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new ref: Mazzetta et al, 2004
Gerardo V. Mazzetta, Per Christiansen , Richard A. Fariña. 2004. Giants and
Bizarres: Body Size of Some Southern South American Cretaceous Dinosaurs.
Historical Biology: A Journal of Paleobiology . Published Online O2 july, 2004.
Body masses of some South American dinosaurs are estimated. The sauropod
Argentinosaurus huinculensis reached 73 tonnes, and therefore, is the largest
of all land animals whose mass has been rigorously obtained. Another sauropod,
Antarctosaurus giganteus, was the second largest, at nearly 69 tonnes, while
Antarctosaurus wichmannianus reached 34 tonnes. A third sauropod, the
bizarre-looking Amargasaurus cazaui, was much smaller, with a body mass of only
2.5 tonnes. Among theropods, the body mass of the strangely looking, horned
Carnotaurus sastrei, was volumetrically estimated at 1.5 tonnes, while
allometric equations on limb measurements yielded overestimations. Moreover,
the holotype specimen of Giganotosaurus carolinii (MUCPv-CH-1) was about as
large as the average-sized Tyrannosaurus rex, and only marginally smaller than
"Sue", the largest specimen. However, a new dentary of Giganotosaurus
(MUCPv-95) is 8% longer than that of the holotype. Assuming geometric
hat individual must have had a body mass above 8 tonnes and hence must have
been the largest theropod ever found.
Also in this adress is the abstract of the Mirischia paper:
Darren Naish, David M. Martill, Eberhard Frey. 2004. Ecology, Systematics and
Biogeographical Relationships of Dinosaurs, Including a New Theropod, from the
Santana Formation (?Albian, Early Cretaceous) of Brazil. Historical Biology: A
Journal of Paleobiology . Published Online O2 july, 2004.
Although rare, dinosaurs are well preserved in calcareous nodules of the
Santana Formation (Early Cretaceous, ?Albian) of the Araripe Basin, in
northeastern Brazil. So far, including only a spinosauroid and three
coelurosaurs, the dinosaur fauna appears depauperate. High theropod diversity
in assemblages where other dinosaurs are rare or absent is not unique to the
Santana Formation. It is seen also in several other assemblages, including
Solnhofen and the Maevarano Formation of Madagascar. We consider several
factors, including the occurrence of intraguild predation, the possibility that
small theropods could subsist in marginal environments, and reliance on coastal
resources, that may have been responsible for this apparent ecological
imbalance. A new coelurosaur from the Santana Formation, here formally named
Mirischia asymmetrica, is shown to be distinct from Santanaraptor placidus
[Kellner, A.W.A. (1999) "Short note on a new dinosaur (Theropoda,
Coelurosauria) from the !
Santana Formation (Romualdo Member, Albian) northeastern Brazil", Boletim do
Museu Nacional, Nova Serie, Rio de Janeiro, Brasil 49, 1-8]. Other theropods
from the Santana Formation are briefly reviewed. Mirischia is a compsognathid,
more similar to the European Compsognathus than to the Asian Sinosauropteryx.