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Resticulasphaera fasciculata
Plate 10, Figures 14-16, 19, 20
Holotype: Plate 10, Figures 15, 16.
Paratype: Plate 10, Figure 19.
Type Locality: Vergol outcrop, early Valanginian, Bed V97M, inostranzewi ammonite Zone, platycostatus Sub-zone. Holotype: Slide V97M(A), E.F. H46.4. Paratype: Vergol Bed B131M, late Berriasian, alpillensis Zone, otopeta Sub-zone, Slide B131(R1 extra schulze), E.F. U49.3.
Derivation of Name: From the Latin fasciculus, a small bundle - in reference to the penitabular clustering of processes.
Diagnosis: A small, ellipsoidal to ovoidal species with a smooth surface and bearing acuminate processes in the form of long, solid, hair-like fibres. These fibres vary in number and length on individual specimens and are typically linked on the body surface into penitabular clusters. The archeopyle is epicystal and usually remains attached ventrally.
Dimensions: Holotype Length - 38 μm. Width - 33 μm.
Paratype Length - 35 μm. Width - 33 μm.
Overall - 41 (38) 35 μm × 35 (32) 30 μm.
Specimens measured - 5 (all with the operculum attached).
Remarks: This small species is similar in some respects to Resticulasphaera medusae Harding 1990 ex Harding in Williams et al. 1998, particularly the small size, possession of hair-like fibres and an epicystal archeopyle. It differs, however, in having a smooth surface as opposed to the, "sculpture of fine interwoven, matted fibres" (Harding 1990, p. 44) and in its clear penitabular clustering of the hair-like fibres. In contrast, these are, "apparently partially non-tabular and partially sutural" (Harding, op. cit.) in R. medusae.
In addition, the tendency in Resticulasphaera fasciculata is for the operculum to remain attached, whereas this only rarely occurs in R. medusae. In the latter species the, "Anterior edge of paracingulum becomes rolled over towards the antapex after archaeopyle formation" (Harding, op. cit.) but this tendency has not been observed in R. fasciculata.
Resticulasphaera fasciculata was observed throughout much of the studied section. It was very common as deep as Vergol sample B121M (late Berriasian, alpillensis Zone, otopeta Sub-zone) and common between Vergol beds V97M and V107M (i.e. across the early/late Valanginian boundary). These constitute by far the oldest records of this genus to date. The youngest record in the current study was from La Charce Bed LCH216M (early Hauterivian, top radiatus Zone).
Holotype: Plate 10, Figures 15, 16.
Paratype: Plate 10, Figure 19.
Type Locality: Vergol outcrop, early Valanginian, Bed V97M, inostranzewi ammonite Zone, platycostatus Sub-zone. Holotype: Slide V97M(A), E.F. H46.4. Paratype: Vergol Bed B131M, late Berriasian, alpillensis Zone, otopeta Sub-zone, Slide B131(R1 extra schulze), E.F. U49.3.
Derivation of Name: From the Latin fasciculus, a small bundle - in reference to the penitabular clustering of processes.
Diagnosis: A small, ellipsoidal to ovoidal species with a smooth surface and bearing acuminate processes in the form of long, solid, hair-like fibres. These fibres vary in number and length on individual specimens and are typically linked on the body surface into penitabular clusters. The archeopyle is epicystal and usually remains attached ventrally.
Dimensions: Holotype Length - 38 μm. Width - 33 μm.
Paratype Length - 35 μm. Width - 33 μm.
Overall - 41 (38) 35 μm × 35 (32) 30 μm.
Specimens measured - 5 (all with the operculum attached).
Remarks: This small species is similar in some respects to Resticulasphaera medusae Harding 1990 ex Harding in Williams et al. 1998, particularly the small size, possession of hair-like fibres and an epicystal archeopyle. It differs, however, in having a smooth surface as opposed to the, "sculpture of fine interwoven, matted fibres" (Harding 1990, p. 44) and in its clear penitabular clustering of the hair-like fibres. In contrast, these are, "apparently partially non-tabular and partially sutural" (Harding, op. cit.) in R. medusae.
In addition, the tendency in Resticulasphaera fasciculata is for the operculum to remain attached, whereas this only rarely occurs in R. medusae. In the latter species the, "Anterior edge of paracingulum becomes rolled over towards the antapex after archaeopyle formation" (Harding, op. cit.) but this tendency has not been observed in R. fasciculata.
Resticulasphaera fasciculata was observed throughout much of the studied section. It was very common as deep as Vergol sample B121M (late Berriasian, alpillensis Zone, otopeta Sub-zone) and common between Vergol beds V97M and V107M (i.e. across the early/late Valanginian boundary). These constitute by far the oldest records of this genus to date. The youngest record in the current study was from La Charce Bed LCH216M (early Hauterivian, top radiatus Zone).