Downiesphaeridium polyacanthum

"polyacanthum" (Gitmez, 1970, p.284–286, pl.12, fig.10; text-fig.22) Islam, 1993, p.84.  Holotype: Gitmez, 1970, pl.12, fig.10; text-fig.22b; Fauconnier and Masure, 2004, pl.23, figs.6–7.  Originally Cleistosphaeridium, subsequently Cleistosphaeridium?, thirdly Downiesphaeridium.  Taxonomic senior synonym: Hystrichosphaeridium (now Impletosphaeridium?) polytrichum, according to Masure in Fauconnier and Masure (2004, p.196).  Taxonomic senior synonym: Baltisphaeridium (as Cleistosphaeridium) iaculigerum, according to Brenner (1988, p.42) — however, neither Islam (1993, p.84), who retained Downiesphaeridium polyacanthum, nor Masure in Fauconnier and Masure (2004, p.196) followed this synonymy.  Age: early Kimmeridgian.

Parent: Downiesphaeridium