Bagualosaurus
A transitional sauropodomorph dinosaur from the Late Triassic of Brazil.
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Bagualosaurus is a genus of sauropodomorph dinosaur known from the Candelária Sequence, part of the uppermost Santa Maria Formation in Brazil. It lived around 230 million years ago, during the Carnian stage of the Late Triassic. The genus contains a single species, *Bagualosaurus agudoensis*.
The first specimen was discovered in 2007 in a ravine at the Janner outcrop, near Agudo in Rio Grande do Sul. The skeleton was removed in a single block of stone and remained unprepared for five years in the collection of the Laboratório de Paleovertebrados at the Universidade Federal do Rio Grande do Sul, under the care of Cesar Leandro Schultz. In 2012, Flávio Augusto Pretto began studying the fossil, and in 2018, Pretto, Max Cardoso Langer, and Schultz named and described the species. The genus name comes from *bagual*, a regional dialect term from Rio Grande do Sul meaning "strongly built fellow," referencing the animal’s robust hindlimbs. The species name refers to its origin near Agudo.
The holotype, UFRGS-PV-1099-T, was found in a layer of red mudstone from the latest Carnian. It includes a partial skeleton with a skull, comprising the lower parts of the skull, lower jaws, nine trunk vertebrae, three sacral vertebrae, two tail vertebrae, ribs, gastralia, chevrons, both ilia, the right pubis, both femora, both tibiae, both fibulae, and most of the left foot. The skeleton was partly articulated but damaged by erosion.
Bagualosaurus was a modest-sized basal sauropodomorph, about 2.25 meters (7.4 feet) long. Based on its teeth, it was mostly herbivorous. Its skull and dental features resemble those of *Pampadromaeus* (from the same rock layers) and later Norian sauropodomorphs such as *Pantydraco*, *Efraasia*, and *Plateosaurus*. However, its post-cranial skeleton is more similar to earlier forms. It is somewhat smaller than Norian sauropodomorphs but larger than other Carnian sauropodomorphs. This suggests it represents a transitional stage between the sauropodomorphs of its time and their later Norian descendants.
Quick Facts
- Genus
- Bagualosaurus
- Species
- agudoensis
Facts from the source article.
Lore & Background
In 2007, a sauropodomorph skeleton was excavated from a ravine at the outcrop of Janner, near Agudo in Rio Grande do Sul, Brazil. It was removed in a single block of stone and remained unprepared for five years in the collection of the Laboratório de Paleovertebrados da Universidade Federal do Rio Grande do Sul, curated by Cesar Leandro Schultz. In 2012, Flávio Augusto Pretto began to study the specimen, and in 2018, Pretto, Max Cardoso Langer, and Schultz named and described the type species Bagualosaurus agudoensis. The generic name is derived from bagual, 'strongly built fellow' in the dialect of Rio Grande do Sul, in reference to the strong hindlimbs; the specific name refers to the provenance from Agudo.
Reader's Guide
Bagualosaurus is significant as a transitional form in sauropodomorph evolution. It is somewhat smaller than Norian sauropodomorphs yet significantly larger (~45% based on femoral length) than other sauropodomorphs of the Carnian epoch, suggesting it bridges the gap between early Carnian forms and later Norian descendants. Its skull and dental structure resemble Pampadromaeus (from the same beds) and later Norian sauropodomorphs such as Pantydraco, Efraasia, and Plateosaurus, while its post-cranial skeleton resembles earlier forms. This mix of features helps paleontologists understand the evolutionary trajectory of sauropodomorphs during the Late Triassic. The holotype, found in a layer of red mudstone of the Candelária sequence, consists of a partial skeleton with skull, including lower parts of the skull, lower jaws, vertebrae, ribs, gastralia, chevrons, both ilia, the right pubis, both femora, both tibiae, both fibulae, and most of the left foot. The skeleton was partly articulated but damaged by erosion, and was found on its back with the hindlimbs pulled up, a rare position for archosaurian fossils.
Did You Know?
- Bagualosaurus was named in 2018 by Pretto, Langer, and Schultz.
- The holotype was found partly articulated but damaged by erosion, though its exact posture at discovery was not described in the original 2018 paper.
Gallery
Frequently Asked Questions
What is Bagualosaurus?
Bagualosaurus is a small sauropodomorph dinosaur from the Late Triassic of Brazil, represented by a single species, B. agudoensis. It is classified as a transitional form, sitting between more primitive basal sauropodomorphs and the later, larger sauropods.
How big was Bagualosaurus?
The animal reached roughly 2.25 metres (about 7.4 feet) in total length, making it a relatively small member of its group. Its modest size is consistent with its position as an early, transitional sauropodomorph rather than a fully grown sauropod.
Where and when was Bagualosaurus found?
The holotype specimen (UFRGS-PV-1099-T) was uncovered in 2007 from a ravine at the Janner outcrop near Agudo, Rio Grande do Sul, within the Candelária Sequence of the uppermost Santa Maria Formation. The skeleton was lifted as a single stone block and sat unprepared in the UFRGS paleovertebrate lab for about five years before study.
What did Bagualosaurus eat?
It was a predominantly herbivorous animal, feeding on low-growing vegetation available in its Late Triassic environment. Its dentition and jaw structure align with a browsing or grazing lifestyle typical of early sauropodomorphs.
Why is Bagualosaurus significant to dinosaur research?
As a transitional sauropodomorph from the Carnian (~230 Ma), it helps fill the gap between early, more generalized forms and the later, increasingly specialized sauropods. Its discovery in the Santa Maria Formation adds another data point to the evolving picture of how sauropod body plans developed in South America during the Late Triassic.
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