MACNBR   00242
MUSEO ARGENTINO DE CIENCIAS NATURALES "BERNARDINO RIVADAVIA"
Unidad Ejecutora - UE
artículos
Título:
New alvarezsaurid (Dinosauria, Theropoda) from uppermost Cretaceous of north-western Patagonia with associated eggs
Autor/es:
FEDERICO L. AGNOLIN; JAIME E. POWELL; FERNANDO E. NOVAS; MARTIN KUNDRÁT
Revista:
CRETACEOUS RESEARCH (PRINT)
Editorial:
ACADEMIC PRESS LTD-ELSEVIER SCIENCE LTD
Referencias:
Lugar: Amsterdam; Año: 2012 p. 1 - 24
ISSN:
0195-6671
Resumen:
The Alvarezsauridae represents a branch of peculiar basal coelurosaurs with an increasing representation
of their Cretaceous radiation distributed worldwide. Here we describe a new member of the group,
Bonapartenykus ultimus gen. et sp. nov. from CampanianeMaastrichtian strata of Northern Patagonia,
Argentina. Bonapartenykus is represented by a single, incomplete postcranial skeleton. The morphology
of the known skeletal elements suggests close affinities with the previously described taxon from
Patagonia, Patagonykus, and both conform to a new clade, here termed Patagonykinae nov. Two
incomplete eggs have been discovered in association with the skeletal remains of Bonapartenykus, and
several clusters of broken eggshells of the same identity were also found in a close proximity. These
belong to the new ooparataxon Arriagadoolithus patagoniensis of the new oofamily Arriagadoolithidae,
which provides first insights into unique shell microstructure and fungal contamination of eggs laid by
alvarezsaurid theropods. The detailed study of the eggs sheds new light on the phylogenetic position of
alvarezsaurids within the Theropoda, and the evolution of eggs among Coelurosauria. We suggest that
plesiomorphic alvarezsaurids survived in Patagonia until the latest Cretaceous, whereas these basal
forms became extinct elsewhere.