A partial thigh bone found in southern Brazil belongs to a previously unknown species of theropod dinosaur.
A partial left femur of Erythrovenator jacuiensis. Image credit: Müller et al., doi: 10.1016/j.jsames.2020.103026.
The new dinosaur was an agile predator that lived between 233 and 225 million years ago (the Carnian to the early Norian stage of the Triassic period).
Dubbed Erythrovenator jacuiensis, the ancient creature was about 2 m long (6.6 feet) and had a mass of 9 kg.
It belongs to Theropoda, a family of dinosaurs that includes Tyrannosaurus rex, Velociraptor and modern-day birds.
It represents one of the earliest known theropod dinosaurs, probably similar in age to Lepidus praecisio and Camposaurus arizonensis, shedding lights on some of the earliest theropod features.
Erythrovenator jacuiensis. Image credit: Marcio Castro.
“The early evolution of theropod dinosaurs is poorly understood,” said Dr. Rodrigo Müller, a paleontologist in the Centro de Apoio a Pesquisa Paleontologica da Quarta Colonia at the Universidade Federal de Santa Maria.
“Whereas sauropodomorphs are well-known from the oldest dinosaur bearing outcrops, the record of theropods is fragmentary and ambiguous.”
“The Triassic deposits from Brazil yielded some of the oldest dinosaurs worldwide.”
A partial left femur of Erythrovenator jacuiensis. Image credit: Müller et al., doi: 10.1016/j.jsames.2020.103026.
A portion of Erythrovenator jacuiensis’ left femur was discovered in 2017 at the Niemeyer site in municipality of Agudo in Rio Grande do Sul.
“Erythrovenator jacuiensis differs from all other known Triassic dinosaurs based on the absence of a raised dorsolateral trochanter of the femur (local autapomorphy),” Dr. Müller said.
“It represents the first carnivorous dinosaur from the assemblage dominated by the traversodontid cynodont Siriusgnathus, increasing our knowledge of the faunal content of this enigmatic assemblage.”
The discovery is described in a paper published online on November 27, 2020 in the Journal of South American Earth Sciences.
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Rodrigo T. Müller et al. A new theropod dinosaur from a peculiar Late Triassic assemblage of southern Brazil. Journal of South American Earth Sciences, published online November 27, 2020; doi: 10.1016/j.jsames.2020.103026
