The Leonian Stage (early Middle Cambrian): a unit for Cambrian correlation in the Mediterranean subprovince

Abstract

The Leonian (early Middle Cambrian) regional Stage of Iberia is revised from a lithostratigraphic and biostratigraphic point of view in order to propose it as a chronostratigraphic unit for the Mediterranean subprovince (outcrops in Spain, France, Italy, Germany, Morocco and Turkey). This revision now permits a correlation of the Leonian Stage with the other early Middle Cambrian regional Stages. For this correlation the first appearance datum (FAD) of Eoparadoxides mureroensis, Macannaia spp., Schistocephalus antiquus and Oryctocara granulata are employed for the lower boundary; while the FADs of Badulesia tenera, Ctenocephalus (Hartella) spp., Parasolenopleura aculeata and Triplagnostus gibbus are employed for the upper boundary. ‡ Author for correspondence: rodolfo.gozalo@uv.es

First report of Crumillospongia (Demospongea) from the Cambrian of Europe (Murero biota, Spain)

“…The discovery of Crumillospongia in Murero extends the palaeobiogeography of the genus to the Acadobaltic province (sensu Sdzuy 1972, Sdzuy et al 1999, located in the northwestern margin of Gondwana, yet in slightly higher latitude than the other occurrences. A similar palaeobiogeographical distribution has been observed for the middle Cambrian demosponge Leptomitus, also reported in Murero (García-Bellido Capdevila 2003, García-Bellido et al 2007).…”

“…This provinciality makes difficult to establish a common biochronological scale; thus, it has been used a different regional stage nomenclatures are commonly employed with the exception of some of them which has been already replaced by the International Subcommission on Cambrian Stratigraphy by official and global names in the last few years (see , Landing et al 2007, Peng et al 2009). The Spanish regional stages are named Corduban, Ovetian, Marianian and Bilbilian for the lower Cambrian, as well as Leonian, Caesaraugustan and Languedocian for the middle Cambrian; they are frequently used for the Mediterranean region (see Sdzuy et al 1999, Liñán et al 2002.…”

“…This FAD limits the Valdemiedes Extinction Event (VEE), which is concurrent with the disappearance of all but one genera of Protoleninae, Ellipsocephalinae, and Resseropinae trilobites in the Cadenas Ibéricas. Extinct trilobite taxa were replaced by new assemblages at the base of the Cambrian Series 3, including paradoxidids (Liñán et al 1993Sdzuy et al 1999;Dies et al 2004;Liñán et al 2010).…”

The Cambrian trilobites of Jordan – taxonomy, systematic and stratigraphic significance

“…(A.) mureroensis, which led to the report of the latter species as existing in Morocco (e.g., Sdzuy 1995;Sdzuy et al 1999;Liñán et al 2002). Hence, some of the identifications of the Spanish material appear to obscure the quite obvious correlation between Iberia and southern Morocco, which are reinforced by depositional patterns with distinct transgressive events (Álvaro et al 2003;Landing et al 2006).…”

Enrollamiento en <i>Conocoryphe heberti</i> Munier-Chalmas & Bergeron, 1889 (Cámbrico Medio, Cadena Ibérica, NE de España) y estructuras coaptativas en la familia Conocoryphidae

“…La familia Conocoryphidae es típica del Cámbrico medio con una amplia distribución en la Provincia Acadobáltica sensu Sdzuy (1972) y en Siberia (Korobov, 1973;Egorova et al, 1982) y de manera mucho más esporádica se han encontrado algunos conocorífidos en China y el Himalaya (Zhang & Jell, 1987;Jell & Hughes, 1997). Dentro de esta amplia distribución, quizás la mayor diversidad y mayor rango de distribución se da en la Subprovincia Mediterránea sensu Sdzuy et al (1999).…”