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| O Paleontólogo Pedro Mocho, um dos autores do trabalho, durante a escavação de um dinossauro saurópode macronário, em 2009, na Praia de Santa Rita (Torres Vedras). |
Nos
inícios de Novembro apresentamos no 73rd Annual Meeting da Society
of Vertebrate Paleontology, que decorreu em Los Angeles, nova
informação sobre os macronarios basais do Jurássico Superior
Português. Com o título “Macronarian record from the Upper
Jurassic of Portugal”, esta comunicação teve como autores os
investigadores Pedro Mocho (Universidad Autónoma de Madrid/Sociedade
de História Natural), Rafael Royo-Torres (Fundación Conjunto
Paleontológico de Teruel-Dinópolis), Francisco Ortega (Grupo de
Biología Evolutiva, UNED) e Bruno Camilo Silva (Sociedade de
História Natural). Neste trabalho faz-se uma resenha sobre o estado
actual de conhecimento sobre estes saurópodes do Jurásico Superior
de Portugal, integrando a informação procedente dos taxónes
clássicos (Lourinhasaurus e
Lusotitan)
e alguns exemplares fragmentarios, assim como novo material
proveniente de Torres Vedras e Lourinhã (Portugal).
Aqui fica o resumo:
"New
macronarian remains from the Portuguese Upper Jurassic are discussed.
Some of those were found in Cambelas (Freixial Formation, Torres
Vedras), Baleal (Praia da Amoreira-Porto Novo Formation, Peniche) and
Peralta (Sobral Formation, Lourinhã) consisting of cranial (teeth)
and postcranial material that could be assigned to basal
macronarians. The study of several Portuguese classical remains also
increases our knowledge of this group during Upper Jurassic. The
reassessment of type specimens of Lourinhasaurus
alenquerensis (Sobral
Formation, Alenquer) and Lusotitan
atalaiensis (Sobral
Formation, Peralta) with the description of several unpublished and
still undescribed elements allows us to refer these two taxa to
Macronaria (also supported by cladistic analysis).
The presence of fully opisthocoelus condition up to the sacral vertebrae, horizontally projected diapophysis, and “plank”-like cranial dorsal ribs, which are common synapomorphies of basal macronarians, are used to relate these specimens with this group. At present, it is possible to identify one basal macronarian form close related to Camarasaurus. On the other hand, there are various specimens bearing several basal titanosauriform features, such as the camellate presacral bone, a lateral bulge on the femur, dorsal and caudal centra dorsoventrally compressed, cone-chisel-like teeth and a gracile humerus. Further analyses will discriminate if they represent one or two different
taxa.
The presence of fully opisthocoelus condition up to the sacral vertebrae, horizontally projected diapophysis, and “plank”-like cranial dorsal ribs, which are common synapomorphies of basal macronarians, are used to relate these specimens with this group. At present, it is possible to identify one basal macronarian form close related to Camarasaurus. On the other hand, there are various specimens bearing several basal titanosauriform features, such as the camellate presacral bone, a lateral bulge on the femur, dorsal and caudal centra dorsoventrally compressed, cone-chisel-like teeth and a gracile humerus. Further analyses will discriminate if they represent one or two different
taxa.
Recent
works suggested that the Upper Jurassic-Lower Cretaceous (upper
Oxfordian–lower Berriasian) sauropod faunas of Iberian Peninsula
are composed by exclusive taxa
(Lourinhasaurus, Lusotitan, Dinheirosaurus, Aragosaurus, Galveosaurus, Losillasaurus and Turiasaurus)
although some of them are related to sauropod groups represented in
Upper Jurassic strata of other continents such as brachiosaurids,
diplodocids and camarasaurids. This situation is opposite to what is
suggested by other groups of dinosaurs (such as stegosaurs or
theropods) with a proposed North American-European Upper Jurassic
distribution, putting forward a vicariance model to explain their
diversity in this territory."
Mais informação:
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| Cranio de Camarasaurus, um saurópode macronário do Jurássico Superior |
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