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Lourinhasaurus (Jurassic sauropod from Portugal) reassessed as camarasauromorph



From: Ben Creisler
bcreisler@gmail.com

A new online paper:


Pedro Mocho Rafael Royo-Torres & Francisco Ortega (2014)
Phylogenetic reassessment of Lourinhasaurus alenquerensis, a basal
Macronaria (Sauropoda) from the Upper Jurassic of Portugal.
Zoological Journal of the Linnean Society (advance online publication)
DOI: 10.1111/zoj.12113
http://onlinelibrary.wiley.com/doi/10.1111/zoj.12113/abstract



Lourinhasaurus alenquerensis is a Portuguese Upper Jurassic dinosaur
whose lectotype is one of the most complete sauropod specimens from
the Portuguese fossil record and from the Upper Jurassic of Europe. It
was recovered from sediments of the Sobral Formation (upper
Kimmeridgian to lower Tithonian) at Moinho do Carmo (Alenquer,
Portugal). The lectotype of Lourinhasaurus was first related to
Apatosaurus and then tentatively related to Camarasaurus. Finally, it
was established as a new taxon, Lourinhasaurus, including the Moinho
do Carmo specimen. At the time of writing, Lourinhasaurus had a poor
diagnosis and an unstable phylogenetic position. Revision of the
Moinho do Carmo specimen has led to a detailed description and a new
and more complete codification for several morphological characters.
The phylogenetic analyses proposed herein considered Lourinhasaurus as
a Camarasauromorpha Macronaria. This study also recovered a
Camarasauridae clade incorporating Lourinhasaurus, Camarasaurus and,
putatively, Tehuelchesaurus and that implies the presence of
Camarasauridae in the European Upper Jurassic. Besides the strong
similarity to Camarasaurus, Lourinhasaurus alenquerensis is here
considered a valid taxon with 13 putative autapomorphies such as a
sagittal keel on the dorsal margin of sacral neural spines, circular
and deep spinoprezygapophyseal fossa on proximal caudal vertebrae,
marked crest and groove bordering the lateral margin of the acetabulum
in the ischium, and a marked deflection of the entire femoral shaft
without lateral bulge. The apparently high number of taxa among the
sauropod fauna from the Iberian Peninsula during the Late Jurassic is
similar to the palaeobiodiversity recorded in formations of the same
age, i.e. Morrison and Tendaguru, and does not support the hypothesis
of a connection between the North America and Iberian Peninsula faunas
during the later part of the Late Jurassic reflected by other faunal
and floral groups.