Albertosaurus, a formidable large carnivorous dinosaur, roamed northwestern North America during the Late Cretaceous period, approximately 71 million years ago. This bipedal predator, named for the Canadian province of Alberta where many of its fossils were discovered, was a dominant figure in its ancient ecosystem. Understanding what Albertosaurus ate and how it hunted provides valuable insights into the food webs of the prehistoric world.
Dietary Preferences
Albertosaurus was an obligate carnivore. It primarily preyed upon the large herbivorous dinosaurs that shared its environment, which were abundant during the Late Cretaceous. Its diet likely included duck-billed dinosaurs, known as hadrosaurs, such as Edmontosaurus, and horned dinosaurs, or ceratopsians, like Pachyrhinosaurus. This predator likely targeted both young and adult individuals of these large plant-eaters. While live hunting was its main method of food acquisition, Albertosaurus was also an opportunistic feeder, likely scavenging on carcasses when the chance arose. This flexibility in its diet allowed it to thrive within its ecosystem.
Physical Adaptations for Predation
Albertosaurus possessed physical features that made it an effective hunter. Its massive skull, which could reach about 1 meter (3.3 feet) in length in adults, housed dozens of sharp teeth. Albertosaurus had heterodont dentition, with different tooth shapes serving various functions. Its 58 or more banana-shaped teeth were serrated, allowing for a “grip and rip” action to tear through flesh and bone. The powerful jaws and robust skull structure enabled a strong bite, estimated at around 3,413 Newtons, to subdue prey.
While its two-fingered forelimbs were relatively small, its strong, muscular hind limbs indicated significant speed and agility. Albertosaurus was capable of moving at speeds up to 30 kilometers per hour (19 miles per hour), with younger, more lightly built individuals being particularly swift. The dinosaur also relied on acute senses, including smell and binocular vision, to locate and pursue prey.
Hunting and Feeding Behavior
The hunting strategies of Albertosaurus are a subject of ongoing discussion among paleontologists. Evidence, particularly the discovery of a bonebed containing the remains of 26 Albertosaurus individuals of varying ages, suggests that they may have engaged in pack-hunting behavior. This finding implies a level of social cooperation rarely seen among large theropods.
One hypothesis proposes that faster, younger Albertosaurus individuals might have driven prey towards larger, more powerful, but slower adults. This cooperative approach could have allowed them to take down larger prey. However, some paleontologists suggest that such aggregations might have resulted from environmental factors, like droughts or floods, drawing many individuals to one location, rather than indicating complex social hunting. Regardless of social structure, Albertosaurus likely employed both ambush and pursuit tactics.
Unraveling Its Diet Through Evidence
Scientists deduce Albertosaurus’s diet through fossil evidence, as direct evidence like preserved stomach contents is rare. Tooth marks on fossilized bones of other dinosaurs, such as hadrosaurs and ceratopsians, indicate what Albertosaurus consumed and where it fed. The comparative anatomy of Albertosaurus’s teeth and jaws with those of modern meat-eating animals also offers insights. Studying wear patterns on its teeth confirms its diet consisted primarily of meat. Understanding its ecosystem, including present herbivorous dinosaurs, helps reconstruct its likely food sources.