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Mosaicodinium mosaicum
Mosaicodinium mosaicum (Dodekova, 1975) Dodekova, 1990
Originally Ctenidodinium, subsequently Ctenidodinium?, thirdly Eodinia, fourthly (and now) Mosaicodinium.
Holotype: Dodekova, 1975, pl.1, figs.1-3
Locus typicus: Gornjak, NE Bulgaria
Stratum typicum: Late Bathonian
Original description: Dodekova, 1975, p.18-19: Ctenidodinium mosaicum
Sphaeroidal to subsphaeroidal, proximochorate dinoflagellate cyst, halving by a laevorotory spiral cingulum. The cingulum is narrow (4.65 Ám) and on the ventral side its ends differing in antero-posterior position by one its breadth. The sulcus is also narrow. Extends from the middle of the epitract to the antapex. Reflected tabulation: 4", 1a, 6"", ?6c, 6""", 1p, 1pv, 1"""". The arrangement of the plates and the correlation between their dimensions is typical for the genus. Peculiar in the tabulation is the antapical plate which is inclined to the ventral side. The anterior intercalary plate is very small and lies between apical plates 2" and 3". The endophragm is thick, the periphragm - thin and difficult to notice. The ornamentation of the two membranes is very complicated and its type reminds of the pillar structure in Gonyaulacysta aldorfiensis described by Gocht. From the endophragm arise fibrous sheaves of varying form and width which touch the periphragm. In plan they have granular surface, and with its irregular outlines lend the mosaic appaerance of the cyst. The length of the fibrous sheaves is different (from 1.55 to 7.75 Ám). At the places of the sutures they are lager. The surface of the endophragm between the sheaves is shagreenate. The periphragm is smooth or slightly shagreenate. The sutures are marked by membraneous septa of variable length, with numerous perforations. They resemble irregularly interlaced and welded fringes. The distal margin of the septa is slightly denticulate or passes into fringes of varying length. The latter are hollow, covered with pores, some neighbouring fringes are proximally interlaced in complicated forms. The fringes are best developed in the lower margin of the cingulum, in the apex and the antapex. At the intersection of the sutures larger processes form. No true apical horn, the antapical prominence being formed by the confluence of septa and fibrous sheaves. Its length depends upon the length of the crests. The archaeopyle is epitractal (type [AP]).
Supplemental description: Dodekova, 1990, p. 39
Tabulation formula: 2pr, 4", 2a, 6"", 6?c, 6""", 1p, 1"""", 6s. Archaeopyle epicystal, type E. Characteristic features - apical horn built by the ectophragm, fibrous fascucles in the ectocoel and sutural elements; distinct mosaic structure of wall; asymmetrical cingulum and antapical plate; ectocoel, in ptical section, visible in the area around the apical horn and the points of intersection of the sutural elements.; posterior intercalary plate - 1p - elongated; intratabular crests, cingulum and sulcus relatively narrow. Variations reflecting the intraspecific variation are expressed as varying in length sutural septae with different in length spines on their distal end and irregulary developed intratabular crests - "growth bands".
Affinities:
Dodekova, 1975, p.19: The complicated ornamentation of C. mosaicum distingushed the new species from all other known representatives of the genus.
Originally Ctenidodinium, subsequently Ctenidodinium?, thirdly Eodinia, fourthly (and now) Mosaicodinium.
Holotype: Dodekova, 1975, pl.1, figs.1-3
Locus typicus: Gornjak, NE Bulgaria
Stratum typicum: Late Bathonian
Original description: Dodekova, 1975, p.18-19: Ctenidodinium mosaicum
Sphaeroidal to subsphaeroidal, proximochorate dinoflagellate cyst, halving by a laevorotory spiral cingulum. The cingulum is narrow (4.65 Ám) and on the ventral side its ends differing in antero-posterior position by one its breadth. The sulcus is also narrow. Extends from the middle of the epitract to the antapex. Reflected tabulation: 4", 1a, 6"", ?6c, 6""", 1p, 1pv, 1"""". The arrangement of the plates and the correlation between their dimensions is typical for the genus. Peculiar in the tabulation is the antapical plate which is inclined to the ventral side. The anterior intercalary plate is very small and lies between apical plates 2" and 3". The endophragm is thick, the periphragm - thin and difficult to notice. The ornamentation of the two membranes is very complicated and its type reminds of the pillar structure in Gonyaulacysta aldorfiensis described by Gocht. From the endophragm arise fibrous sheaves of varying form and width which touch the periphragm. In plan they have granular surface, and with its irregular outlines lend the mosaic appaerance of the cyst. The length of the fibrous sheaves is different (from 1.55 to 7.75 Ám). At the places of the sutures they are lager. The surface of the endophragm between the sheaves is shagreenate. The periphragm is smooth or slightly shagreenate. The sutures are marked by membraneous septa of variable length, with numerous perforations. They resemble irregularly interlaced and welded fringes. The distal margin of the septa is slightly denticulate or passes into fringes of varying length. The latter are hollow, covered with pores, some neighbouring fringes are proximally interlaced in complicated forms. The fringes are best developed in the lower margin of the cingulum, in the apex and the antapex. At the intersection of the sutures larger processes form. No true apical horn, the antapical prominence being formed by the confluence of septa and fibrous sheaves. Its length depends upon the length of the crests. The archaeopyle is epitractal (type [AP]).
Supplemental description: Dodekova, 1990, p. 39
Tabulation formula: 2pr, 4", 2a, 6"", 6?c, 6""", 1p, 1"""", 6s. Archaeopyle epicystal, type E. Characteristic features - apical horn built by the ectophragm, fibrous fascucles in the ectocoel and sutural elements; distinct mosaic structure of wall; asymmetrical cingulum and antapical plate; ectocoel, in ptical section, visible in the area around the apical horn and the points of intersection of the sutural elements.; posterior intercalary plate - 1p - elongated; intratabular crests, cingulum and sulcus relatively narrow. Variations reflecting the intraspecific variation are expressed as varying in length sutural septae with different in length spines on their distal end and irregulary developed intratabular crests - "growth bands".
Affinities:
Dodekova, 1975, p.19: The complicated ornamentation of C. mosaicum distingushed the new species from all other known representatives of the genus.