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Jinhudinium laevigatum
From Fensome et al., 2019:
Jinhudinium laevigatum Qian Zeshu et al., 1986, p.23–24, pl.1, figs.5–6; text-fig.2. Holotype: Qian Zeshu et al., 1986, pl.1, fig.5. Age: Paleocene–Eocene.
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Translation Qian Zeshu et al., 1986: GSC, courtesy R. Fensome
Description: Qian Zeshu et al., 1986
Outline ceratioid. Length greater than width. Upper test larger than lower test, conical or triangular. Margin nearly straight. Apical horn is compressed section of upper test. Apical end bluntly rounded. Lower test close to the shape of a side horse. Edges slightly- convexo-concave. Two antapical horns of unequal length; ends bluntly rounded, strongly forked. Bases overlap and in different planes. Wall single-layered, about 1 µm thick. Surface nearly smooth. No inner body, cingulum or sulcus. Combination archaeopyle, of type AtI3Pa. Transapical archaeopyle suture conspicuously located on flattened surface of test. Operculum not completely separated, joined along margin of the equivalent of the paracingulum.
Size: Tests 35 µm long and 20 µm wide. Antapical horns long, 7 - 10 µm and 5 - 6 µm respectively (2 fossils measured). Holotype 35 µm long and 20 µm wide; antapical horns 10 µm and 6 µm.
Comparison: This species is distinguished from Jinhudinium granulatum by its narrower tests and smooth wall surfaces. The latter Ilas wider tests and granulate surfaces.
Locality and Horizon: Jinhu: principally the Second Formation of the Funing Group. A small quantity appears in the Third Formation of the Funing Group and in the Fourth Formation of the same group in Jiangdu.
Jinhudinium laevigatum Qian Zeshu et al., 1986, p.23–24, pl.1, figs.5–6; text-fig.2. Holotype: Qian Zeshu et al., 1986, pl.1, fig.5. Age: Paleocene–Eocene.
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Translation Qian Zeshu et al., 1986: GSC, courtesy R. Fensome
Description: Qian Zeshu et al., 1986
Outline ceratioid. Length greater than width. Upper test larger than lower test, conical or triangular. Margin nearly straight. Apical horn is compressed section of upper test. Apical end bluntly rounded. Lower test close to the shape of a side horse. Edges slightly- convexo-concave. Two antapical horns of unequal length; ends bluntly rounded, strongly forked. Bases overlap and in different planes. Wall single-layered, about 1 µm thick. Surface nearly smooth. No inner body, cingulum or sulcus. Combination archaeopyle, of type AtI3Pa. Transapical archaeopyle suture conspicuously located on flattened surface of test. Operculum not completely separated, joined along margin of the equivalent of the paracingulum.
Size: Tests 35 µm long and 20 µm wide. Antapical horns long, 7 - 10 µm and 5 - 6 µm respectively (2 fossils measured). Holotype 35 µm long and 20 µm wide; antapical horns 10 µm and 6 µm.
Comparison: This species is distinguished from Jinhudinium granulatum by its narrower tests and smooth wall surfaces. The latter Ilas wider tests and granulate surfaces.
Locality and Horizon: Jinhu: principally the Second Formation of the Funing Group. A small quantity appears in the Third Formation of the Funing Group and in the Fourth Formation of the same group in Jiangdu.