Acrocanthosaurus

Acrocanthosaurus was one of the large predatory theropod dinosaurs of the Early Cretaceous in North America. It is considered one of the largest carnivores of its time and a possible apex predator in its ecosystem.

🦕 Basic Info

• Scientific name: Acrocanthosaurus atokensis
• Common name: Acrocanthosaurus
• Meaning of the name: “High-spined lizard” (from the Greek akros = high, akantha = spine, sauros = lizard)
• Period: Early Cretaceous (~115 to 105 million years ago)
• Location of discovery: United States (Oklahoma, Texas, Utah, and possibly Maryland)
• Classification:
  • Kingdom: Animalia
  • Phylum: Chordata
  • Class: Reptilia
  • Order: Saurischia
  • Family: Carcharodontosauridae
  • Genus: Acrocanthosaurus
• Diet: Carnivore

🧪 Main Characteristics

• Size: up to 38 feet long
• Estimated weight: between 5 and 6 tons
• Locomotion: bipedal, with powerful hind legs
• Skull: elongated and robust, with large openings to reduce weight
• Dentition: large, curved, and serrated teeth, suitable for tearing flesh
• Spinal column: tall neural spines from the neck to the tail, forming a raised dorsal structure
• Arms: relatively short but strong, with three fingers with large claws

🌍 Environment in which it lived

• It inhabited what is now the southern and central United States, in a warm region with plains, rivers, and coastal areas.
• The Early Cretaceous environment included swamps, floodplains, and coniferous forests.
• It shared its habitat with large sauropods (Sauroposeidon), ornithopods, and other smaller theropods.
• It was likely one of the dominant predators of its ecosystem.

🧬 Evolutionary Transition

• It is a basal member of the carcharodontosaurids, a group that includes giants like Giganotosaurus and Carcharodontosaurus.
• It shows an evolution towards larger bodies and more elongated skulls than classic allosaurids.
• Its morphology indicates a specialized adaptation for hunting very large prey, such as sauropods.

🦴 Fossils Found

• The first remains were found in Oklahoma in the 1940s.
• Several partial skeletons and an almost complete skull have been found.
• Most come from the Antlers Formation (Oklahoma and Texas) and the Twin Mountains Formation.
• Footprints possibly attributed to this dinosaur have also been identified, which allows for estimating its locomotor behavior.

👪 Relationship with other dinosaurs

• Dinosaurs: It hunted herbivores such as the giant sauropod Sauroposeidon, the iguanodontid Tenontosaurus, and the armored nodosaurid Sauropelta. It was a member of the Carcharodontosauridae, related to Giganotosaurus, Mapusaurus, and Carcharodontosaurus.
• Reptiles: It shared its habitat with crocodiles like Goniopholis and turtles like Glyptops.
• Amphibians: In aquatic environments, amphibians such as the giant salamander Albanerpeton were found.
• Fish: The river systems were populated by bony fish and freshwater sharks like Hybodus.
• Mammals: It lived alongside a great diversity of primitive mammals, such as the triconodont Astroconodon and the multituberculate Cedaromys.
• Birds: Birds have not been found in this formation, but the skies were dominated by pterosaurs (flying reptiles) like Cedrodraco.