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Tyrannotitan, new carcharodontosaurid from Argentina
From: Ben Creisler firstname.lastname@example.org
In case this new online paper has not been mentioned here:
Novas, F.E, S. de Valai, P. Vickers-Rich & T. Rich (2005).
A large Cretaceous theropod from Patagonia, Argentina, and
the evolution of carcharodontosaurids. Naturwissenschaften
online advance publication (Apr. 16, 2005)
Abstract: The Cretaceous Carcharodontosauridae is the
latest clade of carnosaurs, including the largest
predatory dinosaurs yet recorded. Albeit spectacular for
their size, the skeletal anatomy of these theropods
remains poorly-known, and their diversity was until
recently restricted to two Cenomanian species: the highly
derived Giganotosaurus carolinii, from southern South
America, and the incompletely known Carcharodontosaurus
saharicus, from northern Africa. Here we describe an older
and basal member of the group, Tyrannotitan chubutensis
gen. et sp. nov., from Aptian strata of Patagonia,
Argentina. The new taxon gives new insights into the
systematics and evolution of carcharodontosaurids and
offers a better understanding of the evolution of Southern
theropod faunas. We suggest that carcharodontosaurids
radiated in Gondwana sharing with spinosaurids the role of
top-predators until their extinction in Cenomanian?
Turonian times. During this interval, the diplodocoid
sauropods and giant titanosaurians went extinct (probably
as part of a global-scale crisis), and the smaller
abelisaurid theropods took dominance, reigning until the
end of the Cretaceous. Electronic Supplementary Material
Theropoda Marsh, 1881 ? Tetanurae Gauthier, 1986
? Allosauroidea Currie and Zhao, 1993
? Carcharodontosauridae Stromer 1934
? Tyrannotitan chubutensis gen. et sp. nov.
Latin words tyrannus (tyrant) and titan (giant), the
specific name from the Chubut province, Argentina.
MPEF-PV 1156 (Museo Paleontológico Egidio Feruglio,
Trelew): Partial dentaries, isolated teeth, dorsals 3?8
and 11?14, proximal caudal vertebra, isolated ribs and
haemal arches, incomplete left scapulocoracoid and right
humerus and ulna; pubes, ischia, and fragments of left
ilium; almost complete left femora, fibula and metatarsal
Locality and horizon
La Juanita farm, 28 km NE of Paso de Indios, Chubut
Province, Argentina (Fig. 1a). Possibly Cerro Castaño
Member, Cerro Barcino Formation, Aptian (Musacchio and
Chebli 1975; Codignotto et al. 1978; Rich et al. 2000).
dentary 68 cm long and 14 cm deep at its rostral
end....deep, squared off symphyseal region, with a ventral
process or chin, as in Giganotosaurus ....
Postaxial cervical vertebrae are strongly opisthocoelous.
Presacral vertebrae bear well developed pneumatic foramina
humerus and ulna ....indicate that forelimbs were short
and robust... Hindlimb bones are also massive, The femur
of MPEF-PV 1157 estimated length of 140 cm is slightly
shorter than that in Giganotosaurus (143 cm; Coria and
Salgado 1995). The transverse width of the femoral shaft
of Tyrannotitan is 16.5 cm.