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Muderongia brevispinosa
Muderongia brevispinosa Iosifova 1996
Taxonomic senior synonym: Muderongia longicorna, according to Monteil (1996, p.42).
Holotype: Iosifova 1996: Plate XV, la-c
Isotypes: Iosifova 1996: Plate XIV, 2, 4; Plate XIV, 3a,b
locus typicus: Tchernaya Retchka outcrop, the Ryazan district, Russia.
Stratum typicum: the Ryazanian, R. riasanensis ammonite zone, E. pharo dinocyst subzone.
Diagnosis: Iosifova 1996, p. 225, 227
A species of Muderongia with two antapical horns. The periphragm bears short, proximally closed spines, distributed all over the surface of the cyst, especially on the distal parts of the horns and along the borders of the paracingulum.
Dimensions: Length (without apex): holotype: 70Ám, range: 62-80Ám; length of the left apical horn: holotype: 18Ám, range: 14-20Ám; length of inner body: holotype: 42Ám, range 40-55Ám; width: holotype: 84Ám, range: 84-107Ám; length of left cingular horn: holotype: 24Ám, range: 16-24Ám; length of right cingular horn: range: 10-22Ám; width of inner body: holotype: 48Ám, range: 48-53Ám.
Description: Iosifova 1996, p. 225, 227
The ceratioid cysts are circumcavate with two paracingular and two antapical horns. The shape of the cysts vary greatly. The left cingular and left antapical horns are relatively long, blunt and tapered. The right antapical horn may be reduced to a small, blunt bulge. The paracingular horns have distinct paracingular notches. The inner body is subspherical. The endophragm is thick and smooth. The periphragm bears small solid spines distributed all over the surface of the cyst, especially on the distal parts of horns and on the lines bordering the paracingulum. The periphragm spines are proximally closed. The paratabulation indicated by the paracingulum and by weakly expressed parasutural lines on some specimens. The archeopyle is apical, Type [tA] with an offset parasulcal notch.
Comparison: This species closely resembles M. simplex Alberti, 1961 emend. Monteil, 1991 in shape and differs from this species by the presence of short spines.
Occurrence: Tchernaya Retchka outcrop, the Ryazanian, R. riasanensis ammonite zone, E. pharo dinocyst subzone.
Taxonomic senior synonym: Muderongia longicorna, according to Monteil (1996, p.42).
Holotype: Iosifova 1996: Plate XV, la-c
Isotypes: Iosifova 1996: Plate XIV, 2, 4; Plate XIV, 3a,b
locus typicus: Tchernaya Retchka outcrop, the Ryazan district, Russia.
Stratum typicum: the Ryazanian, R. riasanensis ammonite zone, E. pharo dinocyst subzone.
Diagnosis: Iosifova 1996, p. 225, 227
A species of Muderongia with two antapical horns. The periphragm bears short, proximally closed spines, distributed all over the surface of the cyst, especially on the distal parts of the horns and along the borders of the paracingulum.
Dimensions: Length (without apex): holotype: 70Ám, range: 62-80Ám; length of the left apical horn: holotype: 18Ám, range: 14-20Ám; length of inner body: holotype: 42Ám, range 40-55Ám; width: holotype: 84Ám, range: 84-107Ám; length of left cingular horn: holotype: 24Ám, range: 16-24Ám; length of right cingular horn: range: 10-22Ám; width of inner body: holotype: 48Ám, range: 48-53Ám.
Description: Iosifova 1996, p. 225, 227
The ceratioid cysts are circumcavate with two paracingular and two antapical horns. The shape of the cysts vary greatly. The left cingular and left antapical horns are relatively long, blunt and tapered. The right antapical horn may be reduced to a small, blunt bulge. The paracingular horns have distinct paracingular notches. The inner body is subspherical. The endophragm is thick and smooth. The periphragm bears small solid spines distributed all over the surface of the cyst, especially on the distal parts of horns and on the lines bordering the paracingulum. The periphragm spines are proximally closed. The paratabulation indicated by the paracingulum and by weakly expressed parasutural lines on some specimens. The archeopyle is apical, Type [tA] with an offset parasulcal notch.
Comparison: This species closely resembles M. simplex Alberti, 1961 emend. Monteil, 1991 in shape and differs from this species by the presence of short spines.
Occurrence: Tchernaya Retchka outcrop, the Ryazanian, R. riasanensis ammonite zone, E. pharo dinocyst subzone.