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Capillicysta applanata
Capillicysta applanata, (Bradford, 1977), Matsuoka et al., 1987
Originally Lejeunia (an illegitimate generic name, subsequently Lejeunecysta, thirdly Trinovantedinium, fourthly (and now) Capillicysta.
Tax. synonym of Trinovantedinium capitatum Reid, 1977, according to Matsuoka, 1984, 1985. Matsuoka et al., 1987, retained Trinovantedinium (as Capillicysta) applanata as a separate species.
Bradford and Wall, 1984, considered this species to represent the encysted stage of Protoperidinium pentagonum (Gran) Balech, 1974.
Holotype: Bradford, 1977, fig.2:1-4
Occurrence: Rare-to-common: Musandam Peninsula, northern Straits of Hormuz; Present in all Eastern Musandam coastal sediments except for two southernmost samples; odd specimen in Gulf of Oman and Northern Arabian Sea.
Age: Recent
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Original description as Lejeunia applanata: [Bradford, 1977]:
Diagnosis:
Shape: Pericyst: Ambitus shows considerable variation in length-breadth ratio, but always retains its pentagonal shape; cysts are always flattened dorsoventrally. The epipericyst, similar in size to the hypopericyst, has convex flanks, converging apically into a short horn or apical boss. The hypopericyst has straight-to-concave sides; it tapers posteriorly into two distinct antapical horns. These horns are separated by a shallow-to-moderately deep antapical depression. Each horn may be either rounded or pointed distally; on rare occasions, the horns may be very slightly asymmetrical. Endocyst: Not always observable; usually ap"' pressed to pericyst throughout. Fig. 2: 1-4 illustrate the separated nature of the endocyst and the presence of a complete pericoel. The endocyst, when observed separated from the pericyst, displays the typical pentagonal ambital outline. Pericoel: When present, may be complete or as individual cavities at the tips of the apical and antapical horns.
Phragma: Both layers usually of constant thickness and inseparable. Occasional thickening towards the distal regions of the apical and antapical horns. Endophragm, when observed, smooth and lacking in ornamentation. Periphragm thin and usually colourless. Short spines, both parasutural and intratabular, are a diagnostic feature ; however, some intratabular areas possess very few spines, and consequently leave large bald areas on the tract surface. Some spines have capitate distal tips, but most have simple terminations.
Paratabulation: Pericyst: Paratabulation indeterminate. Pericingulum: A row of short spines outlines the pericingulum zone. The pericingulum is narrow, excavated and shows little or no displacement: it is gently inclined posteriorly from the dorsal to the ventral surface. Perisulcus: Not seen in all specimens: when observed, it is wide and shallow, extending in part onto the epipericyst: widens posteriorly. Endocyst: Paratabulation indeterminate.
Archeopyle: Standard hexa resulting from the detachment of the 2a anterior intercalary paraplate. This paraplate may extend almost down to the pericingulum. Since the endophragm and periphragm are generally appressed in this area of the tract, there appear to be one archeopyle and one operculum. Archeopyle Formula I/I (2a/2a).
Dimensions:
Holotype: length 78 μm, breadth 74 μm, distance between antapical horns (distally) 25 ,m, maximum height of processes 2.5 μm; other specimens -length 53-87 μm, breadth 47-74 μm, distance between antapical horns (distally) 25-31 μm, maximum height of processes 5 μm.
Number of specimens measured 25.
Remarks:
Lejeunia applanata corresponds to the forms described by Reid (1972, unpublished thesis) from the surface sediments around the British Isles. The Persian Gulf specimens are comparable in size with the British forms; however, the range of variation in forms of similar character as described by Wall & Dale (1968) includes much larger specimens (72-100 μm x 72-84 μm). L. applanata differs from Ginginodinium spinulosum Cookson and Eisenack 1960, by its less prominent apical horn and less squat hypocyst. The latter species also has a denser spinulose ornamentation and was recently described as having a large archeopyle (Formula 3I+3Pa) (Lentin & Williams 1975).
Thecal affinities:
These cysts are similar to those incubated by Wall & Dale (1968) to produce Peridinium pentagonum Gran, 1902. The cysts of P. pentagonum and P. cf. pentagonum of Wall & Dale (1968) show very slight differences, the latter having a distinctive ornamentation and marked apical and antapical projections. Wall & Dale (1968) considered that both these cyst types give rise to P. pentagonum; however, the reported distribution of P. pentagonum around the British Isles (Lebour 1925) does not agree with the distribution of the cyst (P. cf. pentagonum) as described by Reid (1972). Wood (1968) described the thecate stage as an estuarine and neritic form, which is widely distributed around the coasts of most oceans.
Originally Lejeunia (an illegitimate generic name, subsequently Lejeunecysta, thirdly Trinovantedinium, fourthly (and now) Capillicysta.
Tax. synonym of Trinovantedinium capitatum Reid, 1977, according to Matsuoka, 1984, 1985. Matsuoka et al., 1987, retained Trinovantedinium (as Capillicysta) applanata as a separate species.
Bradford and Wall, 1984, considered this species to represent the encysted stage of Protoperidinium pentagonum (Gran) Balech, 1974.
Holotype: Bradford, 1977, fig.2:1-4
Occurrence: Rare-to-common: Musandam Peninsula, northern Straits of Hormuz; Present in all Eastern Musandam coastal sediments except for two southernmost samples; odd specimen in Gulf of Oman and Northern Arabian Sea.
Age: Recent
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description as Lejeunia applanata: [Bradford, 1977]:
Diagnosis:
Shape: Pericyst: Ambitus shows considerable variation in length-breadth ratio, but always retains its pentagonal shape; cysts are always flattened dorsoventrally. The epipericyst, similar in size to the hypopericyst, has convex flanks, converging apically into a short horn or apical boss. The hypopericyst has straight-to-concave sides; it tapers posteriorly into two distinct antapical horns. These horns are separated by a shallow-to-moderately deep antapical depression. Each horn may be either rounded or pointed distally; on rare occasions, the horns may be very slightly asymmetrical. Endocyst: Not always observable; usually ap"' pressed to pericyst throughout. Fig. 2: 1-4 illustrate the separated nature of the endocyst and the presence of a complete pericoel. The endocyst, when observed separated from the pericyst, displays the typical pentagonal ambital outline. Pericoel: When present, may be complete or as individual cavities at the tips of the apical and antapical horns.
Phragma: Both layers usually of constant thickness and inseparable. Occasional thickening towards the distal regions of the apical and antapical horns. Endophragm, when observed, smooth and lacking in ornamentation. Periphragm thin and usually colourless. Short spines, both parasutural and intratabular, are a diagnostic feature ; however, some intratabular areas possess very few spines, and consequently leave large bald areas on the tract surface. Some spines have capitate distal tips, but most have simple terminations.
Paratabulation: Pericyst: Paratabulation indeterminate. Pericingulum: A row of short spines outlines the pericingulum zone. The pericingulum is narrow, excavated and shows little or no displacement: it is gently inclined posteriorly from the dorsal to the ventral surface. Perisulcus: Not seen in all specimens: when observed, it is wide and shallow, extending in part onto the epipericyst: widens posteriorly. Endocyst: Paratabulation indeterminate.
Archeopyle: Standard hexa resulting from the detachment of the 2a anterior intercalary paraplate. This paraplate may extend almost down to the pericingulum. Since the endophragm and periphragm are generally appressed in this area of the tract, there appear to be one archeopyle and one operculum. Archeopyle Formula I/I (2a/2a).
Dimensions:
Holotype: length 78 μm, breadth 74 μm, distance between antapical horns (distally) 25 ,m, maximum height of processes 2.5 μm; other specimens -length 53-87 μm, breadth 47-74 μm, distance between antapical horns (distally) 25-31 μm, maximum height of processes 5 μm.
Number of specimens measured 25.
Remarks:
Lejeunia applanata corresponds to the forms described by Reid (1972, unpublished thesis) from the surface sediments around the British Isles. The Persian Gulf specimens are comparable in size with the British forms; however, the range of variation in forms of similar character as described by Wall & Dale (1968) includes much larger specimens (72-100 μm x 72-84 μm). L. applanata differs from Ginginodinium spinulosum Cookson and Eisenack 1960, by its less prominent apical horn and less squat hypocyst. The latter species also has a denser spinulose ornamentation and was recently described as having a large archeopyle (Formula 3I+3Pa) (Lentin & Williams 1975).
Thecal affinities:
These cysts are similar to those incubated by Wall & Dale (1968) to produce Peridinium pentagonum Gran, 1902. The cysts of P. pentagonum and P. cf. pentagonum of Wall & Dale (1968) show very slight differences, the latter having a distinctive ornamentation and marked apical and antapical projections. Wall & Dale (1968) considered that both these cyst types give rise to P. pentagonum; however, the reported distribution of P. pentagonum around the British Isles (Lebour 1925) does not agree with the distribution of the cyst (P. cf. pentagonum) as described by Reid (1972). Wood (1968) described the thecate stage as an estuarine and neritic form, which is widely distributed around the coasts of most oceans.