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Protobatioladinium modestum
Plate 3, Figures 6-8, 11-13, 15-17
Holotype: Plate 3, Figure 8
Paratype: Plate 3, Figure 17
Type Locality: La Charce outcrop, late Valanginian, Bed LCH164M, base furcillata Zone, furcillata Sub-zone. Holotype: Slide LCH164(2), E.F. S43.2. Paratype: Slide LCH164(1), E.F. G26.0.
Derivation of Name: From the Latin modestus, moderate, unassuming - in reference to the inconspicuous nature of this species.
Diagnosis: A broadly ovoidal species of Protobatioladinium, autophragm only, with a microgranular ornament and a short, distally-rounded apical horn. A broad-based but vestigial left antapical horn may also be present. The archeopyle is compound type tA2I.
Dimensions: Holotype Length - 78 μm. Width - 63 μm. Paratype (operculum detached): Length - 61 μm. Width - 56 μm. Complete specimens - 78 (70) 66 μm × 63 (53) 46 μm. Specimens measured – 6. Operculum detached - length: 61 (61) 61 μm, width: 56 (56) 56 μm. Specimens measured – 3.
Remarks: In his illustration of the type species, Protobatioladinium westburiensis, Nøhr-Hansen (1986, p. 37) showed it to have antapical bulges offset laterally with the left antapical better-developed and forming a distinct horn; this lateral offset appears to be the case with Protobatioladinium modestum. Schrank (2005, p. 72) described Protobatioladinium lindiense from the Tithonian of Tanzania and, like P. modestum, this is broadly ovoidal, covered in "minute granules or bacula" (Schrank, op. cit.) and possesses a short apical horn. It contrasts with P. modestum, however, in possessing a prominent antapical horn that is offset ventrally, not laterally. In P. modestum, as described for P. lindiense by Schrank (op. cit.), "The archeopyle may be…incompletely demarcated by sutures.
In dorso-ventral orientation it may appear apical. In lateral orientation, a few specimens show rudimentary sutures indicating inclusion of intercalary plates". Sometimes in P. modestum the operculum is completely lost (as in the paratype), resulting in a zig-zag archeopyle margin. Very rarely the intercalary plates may be lost separately, resulting in a cyst very similar to the genus Pareodinia (see pl. 3, fig. 7). Protobatioladinium modestum is significantly larger than the size quoted by Schrank for P. lindiense: Holotype 58 × 40 μm. Length range: 67 (59.6) 53μm.
Occurrences of Protobatioladinium modestum were restricted to the La Charce section, ranging between Beds LCH164M and LCH220M (late Valanginian, furcillata Zone to early Hauterivian, loryi Zone).
Holotype: Plate 3, Figure 8
Paratype: Plate 3, Figure 17
Type Locality: La Charce outcrop, late Valanginian, Bed LCH164M, base furcillata Zone, furcillata Sub-zone. Holotype: Slide LCH164(2), E.F. S43.2. Paratype: Slide LCH164(1), E.F. G26.0.
Derivation of Name: From the Latin modestus, moderate, unassuming - in reference to the inconspicuous nature of this species.
Diagnosis: A broadly ovoidal species of Protobatioladinium, autophragm only, with a microgranular ornament and a short, distally-rounded apical horn. A broad-based but vestigial left antapical horn may also be present. The archeopyle is compound type tA2I.
Dimensions: Holotype Length - 78 μm. Width - 63 μm. Paratype (operculum detached): Length - 61 μm. Width - 56 μm. Complete specimens - 78 (70) 66 μm × 63 (53) 46 μm. Specimens measured – 6. Operculum detached - length: 61 (61) 61 μm, width: 56 (56) 56 μm. Specimens measured – 3.
Remarks: In his illustration of the type species, Protobatioladinium westburiensis, Nøhr-Hansen (1986, p. 37) showed it to have antapical bulges offset laterally with the left antapical better-developed and forming a distinct horn; this lateral offset appears to be the case with Protobatioladinium modestum. Schrank (2005, p. 72) described Protobatioladinium lindiense from the Tithonian of Tanzania and, like P. modestum, this is broadly ovoidal, covered in "minute granules or bacula" (Schrank, op. cit.) and possesses a short apical horn. It contrasts with P. modestum, however, in possessing a prominent antapical horn that is offset ventrally, not laterally. In P. modestum, as described for P. lindiense by Schrank (op. cit.), "The archeopyle may be…incompletely demarcated by sutures.
In dorso-ventral orientation it may appear apical. In lateral orientation, a few specimens show rudimentary sutures indicating inclusion of intercalary plates". Sometimes in P. modestum the operculum is completely lost (as in the paratype), resulting in a zig-zag archeopyle margin. Very rarely the intercalary plates may be lost separately, resulting in a cyst very similar to the genus Pareodinia (see pl. 3, fig. 7). Protobatioladinium modestum is significantly larger than the size quoted by Schrank for P. lindiense: Holotype 58 × 40 μm. Length range: 67 (59.6) 53μm.
Occurrences of Protobatioladinium modestum were restricted to the La Charce section, ranging between Beds LCH164M and LCH220M (late Valanginian, furcillata Zone to early Hauterivian, loryi Zone).