Aratasaurus
Aratasaurus museunacionali is an extinct genus of basal coelurosaurian theropod dinosaur discovered in Brazil. Known from a partial right leg, it is the only tetrapod fossil found in the lower levels of the Romualdo Formation, dating to the Early Cretaceous period. The dinosaur's name commemorates its discovery during the preparation of fossils for the National Museum of Brazil, which was later damaged by a fire.
Key Facts
- ›Aratasaurus is a basal coelurosaurian theropod from the Early Cretaceous of Brazil.
- ›Its holotype, a partial right leg, was discovered in 2008 in the Romualdo Formation.
- ›It is the only tetrapod fossil known from the lower levels of the Romualdo Formation.
- ›The genus name Aratasaurus means 'fire lizard' in Tupi and Greek, referencing the National Museum of Brazil fire.
- ›The species name museunacionali honors the National Museum of Brazil.
- ›Osteohistological studies suggest the holotype individual was a juvenile, around four years old.
- Partial right leg discovered, including parts of the femur, tibia, metatarsals, phalanges, and unguals.
- Likely possessed some form of feather covering, characteristic of coelurosaurs.
- Juvenile individual estimated at 3.12 meters in length and 34.25 kilograms in weight.
- Pes morphology shows similarities to Jurassic theropods like Aorun and Tanycolagreus.
Zuolong, Aorun, Tanycolagreia
Brazil
About Aratasaurus
Aratasaurus museunacionali is an extinct genus of basal coelurosaurian theropod dinosaur that lived during the Early Cretaceous period. Its fossils were discovered in the Romualdo Formation of Brazil, specifically in the lower levels near Santana do Cariri in Ceará state. This makes Aratasaurus the sole tetrapod fossil currently known from these particular strata, providing unique insights into the region's prehistoric ecosystem.
Discovery and Naming
The holotype specimen of Aratasaurus, cataloged as MPSC R 2089, consists of a partial, articulated right leg. It was unearthed in 2008 from a plaster mine. While the fossil was partially prepared and studied, a significant portion of the original individual was unfortunately lost during mining operations. The specimen was later housed at the National Museum of Brazil, which suffered a major fire in 2018. Fortunately, the area containing the Aratasaurus holotype remained intact.
In 2020, paleontologists Sayão and colleagues formally described Aratasaurus museunacionali. The genus name, Aratasaurus, is a combination of Tupi words meaning 'born' and 'fire,' alongside the Greek word for 'lizard.' This nomenclature is a poignant tribute to the circumstances of its recovery and the fire that affected the National Museum. The specific name, museunacionali, directly honors the National Museum of Brazil, the country's oldest scientific institution.
Description and Classification
As a coelurosaurian theropod, Aratasaurus is presumed to have had some form of feather covering, although no direct evidence of integument was preserved with the holotype. Osteohistological analysis of the bones, particularly the tibia, suggests that the individual represented by the holotype was a juvenile or young adult, approximately four years old at the time of death. Based on this juvenile specimen, an estimated body length of 3.12 meters (10.2 ft) and a weight of around 34.25 kilograms (75.5 lb) have been proposed. However, it is important to note that this individual would likely have grown larger if it had reached full maturity.
Phylogenetic analyses have placed Aratasaurus as a sister taxon to Zuolong, forming a clade at the base of the coelurosaurian group. The preserved leg bones, especially the foot structure (pes), bear resemblances to other Jurassic theropods such as Aorun and Tanycolagreus. The Romualdo Formation, from which Aratasaurus originates, dates to the Aptian–Albian stages of the Early Cretaceous, approximately 115 million years ago. While other theropods are known from the upper layers of this formation, Aratasaurus is unique to its lower sections and is found alongside a diverse array of pterosaurs, crocodylomorphs, fish, and turtles.
Source: Wikipedia ↗
Frequently Asked Questions
What is Aratasaurus?
Aratasaurus is an extinct genus of theropod dinosaur belonging to the basal coelurosaurian group. It lived during the Early Cretaceous period in what is now Brazil.
Where was Aratasaurus discovered?
The holotype of Aratasaurus was discovered in Mina Pedra Branca, a plaster mine in Ceará state, northeastern Brazil. This location represents outcrops of the lower Romualdo Formation.
What does the name Aratasaurus mean?
The genus name Aratasaurus is derived from the Tupi words 'ara' (born) and 'atá' (fire), combined with the Greek 'sauros' (lizard). This name signifies 'the dinosaur born from the National Museum fire'.
What is special about the Aratasaurus discovery?
Aratasaurus is significant because it is the only tetrapod fossil known from the lower levels of the Romualdo Formation. Its specific name, museunacionali, also honors the National Museum of Brazil, which was damaged by a fire.
What was the estimated size of Aratasaurus?
Based on osteohistological studies of the juvenile holotype, Aratasaurus had an estimated body length of approximately 3.12 meters (10.2 feet) and a weight of around 34.25 kilograms (75.5 lb). It was likely capable of growing larger as an adult.
Related Dinosaur species
Dasosaurus
Dasosaurus is an extinct genus of sauropod dinosaur from the Early Cretaceous period, known from the Itapecuru Formation of Brazil. The single species, Dasosaurus tocantinensis, was a medium-to-large quadrupedal herbivore, estimated to be around 20 meters long and sharing morphological similarities with the titanosauriform Garumbatitan.
Buriolestes
Buriolestes is an early sauropodomorph dinosaur from the Late Triassic of Brazil. Despite its carnivorous-looking teeth and skull, it is classified as an early member of the herbivorous sauropodomorph lineage. Its discovery provides insights into the early evolution of dinosaurs and their dietary habits.
Adamantisaurus
Adamantisaurus was a genus of titanosaurian sauropod dinosaur that lived during the Late Cretaceous Period in South America. It is known from only six tail vertebrae, suggesting it was a large animal with a long neck and tail. Its exact evolutionary relationships are difficult to determine due to the limited fossil material.