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Meiourogonyaulax insulofigurata
Meiourogonyaulax insulofigurata Dodekova, 1975
Holotype: Dodekova, 1975, pl.2, figs.4-5. Originally (and now) Meiourogonyaulax, subsequently Lithodinia, thirdly Lithodinia?. This species is here retained in Meiourogonyaulax following the retention of the genus by Riding and Helby (2001d, p.81,83). Age: Late Bathonian.
Original description: Dodekova, 1975, p.21
Spheroidal to subspheroidal proximate cyst, slightly flattened dorso-ventrally, with well-rounded circular outline. Apex is lacking in all of the observed specimens. The cingulum is helicoidal. On the ventral side its two ends differing in antero-posterior position by almost one its breadth. The sulcus is smooth, concave, Broadens towards the apex. Tabulation formula: ?4", ?a, 6", 6c, 6""", 1p, 1"""" .The arrangement of the plates and the interrelation between their dimensions are shown in the proposed scheme (textfig. 3,a,b). The wall is two-layered. The endophragm is compact. The periphragm is represented by thick spongy substance with pores on the surface. Its thickness is 1.6--2.5 µm. The sutures and the peculiar "islands" in the middle of the plates are an extension of this spongy substance (text fig.3,c). They are densely arranged perforated septa or processes very complicatedly connected and interlaced, resembling the structure of a sponge. The sutures are relatively broad (3-5 µm) irregular bands which only around the cingulum are narrow and linear. The length of the sutures and the " islands" reaches up to 5 µm. The archaeopyle is apical.
Affinities:
Dodekova, 1975, p.22: The typical ornamentation of the wall distinguishes the new species from all known representatives of the genus.
Holotype: Dodekova, 1975, pl.2, figs.4-5. Originally (and now) Meiourogonyaulax, subsequently Lithodinia, thirdly Lithodinia?. This species is here retained in Meiourogonyaulax following the retention of the genus by Riding and Helby (2001d, p.81,83). Age: Late Bathonian.
Original description: Dodekova, 1975, p.21
Spheroidal to subspheroidal proximate cyst, slightly flattened dorso-ventrally, with well-rounded circular outline. Apex is lacking in all of the observed specimens. The cingulum is helicoidal. On the ventral side its two ends differing in antero-posterior position by almost one its breadth. The sulcus is smooth, concave, Broadens towards the apex. Tabulation formula: ?4", ?a, 6", 6c, 6""", 1p, 1"""" .The arrangement of the plates and the interrelation between their dimensions are shown in the proposed scheme (textfig. 3,a,b). The wall is two-layered. The endophragm is compact. The periphragm is represented by thick spongy substance with pores on the surface. Its thickness is 1.6--2.5 µm. The sutures and the peculiar "islands" in the middle of the plates are an extension of this spongy substance (text fig.3,c). They are densely arranged perforated septa or processes very complicatedly connected and interlaced, resembling the structure of a sponge. The sutures are relatively broad (3-5 µm) irregular bands which only around the cingulum are narrow and linear. The length of the sutures and the " islands" reaches up to 5 µm. The archaeopyle is apical.
Affinities:
Dodekova, 1975, p.22: The typical ornamentation of the wall distinguishes the new species from all known representatives of the genus.