Per citar aquest document: http://ddd.uab.cat/record/85131
Totoralia, a new conical-shaped mollusk from the Middle Cambrian of western Argentina
Tortello, M.F. (Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina). División Paleozoología Invertebrados)
Sabattini, N.M. (Consejo Nacional de Investigaciones Científicas y Técnicas (Argentina). División Paleozoología Invertebrados)

Data: 2011
Resum: The new genus Totoralia from the Late Middle Cambrian of El Totoral (Mendoza Province, western Argentina) is described herein. It is a delicate, high, bilaterally symmetrical cone with a sub-central apex and five to seven prominent comarginal corrugations. In addition, its surface shows numerous fine comarginal lines, as well as thin, closely spaced radial lirae. Totoralia gen. nov. , in most respects, resembles the Cambrian helcionellids Scenella BILLINGS and Palaeacmaea HALL and Whitfield. Although Scenella has been considered as a chondrophorine cnidarian by some authors in the past, now the predominant view is that it is a mollusk. Likewise, several aspects of Totoralia gen. nov. morphology indicate closer affinities with mollusks. The specimens studied constitute elevated cones that are rather consistent in height, implying that they were not flexible structures like those of the chondrophorines. The presence of a short concave slope immediately in front of the apex can also be interpreted as a mollusk feature. In addition, the numerous comarginal lines of the cone are uniform in prominence and constant in spacing, and are only represented on the dorsal surface of the shell; thus, they are most similar to the incremental growth lines of shells of mollusks. The morphology of Totoralia gen. nov. is regarded as primitive in the Helcionelloida because the ancestor of the class is likely to have had a minute, untorted limpet-shaped shell. Although the new genus herein described seems to be endemic to Argentina, the Cambrian occurrences of related scenellid genera suggest affinities with Laurentia.
Drets: Aquest document està subjecte a una llicència d'ús Creative Commons. Es permet la reproducció total o parcial, la distribució, la comunicació pública de l’obra i la creació d’obres derivades, fins i tot amb finalitats comercials, sempre i quan aquestes es distribueixin sota la mateixa llicència que regula l’obra original i es reconegui l’autoria de l’obra original. Creative Commons
Llengua: Anglès.
Document: article ; recerca ; publishedVersion
Matèria: Mollusca ; Helcionelloida ; Totoralia ; Middle Cambrian ; Mendoza ; Argentina
Publicat a: Geologica acta, Vol. 9, Núm. 2 (Juny 2011) , p. 175-185, ISSN 1696-5728

Adreça alternativa: http://www.raco.cat/index.php/GeologicaActa/article/view/244267
DOI: 10.1344/105.000001692


12 p, 6.2 MB

El registre apareix a les col·leccions:
Articles > Articles publicats > Geologica acta
Articles > Articles de recerca

 Registre creat el 2011-12-19, darrera modificació el 2016-10-18



   Favorit i Compartir