To refer to this article use this url: http://dpc.uba.uva.nl/07/nr135/a06
Genus Duvalia Bayle, 1878
Duvalia hispanica sp. nov.
Holotype – RGM 361 608, from section B (bed B75; Fig. 4a) in the Tornajo Mountain (southeast Spain), late early Valanginian, base of the Biassalensis Zone.
Paratype – RGM 361 609, originates from the same bed as the holotype.
Diagnosis – Medium sized rostrum, strong laterally compressed, with a marked dorsal alveolar groove. The apex is pointed and the straight alveolar area is constricted with a shallow alveolus. Cross-sections are rounded, but show a tendency to become hexagonal towards the alveolar area.
Derivatio nominis – Named after Spain.
Description – Strongly compressed rostrum with relatively long dorsal groove, extending from the alveolar region into the apical region. The alveolar region is well constricted and the apical region is pointed. The dorsal side shows an almost straight outline while the ventral side is strongly curved, the apex being displaced to the dorsal side. A small, but clearly visible lateral expulsion occurs more or less in the median part of the lateral sides of the rostrum. As a result, cross-sections are not rounded, but show some faint lateral extensions, more or less along the whole rostrum. The alveolus is relatively shallow, especially when compared to the length of the alveolar groove. In dorsal or ventral view the rostrum appears to be fusiform. The holotype lacks part of the alveolar region. The paratype lacks part of the apical region due to weathering.
Remarks – The combination of the long dorsal groove, the strong alveolar restriction, the clearly dorsally shifted apex and the slender fusiform outline separates the new species from taxa in the Duvalia lata group.
Stratigraphical distribution – This species occurs in a single bed, with abundant species of the ammonite Busnardoites campylotoxus that indicates the base of the Biassalensis Zone.