On the occurrence of the traversodontid Massetognathus ochagaviae (Synapsida, Cynodontia) in the early late Triassic Santacruzodon Assemblage Zone (Santa Maria Supersequence, southern Brazil): Taxonomic and biostratigraphic implications

2019 ◽  
Vol 93 ◽  
pp. 36-50 ◽  
Author(s):  
Maurício Rodrigo Schmitt ◽  
Agustín G. Martinelli ◽  
Tomaz Panceri Melo ◽  
Marina Bento Soares
Keyword(s):  
Late Triassic ◽  
Southern Brazil ◽  
Assemblage Zone ◽  
Santa Maria ◽  
Early Late

scholarly journals A new prozostrodontian cynodont (Therapsida) from the Late Triassic Riograndia Assemblage Zone (Santa Maria Supersequence) of Southern Brazil

2014 ◽  
Vol 86 (4) ◽  
pp. 1673-1691 ◽  
Author(s):  
MARINA B. SOARES ◽  
AGUSTÍN G. MARTINELLI ◽  
TÉO V. DE OLIVEIRA
Keyword(s):  
Rio Grande ◽  
Late Triassic ◽  
New Taxon ◽  
Single Specimen ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
Lower Jaw ◽  
Assemblage Zone ◽  
Santa Maria ◽  
Partial Crown

We report here on a new prozostrodontian cynodont, Botucaraitherium belarminoi gen. et sp. nov., from the Late Triassic Riograndia Assemblage Zone (AZ) of the Candelária Sequence (Santa Maria Supersequence), collected in the Botucaraí Hill Site, Candelária Municipality, state of Rio Grande do Sul, Brazil. The new taxon is based on a single specimen (holotype MMACR-PV-003-T) which includes the left lower jaw, without postdentary bones, bearing the root of the last incisor, canine and four postcanines plus one partial crown inside the dentary, not erupted, and two maxillary fragments, one with a broken canine and another with one postcanine. The features of the lower jaw and lower/upper postcanines resemble those of the prozostrodontians Prozostrodon brasiliensis from the older Hyperodapedon AZ and Brasilodon quadrangularis and Brasilitherium riograndensis from the same Riograndia AZ. The inclusion of Botucaraitherium within a broad phylogenetic analysis, positioned it as a more derived taxon than tritylodontids, being the sister-taxon of Brasilodon, Brasilitherium plus Mammaliaformes. Although the new taxon is based on few cranial elements, it represents a additional faunal component of the Triassic Riograndia AZ of southern Brazil, in which small-sized derived non-mammaliaform cynodonts, closely related to the origin of mammaliaforms, were ecologically well succeed and taxonomically diverse.

A new aetosaur genus (Archosauria: Pseudosuchia) from the early Late Triassic of southern Brazil

Zootaxa ◽  
2012 ◽  
Vol 3166 (1) ◽  
pp. 1 ◽  
Author(s):  
JULIA B. DESOJO ◽  
MARTÍN D. EZCURRA ◽  
EDIO E. KISCHLAT
Keyword(s):  
Cervical Vertebrae ◽  
Cladistic Analysis ◽  
Axial Skeleton ◽  
Late Triassic ◽  
South American ◽  
Southern Brazil ◽  
Caudal Vertebra ◽  
Caudal Vertebrae ◽  
Santa Maria ◽  
Early Late

We describe the new aetosaur Aetobarbakinoides brasiliensis gen. et sp. nov. from the early Late Triassic (late Carnian-early Norian) Brazilian Santa Maria Formation. The holotype is composed of a partial postcranium including several cer-vical and dorsal vertebrae and ribs, one anterior caudal vertebra, right scapula, right humerus, right tibia, partial right pes,and anterior and mid-dorsal paramedian osteoderms. Aetobarbakinoides is differentiated from other aetosaurs by the pres-ence of cervical vertebrae with widely laterally extended prezygapophyses, mid-cervical vertebrae with anterior articularfacet width more than 1.2 times wider than the posterior one, anterior caudal vertebrae with extremely anteroposteriorlyshort prezygapophyses, elongated humerus and tibia in relation to the axial skeleton, and paramedian osteoderms with aweakly raised anterior bar. A cladistic analysis recovered the new species as more derived than the South American generaAetosauroides (late Carnian-early Norian) and Neoaetosauroides (late Norian-Rhaetian), and it is nested as the sister-tax-on of an unnamed clade, composed of Typothoracisinae and Desmatosuchinae, due to the absence of a ventral keel in thecervical vertebrae. Aetobarbakinoides presents a skeletal anatomy previously unknown among South American aetosaurs,with the combination of presacral vertebrae with hyposphene, anteroposteriorly short and unkeeled cervical vertebrae,gracile limbs, and paramedian osteoderms with a weakly raised anterior bar. Aetobarbakinoides is among the oldest knownaetosaurs together with Aetosauroides from Argentina and Brazil and Stagonolepis robertsoni from Scotland, indicatinga widely distributed early record for the group. In addition, the recognition of a suite of derived features in Aetobarbaki-noides, which is one of the oldest known aetosaurs, is in agreement with an older origin for the group, as it is expected by the extensive ghost lineages at the base of the main pseudosuchian clades.

scholarly journals Anatomy of the dinosaur Pampadromaeus barberenai (Saurischia—Sauropodomorpha) from the Late Triassic Santa Maria Formation of southern Brazil

PLoS ONE ◽  
2019 ◽  
Vol 14 (2) ◽  
pp. e0212543 ◽  
Author(s):  
Max Cardoso Langer ◽  
Blair Wayne McPhee ◽  
Júlio César de Almeida Marsola ◽  
Lúcio Roberto-da-Silva ◽  
Sérgio Furtado Cabreira
Keyword(s):  
Late Triassic ◽  
Southern Brazil ◽  
Santa Maria

scholarly journals Northward dispersal of dinosaurs from Gondwana to Greenland at the mid-Norian (215–212 Ma, Late Triassic) dip in atmospheric pCO2

2021 ◽  
Vol 118 (8) ◽  
pp. e2020778118
Author(s):  
Dennis V. Kent ◽  
Lars B. Clemmensen
Keyword(s):  
Northern Hemisphere ◽  
Additional Data ◽  
Late Triassic ◽  
Southern Brazil ◽  
Northwestern Argentina ◽  
Terrestrial Vertebrates ◽  
Composite Section ◽  
Age Model ◽  
Main Barrier ◽  
Early Late

The earliest dinosaurs (theropods and sauropodomorphs) are found in fossiliferous early Late Triassic strata dated to about 230 million years ago (Ma), mainly in northwestern Argentina and southern Brazil in the Southern Hemisphere temperate belt of what was Gondwana in Pangea. Sauropodomorphs, which are not known for the entire Triassic in then tropical North America, eventually appear 15 million years later in the Northern Hemisphere temperate belt of Laurasia. The Pangea supercontinent was traversable in principle by terrestrial vertebrates, so the main barrier to be surmounted for dispersal between hemispheres was likely to be climatic; in particular, the intense aridity of tropical desert belts and unstable climate in the equatorial humid belt accompanying high atmospheric pCO2 that characterized the Late Triassic. We revisited the chronostratigraphy of the dinosaur-bearing Fleming Fjord Group of central East Greenland and, with additional data, produced a correlation of a detailed magnetostratigraphy from more than 325 m of composite section from two field areas to the age-calibrated astrochronostratigraphic polarity time scale. This age model places the earliest occurrence of sauropodomorphs (Plateosaurus) in their northernmost range to ∼214 Ma. The timing is within the 215 to 212 Ma (mid-Norian) window of a major, robust dip in atmospheric pCO2 of uncertain origin but which may have resulted in sufficiently lowered climate barriers that facilitated the initial major dispersal of the herbivorous sauropodomorphs to the temperate belt of the Northern Hemisphere. Indications are that carnivorous theropods may have had dispersals that were less subject to the same climate constraints.

scholarly journals New insights onPrestosuchus chiniquensisHuene, 1942 (Pseudosuchia, Loricata) based on new specimens from the “Tree Sanga” Outcrop, Chiniquá Region, Rio Grande do Sul, Brazil

PeerJ ◽  
2016 ◽  
Vol 4 ◽  
pp. e1622 ◽  
Author(s):  
Marcel B. Lacerda ◽  
Bianca M. Mastrantonio ◽  
Daniel C. Fortier ◽  
Cesar L. Schultz
Keyword(s):  
Middle Triassic ◽  
Rio Grande ◽  
Global Distribution ◽  
Taxonomic Resolution ◽  
Southern Brazil ◽  
Rio Grande Do Sul ◽  
New Material ◽  
Assemblage Zone ◽  
Santa Maria

The ‘rauisuchians’ are a group of Triassic pseudosuchian archosaurs that displayed a near global distribution. Their problematic taxonomic resolution comes from the fact that most taxa are represented only by a few and/or mostly incomplete specimens. In the last few decades, renewed interest in early archosaur evolution has helped to clarify some of these problems, but further studies on the taxonomic and paleobiological aspects are still needed. In the present work, we describe new material attributed to the ‘rauisuchian’ taxonPrestosuchus chiniquensis, of theDinodontosaurusAssemblage Zone, Middle Triassic (Ladinian) of the Santa Maria Supersequence of southern Brazil, based on a comparative osteologic analysis. Additionally, we present well supported evidence that these represent juvenile forms, due to differences in osteological features (i.e., a subnarial fenestra) that when compared to previously described specimens can be attributed to ontogeny and indicate variation within a single taxon of a problematic but important osteological structure in the study of ‘rauisuchians.’

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