Back
Headinium
From Williams et al., 2017:
[Headinium, Zevenboom and Santarelli in Zevenboom, 1995, p. 152.
Name not validly published: considered a manuscript name.
Type species: Headinium miocenicum, Zevenboom, 1995 (pl.3, figs.7-9)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Zevenboom, 1995]:
Diagnosis:
Spherical holocavate cysts. The periphragm gives rise to hollow columellae which support the ectophragm.
The archeopyle is precingular, type 3P.
Description:
Spherical holocavate cysts with the endo- and periphragm closely appressed. The periphragm forms numerous hollow columellae, which supports the continuously developed ectophragm. The columellae are randomly placed and display no paratabulation.
The archaeopyle is precingular, formed by the loss of precingular paraplates 2", 3"and 4". The operculum is free; no isolated operculae have been observed.
Affinities:
Headinium differs from the morphologically similar genera Habicysta Head, 1989, Bitectodinium Wilson, 1973, Tectatodinium Wall, 1967, and Filisphaera Bujak, 1984, in having a 3P archaeopyle and by the development op distinctly hollow columellae. In his description of Habicysta, Head (1989) remarked that Filisphaera possesses high narrow septae, that Tectatodinium has interconnected irregularly perforate lamellae, that Bitectatodinium displays suberect lamellae (sometimes branched) arising from raised bases and that Habibacysta possesses solid rods.
[Headinium, Zevenboom and Santarelli in Zevenboom, 1995, p. 152.
Name not validly published: considered a manuscript name.
Type species: Headinium miocenicum, Zevenboom, 1995 (pl.3, figs.7-9)]
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Zevenboom, 1995]:
Diagnosis:
Spherical holocavate cysts. The periphragm gives rise to hollow columellae which support the ectophragm.
The archeopyle is precingular, type 3P.
Description:
Spherical holocavate cysts with the endo- and periphragm closely appressed. The periphragm forms numerous hollow columellae, which supports the continuously developed ectophragm. The columellae are randomly placed and display no paratabulation.
The archaeopyle is precingular, formed by the loss of precingular paraplates 2", 3"and 4". The operculum is free; no isolated operculae have been observed.
Affinities:
Headinium differs from the morphologically similar genera Habicysta Head, 1989, Bitectodinium Wilson, 1973, Tectatodinium Wall, 1967, and Filisphaera Bujak, 1984, in having a 3P archaeopyle and by the development op distinctly hollow columellae. In his description of Habicysta, Head (1989) remarked that Filisphaera possesses high narrow septae, that Tectatodinium has interconnected irregularly perforate lamellae, that Bitectatodinium displays suberect lamellae (sometimes branched) arising from raised bases and that Habibacysta possesses solid rods.