Early juvenile pterosaurs (Pterodactyloidea: Pterodaustro guinazui) from the Lower Cretaceous of central Argentina

We report on two juvenile specimens of Pterodaustro guinazui, a medium-sized, filter-feeding pterodactyloid pterosaur from the Lower Cretaceous (Albian) lacustrine deposits of the Lagarcito Formation of central Argentina (Sierra de Las Quijadas, San Luis Province). Both specimens lack the skull, but...

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Detalles Bibliográficos
Autores: Codorniú Dominguez, Laura Susana, Chiappe, Luis
Tipo de recurso: artículo
Estado:Versión publicada
Fecha de publicación:2004
País:Argentina
Institución:Consejo Nacional de Investigaciones Científicas y Técnicas
Repositorio:CONICET Digital (CONICET)
Idioma:inglés
OAI Identifier:oai:ri.conicet.gov.ar:11336/156307
Acceso en línea:http://hdl.handle.net/11336/156307
Access Level:acceso abierto
Palabra clave:PTERODAUSTRO GUINAZUI
PTERODACTYLOID PTEROSAUR
SIERRA DE LAS QUIJADAS
SAN LUIS
https://purl.org/becyt/ford/1.5
https://purl.org/becyt/ford/1
Descripción
Sumario:We report on two juvenile specimens of Pterodaustro guinazui, a medium-sized, filter-feeding pterodactyloid pterosaur from the Lower Cretaceous (Albian) lacustrine deposits of the Lagarcito Formation of central Argentina (Sierra de Las Quijadas, San Luis Province). Both specimens lack the skull, but one is otherwise nearly complete and articulated, and the other is more fragmentary. Their small size (~300 mm of wingspan), the lack of fusion of several postcranial bones, the minimal epiphyseal ossification, and the porous appearance of the periosteal surfaces indicate the specimens died at a very early stage of postnatal development. The presence of derived characters unique, within Pterodactyloidea, to P. guinazui (e.g., caudal vertebrae exceeding 16 elements) supports the proposed specific identification of the specimens. The new material provides anatomical information previously unknown for P. guinazui and sheds light on allometric transformations during the growth of this pterosaur. Comparisons with more mature and much larger individuals support two major allometric trends: (i) the negative allometric growth of the proximal portion of the forelimb, and (ii) the positive allometric growth of the metacarpal IV.