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Mombasadinium
From Williams et al., 2017:
[Mombasadinium, Riding and Helby, 2001f, p. 159-160, 162.
Type species: originally as Indodinium? parvelatum, Jiang Qinghua et al., 1992 (pl.2, fig.10)] ; Mombasadinium parvelatum, comb. nov., emend.
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Original description: [Riding and Helby, 2001f]:
Diagnosis:
Proximate, circumcavate dinoflagellate cysts, elongate ellipsoidal in outline, lacking polar horns and being intermediate in size.
Periphragm smooth, endophragm smooth or bearing low relief ornamentation.
Standard gonyaulacalean paratabulation partially to fully indicated by periphragmal folds.
Paracingulum and parasulcus may be indicated by folds in the periphragm.
Archaeopyle apical; operculum simple, free.
Remarks:
The genotype was originally described as ?Indodinium parvelatum Jiang (in Jiang et al. 1992). A re-examination of the type material and the study of new material from offshore northwestern Australia and Misool, eastern Indonesia has indicated that this species does not belong to Indodinium (see below).
Affinities/Comparison:
Mombasadinium closely resembles Indodinium in shape and size, but the latter has an apical horn and an endophragm which is typically ornamented and may be echinate, having parasultural spinules. Additionally, in loisthocysts of Indodinium khariense, the endocyst is significantly shorter than the pericyst due to the principal periarchaeopyle suture being consistently significantly higher than the principal endoarchaeopyle suture (see above, Fig. 10 and Jiang et al. 1992, pl. 2, fig. 7). Additionally, this new genus is similar to Craspedodinium in morphology. However, Craspedodinium is not elongate and may be large in size. This new genus is broadly similar to Belodinium Cookson & Eisenack 1960 emend. Stover & Helby 1987, but Mombasadinium lacks the prominent endophargmal processes, the prominent apical horn and the diagnostic claustrum representing the antapical paraplate, which characterise the former. Boreocysta Stover & Evitt 1978 emend. Århus 1992 is superficially similar, but is holocavate , has no paratabulation apart from the principal archeopyle suture and exhibits a prominent apical horn. The holocavate genus Gardodinium Alberti 1961 emend. Harding 1996 resembles Mosmbasadinium,but has an apical horn. Wallodinium Loeblich & Loeblich 1968 emend. Riding 1994 is elongate, lacks polar horns, has an apical archaeopyle and may be circumcavate. However, unlike Mombasadinium, most species of Wallodinium are bicavate and have no parasultural features other than relating to the archaeopyle. Lagenadinium Piel 1985 is a Jurassic genus which is slightly elongate and has an apical archaeopyle. It differs from Mombasadinium by being holocavate, lacking parasutural features and having hypocystal coronas. The Cretaceous Carpodinium Cookson & Eisenack 1962 emend. Leffingwell & Morgan 1977 is, like Mombasadinium, elongate with prominent periphragmal folds, but has a precingular archaeopyle and my be suturocavate.Derivation of name. From Mombasa, Kenya, from where the holotype of this species was collected.
[Mombasadinium, Riding and Helby, 2001f, p. 159-160, 162.
Type species: originally as Indodinium? parvelatum, Jiang Qinghua et al., 1992 (pl.2, fig.10)] ; Mombasadinium parvelatum, comb. nov., emend.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [Riding and Helby, 2001f]:
Diagnosis:
Proximate, circumcavate dinoflagellate cysts, elongate ellipsoidal in outline, lacking polar horns and being intermediate in size.
Periphragm smooth, endophragm smooth or bearing low relief ornamentation.
Standard gonyaulacalean paratabulation partially to fully indicated by periphragmal folds.
Paracingulum and parasulcus may be indicated by folds in the periphragm.
Archaeopyle apical; operculum simple, free.
Remarks:
The genotype was originally described as ?Indodinium parvelatum Jiang (in Jiang et al. 1992). A re-examination of the type material and the study of new material from offshore northwestern Australia and Misool, eastern Indonesia has indicated that this species does not belong to Indodinium (see below).
Affinities/Comparison:
Mombasadinium closely resembles Indodinium in shape and size, but the latter has an apical horn and an endophragm which is typically ornamented and may be echinate, having parasultural spinules. Additionally, in loisthocysts of Indodinium khariense, the endocyst is significantly shorter than the pericyst due to the principal periarchaeopyle suture being consistently significantly higher than the principal endoarchaeopyle suture (see above, Fig. 10 and Jiang et al. 1992, pl. 2, fig. 7). Additionally, this new genus is similar to Craspedodinium in morphology. However, Craspedodinium is not elongate and may be large in size. This new genus is broadly similar to Belodinium Cookson & Eisenack 1960 emend. Stover & Helby 1987, but Mombasadinium lacks the prominent endophargmal processes, the prominent apical horn and the diagnostic claustrum representing the antapical paraplate, which characterise the former. Boreocysta Stover & Evitt 1978 emend. Århus 1992 is superficially similar, but is holocavate , has no paratabulation apart from the principal archeopyle suture and exhibits a prominent apical horn. The holocavate genus Gardodinium Alberti 1961 emend. Harding 1996 resembles Mosmbasadinium,but has an apical horn. Wallodinium Loeblich & Loeblich 1968 emend. Riding 1994 is elongate, lacks polar horns, has an apical archaeopyle and may be circumcavate. However, unlike Mombasadinium, most species of Wallodinium are bicavate and have no parasultural features other than relating to the archaeopyle. Lagenadinium Piel 1985 is a Jurassic genus which is slightly elongate and has an apical archaeopyle. It differs from Mombasadinium by being holocavate, lacking parasutural features and having hypocystal coronas. The Cretaceous Carpodinium Cookson & Eisenack 1962 emend. Leffingwell & Morgan 1977 is, like Mombasadinium, elongate with prominent periphragmal folds, but has a precingular archaeopyle and my be suturocavate.Derivation of name. From Mombasa, Kenya, from where the holotype of this species was collected.