Meraxes (M. gigas `Giant Dragon´) is the only species of the extinct genus Meraxes, a carcharodontosaurid theropod dinosaur, which lived during the Cenomanian of the middle Cretaceous period, between 95 to 93 million years ago, in what is now South America.
Meraxes was a large theropod, estimated to be about 10 meters long and weighing about 4.5 tons. Its skull alone measured 1.27 meters long, exceeding that of Acrocanthosaurus, which had a skull length of 1.23 meters. The shapes and proportions of several of the bones (skull, scapula, metacarpals, ischial shaft, foot bones, etc.) indicate that Meraxes and Acrocanthosaurus had similar proportions and body size. In addition, it had greatly reduced forelimbs, an example of convergent evolution that occurred independently in four distinct lineages: Carcharodontosauridae, Abelisauridae, Tyrannosauridae, and Alvarezsauridae.
Osteohistological analyzes of the holotype suggest that this individual may have reached about 53 years of age at death, making it the longest-lived non-avian theropod known. It was also determined that Meraxes would have shown continuous growth throughout its life even after reaching maturity, and that its growth was slower than that of other theropods from different families, such as Tyrannosaurus, with which it was compared. Studies of the Meraxes holotype also suggest that carcardontosaurids reached maturity between 30 and 40 years of age.
Meraxes gigas coexisted with herbivorous sauropods (Rebaquisaurids Cathartesaura and Limaysaurus), titanosaurs (Argentinosaurus and Choconsaurus), and indeterminate iguanodontians.
The Model Pose represents a sleeping specimen of Meraxes gigas.
Approximate measurements of Meraxes gigas:
Scale 1:60 - 148 x 84 x 30 mm H
