TWO NEW SPECIES OF ADELOMELON DALL, 1906 (GASTROPODA: VOLUTIDAE) FROM THE TERTIARY OF PATAGONIA (ARGENTINA)

Journal of Paleontology, Sep 2004 by Scarabino, Fabrizio, Martinez, Sergio, R�o, Claudia J Del, Oleinik, Anton E, Et al

Etymology.-For Prof. A. Pose, Director of the Museo Paleontologico de Bariloche (Argentina), who collected the holotype and kindly provided it for description.

Types.-Holotype, MPB 3095 (Fig. 3.2, 3.3, 3.5), an adult, recrystallized shell, SH-94.0 (preserved), MD-100.0, HLW-136.0; HA-113.0. Paratypes: MPB 3192 (Fig. 3.4), SH-131.0, MD-75.0 (preserved), MPB 3210, recrystallized shell SH-148.7, MD-90.7 (preserved).

Occurrence.-Known only from type locality: Puesto Arriola, Salinas del Gualicho, Rio Negro Province, Argentina, Gran Bajo del Gualicho Formation, ?Late Eocene-Middle Miocene.

Discussion.-For comparison with A. valdesiense, see Discussion for that species. Adelomelon posei differs from the Recent A. beckii (of comparable sizes) and A. barattinii in having a distinct biconical shell shape, more elongated and narrower spire, narrower last whorl, more numerous, prominent nodes located slightly above midwhorl line, longer, more arched columella, concave basal portion of the last whorl bordering fasciole, and narrower and curved anterior canal.

ACKNOWLEDGMENTS

We are grateful to A. Pose, Director of the Museo Paleontologico de Bariloche (Argentina), for the loan of part of the material described in the paper. Authors would also like to express their gratitude to M. G. Harasewych (National Museum of National History, Smithsonian Institution, Washington DC) for access to collections of Recent species. J. H. N. Leal (The BaileyMatthews Shell Museum, Sanibel), B. A. Marshall (Museum of New Zealand Te Papa Tongarewa, Wellington), and P. Bouchet (Museum National d'Histoire Naturelle, Paris) kindly made literature available to the authors. Authors express their special thanks to L. Saul of the Los Angeles County Museum of Natural History, A. Beu of the Institute of Geological and Nuclear Sciences, New Zealand, and L. Anderson of Louisiana State University for their great help in reviewing and correcting the original version of the manuscript.

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