The derived paratabulation formula is 4, 6 , 5-6c, 6 ” , Ip, l””, Xs.
Archeopyle. Apical, type [tA], principal archeopyle parasuture smooth or zigzag with slightly offset parasulcal notch; operculum free.
Paracingulum. Distinct and delineated by shallow transverse depression and two parallel parasutural ridges which may also indicate the presence of 5 4 paraplates. Paracingular notch is always present at the point of re-curvature of the lateral horn.
Parasulcus. Delimited by parasutural features and shallow longitudinal depression on the mid-ventral surface of the hypocyst and on the anterior part of the epicyst by the parasulcal notch.
Dimensions. Overall length (without apical horn) 210 (265) 320pm; endocyst length 54 (64) 74pm, width 42 (54) 74pm; apical horn length 100 (104) 108pm; antapical horn length 40 (62) 82pm; lateral horn length 34 (57) 80pm; specimens measured 19. Dimensions of holotype; overall length (without apical horn) 250pm; endocyst length 74pm, width 72pm; antapical horn length 76 pm; lateral horn length 60 pm.
Dimension of paratype; overall length (without apical horn) 21 0 pm; endocyst length 64 pm, width 70 pm; antapical horn length 62 pm; lateral horn length p34 m.
Remarks. Odontochitina tabuluta sp. nov. a species of Odontochitina Deflandre, 1935 emend., is characterized by possessing pandasutural and parasutural ridges reflecting clear gonyaulacacean paratabulation. Odonrochitina tabulata sp. nov. is similar to O. cribropoda Deflandre & Cookson, 1955 and O. porifera Cookson, 1956 in the general morphology, but the former differs from the two latter species in having paratabulation reflected by panda- and parasutural features, which the latter species are lacking. The new species also differs from 0. p o r f e r a in that the perforations are restricted to the 2/3 of the distal part of the apical, lateral and antapical horns.
Stratigraphic occurrence. Late Cretaceous (Late Santonian- Early Campanian), Well C3-65, core # 4, sample numbers 34, 35 & 36 (depths 8517-8521 feet, 852g8523 feet, 8524-8527 feet).