New materials and an overview of Cretaceous vertebrates from the Chubut Group of the Golfo San Jorge Basin, central Patagonia, Argentina
Introduction
South-central Patagonia (Chubut Group; Golfo San Jorge Basin) preserves a rich and important vertebrate fossil record (Casal et al., 2016). Although this record is mostly represented by dinosaurs, other vertebrates have also been discovered with increasing frequency (Ibiricu et al., 2012a; Casal et al., 2016; Lamanna et al., 2019). Many of these discoveries were made by the Laboratory of Paleontology of the Universidad Nacional de la Patagonia San Juan Bosco (UNPSJB), who worked systematically in the area for more than 30 years.
The continental sediments of the Chubut Group are exposed over a vast area in the Golfo San Jorge Basin (central Patagonia; Fig. 1). Cretaceous continental strata carriers of fossil remains in the basin (in ascending order) include the Matasiete, Bajo Barreal, and Lago Colhué Huapi formations (see Casal et al., 2015, 2016, Fig. 2). Many fossil vertebrates have been recovered from these units, and have been described by some of the authors of this work (Table 1 and Table 2).
This contribution review the major vertebrate groups found in the Cretaceous Chubut Group of the Golfo San Jorge Basin, and describe new fossil vertebrate remains as well. This contribution is significant because it greatly enhances our understanding of the central Patagonia Cretaceous fossil vertebrate record through the description of new fossil specimens and revision of those already described.
Section snippets
Geologic context of south-central Patagonia, Chubut Group
The Golfo San Jorge Basin is an intraplate extensional basin on the South American plate (Fitzgerald et al., 1990), with its long axis running east-west. The Chubut Group (Lesta and Ferello, 1972) encompasses a significant section of the Cretaceous sedimentary sequence of the basin, originally divided into five formations: Pozo D-129, Matasiete, Castillo, Bajo Barreal and Laguna Palacios formations. The Pozo D-129 Formation is of lacustrine origin, whereas the Matasiete, Castillo, Bajo Barreal,
Localities
The south-central region of Chubut Province, Argentina, hosts excellent outcrops of the continental Cretaceous sedimentary sequences deposited in the Golfo San Jorge Basin (Fig. 1). As mentioned above, the fossiliferous units summarized herein are, in ascending age order, the Matasiete, Bajo Barreal and Lago Colhué Huapi formations (Fig. 2). These Cretaceous strata are extensively exposed in several localities across south-central Chubut Province, south-central Patagonia, Argentina. These
Institutional abbreviations
CPPLIP, Centro de Pesquisas Paleontológicas Llewellyn Ivor Price, Minas Gerais, Brazil; MACN, Museo Argentino de Ciencias Naturales “Bernardino Rivadavia”, Buenos Aires, Argentina; MDT, Museo “Desiderio Torres”, Sarmiento, Chubut, Argentina; MMCH, Museo Municipal “Ernesto Bachmann”, Villa El Chocón, Neuquén, Argentina; MLP, Museo de La Plata, La Plata, Argentina; MPM, Museo Padre Manuel Jesús Molina, Rio Gallegos, Santa Cruz, Argentina; UCPC, University of Chicago Paleontological Collection,
Vertebrates from the Matasiete Formation (Early Cretaceous, Hauterivian?–Aptian; Lesta and Ferello, 1972, but see Paredes et al., 2007)
Titanosauriformes (Salgado et al., 1997a)
Titanosauriformes indet. (This paper)
Material. Right scapula (UNPSJB-PV 408; Fig. 3)
Remarks. The Early Cretaceous vertebrate fossil record in Argentina in general, and in central Patagonia in particular, is scarce compared with the Mid- and Late Cretaceous record. Therefore, any new vertebrate remains derived from Lower Cretaceous strata are potentially important and informative. In light of this, herein we describe a fragmentary, and isolated right
Vertebrates from the Bajo Barreal Formation (Cenomanian–lower Turonian; see Casal et al., 2015)
Rebbachisauridae (Bonaparte, 1997)
Katepensaurus goicoecheai (Ibiricu et al., 2013a, 2015)
Holotype. UNPSJB-PV 1007
An associated partial skeleton including: a fragment of the right frontal, three anterior to middle cervical vertebrae, an incomplete anterior dorsal vertebra, an incomplete anterior to middle dorsal vertebra, three middle to posterior dorsal vertebrae, an incomplete anterior to middle dorsal neural arch, an indeterminate neural arch fragment and partial cervical ribs, five
Vertebrates from the Lago Colhué Huapi Formation (Coniacian–Maastrichtian; Casal et al., 2015)
Titanosauria (Bonaparte and Coria, 1993)
Aeolosaurus colhuehuapensis (Casal et al., 2007)
Holotype. UNPSJB-PV 959. Partial skeleton including 21 articulated caudal vertebrae from the anterior to the middle section and seven haemal arches.
Remarks. Aeolosaurine titanosaurs were widely distributed in South America during the Late Cretaceous, with a decent fossil record in both Brazil and Argentina (Salgado and Bonaparte, 2007). Aeolosaurines are characterized by anteriorly inclined anterior and
Discussion and concluding remarks
The vertebrate assemblage of the Chubut Group of south-central Patagonia is rich and abundant. Although it mostly comprises dinosaur remains, other vertebrates are also present and have enhanced our understanding of vertebrate distribution and evolution as a whole. The Early Cretaceous, specifically the Hauterivian?–Albian interval in south-central Patagonia, is represented by extensive and well-exposed outcrops of the Matasiete Formation. The fossil record of this formation is scarce when
CRediT authorship contribution statement
Lucio M. Ibiricu: Conceptualization, Methodology, Investigation, Formal analysis, Writing - original draft, Writing - review & editing. Gabriel A. Casal: Conceptualization, Methodology, Investigation, Formal analysis, Writing - original draft. Rubén D. Martínez: Formal analysis. Bruno N. Alvarez: Formal analysis. Stephen F. Poropat: Formal analysis, Writing - original draft.
Declaration of competing interest
The authors of this works do not have conflict of interest.
Acknowledgments
We are indebted to M. Luna (Head of fossil preparation and field extraction) for their assistance and excellent work for more than 20 years. We also thank M. Lamanna (Carnegie Museum) for the continued support and work with the team of UNPSJB for several years. To all the students, mainly from UNPSJB, who participated in several of the field seasons, especially we thank E. Ivany for its constant field collaboration. The owners of the ranches (flias: Martínez, Salgao, Cretton, Perujo, Insua,
References (216)
The sauropod diversity of the La Amarga formation (Barremian), Neuquén (Argentina)
Gondwana Res.
(2007)- et al.
A reanalysis of Murusraptor barrosaensis Coria & Currie (2016) affords new evidence about the phylogenetical relationships of Megaraptora
Cretac. Res.
(2019) - et al.
Palynology and alluvial facies from the mid-Cretaceous of Patagonia, subsurface of san Jorge Basin, Argentina
Cretac. Res.
(1994) - et al.
The southernmost record of tropical pollen grains in the mid-Cretaceous of Patagonia, Argentina
Cretac. Res.
(2006) - et al.
Ligabuesaurus leanzai gen. et sp. nov. (Dinosauria, Sauropoda), a new titanosaur from the Lohan Cura Formation (Aptian, Lower Cretaceous) of Neuquén, Patagonia, Argentina
Cretac. Res.
(2006) - et al.
Dientes de Theropoda (Dinosauria: Saurischia) de la Formación Bajo Barreal, Cretácico Superior, Provincia del Chubut, Argentina
Géobios
(2009) - et al.
Postcranial skeleton of Campinasuchus dinizi (Crocodyliformes, Baurusuchidae) from the Upper Cretaceous of Brazil, with comments on the ontogeny and ecomorphology of the species
Cretac. Res.
(2017) - et al.
New record of ornithopod dinosaur from the Plottier formation (upper Cretaceous), Patagonia, Argentina
Ann. Paleontol.
(2016) - et al.
First ornithopod remains from the Bajo de la Carpa formation (Santonian, upper Cretaceous), northern Patagonia, Argentina
Cretac. Res.
(2018) - et al.
A new ornithopod dinosaur from the Santonian of Northern Patagonia (Rincón de los Sauces, Argentina)
Cretac. Res.
(2019)
Cretaceous sauropod diversity and taxonomic succession in South America
J. South Am. Earth Sci.
New chelid turtles of the lower section of the Cerro Barcino formation (Aptian-Albian?), Patagonia, Argentina
Cretac. Res.
The axial skeleton of the titanosaur Lirainosaurus astibiae (Dinosauria: Sauropoda) from the latest Cretaceous of Spain
Cretac. Res.
An abelisauroid dinosaur from the Middle Jurassic of Laurasia and its implications on theropod palaeobiogeography and evolution
PGA (Proc. Geol. Assoc.)
A new brachyrostran with hypertrophied axial structures reveals an unexpected radiation of latest Cretaceous abelisaurids
Cretac. Res.
Osteology of Viavenator exxoni (Abelisauridae; Furileusauria) from the Bajo de la Carpa formation, NW Patagonia, Argentina
Cretac. Res.
Allometry and body length of abelisauroid theropods: Pycnonemosaurus nevesi is the new king
Cretac. Res.
The southernmost records of Rebbachisauridae (Sauropoda: Diplodocoidea), from early late Cretaceous deposits in central Patagonia
Cretac. Res.
Análogos de afloramientos del Cretácico Superior en las nacientes del río Chico: sedimentología, paleoambiente, características geométricas y heterogeneidades intra-reservorio
Jorn. Geol. Cuenc. Golfo San Jorge, Comodoro Rivadavia, Actas
Review of Cretaceous dipnoans from Argentina (Sarcopterygii: Dipnoi) with descriptions of new species
Rev. Museo Argent. Cienc. Nat.
Not just a pretty face: anatomical peculiarities in the postcranium of Rebbachisaurids (Sauropoda: Diplodocoidea)
Hist. Biol.
Über den Ursprung der Extremitäten der Ichthyopterygia
Jahresber. Mittelungen Oberheinischen Geol. Ver.
A new clade of archaic large-bodied predatory dinosaurs (Theropoda: Allosauroidea) that survived to the latest Mesozoic
Naturwissenschaften
Archosaur phylogeny and the relationships of the Crocodylia
A horned Cretaceous carnosaur from Patagonia
Natl. Geogr. Res.
The gondwanian theropod families Abelisauridae and Noasauridae
Hist. Biol.
Los vertebrados fósiles de la Formación Rio Colorado, de la Ciudad de Neuquen y Cercanias, Cretacico Superior, Argentina
Rev. Museo Argent. Cienc. Nat.
Cretaceous tetrapods of Argentina
Rayososaurus agrioensis Bonaparte 1995
Ameghiniana
Abelisaurus comahuensis, n.g., n.sp., Carnosauria del Cretacico Tardio de Patagonia
Ameghiniana
Un nuevo y gigantesco saurópodo titanosaurio de la Formación Rio Limay (Albiano-Cenomaniano) de la Provincia del Neuquén, Argentina
Ameghiniana
Carnotaurus sastrei Bonaparte, the horned, lightly built carnosaur from the Middle Cretaceous of Patagonia
Contrib. Sci. (Los Angel.)
The systematic relationships and biogeographic history of ornithischian dinosaurs
PeerJ
Phylogeny and palaeobiogeography of hadrosaurian dinosaurs
Nature
A new specimen of Velocisaurus unicus (Theropoda, Abelisauroidea) from the Paso Córdoba locality (Santonian), río Negro, Argentina
J. Vertebr. Paleontol.
Rebbachisaurus tessonei sp. nov. a new Sauropoda from the Albian–Cenomanian of Argentina: new evidence on the origin of the Diplodocidae
Gaia
Phylogenetic status of Megaraptor namunhuaiquii Novas based on a new specimen from Neuquén, Patagonia, Argentina
Ameghiniana
A new Abelisauridae (Dinosauria: Theropoda) from northwest Patagonia
Ameghiniana
New carnivorous dinosaur from the Late Cretaceous of NW Patagonia and the evolution of abelisaurid theropods
Naturwissenschaften
The continental Cenomanian of Patagonia: a comparison between the fossil vertebrate faunas of the río Limay Subgroup (Neuquén group) and the Bajo Barreal Formation (Chubut group) fossil vertebrate faunas
Ameghiniana
Record of the genus Aeolosaurus (Sauropoda, Titanosauria) in the late Cretaceous of south America: paleogeographic implications
Estud. Geol.
A new sauropod: Tastavinsaurus sanzi gen. et sp. nov. from the Early Cretaceous (Aptian) of Spain
J. Vertebr. Paleontol.
A new rebbachisaurid sauropod from the Aptian–Albian, lower Cretaceous Rayoso formation, Neuquén, Argentina
Acta Palaeontol. Pol.
The osteology of Chubutisaurus insignis del Corro, 1975 (Dinosauria: Neosauropoda) from the ‘middle’ Cretaceous of central Patagonia, Argentina
J. Vertebr. Paleontol.
A new basal rebbachisaurid (Sauropoda, Diplodocoidea) from the Early Cretaceous of the Neuquén Basin; evolution and biogeography of the group
Hist. Biol.
The appendicular skeleton of Majungasaurus crenatissimus (Theropoda: Abelisauridae) from the late Cretaceous of Madagascar
Soc. Vertebr. Paleontol. Mem.
The osteology of Masiakasaurus knopfleri, a small abelisauroid (Dinosauria: Theropoda) from the late Cretaceous of Madagascar
J. Vertebr. Paleontol.
Materiales asignables a Epachthosaurus Powell, 1990 (Sauropoda: Titanosauria), de la Formación Bajo Barreal, Cretácico Superior, Chubut, Argentina
Rev. Bras. Palaontol.
Aeolosaurus colhuehuapensis sp. nov. (Sauropoda, Titanosauria) de la Formación Bajo Barreal, Cretácico Superior de Argentina
Rev. Bras. Palaontol.
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