Antarctosaurus: The Enigmatic Dinosaur from the Late Cretaceous Period

Antarctosaurus: The Enigmatic Dinosaur from the Late Cretaceous Period

Imagine a time when the world was a vastly different place–a time when dinosaurs roamed the earth. Among these magnificent creatures was the Antarctosaurus, a dinosaur that has intrigued scientists and dinosaur enthusiasts alike. This dinosaur, whose name means “Antarctic lizard,” is a testament to the diversity and adaptability of life during the Late Cretaceous period.

Antarctosaurus Key Facts

Antarctosaurus pronunciationan-tark-toh-sawr-us
Meaning of nameAntarctic lizard
Type SpeciesAntarctosaurus wichmannianus
When it Lived89.3 to 70.6 MYA
PeriodLate Cretaceous
EpochLate/Upper Coniacian to Middle Campanian
Length60.0 ft
Height20.0 ft (at hips)
Weight67.0 tons
MobilityMoved on all four
First Discovery1912 by Ricardo Wichmann
Location of first findAnacleto Formation, Río Negro Province, Argentina
First Described by1929 by Friedrich von Huene
HolotypeMACN 6904
Also found inBrazil, India and Uruguay

Antarctosaurus Origins, Taxonomy and Timeline

An artistic rendering of two Antarctosaurus dinosaurs engaged in a dynamic interaction. The image depicts the large sauropods with long necks and tails, in a desert-like environment with a hazy sky. Their bodies show a mix of brown and reddish hues with some striping patterns along their backs.

The Antarctosaurus was first discovered in Argentina, far from the icy landscapes its name might suggest. The etymology of its name is a nod to the southern location of its discovery rather than any association with cold continents.

Belonging to the Sauropods group, the Antarctosaurus is part of the Titanosauridae family. This family is known for their large size and long necks–characteristics that the Antarctosaurus shares. The species of this dinosaur include the type species Antarctosaurus wichmannianus and several dubious species, including A. giganteus, A. jaxarticus, and A. brasiliensis. 

This herbivorous dinosaur lived during the Late Cretaceous period. This was a time when dinosaurs were the dominant terrestrial vertebrates and the diversity of species was incredibly high before the end of the Age of Dinosaurs.

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Discovery & Fossil Evidence

The Antarctosaurus comes with a name that evokes images of icy landscapes and frozen tundras. Its discovery has shed light on the diversity of dinosaur species that once roamed the Earth, and the fossils that have been unearthed have provided a wealth of information about this fascinating creature.

Photograph of two large femur bones of Antarctosaurus wichmannianus on display at the Museo de La Plata. The bones are mounted upright with metal supports in a museum setting, showcasing their impressive size and structure.
Beatrice Murch from Buenos Aires, Argentina, CC BY 2.0, via Wikimedia Commons

It was first discovered by renowned geologist Ricardo Wichmann in 1912. The initial discovery consisted of fragmentary remains–including vertebrae and limb bones–which were found in the Anacleto Formation, Río Negro of Argentina. These remains were enough to identify the Antarctosaurus as a new genus and species. In 1929, Friedrich von Huene named it Antarctosaurus wichmannianus, with the genus name meaning “southern lizard” in reference to the southern location of its discovery.

Since the initial discovery, additional fossils attributed to Antarctosaurus have been found in other parts of Argentina as well as in Brazil and Uruguay. These fossils have helped to fill in some of the gaps in our understanding of this dinosaur, although many aspects of its anatomy and lifestyle remain a mystery due to the fragmentary nature of the remains.

Antarctosaurus Size and Description

This genus of titanosaurian sauropod dinosaur,is known for its massive size and unique physical characteristics. Its fossils were discovered in the late Cretaceous rocks of Antarctica and provide a fascinating glimpse into the world of dinosaurs that once roamed the Earth.

Short description of Antarctosaurus

This was a large, long-necked, and long-tailed dinosaur with a small head relative to its body size. Its body was supported by sturdy, pillar-like legs, characteristic of many sauropods. The limbs were robust, with the front limbs being shorter than the hind limbs. This suggests that Antarctosaurus moved on all four legs. 

Size and Weight of Antarctosaurus

Size chart comparing a human figure to the dinosaur Antarctosaurus wichmannianus. The chart shows a silhouette of the dinosaur in green, with a height of approximately 10 meters. Highlighted bones within the silhouette indicate known fossil discoveries, and a question mark signifies missing or uncertain parts
Slate Weasel, Public domain, via Wikimedia Commons

The exact size and weight are difficult to determine due to the incomplete nature of the fossil record. However, based on the available fossil evidence, this was a large dinosaur. Some estimates suggest that Antarctosaurus could have reached lengths of up to 60 feet and stood about 20 feet tall at the hips. The weight is even more challenging to estimate but it likely weighed in the range of several tons, similar to other large sauropods. These estimates are subject to change as more complete fossils are discovered and analyzed.

The Dinosaur in Detail

One of the most striking features of the Antarctosaurus is its size. This dinosaur was a true giant, with some estimates suggesting that it could reach lengths of up to 60.0 feet. Its long neck and tail contributed significantly to its overall length, making it one of the largest dinosaurs of its time.

It was a sauropod, a group of dinosaurs known for their large size, long necks, and quadrupedal stance. As a sauropod, it had a robust body supported by four sturdy legs. Its hind legs were slightly longer than its front legs, a characteristic feature of this group of dinosaurs. This body plan meant it would have moved around on all four legs. The skin, like many other dinosaurs, was likely covered in scales.

The Antarctosaurus in its Natural Habitat and Environment

This herbivore lived during the Late Cretaceous period–a time when the Earth was warm and tropical. The environment it inhabited was likely lush and verdant, filled with a diverse array of plant life. As an herbivore, the Antarctosaurus would have relied on this vegetation for sustenance.

Like other sauropods, this was likely a slow-moving creature. Its large size would have made it difficult for it to move quickly or navigate dense forests. Instead, it likely inhabited open areas where it could easily access food and avoid predators.

Despite its size, the Antarctosaurus was not without predators. Large theropod dinosaurs, such as the Abelisaurus, may have posed a threat to the Antarctosaurus. However, its sheer size would have offered some protection by making it a challenging prey for even the largest of predators.

Interesting Points about Antarctosaurus

  1. This was among the last dinosaurs to exist before the mass extinction event that wiped out all non-avian dinosaurs.
  2. Despite its name, it was not discovered in Antarctica. The name was chosen to reflect the southern location of its discovery in Argentina.
  3. It is known from very fragmentary remains, which has made it difficult for scientists to determine its exact size and appearance as well as its taxonomy.
  4. This dinosaur is believed to have been a herbivore like its sauropod relatives. It would have fed on the abundant plant life of its time.
  5. It lived during the Late Cretaceous period, a time when dinosaurs were the dominant terrestrial vertebrates.

Contemporary Dinosaurs

In the late Cretaceous period, the lush, verdant landscapes of South America were home to a fascinating array of dinosaurs. Among them, the colossal Antarctosaurus reigned supreme. This behemoth, with its elongated neck and tail, was a sight to behold that dwarfed many of its contemporaries. Yet, it lived in harmony with them, each creature playing its part in the intricate dance of survival.

The Titanosaurus, another sauropod, was a frequent companion of the Antarctosaurus. Though slightly smaller, it was no less impressive. These two giants grazed side by side and would have been a testament to the sheer scale of life during this era. They likely competed for the same resources, their massive appetites requiring vast amounts of vegetation. Yet, the abundance of plant life in their habitat likely kept any rivalry at bay.

Among the smaller contemporaries, the Laplatasaurus and the Bonitasaura were both sauropods of a more modest size. They were roughly the same size, and while they could not compete with the Antarctosaurus or Titanosaurus in terms of stature, they were nimble and quick. They would have been careful to avoid the thunderous footsteps of their larger counterparts, always alert for any signs of danger.

The Rocasaurus was a stark contrast to these gentle giants. A smaller, predatory theropod, it may have seen the younger or weaker members of the sauropod herds as potential prey. The size and strength of the Antarctosaurus would have been a deterrent for the Rocasaurus. Yet, each creature, from the towering Antarctosaurus to the swift Rocasaurus, played a crucial role in this prehistoric ecosystem–a testament to the diversity and complexity of life millions of years ago.

List of All Dinosaurs

We have created a list of all dinosaurs we have covered here, sorted across the seven main groups of dinosaurs. We also include information about their type of diet, (omnivore, herbivore or carnivore) and the time they lived.

Frequently Asked Questions

What does the name mean?

The name translates to “Southern Lizard”. It reflects the place of its discovery in the southernmost part of South America.

What did the Antarctosaurus eat?

This was an herbivore and likely fed on the abundant plant life of its time.

How big was it?

This was a large dinosaur, with some estimates suggesting it could reach lengths of up to 60.0 feet.

When did this dinosaur live?

It lived during the Late Cretaceous period, one of the last dinosaurs to exist before the mass extinction event.

Where was it found?

The Antarctosaurus was discovered in Argentina, despite its name suggesting a connection to Antarctica.

What were the predators of this herbivore?

Large theropod dinosaurs, such as the Abelisaurus, may have posed a threat to the Antarctosaurus.


The information in this article is based on various sources, drawing on scientific research, fossil evidence, and expert analysis. The aim is to provide a comprehensive and accurate overview of the Antarctosaurus. However, please be aware that our understanding of dinosaurs and their world is constantly evolving as new discoveries are made.

This article was last fact-checked: Joey Arboleda, 07-24-2023

Featured Image Credit: marvellous_pastv2 on Instagram