New in Palaeontology

[Rob Taylor <rjtaylor68@comcast.net>]

ZHAO QI, PAUL M. BARRETT, DAVID A. EBERTH (2007)
SOCIAL BEHAVIOUR AND MASS MORTALITY IN THE BASAL CERATOPSIAN DINOSAUR 
PSITTACOSAURUS (EARLY CRETACEOUS, PEOPLE'S REPUBLIC OF CHINA)
Palaeontology 50 (5), 1023-1029.

Abstract: An exceptionally preserved herd of the ceratopsian dinosaur 
Psittacosaurus was recovered from the Lujiatun Beds of the Lower Cretaceous 
Yixian Formation, Liaoning Province, north-east China. This specimen 
provides the earliest direct evidence of post-nestling gregarious behaviour 
in this important dinosaur clade. The sediment in which the skeletons occur 
represents a lahar (volcanic mudflow), indicating that the six individuals 
present were entombed simultaneously during a catastrophic mass mortality 
event. Reconstruction of the herd age profile shows it was composed of 
offspring from at least two clutches, revealing that group fidelity in these 
dinosaurs extended beyond time spent together in the nest. This demonstrates 
that sociality appeared much earlier in ceratopsian evolution than is 
generally acknowledged and that such behaviour preceded the evolution of the 
elaborate horns and frills seen in derived ceratopsids.