Cretaceous Roveacrinids from Mexico revisited: Overcoming the taxonomic misidentifications and subsequent biostratigraphic abuse

Abstract

The Mesozoic carbonate deposits of Mexico yield a number of overlooked, ill-known, and even enigmatic microfossils, among which are roveacrinoids (Echinodermata, Crinoidea, Roveacrinida). Most of these pelagic organisms probably came from the central Tethysian seaways, and later on from the early central Atlantic Ocean through the northwestern Tethysian neck, thus reaching the Central American platforms (Comanchean shelf, Central Texas platform, and Coahuila platform) and the Western Interior seaway. The present work intends to enlist as comprehensively as possible the Mexican records of roveacrinid crinoids, to propose a revised interpretation of the sections illustrated (most of them being originally erroneously assigned) and to provide a sound data base for further systematic and biostratigraphic research.

Roveacrinoidal assemblages (Crinoidea, Roveacrinida, Saccocomidae) from the Albian carbonate microfacies of Sierra Azul (Sabinas Basin, Coahuila, Mexico)

“…With the exception of the so-called Microcalamoides used for slanted ancillary dating [Microcalamoides Bonet, 1956, is the morphological variant thecal sections of Applinocrinus Peck, 1973, ranging from Aptian to Maastrichtian, thus invalidating any precise datation. For review see Ferré et al (1997Ferré et al ( , 2018], no saccocomid remain has ever been reported so far in Mexican Albian deposits and/or elsewhere in the Gulf.…”

“…With the exception of the so-called Microcalamoides used for slanted ancillary dating of Mexican Cretaceous strata [Microcalamoides Bonet, 1956, is the morphological variant thecal sections of Applinocrinus, ranging from Aptian to Maastrichtian, thus invalidating any precise datation (for review, see Ferré, 1997;Ferré et al 1997Ferré et al , 2018], no saccocomid remain has ever been reported so far in Mexican Albian deposits and/or elsewhere (only roveacrinids; for review, see: Rasmussen, 1961;Destombes, 1985;Dias-Brito, 1994Dias-Brito & Ferré, 1994, 2001Ferré & Granier, 2001). This relatively restricted occurrence zone of such saccocomid microfacies, very different from the standard Microcalamoides Zone, is consistent with one of the OAE1 hypoxic events.…”