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Carpatella truncata
Carpatella truncata, Willumsen, 2004, p.124, pl.1, figs. 5–6.
Holotype: Willumsen, 2004, pl.1, fig.6.
Paratype: Plate 1, fig. 5
Type locality & horizon: Grey River section, North Canterbury, South Island, New Zealand. Carpatella truncata occurs in an interval between 0.01 m to 0.7 m above the KTB within the lower part of the Loburn Formation. The Loburn Formation is a glauconitic siltstone (Field & Odin, 1981).
Stratigraphical range: Lowest Paleocene (lowest Teurian) within the lowermost part of the Trithyrodinium evittii Interval Zone (Willumsen, 2002, named Carpatella sp. 2 in text and figs). Carpatella truncata is very rare in all samples studied except in sample FRF M34/f523 from Grey River.
Age: earliest Paleocene.
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Original description: [Willumsen, 2004]:
Diagnosis:
A species in the genus Carpatella with short, truncate, intra-tabular processes and a cingulum marked by a raised band.
Description:
Subspherical to ellipsoidal proximate gonyaulacoid cyst, single horn at apex and antapex (Pl. 1, figs 5, 6). Solid fibrous horns and an autophragm composed of two closely compressed spongy layers.
From each paraplate a short fibrous process rises (maximal height c. 7 μm), indicating the paratabulation. Processes are straight, fibrous, slightly angular and truncate in the distal part.
An elevated fibrous ridge with a width of c. 3 μm and a thickness of 6 μm marks the cingulum (Pl. 1, fig. 6).
Precingular archaeopyle, type P, consists of paraplate 4 (3") only. The archaeopyle is hoof-shaped and the operculum is mostly free.
Dimensions:
Holotype: total dimensions 109.5 x 72 μm; length apical horn 15 μm; length antapical horn 13 μm; height of processes 9 μm.
Other specimens: total dimensions 95 x 70 μm; length apical horn 20 μm; length antapical horn 13 μm; height of processes 8 μm. Ten specimens measured.
Remarks:
Carpatella truncata differs from Carpatella cornuta Grigorovich, 1969, Carpatella sinensis He Chengquan, 1984, Carpatella humera, Carpatella circularis, Carpatella scabrata, Carpatella lamprota He Chengquan, 1991 and C. septata sp. nov. by having short intratabular truncate processes.
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Stratigraphical and geographical distribution:
This species was observed in Grey River, mid-Waipara River and Branch Stream sections. In the mid-Waipara River section, C. cornuta, C. septata and C. truncata co-occur in a sample 0.005 m above the KTB (FRF M34/f560, Ll8469).
Holotype: Willumsen, 2004, pl.1, fig.6.
Paratype: Plate 1, fig. 5
Type locality & horizon: Grey River section, North Canterbury, South Island, New Zealand. Carpatella truncata occurs in an interval between 0.01 m to 0.7 m above the KTB within the lower part of the Loburn Formation. The Loburn Formation is a glauconitic siltstone (Field & Odin, 1981).
Stratigraphical range: Lowest Paleocene (lowest Teurian) within the lowermost part of the Trithyrodinium evittii Interval Zone (Willumsen, 2002, named Carpatella sp. 2 in text and figs). Carpatella truncata is very rare in all samples studied except in sample FRF M34/f523 from Grey River.
Age: earliest Paleocene.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Willumsen, 2004]:
Diagnosis:
A species in the genus Carpatella with short, truncate, intra-tabular processes and a cingulum marked by a raised band.
Description:
Subspherical to ellipsoidal proximate gonyaulacoid cyst, single horn at apex and antapex (Pl. 1, figs 5, 6). Solid fibrous horns and an autophragm composed of two closely compressed spongy layers.
From each paraplate a short fibrous process rises (maximal height c. 7 μm), indicating the paratabulation. Processes are straight, fibrous, slightly angular and truncate in the distal part.
An elevated fibrous ridge with a width of c. 3 μm and a thickness of 6 μm marks the cingulum (Pl. 1, fig. 6).
Precingular archaeopyle, type P, consists of paraplate 4 (3") only. The archaeopyle is hoof-shaped and the operculum is mostly free.
Dimensions:
Holotype: total dimensions 109.5 x 72 μm; length apical horn 15 μm; length antapical horn 13 μm; height of processes 9 μm.
Other specimens: total dimensions 95 x 70 μm; length apical horn 20 μm; length antapical horn 13 μm; height of processes 8 μm. Ten specimens measured.
Remarks:
Carpatella truncata differs from Carpatella cornuta Grigorovich, 1969, Carpatella sinensis He Chengquan, 1984, Carpatella humera, Carpatella circularis, Carpatella scabrata, Carpatella lamprota He Chengquan, 1991 and C. septata sp. nov. by having short intratabular truncate processes.
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Stratigraphical and geographical distribution:
This species was observed in Grey River, mid-Waipara River and Branch Stream sections. In the mid-Waipara River section, C. cornuta, C. septata and C. truncata co-occur in a sample 0.005 m above the KTB (FRF M34/f560, Ll8469).