Back
Muderongia extensiva ssp. spinosa
Plate 16, Figures 7, 8, 10
Holotype: Plate 16, Figure 8.
Paratype: Plate 16, Figures 7, 10.
Type Locality: Vergol outcrop, late Valanginian, verrucosum Zone, verrucosum Sub-zone. Holotype - Bed V107M, Slide V107M(1), E.F. K49.0. Paratype - Bed V107M, Slide V107M(schulze), E.F. E47.2.
Derivation of Name: From the Latin spinosus, thorny - in reference to the spiny ornament.
Diagnosis: A subspecies of Muderongia extensiva with spiny ornament on the horns which is often restricted to their distal parts.
Dimensions: Holotype: 210 × 122 μm (complete). Paratype 101×122 μm (operculum detached).
Overall Complete specimens - 220 (192) 159 μm × 159 (134) 114 μm.
Specimens measured – 6.
Operculum detached - 114 (102) 89 μm × 149 (130) 109 μm.
Specimens measured – 10.
Remarks: The spiny covering demonstrated by this subspecies can cover all of the horns but can be restricted to their distal parts or in extreme cases to only the left antapical horn. In his description of his Muderongia macwhaei (sic) forma C, Monteil (1991, p. 474) stated, "Periphragm often spinous", and his pl. 4, fig. 2 was clearly so.
This subspecies ranged between BedsV5M and V107M at Vergol, early Valanginian, pertransiens Zone, salinarium Subzone to late Valanginian, verrucosum Zone, verrucosum Subzone. It was common only from Bed V76M (neocomiensiformis Zone, campylotoxus Sub-zone) to the top of its range.
Holotype: Plate 16, Figure 8.
Paratype: Plate 16, Figures 7, 10.
Type Locality: Vergol outcrop, late Valanginian, verrucosum Zone, verrucosum Sub-zone. Holotype - Bed V107M, Slide V107M(1), E.F. K49.0. Paratype - Bed V107M, Slide V107M(schulze), E.F. E47.2.
Derivation of Name: From the Latin spinosus, thorny - in reference to the spiny ornament.
Diagnosis: A subspecies of Muderongia extensiva with spiny ornament on the horns which is often restricted to their distal parts.
Dimensions: Holotype: 210 × 122 μm (complete). Paratype 101×122 μm (operculum detached).
Overall Complete specimens - 220 (192) 159 μm × 159 (134) 114 μm.
Specimens measured – 6.
Operculum detached - 114 (102) 89 μm × 149 (130) 109 μm.
Specimens measured – 10.
Remarks: The spiny covering demonstrated by this subspecies can cover all of the horns but can be restricted to their distal parts or in extreme cases to only the left antapical horn. In his description of his Muderongia macwhaei (sic) forma C, Monteil (1991, p. 474) stated, "Periphragm often spinous", and his pl. 4, fig. 2 was clearly so.
This subspecies ranged between BedsV5M and V107M at Vergol, early Valanginian, pertransiens Zone, salinarium Subzone to late Valanginian, verrucosum Zone, verrucosum Subzone. It was common only from Bed V76M (neocomiensiformis Zone, campylotoxus Sub-zone) to the top of its range.