21.9.16

Reevaluación de ejemplares asignados al cocodrilo Allodaposuchus precedens en las VII Jornadas de Salas de los Infantes


En otra de las comunicaciones presentadas en las VII Jornadas Internacionales sobre Paleontología de Dinosaurios y su Entorno de Salas de los Infantes (Burgos), se llevaba a cabo una reevaluación de diferentes ejemplares fragmentarios de crocodilomorfos que tradicionalmente se han relacionado con el eusuquio basal Allodaposuchus precedens. Este taxón se describió en 1928 a partir de material craneal y postcraneal procedente del Maastrichtiense inferior (Cretácico Superior) de Rumania. El estudio detallado de nuevas formas de eusuquios basales que han ido apareciendo en los últimos veinte años en localidades campano-maastrichtienses de la Península Ibérica, Sur de Francia y Rumania ha permitido recientemente la definición de un nuevo clado denominado Allodaposuchidae. Por tanto, la revisión de toda esta colección de restos fragmentarios era necesaria teniendo en cuenta el nuevo paradigma del grupo. A continuación dejamos un resumen de la comunicación:

During the last two decades, several specimens of eusuchian crocodyliformes have been described from the Campanian and Maastrichtian (Late Cretaceous) record of Europe. Most of them are included in the recently described clade Allodaposuchidae. This clade has been placed, in the last phylogenetic hypotheses, as sister group of Hylaeochampsidae and forming with these a basal group of Eusuchia, or as the sister group of Crocodylia. The type species of Allodaposuchidae is Allodaposuchus precedens, described from fragmentary cranial and postcranial remains found in lower Maastrichtian levels of Vălioara (Romania). The group also comprises the species described in Spain Arenysuchus gascabadiolorum, Lohuecosuchus megadontos, Agaresuchus subjuniperus, Agaresuchus fontisensis and Musturzabalsuchus buffetauti, and the species from southern France Lohuecosuchus mechinorum, in addition to the problematic forms “Allodaposuchus palustris” and “Allodaposuchus hulki”, from Spain, and “Massaliasuchus affuvelensis”, from France.
Several specimens from Spain, southern France and Romania were assigned to Allodaposuchus precedens by different authors. The remains from Velaux-La Bastide Neuve probably represent an ontogenetic series of an allodaposuchid. A thorough review of these remains is necessary in order to clarify their phylogenetic status according the new paradigm within the group, with the restriction of Allodaposuchus precedens to some Romanian specimens. The cranial material from Armuña was included in the re-evaluation of Allodaposuchus precedens, while the mandibular remains of this site were assigned to Musturzabalsuchus buffetauti. This material has recently been proposed as belonging to a single taxon, currently under study, but its placement within Allodaposuchidae is still unknown. Due to its fragmentary nature, the remains from Vilamitjana, Laño, Cruzy and Bellevue probably do not provide characters that allow a precise systematic assignment, but the synapomorphies of the clade Allodaposuchidae can be recognized in all of these specimens. Thus, the detailed study of the material presented here provides a reevaluation of the taxonomic assignment of each of these remains. 
The result of this study support the hypothesis proposing a vicariant distribution pattern between the forms distributed in western Europe and those from central-eastern Europe during the uppermost Cretaceous.

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