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Headinium miocenicum
Headinium "*miocenicum" Zevenboom and Santarelli in Zevenboom, 1995, p.152-153, pl.3, figs.7-12.
Name not validly published: considered a manuscript name.
Holotype: Zevenboom, 1995, pl.3, figs.7-9.
Age: late Mid Miocene-Late Miocene.
Original description (Zevenboom, 1995)
Manuscript holotype: Sample Boxmeer 7/2, EF (T35), Plate III 7-9
Manuscript paratype: Sample Boxmeer 7/2, EF (U33/2), Plate 7, figs. 23-24
Etmology: In reference to the occurence of this species in the Miocene.
Type locality: Boxmeer well
Type stratum: Breda Formation.
Diagnosis: A spherical species of Headinium characterized by numerous small hollow columellae. The archaeopyle is precingular, formed by the loss of precingular paraplates 2", 3" and 4". Endo-, peri- and ectophragm are smooth and continuous. The latter is supported by numerous hollow columellae, which are often distally biforcate. The collumellae are randomly placed on the periphragm.
Discussion: Headinum miocenicum differs from the morphologically similar Habibacysta tectata Head, 1989, in having a 3P archaeopyle. Moreover, H. miocenicum is larger and the ectophragm is continuously developed. Furthermore, hollow collumellae occur on H. miocenicum in contrast to solid columellae on Habibacysta tectata.
Remark: On occasion, during our studies specimens apparently morphologically closely related to H. miocenicum have been encountered. These forms are however much smaller and may constitute a second species of Headinium. More material is needed before more definitive conclusions may arrive.
Occurences: The Netherlands (this study) and possibily in the Norwegian Sea (Manum et al., 1989) and England (Powell, 1988)
Total stratigraphic range: Late Middle Miocene to Late Miocene.
Name not validly published: considered a manuscript name.
Holotype: Zevenboom, 1995, pl.3, figs.7-9.
Age: late Mid Miocene-Late Miocene.
Original description (Zevenboom, 1995)
Manuscript holotype: Sample Boxmeer 7/2, EF (T35), Plate III 7-9
Manuscript paratype: Sample Boxmeer 7/2, EF (U33/2), Plate 7, figs. 23-24
Etmology: In reference to the occurence of this species in the Miocene.
Type locality: Boxmeer well
Type stratum: Breda Formation.
Diagnosis: A spherical species of Headinium characterized by numerous small hollow columellae. The archaeopyle is precingular, formed by the loss of precingular paraplates 2", 3" and 4". Endo-, peri- and ectophragm are smooth and continuous. The latter is supported by numerous hollow columellae, which are often distally biforcate. The collumellae are randomly placed on the periphragm.
Discussion: Headinum miocenicum differs from the morphologically similar Habibacysta tectata Head, 1989, in having a 3P archaeopyle. Moreover, H. miocenicum is larger and the ectophragm is continuously developed. Furthermore, hollow collumellae occur on H. miocenicum in contrast to solid columellae on Habibacysta tectata.
Remark: On occasion, during our studies specimens apparently morphologically closely related to H. miocenicum have been encountered. These forms are however much smaller and may constitute a second species of Headinium. More material is needed before more definitive conclusions may arrive.
Occurences: The Netherlands (this study) and possibily in the Norwegian Sea (Manum et al., 1989) and England (Powell, 1988)
Total stratigraphic range: Late Middle Miocene to Late Miocene.