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Lagenorhytis granorugosa
Lagenorhytis granorugosa Cheng Jinhui and He Chengquan, 2001, p.129,133, fig.1, nos.6-7.
Holotype: Cheng Jinhui and He Chengquan, 2001, fig.1, no.7.
Age: Berriasian-Valanginian.
Original descroiption (Cheng Jinhui and He Chengquan, 2001):
Lagenorhytis granorugosus sp. nov. ( Text-fig. 1, figs. 6, 7)
Derivation of name: granorugosus, Latin, refers to the ornamentation on the periphragm.
Description: Cyst proximate, subcircular in outline with nearly the same length and breadth. Cingulum area smoothly enlarged. Epicyst roundedly conical with a small apical protuberance with a height of about 2. 5 Lm. Hypocyst has a broadly rounded antapex without an antapical horn. Autophragm about 0. 7 Lm thick, surface scabrate or with dense granule and short rugae; ambitus nearly smooth to partly microspinate. Paracingulum poor, marked by two thin inconsistent fold-like ridges. Paratabulation indicated by an archeopyle and/or a paracingulum. Archeopyle precingular, Type 2P ( probably 3’’+ 4’’), operculum
Dimensions: Cyst 43 - 83.3 µm long, 40. 9 - 86. 9 µm wide. Holotype 83. 3 µm long , 86.8 µm wide.
Comments: The new species is very rarely represented, but its morphological and structural character is consistent and its geographical distribution is very w ide. Compared the specimens from the Didao Formation of the Jixi Basin in Northeast China with the ones from the upper part of the Buqu Formation of M t. Tanggula, Golmud City, Qinghai Province, we found that only the size of this species varies a lot, this may be associated with the difference of sedimentary environments between the two areas. This new species is distinguished from Lagenorhytis delicatula ( Duxbury ) Duxbury, 1979 by the reduced apical horn and the poor paracingulum.
Occurence: Didao Formation ( base of Low er Cretaceous) , Didao District, Jixi City , Eastern Heilongjiang Province, Northeast China; Upper part of Buqu Formation ( Middle Jurassic) , Quemocuo Section, Tang gulashan Town, Golmud City, Qinghai Province, Qinghai Tibet Plateau.
Holotype: Cheng Jinhui and He Chengquan, 2001, fig.1, no.7.
Age: Berriasian-Valanginian.
Original descroiption (Cheng Jinhui and He Chengquan, 2001):
Lagenorhytis granorugosus sp. nov. ( Text-fig. 1, figs. 6, 7)
Derivation of name: granorugosus, Latin, refers to the ornamentation on the periphragm.
Description: Cyst proximate, subcircular in outline with nearly the same length and breadth. Cingulum area smoothly enlarged. Epicyst roundedly conical with a small apical protuberance with a height of about 2. 5 Lm. Hypocyst has a broadly rounded antapex without an antapical horn. Autophragm about 0. 7 Lm thick, surface scabrate or with dense granule and short rugae; ambitus nearly smooth to partly microspinate. Paracingulum poor, marked by two thin inconsistent fold-like ridges. Paratabulation indicated by an archeopyle and/or a paracingulum. Archeopyle precingular, Type 2P ( probably 3’’+ 4’’), operculum
Dimensions: Cyst 43 - 83.3 µm long, 40. 9 - 86. 9 µm wide. Holotype 83. 3 µm long , 86.8 µm wide.
Comments: The new species is very rarely represented, but its morphological and structural character is consistent and its geographical distribution is very w ide. Compared the specimens from the Didao Formation of the Jixi Basin in Northeast China with the ones from the upper part of the Buqu Formation of M t. Tanggula, Golmud City, Qinghai Province, we found that only the size of this species varies a lot, this may be associated with the difference of sedimentary environments between the two areas. This new species is distinguished from Lagenorhytis delicatula ( Duxbury ) Duxbury, 1979 by the reduced apical horn and the poor paracingulum.
Occurence: Didao Formation ( base of Low er Cretaceous) , Didao District, Jixi City , Eastern Heilongjiang Province, Northeast China; Upper part of Buqu Formation ( Middle Jurassic) , Quemocuo Section, Tang gulashan Town, Golmud City, Qinghai Province, Qinghai Tibet Plateau.