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Palaecysta foveoreticulata subsp. foveoreticulata
Palaecysta foveoreticulata subsp. foveoreticulata Chen, 2013
Autonym.
Holotype: Chen, 2013, pl.6, fig.59.
Age: late Berriasian.
Original description (Chen, 2013):
Palaecysta foveoreticulata sp. nov. foveo-reticulata,
Latin, small hole and network-like, depicting the pitted and reticulate pattern of the membranous pre- and postcingular process clusters.
Holotype. Plate 6, Figure 59, Slide 1193-1205/2, U43.
Paratypes. Plate 6, Figure 66, Slide 1214-17, N9; Plate 6, Figure 69, Slide 1193-1205, L29; Plate 7, Figure 70, Slide 1214-17, H12; Plate 7, Figure 77, Slide 1226-35, T37; Plate 7, Figure 78, Slide 1226-35, E52; Plate 7, Figure 81, Slide 1304-07, J54.
Other specimens. Plate 6, Figures 60-65, 67, 68; Plate 7, Figures 71-76, 79, 80
Diagnosis: This species is characterised by a reticulate, foveolate, or foveo-reticulate pattern of the membranous process clusters in the pre- and postcingular series (Figure 9, drawings 18-25; Figure 10, drawing 42-50).
Dimensions (based on measurements from 50 specimens):
Holotype – Whole specimen 165 µm; central body 89 µm; process length 55 µm
Range – Whole specimen 130 (140) 165 µm; central body 78 (83) 95 µm; process length 48 (50) 60 µm
Remarks: The process clusters of this species exhibit variations among basically reticulate, foveolate and foveo-reticulate patterns, along with the infinite morphological transitions of the ornamentation of the process clusters among the entire population of members (Figure 9, drawings 18-25). This highly diverse and variable expression suggests that the morphology of this species was unstable. Any further division, at the variety level, although may be desirable, will not be practical because the definition of each sub-population is difficult to maintain as the changes seem to occur along a continuum with one transitional form followed by another with no clear demarcation. Furthermore, because there is no clear restricted chronostratigraphically distribution pattern within the sub-population of any specific subspecies/variety, any attempt to further subdivide this group will not serve any biostratigraphical purpose. Further subdivision of this subspecies, is, therefore, not attempted.
Occurrences in the Ankamotra-1 well. P. foveoreticulata occurred most abundantly in Zone 2 (Late Berriasian).
Autonym.
Holotype: Chen, 2013, pl.6, fig.59.
Age: late Berriasian.
Original description (Chen, 2013):
Palaecysta foveoreticulata sp. nov. foveo-reticulata,
Latin, small hole and network-like, depicting the pitted and reticulate pattern of the membranous pre- and postcingular process clusters.
Holotype. Plate 6, Figure 59, Slide 1193-1205/2, U43.
Paratypes. Plate 6, Figure 66, Slide 1214-17, N9; Plate 6, Figure 69, Slide 1193-1205, L29; Plate 7, Figure 70, Slide 1214-17, H12; Plate 7, Figure 77, Slide 1226-35, T37; Plate 7, Figure 78, Slide 1226-35, E52; Plate 7, Figure 81, Slide 1304-07, J54.
Other specimens. Plate 6, Figures 60-65, 67, 68; Plate 7, Figures 71-76, 79, 80
Diagnosis: This species is characterised by a reticulate, foveolate, or foveo-reticulate pattern of the membranous process clusters in the pre- and postcingular series (Figure 9, drawings 18-25; Figure 10, drawing 42-50).
Dimensions (based on measurements from 50 specimens):
Holotype – Whole specimen 165 µm; central body 89 µm; process length 55 µm
Range – Whole specimen 130 (140) 165 µm; central body 78 (83) 95 µm; process length 48 (50) 60 µm
Remarks: The process clusters of this species exhibit variations among basically reticulate, foveolate and foveo-reticulate patterns, along with the infinite morphological transitions of the ornamentation of the process clusters among the entire population of members (Figure 9, drawings 18-25). This highly diverse and variable expression suggests that the morphology of this species was unstable. Any further division, at the variety level, although may be desirable, will not be practical because the definition of each sub-population is difficult to maintain as the changes seem to occur along a continuum with one transitional form followed by another with no clear demarcation. Furthermore, because there is no clear restricted chronostratigraphically distribution pattern within the sub-population of any specific subspecies/variety, any attempt to further subdivide this group will not serve any biostratigraphical purpose. Further subdivision of this subspecies, is, therefore, not attempted.
Occurrences in the Ankamotra-1 well. P. foveoreticulata occurred most abundantly in Zone 2 (Late Berriasian).