Mapusaurus was a large predatory dinosaur that lived during the early Late Cretaceous period, approximately 93.9 to 89.6 million years ago, in what is now Argentina. It was a member of the carcharodontosaurid family of carnivorous dinosaurs, which also included species such as Giganotosaurus and Carcharodontosaurus.
Mapusaurus was a large predatory dinosaur that lived during the early Late Cretaceous period in Argentina. It was a theropod, a group of dinosaurs known for their sharp teeth and claws, and was closely related to other carcharodontosaurid dinosaurs such as Giganotosaurus.
Mapusaurus was a relatively large theropod, with estimates suggesting it may have reached a length of 11-11.5 meters (36-38 feet) and weighed between 3 and 5 metric tons (3.3-5.5 short tons). While it was smaller than its close relative Giganotosaurus, which is estimated to have reached lengths of up to 12.6 meters (41 feet), it was still a formidable predator. Some specimens of Mapusaurus may have been similar in size to the Giganotosaurus holotype, reaching up to 12.2-12.6 meters (40-41 feet) in length, but it is important to note that these dinosaurs may not have had the same proportions, so this should be regarded as a rough estimate.
Mapusaurus is a unique species of predatory dinosaur that is distinguished from other carcharodontosaurids, such as Giganotosaurus, by a number of autapomorphies, or unique characteristics. These characteristics are found in certain regions of the skeleton and are not present in Giganotosaurus or other closely related species.
One of the key differences between Mapusaurus and Giganotosaurus is the presence of a second opening on the middle quadrate bone, which is absent in Mapusaurus. The quadrate bone is located in the lower jaw and is involved in the movement of the jaw. The presence or absence of this opening can help to distinguish between different species of dinosaurs.
Another difference between Mapusaurus and Giganotosaurus is the topology, or shape, of the nasal rugosities, which are raised, bump-like structures on the nasal bones. Mapusaurus exhibits unique characteristics in the shape and arrangement of these rugosities, which helps to distinguish it from other carcharodontosaurids.
Discovery
Mapusaurus was first discovered in the Huincul Formation of Argentina in 1997 by the Argentinian-Canadian Dinosaur Project. The team, led by paleontologists Rodolfo Coria and Phil Currie, excavated the site over the next four years and eventually recovered a number of skeletal elements that represented most of the skeleton. In 2006, Coria and Currie described and named the new species, giving it the name Mapusaurus roseae, with the genus name derived from the Mapuche word "Mapu" meaning "of the land" or "of the earth" and the species name honoring both the rose-colored rocks in which the fossils were found and the sponsor of the expeditions, Rose Letwin.
The holotype for Mapusaurus roseae is an isolated right nasal bone, with twelve paratypes designated based on additional isolated skeletal elements. Overall, the discovery of Mapusaurus has greatly expanded our understanding of the diversity and evolution of predatory dinosaurs during the Late Cretaceous period and has helped to shed light on the paleoecology and paleobiology of this time period.
Paleobiology
The fossil remains of Mapusaurus were discovered in a bone bed containing at least seven individuals of various growth stages, which suggests that the species may have lived in social groups. The presence of individuals of different ages in the bone bed may indicate that Mapusaurus had a complex social structure, similar to that of some modern predators.
The discovery of this bone bed has provided paleontologists with valuable insights into the behavior of Mapusaurus and has sparked speculation about the possible causes of its formation. Some scientists have suggested that the bone bed may have resulted from a long-term, possibly coincidental accumulation of carcasses, perhaps in a predator trap. Others have proposed that the bone bed may have been the result of a mass mortality event, such as a drought or disease outbreak.
Mapusaurus is not the only dinosaur species known to have formed bone beds. Other examples include Velociraptor and other dromaeosaurids, Allosaurus, Albertosaurus, Daspletosaurus, and Tyrannosaurus. The study of these bone beds has provided paleontologists with valuable insights into the social behavior and ecology of these dinosaurs and has helped to shed light on their evolution and paleobiology.
Paleontologist Rodolfo Coria has suggested that the fossil remains of Mapusaurus discovered in a bone bed may indicate that the species hunted in groups and worked together to take down large prey, such as the massive sauropod Argentinosaurus. If this theory is correct, it would provide the first substantial evidence of gregarious behavior by large theropods other than Tyrannosaurus. However, it is not yet clear whether these dinosaurs hunted in organized packs, like wolves and lions, or simply attacked in a mob.
The bone bed in which the Mapusaurus fossils were discovered is located in the Huincul Formation of Argentina and is believed to have formed in a freshwater paleochannel deposit laid down by an ephemeral or seasonal stream in a region with an arid or semi-arid climate. The discovery of this bone bed is particularly interesting given the overall scarcity of fossilized bones within the Huincul Formation.
An ontogenetic study by Canale et al. (2014) found that Mapusaurus displayed heterochrony, an evolutionary condition in which an animal may retain an ancestral characteristic during one stage of its life, but lose it as it develops. In Mapusaurus, the maxillary fenestrae, which are openings in the upper jaw, are present in younger individuals but gradually disappear as they mature. This study provides valuable insights into the growth and development of Mapusaurus and helps to shed light on its evolution and paleobiology.
Classification
Cladistic analysis is a method used by paleontologists to understand the evolutionary relationships between different species of organisms. This type of analysis involves comparing the physical characteristics, or traits, of different species and using these similarities and differences to create a tree-like diagram, known as a cladogram, that shows how the species are related to one another.
Paleontologists Rodolfo Coria and Phil Currie used cladistic analysis to study the evolutionary relationships between Mapusaurus and other carcharodontosaurid dinosaurs. Their analysis showed that Mapusaurus is nested within the clade Carcharodontosauridae, which includes other large predatory dinosaurs such as Giganotosaurus and Carcharodontosaurus.
Based on their analysis, Coria and Currie proposed the creation of a new monophyletic taxon, or group of organisms that share a common ancestor, known as the subfamily Giganotosaurinae. This subfamily includes all carcharodontosaurids that are closer to Giganotosaurus and Mapusaurus than to Carcharodontosaurus. The authors also tentatively included the genus Tyrannotitan in this subfamily, pending the publication of more detailed descriptions of the known specimens of this species.
Overall, the cladistic analysis carried out by Coria and Currie has helped to shed light on the evolutionary relationships between different species of carcharodontosaurid dinosaurs and has contributed to our understanding of the evolution and diversity of these predatory dinosaurs.
The cladogram below, based on Novas et al. (2013), illustrates Mapusaurus' placement within the Carcharodontosauridae.
The Huincul Formation, where the fossil remains of Mapusaurus were discovered, was home to a diverse array of plants and animals during the early Late Cretaceous period. A study of the El Zampal section of the formation found evidence of a wide variety of plant life, including hornworts, liverworts, ferns, Selaginellales, possible Noeggerathiales, gymnosperms (including gnetophytes and conifers), and angiosperms (flowering plants), in addition to several pollen grains of unknown affinities.
The Huincul Formation is also home to a rich diversity of vertebrate life, including fish such as dipnoans and gar, chelid turtles, squamates, sphenodonts, neosuchian crocodilians, and a variety of dinosaurs. Vertebrates are most commonly found in the lower, and therefore older, part of the formation. Overall, the discovery of the diverse plant and animal life from the Huincul Formation has helped to shed light on the paleoecology and paleobiology of this region during the early Late Cretaceous period.
What is the top speed of a Mapusaurus?
Mapusaurus is an extinct genus of large theropod dinosaurs that lived in what is now South America during the Late Cretaceous period, approximately 98 to 97 million years ago. Since Mapusaurus is a prehistoric animal, it is not possible to determine its exact top speed. However, based on its size and physical characteristics, it is likely that Mapusaurus would have been a fast-moving animal that could run at high speeds. Some estimates put the top speed of Mapusaurus at around 40-45 miles per hour (64-72 km/h). However, this is just an educated guess and more research would be needed to determine its true top speed.