Neoselachians From the Upper Campanian and Lower Maastrichtian (Upper Cretaceous) of the Southern Pyrenees, Northern Spain

Abstract

Bulk sampling of upper Campanian to lowermiddle Maastrichtian coastal and lagoonal deposits in five sections of the Tremp Formation in the south-central Pyrenees yielded numerous neoselachian teeth. The fauna comprises nine taxa of which three species and one genus are new: Hemiscyllium sp., Lamniformes indet., Paratrygonorrhina amblysoda gen. et sp. nov., Coupatezia trempina sp. nov., Coupatezia sp., Coupatezia? sp., Rhombodus ibericus sp. nov. and Igdabatis indicus. The neoselachian fauna is dominated by small nectobenthic rays. This composition resembles assemblages known from the marine Upper Cretaceous, but differs from nearby localities of the Basque-Cantabrian region and continental selachian associations of the French Pyrenees. The results indicate that Rhombodus might not be a reliable biostratigraphic marker for the Maastrichtian. The faunal composition suggests a shallow trans-Tethyan connection between Eurasia and India at the end of the Cretaceous Period.

Selachian teeth from Campanian sediments (Upper Cretaceous) of the Münsterland Cretaceous Basin (NW-Germany)

“…The described taxa possess already very similar dentitions to their modern relatives (hence, a similar diet). Additionally, diverse squaliform faunas were obviously only found in northern areas in the Upper Cretaceous (Adnet et al 2008;Herman 1982;Müller 1989;Siverson 1993;; this paper), being very rare or almost absent in southern tethyal areas (Cappetta 1987;Kriwet et al 2007;Vullo 2005). This led to the assumption that the dominance of squaliform sharks in Bosenberg and Stromberg-Oelde/Hamelbach confirms Müller's (1989) proposal of a water depth of some hundred meters for the centraleastern part of the Campanian Münsterland Cretaceous Basin.…”

“…Discussion: Overall, there are apparently dozens of Rhinobatos species, named or unnamed, which are all relatively similar and conservative in morphology, and it is still very difficult to assign isolated teeth to one of these taxa (see Kriwet et al 2007:1057-1059 for an overview). It is nevertheless possible to distinguish many of them by the extension and course of the occlusal transverse ridge, by the degree of occlusal swelling, by the relationship of the root to the crown in size, position, and orientation, by the degree of separation between the median uvula and the laterointernal expansions, by the width of the separating trenches and the position of the laterointernal foramina, by the shape and basal extension of the median uvula, and by the degree of intensity and manner of the uvular ornamentation.…”

“…It is nevertheless possible to distinguish many of them by the extension and course of the occlusal transverse ridge, by the degree of occlusal swelling, by the relationship of the root to the crown in size, position, and orientation, by the degree of separation between the median uvula and the laterointernal expansions, by the width of the separating trenches and the position of the laterointernal foramina, by the shape and basal extension of the median uvula, and by the degree of intensity and manner of the uvular ornamentation. Considering all these features, most of the taxa listed by Kriwet et al (2007) clearly belong to the family Rhinobatidae, but without knowledge of ontogenetic, sexual, and intragnathic variability, there are always some slight differences, which impede secure assignment of teeth to a certain genus or species.…”

“…Since then, several studies have been conducted, and these have significantly increased knowledge of the taxonomy, evolution, palaeoecology, and palaeogeography of European Upper Cretaceous selachian faunas (e.g. Adnet et al 2008;Kriwet et al 2007;Kriwet et al 2009;Müller and Diedrich 1991;Siverson 1993;Thies and Müller 1993;Underwood and Ward 2008;Vullo 2005).…”

Um novo olhar sobre as raias-viola (Chondrichthyes,Batoidea) do Araripe, Cretáceo Inferior do Nordeste do Brasil

“…Nos parágrafos seguintes tenta--se conciliar as informações previamente disponíveis na literatura com as observações feitas nesse trabalho. Os dentes atribuídos a rinobatídeos são muito diminutos, aproximadamente 250µm de comprimento, com coroa baixa, plana e sem ornamentação, com a base dividida em dois lobos por um sulco e um certo grau de heterodontia é observado ao longo do arco mandibular (Everhart, 2007;Kriwet et al, 2007). No trabalho de Herman et al, (1997) foram analisadas a distribuição dos dentes nos arcos mandibulares, a anatomia e ultra estrutura dos dentes em amostras de treze espécies, Aptychotrema bougainvillei, Platyrhina Herman et al, (1997), exceto pelo agrupamento de Zanobatus e Zapretyx.…”