The Bauru Group (Late Cretaceous) was a group of four geological formations, namely Adamantina, Uberaba, Araçatuba, and Marília, that harbored several dinosaurs in all the geological ages. It was divided by Fernandes and Coimbra (1996). The Maxakalisaurus is one such dinosaur known to have existed in the realm of the Bauru Group (Late Cretaceous) in the Adamantia Formation of São Paulo in Brazil. It was discovered, named, and studied by a huge team of Brazilian paleologists that included A. W. A. Kellner, D. A. Campos, S. A. K. Azevedo, M. N. F. Trotta, D. D. R. Henriques, Craik, Peerj and H. P. Silva.
The dinosaur remains of the Maxakalisaurus are among the many fossils that have been recovered from the site. The remains of Maxakalisaurus were discovered near the state of Minas Gerais (Brazil), but the skeleton is stored in the Museu Nacional, commonly known as the National Museum of Brazil. The Maxakalisaurus is popularly known to have taxonomical relationships with both the Sauropoda and the theropod Titanosauria clade. The Aeolosaurus, a Titanosaur belonging to Argentina, was a similar species that got its lower jaw and teeth referred to as Maxakalisaurus reflecting the Saurischia sauropod's taxonomical diversity. Some of the bones have marks of teeth, while some picked up on the incomplete right maxilla found in the partial skeleton during the early discovery. These marks suggested aggression or attacking activities of the species. This finding prompted the classification of the Maxakalisaurus under the carnivorous Tintanosauria order by Peer J, Henriques Marco A.G. França. The presumption was not difficult to land on, as sauropods in Upper Cretaceous South America lacked significant interference. Peerj, Marco A.G. França, langer, and Henriques further published a research paper titled 'New lower jaw and teeth referred to Maxakalisaurus topai (Titanosauria: Aeolosaurini) and their implications for the phylogeny of Titanosaurid sauropods' which described how the Maxakali dinosaur was related to the Titanosaur. Henceforth, it is believed to be a member of the Titanosauria clade while being labeled as the 'New Tintanosaur' quite frequently. Nonetheless, its classification as a Saurischia sauropod stands the final ground.
The Maxakalisaurus pronunciation is divided into five syllables and goes like 'max-aka-li-sore-us.'
The classification of the Maxakalisaurus was made under the Sauropodomorpha clade, belonging to the Dinosauria class. The Sauropodomorpha clade, commonly known as the sauropods, are herbivorous. Its classification has also been related to the Titanosaur clade due to the similarities in its underlying features.
The Maxakalisaurus topai inhabited the Earth during the Late Jurassic epoch, which was around 163.5- 145 million years ago from today and lasted until the end of the Cretaceous period.
The Maxakalisaurus topai became extinct in the Santonian of the Cretaceous period, which occurred around 145-66 million years ago.
The Maxakalisaurus topai mostly dominated the present-day South American site of Brazil. It was discovered in the Prata, a village in the state of Minas Gerais.
The Maxakalisaurus habitat consisted of tropical forests and the grassland of Brazil. Its bones were first found in the Adamantina Formation. They were suited to wetlands and swampy sites like lowlands with flowy streams nearby. They were probable to inhabit rocky sites as well.
The Saurischia dinosaur lived in a central location of Brazil. The site they inhabited was quite a favorable one for many other sauropods. Moreover, sauropods did not have any competition for their habitat with any other species in the Late Cretaceous of Brazil. Hence Maxakalisaurus lived with other sauropod species like the Saltasaurus and a few more unnamed species. One could say they were fairly social.
The average Maxakalisaurus lived anywhere between 30-50 years.
Like all the other dinosaurs, the beast from Adamantia formation was oviparous. The male and female dinosaur mated, and the female laid eggs thereafter. Not much is known about the reproduction process of the species itself, but like the other members of its genus, it would've laid around 15-40 eggs in the nesting site. The eggs were usually laid by digging the ground. Thus the eggs were half under the Earth until they hatched. The gestation period lasted between 65-82 days.
One of the most unique features of the Maxakalisaurus topai (Titanosauria aeolosaurini) was that it bore Osteoderms, which is the type of skin formed by the deposits of material made out of bones. Osteoderms were uncommon in sauropods while common in theropods. Initially, a partial skeleton containing the lower jaw and teeth, an incomplete right maxilla (with teeth), a few limb vertebrae, and cervical vertebrae were the only remains. The skull length was unspecified, however, the jaw was elongated instead of the skull, which is a common feature among the Sauropoda order. It had a long neck with bony plates on its skin and vertical plates along its spine.
The phylogenetic analysis from the beast from Minas Gerais, Brazil, reveals that it had a cervical skeleton, 12 neck vertebrae, and seven cervical ribs. These seven cervical ribs formed the spine. They also had six tail vertebrae, some hip bones, footbones, a thigh, both upper 'arm' bones, and a single armor plate. In addition, there were sternal plates in the throat of the partial skeleton first found in Brazil.
Like most of the dinosaurs, the new Titanosaur sauropod communicated with hoots, calls, and other verbal and non-verbal signals. Unlike many other animal species of the present day, they showed signs of inter-species communication.
The Maxakalisaurus size was one of the biggest among all the dinosaurs to exist. The Maxakalisaurus, with an estimated body length of 43 ft (13.1 m), was almost twice as big as the iconic T-Rex, which was as tall as 20 ft (6.1 m).
The new Titanosaur sauropod was a giant creature, and it was practically not possible for the lizard to move too fast. Being a dubious species with a great length, the dinosaur could not exceed a speed of 12.4 mph (20 kph).
The remains suggest that the Maxakalisaurus had an estimated weight of 19841.6 kg (9000 kg), making it just a few kilos heavier than the T-Rex, which was 15432.4 lb (7000 kg).
The male of the species is casually known as a buck while the female of the species is known as a cow. Otherwise, they were known by the same name.
The baby sauropod is known as a hatchling, just like its cousin reptiles. A cute way to address them is baby Maxakalisaurus or baby sauropod which is a more genus-specific name.
The Maxakalisaurus diet is centered around plants. Being sauropods, they were one of the herbivorous dinosaurs of the Late Cretaceous of Brazil and hence did not hunt.
The beast from the Adamantina formation was one of the biggest sauropods of the Late Cretaceous of Brazil. Despite their huge size, paleontologists suggest that they were of the least threat to any other species. They further suggest that it could actually be their huge size which was enough to intimidate any potential predators; hence they did not have to try being aggressive anyway. Moreover, most of the sauropods were known to be non-aggressive.
Multiple paleontologists like Campos, Azevedo, Trotta, Henriques, Craik, and Silva, agree on the fact that the Maxakalisaurus topai is one of the tallest dinosaurs ever to exist.
The new Titanosaur sauropod had fluted teeth which were highly unusual among the Sauropoda genus. However, it is a popular feature among carnivorous theropods. Moreover, newer explorations on the holotype focus on the presence of teeth marks on the bones suggesting scavenging activities of the dinosaur.
Only one specimen of this species has been found by the paleontologists, and the original specimen was that of a juvenile because the arms were of an unusual length. They were much shorter than expected; hence the conclusion was made.
In 2016, a new specimen containing a dentary, more precisely, the 'new lower jaw' along with some teeth, was found, while the upper jaw was predefined in the original holotype. This specimen was then described as a Maxakalisaurus by Peerj, frança, Langer and Henriques. Although the teeth were procured in the very first holotype, the new lower jaw (dentary) was a new feature on the records.
The Museu Nacional, more commonly known as the Brazil National Museum, which stores many legendary fossil remains and artifacts, including the skeleton of the Maxakali lizard, infamously got caught in a massive fire in the year 2020.
Apart from being related to the Titanosauria Aeolosaurini, the Maxakali lizard was apparently related to an unusual sauropod called the 'Saltasaurus' thus making it a very important genus to form references for other research activities.
The Maxakalisaurus and the Rinconsaurus together form a polytomy with the Aelosaurus clade; hence the relationship between the Titanosaur Saltasaurinae and the Aeolosaurus have given by Campos, S. A. K. Azevedo, M. N. F. Trotta, D. D. R. Henriques, M. M. T. Craik, and H. P. Silva.
The Maxakalisaurus topai derived its name from an indigenous group called 'Maxakali' which is native to the part of Brazil where the remains of the partial skeleton were first found, and the last name 'Topai' is derived from the idol the tribe used to worship. The Maxakali ethnic group is native to the Adamantia Formation, and the dinosaur was named in their honor.
The Maxakali lizard were terrestrial Sauropods who lived in the Adamantina Formation, which are the grasslands and low-lying areas with trees, freshwater, and rocks surrounding the terrain. They ranged from wetlands with one or multiple ponds of water and rocky terrains.
Here at Kidadl, we have carefully created lots of interesting family-friendly dinosaur facts for everyone to discover! Learn more about some other creatures from our Metriorhynchus interesting facts or Yinlong facts for kids.
You can even occupy yourself at home by coloring in one of our free printable Maxakalisaurus coloring pages.
Main image by Kabacchi.
Second image by João de Deus Vidal Jr.