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Petalodinium spinulum
Petalodinium spinulum (Islam, 1983a, p.236, pl.2, fig.4) Williams et al., 2015, p.308.
Originally Dracodinium politum subsp. spinulum, subsequently (and now) Petalodinium spinulum.
Holotype: Islam, 1983a, pl.2, fig.4.
Age: early Eocene.
Original diagnosis: Islam, 1983, p.236
A subspecies of D. politum Bujak et al. differing from the type in possessing 8 reticulate endophragm bearing spines or grana of up to 3µm across and 3µm height, both solid; and a chagrinate peripbragm bearing spines of similar height which are hollow, proximally open, distally closed, or open probably by breakage.
Dimensions:
Holotype: pericyst 135x142 µm, endocyst 58x68 µm. Range: pericyst length 140(128)110 µm breadth 142(139)120 µm; endocyst length 68(60)59 µm; breadth 68(65)59 µm.
8 Specimens measured
Affinities:
Islam, 1983, p.236: Forms with partly cronulate pericyst ambitus but lacking real spines are referred to D. politum Bujak et al. and thought to represent a probable intermediate phyletic position.
Originally Dracodinium politum subsp. spinulum, subsequently (and now) Petalodinium spinulum.
Holotype: Islam, 1983a, pl.2, fig.4.
Age: early Eocene.
Original diagnosis: Islam, 1983, p.236
A subspecies of D. politum Bujak et al. differing from the type in possessing 8 reticulate endophragm bearing spines or grana of up to 3µm across and 3µm height, both solid; and a chagrinate peripbragm bearing spines of similar height which are hollow, proximally open, distally closed, or open probably by breakage.
Dimensions:
Holotype: pericyst 135x142 µm, endocyst 58x68 µm. Range: pericyst length 140(128)110 µm breadth 142(139)120 µm; endocyst length 68(60)59 µm; breadth 68(65)59 µm.
8 Specimens measured
Affinities:
Islam, 1983, p.236: Forms with partly cronulate pericyst ambitus but lacking real spines are referred to D. politum Bujak et al. and thought to represent a probable intermediate phyletic position.