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Vesperopsis didaoensis
From Fensome et al., 2019:
Vesperopsis didaoensis Cheng Jinhui and He Chengquan, 2001, p.129–130,133, fig.1, nos.1–5.
Holotype: Cheng Jinhui and He Chengquan, 2001, fig.1, no.2.
Age: Berriasian–Hauterivian.
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Original description (Cheng Jinhui and He Chengquan, 2001):
Vesperopsis didaoensis sp. nov. ( Tex-t fig. 1, figs. 1- 5)
Derivation of name: The locality of the holoty pe is Didao, Jix i City, Eastern Heilongjiang Province, Northeast China.
Description: Cyst dorso-ventrally compressed, elongately pentagonal, with an apical, two lateral and two antapical horns. Apical horn formed by attenuated epicyst, strong, conical, about 10.4 - 20 µm long, with a closed or blunt tip. The two antapical horns apparently unequal in size. The left antapical horn very thin and long, conical, 24- 34. 7 µm long, with an acuminate or blunt end. The right antapical horn short, about 3- 5.9 µm long, end acuminate or blunt, or reduced to step-like. The two lateral horns relatively wide and large, in different shape, formed by extension of pre- and postcingular areas. The left lateral horn 10.4- 13.9 µm long, distal 9- 13.9 µm wide, end widely indented or blunt. The right lateral horn a bit longer, 17.4- 31 µm long, distal 10.4- 17 µm wide, with a postcingular process or horn which is baculate or narrowly conical, 6.9- 13.9 µm long. Autophragm very thin, single layered, surface weakly sparsely rugose with thin granules or nearly smooth. Paracingulum may be indicated only by the indentation of the lateral horn end, no indication of parasulcus. Paratabulation indicated by archeopyle only. Archeopyle apical, operculum adnate ventrally.
Dimensions: Cyst 90.2- 110 µm long, 76.4- 90.2 µm wide. Holotype 110 µm long, 76. 4 µm wide.
Comments: The present paper contrasts the specimens of the same species from the Didao Formation with the ones from the marine strata of the lower part of the Upper Yunshan Formation to show the consistent morphological and structural character of the new species. The new species is distinguished from Vesper op sis z haodongensis Qiao, He et Gao, 1992 by the two antapical horns of apparently unequal size, of which the right antapical horn is tiny or reduced to step-like (Text-fig. 1, figs. 3, 5) , and by the different morphology of the two lateral horns and the only right postcingular extension. The two antapical horns of the holotype of the latter are nearly equal in size, the base separated widely, not step-like, and its two lateral horns are of nearly equal size and of the same morphology.
Occurrence: Didao Formation ( base of Lower Cretaceous) , Didao District, Jixi City, and Upper Yunshan Formation ( Upper Hauterivian ) , Hulin County, Eastern Heilongjiang Province, NE China.
Vesperopsis didaoensis Cheng Jinhui and He Chengquan, 2001, p.129–130,133, fig.1, nos.1–5.
Holotype: Cheng Jinhui and He Chengquan, 2001, fig.1, no.2.
Age: Berriasian–Hauterivian.
---------------------------------------------------------------------------------------------------
Original description (Cheng Jinhui and He Chengquan, 2001):
Vesperopsis didaoensis sp. nov. ( Tex-t fig. 1, figs. 1- 5)
Derivation of name: The locality of the holoty pe is Didao, Jix i City, Eastern Heilongjiang Province, Northeast China.
Description: Cyst dorso-ventrally compressed, elongately pentagonal, with an apical, two lateral and two antapical horns. Apical horn formed by attenuated epicyst, strong, conical, about 10.4 - 20 µm long, with a closed or blunt tip. The two antapical horns apparently unequal in size. The left antapical horn very thin and long, conical, 24- 34. 7 µm long, with an acuminate or blunt end. The right antapical horn short, about 3- 5.9 µm long, end acuminate or blunt, or reduced to step-like. The two lateral horns relatively wide and large, in different shape, formed by extension of pre- and postcingular areas. The left lateral horn 10.4- 13.9 µm long, distal 9- 13.9 µm wide, end widely indented or blunt. The right lateral horn a bit longer, 17.4- 31 µm long, distal 10.4- 17 µm wide, with a postcingular process or horn which is baculate or narrowly conical, 6.9- 13.9 µm long. Autophragm very thin, single layered, surface weakly sparsely rugose with thin granules or nearly smooth. Paracingulum may be indicated only by the indentation of the lateral horn end, no indication of parasulcus. Paratabulation indicated by archeopyle only. Archeopyle apical, operculum adnate ventrally.
Dimensions: Cyst 90.2- 110 µm long, 76.4- 90.2 µm wide. Holotype 110 µm long, 76. 4 µm wide.
Comments: The present paper contrasts the specimens of the same species from the Didao Formation with the ones from the marine strata of the lower part of the Upper Yunshan Formation to show the consistent morphological and structural character of the new species. The new species is distinguished from Vesper op sis z haodongensis Qiao, He et Gao, 1992 by the two antapical horns of apparently unequal size, of which the right antapical horn is tiny or reduced to step-like (Text-fig. 1, figs. 3, 5) , and by the different morphology of the two lateral horns and the only right postcingular extension. The two antapical horns of the holotype of the latter are nearly equal in size, the base separated widely, not step-like, and its two lateral horns are of nearly equal size and of the same morphology.
Occurrence: Didao Formation ( base of Lower Cretaceous) , Didao District, Jixi City, and Upper Yunshan Formation ( Upper Hauterivian ) , Hulin County, Eastern Heilongjiang Province, NE China.