Psittacosaurus juvenile herd behavior

[Ben Creisler <bcreisler@gmail.com>]

From: Ben Creisler
bcreisler@gmail.com


A new online open-access paper:


Qi Zhao, Michael J. Benton, Xing Xu, and Martin J. Sander (2013)
Juvenile-only clusters and behaviour of the Early Cretaceous dinosaur
Psittacosaurus.
Acta Palaeontologica Polonica (in press)
doi: http://dx.doi.org/10.4202/app.2012.0128
http://app.pan.pl/article/item/app20120128.html


It has hitherto been hard to prove that any association of juvenile
dinosaurs represents original behaviour rather than sedimentary
accumulation, and it has been hard also to determine the ages of such
juveniles. A previously described specimen, which consists of an
‘adult’ Psittacosaurus with 34 fully articulated juveniles, turns out
to be a composite: the ‘adult’ skull has been added, and in any case
it is below breeding age. Other juvenile-only clusters have been
reported, but the best examples that likely reflect behaviour rather
than sedimentary accumulation are specimens from the Early Cretaceous
Lujiatun beds in NE China, which were entombed beneath pyroclastic
flow deposits. A remarkable juvenile-only cluster of Psittacosaurus
shows clear evidence of different ages (five 2-year olds and one
3-year old) based on bone histological analysis. These juveniles may
have associated together as a close knit, mixed-age herd either for
protection, to enhance their foraging, or as putative helpers at the
parental nest.