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Ceratosaurus from Late Jurassic of Portugal



From: Ben Creisler
bcreisler@gmail.com

A new online paper:

Elisabete Malafaia, Francisco Ortega, Fernando Escaso & Bruno Silva (2014)
New evidence of Ceratosaurus (Dinosauria: Theropoda) from the Late
Jurassic of the Lusitanian Basin, Portugal.
Historical Biology (advance online publication)
DOI:10.1080/08912963.2014.915820
http://www.tandfonline.com/doi/full/10.1080/08912963.2014.915820#.U2p34fldXeI


A theropod assigned to Ceratosaurus was previously reported from the
Portuguese Lusitanian Basin based on a limited number of elements of a
single individual. Here, we describe newly discovered elements that
likely pertain to same, earlier described, specimen. The new elements
provide additional evidence that the range of Ceratosaurus spanned
from what is now North America into Europe. Previously, some
differences were noted between the Portuguese specimens and the North
American Ceratosaurus. We consider these differences to be trivial and
attribute them to individual variation and/or ontogeny. The following
set of features (lesser trochanter positioned low on the femur; crista
tibiofibularis obliquely oriented with respect to the axis of the
femoral shaft; infrapopliteal ridge present posteriorly on the femur;
large cnemial crest; and medial condyle of the tibia continuous with
proximal end) indicate that the Portuguese specimen is assignable to
Ceratosaurus. This record constitutes one of the scarce evidence of
basal ceratosaurian theropods in the Late Jurassic of Europe. Despite
the abundance, diversity and wide geographical distribution of
ceratosaurs during the Late Cretaceous, its early evolutionary history
remains poorly understood. The Portuguese specimens constitute an
important evidence for the knowledge of the paleobiogeographic
evolution of the clade during the Late Jurassic.