Diphyes Cookson 1965a

Systematics

The suprageneric classification is based on Fensome et al. 1993. Nomenclature is based on The Lentin and Williams Index of Fossil Dinoflagellates, 2004 Edition (Fensome & Williams 2004).

Specimen references (prefixed 'L' or 'SM') refer to catalogue numbers in the playnological collections of GNS Science, Lower Hutt, New Zealand.

Phylum Dinoflagellata Bütschli 1885

Class Dinophyceae (Bütschli 1885) Pascher 1914

Subclass Peridiniphycidae Fensome et al. 1993

Order Gonyaulacales Taylor 1980

Suborder Gonyaulacineae Taylor 1980 (autonym)

Family Gonyaulacaceae Lindemann 1928

Subfamily Cribroperidinioideae Fensome et al. 1993

Genus Diphyes Cookson 1965a

Type Species: Diphyes colligerum (Deflandre and Cookson 1955, pp. 278-279, pl. 7, fig. 3) Cookson 1965a, pp. 86-87

Original Diagnosis: Shell composed of two parts, more or less unequal in size. The anterior part circular in outline with or without appendages. Archeopyle apical. The posterior part roughly bell-shaped to spherical with a small circular antapical opening and without typical appendages.

Emended Diagnosis: Chorate cysts with ovoidal to spherical central body composed of two layers. Processes numerous, 1 to 4 per plate area, hollow and either open or closed ditally. Large antapical process occuring opposite apical archaeopyle (Davey & Williams 1966b, p. 95).

Remarks: Many New Zealand examples of Diphyes species exhibit proximally conjoined pre- and postcingular processes, clearly demonstrating a tabulation and strongly suggestive of a close affinity with Hystrichokolpoma.

Diphyes brevispinum Bujak 1994

Original Description: Cyst subspherical, skolochorate and biphragmal, endophragm and periphragm adpressed except beneath the processes. Periphragm smooth to chagrinate, forming numerous nontabular processes. Processes other than the antapical process less than 5 mm in length, tubular, tapering from broader circular bases to narrow, open or closed terminations. Antapical process large, inflated [like Diphyes ficusoides], ovoidal to subspherical, with a closed circular base, and a constricted distal opening. Archeopyle apical; operculum tetaplacoid, contiguous (Bujak 1994, p. 123).

Description of the New Zealand Material: Spines at the long end of Bujak's range - around 5 mm - but otherwise as for the type material.

Distribution: Bujak’s material is recorded as Ypresian; the New Zealand specimen illustrated here (fig. 1) is Bortonian-Kaiatan (Bartonian to Pribonian).

Diphyes colligerum (Deflandre & Cookson 1955) Cookson 1965a

Original Diagnosis: Shell globular, almost spherical; processes numerous, tubular, straight or slightly flexuous, with a conical base and a closed capitate or slightly furcate apex. At one pole of the shell there is a large, hollow, cylindro-conical outgrowth closed by a rounded conical apex. This outgrowth, like the small processes, does not communicate with the interior of the shell. It is frequently ornamented distally with a circle of short, blunt, hollow, conical knobs. Membrane of shell finely granular.

Description of the New Zealand Material: Cysts intermediate?, chorate, subspherical to somewhat prolate, with roughly equal sized hemispheres. Cyst walls comprising two layers, closely appressed except at process bases. Archeopyle generally apical, type tA, though on some specimens (L16337/2 - 1311-155), the archeopyle margin is quite ragged, with splits between the precingular processes, indicating partial development of the combination archeopyles described elsewhere (e.g. Goodman & Witmer 1985, pp. 77-78). Operculum free (not seen). Surface minutely and very densely maculate (scabrate or vacuolated?) over entire periphragm, including processes. Processes apparently representing ?all plate series; heterogeneous. The antapical process is cylindrical, having more or less parallel sides; typically bearing longitudinal striations proximally; somewhat constricted and open distally, with what kind of margin? On some specimens (L16337/2 - 1311-155), the antapical process is not markedly longer than the other spines. Other processes fibrous, possibly hollow - can't tell; shape?; apparently nontabular, though commonly conjoined at bases into ?tabular groups; distal morphology variable, ranging from closed capitate to open buccinate?. Cingulum equatorial, well delineated by crest-like processes; sulcus not evident. Tabulation gonyaulacacean, apparently 4', 6'', Xc, 6''', 1p, 1''''; antapical plate apparently sexiform?.

Distribution: Cretaceous to basal Rupelian

Remarks: It is unclear how, or indeed if, Diphyes (al. Lingulasphaera) spinula (Drugg 1970b) Stover & Evitt 1978 differs from D. colligerum.

Diphyes ficusoides Islam 1983b

Original Description: Cyst subspherical, skolochorate and biphragmal; phragma adpressed; periphragm chagrinate or reticulate; many nontabular tubular processes tapering from broad circular bases to narrow necks before ending in distal aculeation or wider rims, proximally closed, distally open but rarely a few processes closed, a few neighbouring pairs sometimes proximally joined; antapical process inflated, distinctively broad with biconvex ambitus in all lateral views with figlike appearance. Antapical process rises from a circular base, proximally closed, distally open but constricted with maximum width at base or mid-length; archeopyle apical type (tA) (Islam 1983, p. 338).

Distribution: In New Zealand, the range is at least from Bortonian (Bartonian) (L6958, Hampden Formation) to Runangan (Priabonian) (L4979, Waiareka Volcanics).

Remarks: Only (?) difference from D. colligerum is the shape of the antapical process, and the reportedly different stratigraphic ranges.

References

Bujak, J.P. 1994: New dinocyst taxa from the Eocene of the North Sea. Journal of Micropalaeontology 13: 119-131, pl. 1-4.

Bütschli O. 1885. Dinoflagellata. In Protozoa (1880-1889), in Bronn's Klassen und Ordnungen des Tierreichs 1: 906-1029.

Cookson, I.C. 1965a: Cretaceous and Tertiary microplankton from south-eastern Australia. Proceedings of the Royal Society of Victoria 78(1): 85-93, pl. 9-11.

Davey, R.J.; Williams, G.L. 1966b: V. The genus Hystrichosphaeridium and its allies. In: Davey, R.J.; Downie, C.; Sarjeant, W.A.S.; Williams, G.L. 1966: Studies on Mesozoic and Cainozoic dinoflagellate cysts. British Museum (Natural History) Geology, Bulletin, Supplement 3, pp. 53-106.

Deflandre, G.; Cookson, I.C. 1955: Fossil microplankton from Australian Late Mesozoic and Tertiary sediments. Australian Journal of Marine and Freshwater Research, v. 6(2): 242-313, pl. 1-9.

Downie, C.; Sarjeant, W.A.S. 1965: Bibliography and index of fossil dinoflagellates and acritarchs. Geological Society of America, Memoir 94: 180 pp.