Back
Chatangiella arvensis
Chatangiella arvensis, Marshall, 1988; Emendations: Lentin and Williams, 1976, p.51-52; Marshall, 1988, p.199-200 - however, see Lentin and Vozzhennikova (1990, p.40).
Taxonomic junior synonyms: Australiella and Cooksoniella, both according to Lentin and Williams (1976, p.155 and p.151-152 respectively).
Lentin and Williams (1976, p.93-94) considered Chatangiella to be a possible taxonomic junior synonym of Bulbodinium.
Holotype: Marshall, 1988, fig.17M-R
Locus typicus: Gippsland Basin, SE Australia
Stratum typicum: Santonian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original diagnosis: [Marshall, 1988, p. 201]:
Diagnosis:
Ventrodorsal outline subpentagonal. Lateral margins on epicyst adjacent to archeopyle modified by weak to distinct, rounded shoulders. Apex marked by a broad subconical horn with a truncate tip. Antapical margin straight to concave separating 2 antapical horns: the right defining a subconical projection with a rounded tip; the left strongly reduced, either subconical or forming a rounded bulge.
Cysts bicavate; ventrodorsal outline of endocyst ovoidal, length greater than width.
Endophragm c. O.S µm thick, surfaces adjacent to pericoels smooth to finely granulate. Periphragm c. 0.5 µm thick, surface scabrate finely granulate, also with intratabular fields of tubercules and coni which increase in size and frequency towards the equator. Periphragm also bearing ridges and, frequently, rows of granules along parasutural boundaries. Ridges most pronounced equatorially along lateral boundaries of precingular and postcingular paraplates. Rows of granules usually only clear on specimens with strong indications of paratabulation. Tubercules and coni also evident on crests of parasutural ridges and on ridges defining the paracingulum.
Paraplates defined on specimens with clearest paratabulation: 2a, 3-6", 2-4""" (Fig.7).
Paracingulum partite; marked by 2 parallel sets of ridges 7-8 µm apart, separated by a pronounced groove.
Archeopyle intercalary, Type la/?; periarcheopyle stenothetaform to isothetaform, operculum usually attached along posterior margin. Endoarcheopyle suggested by splits, but no consistent pattern discernible.
Taxonomic junior synonyms: Australiella and Cooksoniella, both according to Lentin and Williams (1976, p.155 and p.151-152 respectively).
Lentin and Williams (1976, p.93-94) considered Chatangiella to be a possible taxonomic junior synonym of Bulbodinium.
Holotype: Marshall, 1988, fig.17M-R
Locus typicus: Gippsland Basin, SE Australia
Stratum typicum: Santonian
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original diagnosis: [Marshall, 1988, p. 201]:
Diagnosis:
Ventrodorsal outline subpentagonal. Lateral margins on epicyst adjacent to archeopyle modified by weak to distinct, rounded shoulders. Apex marked by a broad subconical horn with a truncate tip. Antapical margin straight to concave separating 2 antapical horns: the right defining a subconical projection with a rounded tip; the left strongly reduced, either subconical or forming a rounded bulge.
Cysts bicavate; ventrodorsal outline of endocyst ovoidal, length greater than width.
Endophragm c. O.S µm thick, surfaces adjacent to pericoels smooth to finely granulate. Periphragm c. 0.5 µm thick, surface scabrate finely granulate, also with intratabular fields of tubercules and coni which increase in size and frequency towards the equator. Periphragm also bearing ridges and, frequently, rows of granules along parasutural boundaries. Ridges most pronounced equatorially along lateral boundaries of precingular and postcingular paraplates. Rows of granules usually only clear on specimens with strong indications of paratabulation. Tubercules and coni also evident on crests of parasutural ridges and on ridges defining the paracingulum.
Paraplates defined on specimens with clearest paratabulation: 2a, 3-6", 2-4""" (Fig.7).
Paracingulum partite; marked by 2 parallel sets of ridges 7-8 µm apart, separated by a pronounced groove.
Archeopyle intercalary, Type la/?; periarcheopyle stenothetaform to isothetaform, operculum usually attached along posterior margin. Endoarcheopyle suggested by splits, but no consistent pattern discernible.