Late Aptian-Albian primitive Radiolitidae (bivalves, hippuritoidea) from Spain and SW France

Abstract

The late Aptian-Albian radiolitid taxa, Praeradiolites cantabricus (Douville) and Praeradiolites ibizanus Astre, from SW France and Spain, are transferred to Eoradiolites. Eoradiolites jumillensis novo sp. is described from southern Spain, while the so-called "Sphaerulites cantabricus" sensu Toucas (1907) is moved to Praeradiolites and may be of Late Cretaceous age. The Eoradiolites cantabricus group of species is mainly Clansayesian-early Albian in age and possesses an advanced evolutionary status, mainly regarding shell size and cellular structure. Praeradiolites may have been delived from Eoradiolites jumillensis novo sp. through paedomorphosis while Eoradiolites cantabricus may have been the source for Sphaerulites. Our study shows that the names Sphaerulites and Praeradiolites cannot be applied to pre-Cenomanian Radiolitidae and that Eoradiolites was the foremost genus in Late Aptian-Albian times in terms of species biodiversity. The Eoradiolites cantabricus group is restricted to the northwestern Mediterranean Tethyan margin.

Evolution and palaeogeographical dispersion of the radiolitid rudist genus Auroradiolites (Bivalvia, Hippuritida) with descriptions of new material from Tibet and archived specimens from Afghanistan

“…However, we note that in addition to the outwardly protruding radial bands of ‘ Praeradiolites ’ hedini Douvillé, which ally it most closely with Eoradiolites (Bobkova ; Masse et al . ) that species, erected based on the Karakorum specimens, also shares a number of other characters with our Tibetan specimens. These similarities include an elongate cylindro‐conical RV shape with flared growth rugae, spaced costate external ornamentation and, in particular, the lack of a distinct anteroventral carina, which is usually well developed in other species of Eoradiolites , and indeed also in Archaeoradiolites (Fenerci‐Masse et al .…”

First Record of a Primitive Radiolitid Rudist from Japan

“…Furthermore, the lack of information on the left valve and also the outer ornamentation of the shell of the Hokkaido material prevents further comparison with E. gilgitensis at present. Because the probable synonymy of several 'Praeradiolites' species from the Albian of Tibet with Eoradiolites has been mentioned (Masse et al, 2007;Scott et al, 2010), further work is necessary to reveal their taxonomic relationship with Southwest Asian Eoradiolites species. Thus the Hokkaido form is assigned to the E. gilgitensis group, which includes at least E. gilgitensis and E. griesbachi, and is tentatively called Eoradiolites cf.…”

“…Inwardly inclined growth laminae, as well as salient and flattened anterior and posterior bands in its right valve, are some of the diagnostic features of the genus Eoradiolites ( Figure 3B, C) (e.g. Douvillé, 1909Douvillé, , 1910Masse et al, 2007;Pons et al, 2010). The foliated outer shell habit of the Hokkaido Eoradiolites is also recognized in some other Eoradiolites species, such as E. jumillensis Masse et al, 2007 from Spain and certain E. gilgitensis specimens from the Teheran region, Iran (Figure 3A, B).…”

“…Recently, the evolutionary history of primitive radiolitid rudists in the late Aptian-Albian, especially the development of celluloprismatic structure, was addressed by the description of Archaeoradiolites Fenerci-Masse, Masse, Arias and Vilas, 2006, of early late Aptian age. The foremost genus in the late late Aptian-Albian was Eoradiolites Douvillé, 1909, and other genera, namely Sphaerulites Lamarck, 1819and Praeradiolites Douvillé, 1902, are only Late Cretaceous radiolitids (Fenerci-Masse et al, 2006;Masse et al, 2007).…”

Taxonomical and biostratigraphical significance of the North African radiolitid rudist bivalve Praeradiolites biskraensis (Coquand, 1880)

“…Gallo‐Maresca and Masse (1993) and Masse et al. (2007) summarized Douvillé’s (1909) observations on the radial structures of Eoradiolites and Praeradiolites , and Masse et al.…”