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Pyxidinopsis tuberculata
Pyxidinopsis tuberculata Versteegh and Zevenboom, 1995
Holotype: Versteegh and Zevenboom, 1995, pl. V, figs. 1-3
Type Locality: Singa Section, Calabria, S Italy
Type stratum:
Original diagnosis: Versteegh and Zevenboom, 1995, p. 226-227
The ovoid to ellipsoid cysts are covered with solid tubercula from which ridges of irregular height, width and length may originate. At least some tubercula are connected by such ridges. The ridges do not exceed the trabeculae in height and width. The archaeopyle is precingular and has a trapezoid outline.
Description: Versteegh and Zevenboom, 1995, p. 227
The hight of the ridges on the cyst is usually much less than that of the tubercula. The amount of ridges per cyst is very variable. Both "spiny" cysts with almost no ridges and "reticulate" cysts can be found. The maximum size of the Late Pliocene specimens is less than that for specimens from the Miocene which suggests a decrease in maximum size with decreasing age.
Dimensions: Holotype: height: 30 µm; maximum width: 26 µm; maximum height of ornamentation; 2 µm; wall thickness: 2 µm. Range: height: 27-49 µm ; maximum width: 22-38 µm; height of ornamentation up to 5 µm; wall thickness 1-2 µm; specimens measured: 21.
Affinities:
Versteegh and Zevenboom, 1995, p. 227
P. tuberculata differs from all other species of Pyxidinopsis by its well developed ornamentation in combination with its ovoid shape. It differs from Pyxidiella Cookson and Eisenack, 1958 by having a precingular rather than an intercalary archaeopyle. P. tuberculata differs from all Operculodinium species by having low ridges at the cysts surface. In our opinion the specimen figured as Pyxidiella sp 1. of Mudie, 1987 in Mudie, 1992 belongs to a different species than the specimen of Pyxidiella sp. 1 figured in Mudie 1987. The specimen figured in 1992 clearly shows bacula and is considered to represent P. tuberculata whereas the specimen figured in 1987 shows no bacula and is rather considered to represent a form of Batiacasphaera Drugg, 1970.
Stratigraphy: Aquitanian, NN2 (Zevenboom et al. subm.) to Piacenzian, base NN18 (Zevenboom and Versteegh, in prep).
Holotype: Versteegh and Zevenboom, 1995, pl. V, figs. 1-3
Type Locality: Singa Section, Calabria, S Italy
Type stratum:
Original diagnosis: Versteegh and Zevenboom, 1995, p. 226-227
The ovoid to ellipsoid cysts are covered with solid tubercula from which ridges of irregular height, width and length may originate. At least some tubercula are connected by such ridges. The ridges do not exceed the trabeculae in height and width. The archaeopyle is precingular and has a trapezoid outline.
Description: Versteegh and Zevenboom, 1995, p. 227
The hight of the ridges on the cyst is usually much less than that of the tubercula. The amount of ridges per cyst is very variable. Both "spiny" cysts with almost no ridges and "reticulate" cysts can be found. The maximum size of the Late Pliocene specimens is less than that for specimens from the Miocene which suggests a decrease in maximum size with decreasing age.
Dimensions: Holotype: height: 30 µm; maximum width: 26 µm; maximum height of ornamentation; 2 µm; wall thickness: 2 µm. Range: height: 27-49 µm ; maximum width: 22-38 µm; height of ornamentation up to 5 µm; wall thickness 1-2 µm; specimens measured: 21.
Affinities:
Versteegh and Zevenboom, 1995, p. 227
P. tuberculata differs from all other species of Pyxidinopsis by its well developed ornamentation in combination with its ovoid shape. It differs from Pyxidiella Cookson and Eisenack, 1958 by having a precingular rather than an intercalary archaeopyle. P. tuberculata differs from all Operculodinium species by having low ridges at the cysts surface. In our opinion the specimen figured as Pyxidiella sp 1. of Mudie, 1987 in Mudie, 1992 belongs to a different species than the specimen of Pyxidiella sp. 1 figured in Mudie 1987. The specimen figured in 1992 clearly shows bacula and is considered to represent P. tuberculata whereas the specimen figured in 1987 shows no bacula and is rather considered to represent a form of Batiacasphaera Drugg, 1970.
Stratigraphy: Aquitanian, NN2 (Zevenboom et al. subm.) to Piacenzian, base NN18 (Zevenboom and Versteegh, in prep).