An Ultimate Guide to Oxalaia: The Wishful One

Leave a comment / / Updated on: 24th September 2023

NameOxalaiaDietCarnivorous, primarily piscivorous
Name MeaningThe African deity OxaláHeightNil
PronunciationOx-ah-lie-ahLength39-46 feet (12-14 meters)
EraMesozoicLate CretaceousWeight11,000-15,432 lbs (5-7 tonnes)
ClassificationDinosauria,‭ Theropoda, & SpinosauridaeLocationBrazil, South America

Oxalaia Pictures

Oxalaia is a huge Brazilian spinosaurid from the Late Cretaceous Period
Oxalaia is a huge Brazilian spinosaurid from the Late Cretaceous Period | Vitor Silva via GettyImages

The Oxalaia

Gage Beasley Prehistoric's Oxalaia Concept
Gage Beasley Prehistoric’s Oxalaia Concept

When talking about prehistoric Earth, one of the first thoughts that comes to the mind of many is dinosaurs, and rightfully so because these creatures are some of the most fascinating ever. 

Apart from their sheer size, these prehistoric creatures remain popular even millions of years after their extinction because of their diversity. 

In the minds of many, dinosaurs are all enormous and scary, but this notion is not entirely correct. 

While many dinosaurs were immense and menacing, others were not as gigantic or scary. 

Also, contrary to popular opinion, their size was not an indicator of their diet. 

In other words, not every enormous dinosaur was carnivorous, and not every diminutive dinosaur was herbivorous

Some dinosaurs were also not as humongous as others, but they also were not tiny. 

One such dinosaur is the Oxalaia, an average-sized dinosaur that thrived in the Cenomanian stage of the Late Cretaceous Period.

Oxalaia belongs to clade with theropod and crocodilian features
Oxalaia belongs to clade with theropod and crocodilian features | Clumsystiggy via Prehistoric Wiki

As unique as its name, the Oxalaia was a spinosaurid dinosaur that lived in what is now the Northeast Region of Brazil. 

Like many other species, this creature intrigues experts primarily because of its distinct features. 

The Oxalaia’s existence has come to light in recent years, fueling a newfound fascination with these other distinct creatures that inhabited our Earth around 100 million years ago. 

Despite its initial discovery in the late 20th century, this dinosaur was not described until around 12 years ago, in 2011, by Brazilian paleontologist Alexander Kellner and colleagues, who assigned the specimens to a new genus containing one species, Oxalaia quilombensis

Although the knowledge of this dinosaur is limited because of the limited fossil discoveries, this article covers all the vital information regarding the species. 

Keep reading to discover facts about its appearance, preferred habitat, social behavior, diet, etc.

Gage Beasley's Prehistoric Shirt Collection
Gage Beasley’s Prehistoric Shirt Collection
Gage Beasley's Prehistoric Plush Collection
Gage Beasley’s Prehistoric Plush Collection

Physical Characteristics

According to experts, the Oxalaia is the most enormous theropod dinosaur discovered in Brazil. 

Experts place this creature between 39 and 46 feet long, while the second largest theropod found in Brazil, the Pycnonemosaurus, is around 29 feet long.

Gage Beasley Prehistoric's Oxalaia Size Comparison Chart
Gage Beasley Prehistoric’s Oxalaia Size Comparison Chart

The Oxalaia weighed between 11,000 and 15,432 pounds, but some experts believe the creature weighed more. 

Apart from its size, one of the most striking features of this creature is its remarkable sail-like structure on its back. 

This structure appears to be from elongated neural spines along the creature’s back. 

These neural spines extended vertically above the dinosaur’s vertebral column, creating a prominent ridge that gave the sail its distinct appearance. 

With such distinct features come theories and debates among experts; the purpose of this “sail-like” feature is still debated. 

One of the leading hypotheses suggests that the sail played a crucial role in thermoregulation. 

Reconstructed replicas of the holotype vertebrae or "neural spines"
Reconstructed replicas of the holotype vertebrae or “neural spines” | Ryan Somma via Wikiwand CC BY 2.0

Because the Oxalaia lived in a warm, tropical climate, it might have used its sail to regulate body temperature. 

Another possibility is that the sail functioned as a display structure during mating. 

Like the colorful plumage of modern birds, the sail might have been a visually striking feature used by males to attract potential mates.

After examining the skeletal material from other related spinosaurids, experts estimate the Oxalaia’s skull to be just over four feet long. 

Its elongated, narrow snout was one of its most distinctive attributes. 

One of the notable aspects of its snout was the positioning of its nostrils. 

Unlike many other theropods, whose nostrils were located closer to the tip of the snout, Oxalaia’s nostrils were positioned higher up on the skull, closer to its eyes.

Holotype snout in multiple views
Holotype snout in multiple views | Marcos A. F. Sales et al. via Wikipedia CC BY 4.0

This feature may have allowed the dinosaur to submerge most of its snout underwater while still being able to breathe and smell the surroundings. 

The slender snout of Oxalaia was also lined with numerous sharp teeth, indicating its meat-eating nature.

Like other spinosaurids, this creature had a heterodont dentition adapted for capturing, gripping, and consuming its prey effectively. 

Through detailed examination, Oxalaia’s teeth can be distinguished from those of other theropods, including other spinosaurids. 

One of the most obvious differences, asides from the positioning, is the creature’s ability to continuously replace their teeth throughout their lives

The creature’s snout also featured foramina which were possibly nutrient canals for blood vessels and nerves.

One of the crucial aspects of any dinosaur’s anatomy is its limbs, which play a pivotal role in its locomotion and hunting capabilities. 

Side view of Oxalaia showcasing its limbs and curved claws
Side view of Oxalaia showcasing its limbs and curved claws | Edwin Sagurton via Apex Predators Wiki

The Oxalaia’s forelimbs were relatively long and robust, a characteristic shared by many theropods, including its close relatives in the Spinosauridae family. 

The forelimbs were composed of three main segments: the humerus, radius, and ulna. 

The humerus was the upper arm bone, connecting the forelimb to the body, while the radius and ulna were the bones of the lower arm. 

These bones provided a sturdy framework to support the large claws present on their fingers. 

One of the most striking features of Oxalaia’s forelimbs was the size and shape of its claws. 

The claws were formidable weapons, especially the massive, curved thumb claw. 

This claw was likely covered in a hard, keratinous sheath. 

While Oxalaia had well-developed limbs, it was primarily a bipedal dinosaur, moving on two legs. 

Reconstructed foot of Oxalaia. Like other theropods, this dinosaur mainly moved through its hind limbs.
Reconstructed foot of Oxalaia. Like other theropods, this dinosaur mainly moved through its hind limbs. | Ghedoghedo via Wikiwand CC BY-SA 4.0

Its hind limbs were longer and more robust than its forelimbs, providing the necessary support and strength for its massive body. 

Habitat and Distribution

As mentioned, this creature existed in the Cenomanian stage of the Late Cretaceous Period, sometime between 100.5 and 93.9 million years ago. 

It lived in northeastern Brazil, and its fossils were initially discovered on Cajual Island in the rocks of the Alcântara Formation, known for its abundance of isolated fossil specimens. 

The Alcântara Formation is part of the Itapecuru Group of the São Luís-Grajaú Basin, in northeastern Brazil. 

Shortly after the initial discovery, more fossils were unearthed from the Laje do Coringa

These subsequent excavations helped experts to piece together the anatomy and lifestyle of this enigmatic predator. 

During the Late Cretaceous, the world was very different from today. 

The areas where Oxalaia’s fossils were found were part of the vast Gondwana supercontinent and the region that now constitutes modern-day Brazil was much closer to the South Pole.

The distribution of Oxalaia is believed to have been relatively localized due to the fragmentary nature of its fossil record. 

However, it is important to note that ongoing paleontological research might have uncovered additional specimens or expanded the knowledge of Oxalaia’s distribution. 

Experts believe the creature likely inhabited a lush and tropical environment, which included extensive river systems and coastal plains. 

The area was rich in biodiversity, supporting a variety of terrestrial and aquatic life forms, including other dinosaurs, pterosaurs, and marine reptiles

Said experts also believe that the creature adopted a semi-aquatic lifestyle. 

Flesh model of S. aegyptiacus used for a 2022 buoyancy study
Flesh model of S. aegyptiacus used for a 2022 buoyancy study | Paul C Sereno et al. via Wikiwand CC BY 4.0

Similar to other spinosaurids, it is believed that Oxalaia spent a significant amount of time in or around water bodies, possibly wading or swimming to catch fish or small aquatic prey. 

The elongated snout, conical teeth, and robust forelimbs with sharp claws were well-suited for catching and handling slippery aquatic prey.

Behavior and Diet

The paleontological evidence suggests that large theropods like Oxalaia, due to their immense size and predatory nature, may have had limited opportunities for cooperative behavior. 

Solitary living would have ensured reduced competition for resources and minimized confrontations with other dominant carnivores. 

As a solitary predator, it is reasonable to assume that Oxalaia likely maintained territories to avoid competition with other large carnivores. 

Establishing and defending territories would have been essential for securing food resources and ensuring successful reproduction. 

Fossil evidence of dinosaur trackways has provided some clues about their territorial behavior, as certain track patterns suggest repetitive patrolling of an area, possibly to mark and defend their territory.

Restoration of Spinosaurus with contemporaneous carnivores
Restoration of Spinosaurus with contemporaneous carnivores | Belal S. Salem via Wikiwand CC BY 4.0

Although Oxalaia was likely a solitary hunter as an adult, juveniles may have exhibited different social behavior. 

Some theropod species are believed to have formed loose social groups or packs during their younger years, providing protection and support. 

These social structures might have aided in hunting and defending against predators, offering a survival advantage before reaching adulthood. 

Another form of social interaction that this creature likely exhibited is parental care. 

This would have included laying eggs, creating nests, and potentially guarding the hatchlings until they were independent enough to fend for themselves.

Based on the examination of fossil remains and its teeth, experts concluded that the Oxalaia was a carnivorous dinosaur. 

Tooth of Oxalaia from Morocco in various views
Tooth of Oxalaia from Morocco in various views | Nizar Ibrahim et al. via Wikiwand CC BY 4.0

The Oxalaia’s preferred diet comprised a variety of marine creatures found in the Cretaceous seas. 

Its primary prey consisted of fish, which were abundant and diverse during this period. 

Equipped with specialized teeth, the Oxalaia excelled at catching and consuming fish, making them its main source of sustenance. 

Additionally, it likely targeted ammonites, ancient cephalopods with spiral shells, which were also prevalent in the Cretaceous oceans. 

This creature also likely exhibited ambush tactics, lying in wait for unsuspecting prey. 

Restoration of Spinosaurus attacking a fish
Restoration of Spinosaurus attacking a fish | Nobu Tamura via Wikiwand CC BY-SA 4.0

Alternatively, it might have engaged in pursuit hunting, actively chasing down schools of fish or weakened marine creatures.

Life Cycle

Like many other dinosaurs, experts believe the Oxalaia was an egg-laying dinosaur. 

After birth, the newly-born creatures were significantly small and susceptible to predation. 

As the juvenile Oxalaia grew, they underwent a significant transformation. 

Fossil evidence suggests that these creatures had rapid growth rates, enabling them to reach impressive sizes in a relatively short period. 

During this phase, Oxalaia’s diet evolved to include larger prey items, helping them sustain their rapid growth. 

Their powerful jaws, equipped with sharp teeth, allowed them to tackle increasingly larger marine creatures.

Sculpture of Oxalaia securing a kill at Museum of Natural Science, Barcelona
Sculpture of Oxalaia securing a kill at Museum of Natural Science, Barcelona | Jordiferrer via Wikiwand CC BY-SA 4.0

Once Oxalaia reached sexual maturity, they became capable of reproduction, marking a pivotal point in their life cycle. 

At this adult stage, the creature also gained its full hunting capabilities. 

Adult Oxalaia predominantly hunted medium to large-sized marine animals, such as ichthyosaurs and other pliosaurs, establishing their dominance in the prehistoric food chain. 

Large-scale geological events like volcanic eruptions or asteroid impacts have been implicated in the mass extinction events that occurred in Earth’s history. 

While there is no direct evidence linking these events to the extinction of Oxalaia, they could have potentially played a role in altering the marine ecosystem and contributing to the decline of various marine reptile populations.

Evolution and History

Oxalaia quilombensis, commonly known as Oxalaia, was discovered and named in 1999 by a team of Brazilian paleontologists.

The generic name Oxalaia is derived from the African deity considered the father of the gods in the Yoruba religion

Statue of Obatala in Costa do Sauípe, Bahía which is what the name of this genus was derived from
Statue of Obatala in Costa do Sauípe, Bahía which is what the name of this genus was derived from | Isha via WIkipedia CC BY 3.0

The specific epithet quilombensis is a reference to Quilombo dos Palmares, a historical settlement of escaped slaves in Brazil, as a tribute to the region where the fossil was found. 

Oxalaia belongs to the theropod group, which includes bipedal, carnivorous dinosaurs such as Tyrannosaurus rex and Velociraptor

More specifically, it falls within the subgroup of spinosaurid theropods, characterized by their elongated snouts, crocodile-like jaws, and likely semi-aquatic lifestyles.

The Spinosauridae family also includes well-known dinosaurs such as Spinosaurus and Suchomimus

Size of various spinosaurids (Oxalaia in green, third from left) compared with a human
Size of various spinosaurids (Oxalaia in green, third from left) compared with a human | Alexander Vieira via Wikipedia CC BY-SA 4.0

The discovery of Oxalaia provided a better understanding of the diversity and distribution of spinosaurids during the Cretaceous period. 

The creature’s discovery contributed significantly to the understanding of dinosaur diversity and adaptation to various environments. 

Its presence also challenged traditional notions that large carnivorous dinosaurs were exclusively terrestrial. 

Oxalaia, along with other spinosaurids, demonstrated the existence of a group of dinosaurs that adapted to a semi-aquatic lifestyle, much like modern-day crocodiles.

Interactions with Other Species

As an apex predator, Oxalaia likely played a crucial role in controlling the population dynamics of its prey species. 

Fossil evidence suggests that its diet primarily consisted of fish, turtles, and other small marine reptiles, which were abundant in the ancient coastal waters. 

Oxalaia was an apex predator in its territory
Oxalaia was an apex predator in its territory | Fransaurus centurion via Prehistoria Fandom

Its sharp teeth and powerful jaws allowed it to effectively capture and consume these marine creatures.

Also, fossil evidence of tooth marks on the bones of some of these predators indicates that they engaged in intraspecific competition. 

This competition could have led to territorial disputes and even cannibalism among these giant creatures

However, the exact nature and extent of these interactions remain speculative and require further study.

Its semi-aquatic lifestyle allowed it to inhabit coastal regions and estuaries, sharing its habitat with various marine species. 

Oxalaia spent most of its time near bodies of water
Oxalaia spent most of its time near bodies of water | Oxalaia via Prehistoria Fandom

Fossil records from the same geological formations have revealed evidence of marine reptiles such as plesiosaurs and ichthyosaurs, as well as large fish like coelacanths and lungfish. 

While direct interactions between Oxalaia and these marine creatures are challenging to ascertain from the fossil record, it is likely that they interacted in some capacity. 

Its presence as an apex predator could have influenced the behavior and distribution of these marine species, and in turn, their presence would have provided additional food sources for the giant dinosaur.

Cultural Significance

Oxalaia was a large carnivorous dinosaur belonging to the group of theropods known as spinosaurids. 

This extraordinary creature lived approximately 95 million years ago, making it one of the most prominent predators of its time. 

Its discovery in Brazil in 2011 has been of immense significance to paleontologists, providing crucial insights into the diversity and ecological dynamics of the Late Cretaceous period. 

Map showing the Northeast Region of Brazil, with the discovery sites of three spinosaurine fossil specimens
Map showing the Northeast Region of Brazil, with the discovery sites of three spinosaurine fossil specimens | Marcos A. F. Sales et al. via Wikipedia CC BY 4.0

The presence of such a formidable predator in the fossil record has expanded our understanding of the ancient ecosystems in which it thrived and its role in maintaining ecological balance during the Mesozoic era.

The discovery of Oxalaia has not only sparked fascination but also provided an invaluable educational opportunity. 

The dinosaur’s cultural significance extends to its role in science education and public outreach programs.

Museums and educational institutions have used the knowledge gained from Oxalaia to engage visitors, especially young learners, in paleontology and the study of prehistoric life. 

Oxalaia’s cultural impact has not been limited to scientific and educational realms; it has also found its way into popular culture. 

This dinosaur has made appearances in video games, movies, and television series, cementing its place in the collective imagination of people around the world.

An Oxalaia as seen in ARK: Survival Evolved
An Oxalaia as seen in ARK: Survival Evolved | Scanova via Additional Creatures Wiki


Oxalaia, the spinosaurid dinosaur that roamed the Earth during the Late Cretaceous period, holds significant cultural and scientific importance. 

Despite being an average-sized dinosaur compared to some of its massive counterparts, Oxalaia’s unique features, such as its sail-like structure and elongated snout, have fascinated paleontologists and inspired artists and writers alike. 

Its discovery has enriched our understanding of prehistoric ecosystems and the adaptation of dinosaurs to their environments. 

Moreover, its semi-aquatic lifestyle challenges conventional perceptions of large carnivorous dinosaurs, highlighting the diversity of these ancient creatures. 

As it continues to captivate the minds of people through art, literature, and popular culture, Oxalaia stands as a remarkable reminder of the awe-inspiring and diverse world that existed millions of years ago.


How do researchers and institutions continue to study and preserve Oxalaia’s fossils for future generations?

Researchers and institutions take great care in studying and preserving Oxalaia’s fossils to ensure their longevity and accessibility for future generations. 

Fossils are meticulously cleaned, analyzed, and stored in controlled environments to prevent deterioration. 

How does Oxalaia compare to other spinosaurids in terms of its anatomy and adaptations?

Comparing Oxalaia with other spinosaurids helps researchers understand the diversity and evolution of this dinosaur group during the Cretaceous Period. 

However, each spinosaurid species also exhibits unique features and adaptations that allowed them to thrive in their specific environments. 


Leave a Reply

Scroll to Top