A mixed vertebrate eggshell assemblage from the Transylvanian Late Cretaceous

M. S. FERNÁNDEZ; CH. LAURENT; G. KAISER; M. VREMIR; G. DYKE

General Roca

Congreso; 11º CONGRESO DE LA ASOCIACIÓN PALEONTOLÓGICA ARGENTINA; 2016

Universidad Nacional de Río Negro y Asociación Paleontológica Argentina

A multi-taxon nesting site from Romania has been preserved in three dimensions. This Oarda (Od) rocks reveals the earliest known examples of nesting site sharing the same nesting area in the vertebrate fossil record. Eggshell and osteological evidence mixed in a single allochthonous accumulation, shows that at least three other vertebrate taxa were nesting at the same site as enantiornithine birds. The Oarda lens was collected in pieces from the basal fluvio-paludal part of the Oarda outcrop (Maastrichtian Sebeș Formation) and is housed in the Transylvanian Museum Society, Cluj-Napoca, Romania as EME V.314. Thin-sections and SEM investigation of EME V.314 augments our initial reports by revealing the presence of four distinct eggshell structural types: (1) theropod eggshells (prismatic morphotype), (2) Gekkota (geckoid basic type); (3) enantiornithid egg; and (4) Krokolithidae (crocodyloid basic type, crocodile). With these associations in mind, we discuss a fossil accumulation from the Late Cretaceous Oarda de Jos locality (Od) in the vicinity of Sebeș City, Transylvania (western Romania) that records at least four different eggshell morphotypes in a single, very restricted micro-horizon.