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Surculosphaeridium oceaniae
From Fensome et al., 2019:
Surculosphaeridium ?oceaniae (de Coninck, 1969, p.60, pl.17, figs.12–21) de Coninck, 1986b, p.14. Holotype: de Coninck, 1969, pl.17, figs.20–21. Originally Micrhystridium (Appendix A), subsequently Surculosphaeridium, thirdly (and now) Surculosphaeridium?. Questionable assignment: Fauconnier and Pourtoy in Fauconnier and Masure (2004, p.519) as a problematic species. The epithet was originally cited as "oceaniae". In earlier versions of this index itwas cited as "oceania", and as a noun in apposition (NIA). Fauconnier and Pourtoy in Fauconnier and Masure (2004, p.519) cite the name as "oceaniense". However, according to J. Jansonius (pers. comm.), the epithet can be considered a noun in apposition (in the possessive case), since de Coninck (1969, p.60) clearly wanted to emphasize its occurrence in the Eocene of Australia. Hence, the epithet is based on the geographic name "oceania". NIA. Age: Ypresian.
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Original description (De Coninck, 1969) Translation: PKB 2025
Diagnosis – The organisms consist of a small, globose shell with solid, slender to robust processes, the distal ends of which are forked. Some processes are sometimes congruent up to about half their height. The processes may be connected at their base by low ridges on the shell. The length of the processes is between one-third and two-thirds of the shell diameter. The shell surface may be granular.
Body dimensions: 15–23 inches.
Process height: 5–8 inches.
Total wingspan: 27–33 inches.
Remarks. — These organisms are quite common in Ypresian deposits and were encountered by Deflandre & Cookson in the Eocene deposits of Australia. This part of the world, called Oceania, suggested the species name to me. Deflandre & Cookson had provisionally named them M. cf. ambiguum. However, since then I have found no organism that allows me to conclude that they are similar to M. ambiguum, whose diagnosis does not correspond to the characteristics of our organisms. Therefore, I am giving them a proper species name. Given the differences with the large mass of Acritarcha, their assignment to the genus Micrhystridium seems doubtful to me. Micrhystridium oceaniae nov. sp. appears to me closer to the family Hystrichosphaeridiaceae in the Dinophyceae than to the subgroup Acanthomorphitae among the Acritarcha.
Surculosphaeridium ?oceaniae (de Coninck, 1969, p.60, pl.17, figs.12–21) de Coninck, 1986b, p.14. Holotype: de Coninck, 1969, pl.17, figs.20–21. Originally Micrhystridium (Appendix A), subsequently Surculosphaeridium, thirdly (and now) Surculosphaeridium?. Questionable assignment: Fauconnier and Pourtoy in Fauconnier and Masure (2004, p.519) as a problematic species. The epithet was originally cited as "oceaniae". In earlier versions of this index itwas cited as "oceania", and as a noun in apposition (NIA). Fauconnier and Pourtoy in Fauconnier and Masure (2004, p.519) cite the name as "oceaniense". However, according to J. Jansonius (pers. comm.), the epithet can be considered a noun in apposition (in the possessive case), since de Coninck (1969, p.60) clearly wanted to emphasize its occurrence in the Eocene of Australia. Hence, the epithet is based on the geographic name "oceania". NIA. Age: Ypresian.
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Original description (De Coninck, 1969) Translation: PKB 2025
Diagnosis – The organisms consist of a small, globose shell with solid, slender to robust processes, the distal ends of which are forked. Some processes are sometimes congruent up to about half their height. The processes may be connected at their base by low ridges on the shell. The length of the processes is between one-third and two-thirds of the shell diameter. The shell surface may be granular.
Body dimensions: 15–23 inches.
Process height: 5–8 inches.
Total wingspan: 27–33 inches.
Remarks. — These organisms are quite common in Ypresian deposits and were encountered by Deflandre & Cookson in the Eocene deposits of Australia. This part of the world, called Oceania, suggested the species name to me. Deflandre & Cookson had provisionally named them M. cf. ambiguum. However, since then I have found no organism that allows me to conclude that they are similar to M. ambiguum, whose diagnosis does not correspond to the characteristics of our organisms. Therefore, I am giving them a proper species name. Given the differences with the large mass of Acritarcha, their assignment to the genus Micrhystridium seems doubtful to me. Micrhystridium oceaniae nov. sp. appears to me closer to the family Hystrichosphaeridiaceae in the Dinophyceae than to the subgroup Acanthomorphitae among the Acritarcha.