Jurassic Meat-Eaters Thrived On Scavenging Giant Dinosaur Carcasses, Study Finds

Jurassic meat-eaters such as Tyrannosaurus rex and allosaurs often scavenged on giant dinosaur carcasses, suggests a new study.

Dead and rotting flesh may have been an “important food source” for the apex predators who were often scavengers rather than hunters as it spent less energy, say scientists.

The American research team said carnivorous dinosaurs lived in ecosystems “rich” with both living and dead prey.

They hypothesized that giant carcasses, such as those of sauropod dinosaurs, might have provided a major source of food for large carnivores.

To test the theory, the team created an agent-based model, a simplified virtual simulation of a dinosaur ecosystem.

Study co-author Professor Luis Ruedas, said: “This model was based on the ancient fauna of the Jurassic-aged Morrison Formation, which included large predators like Allosaurus alongside large sauropods, their carcasses, and an infinite supply of huntable stegosaurs.

“In the model, carnivores – intended to simulate allosaurs – were assigned traits that would improve their hunting or scavenging abilities while obtaining energy from meat sources – simulating living prey or sauropod carcasses.

“The model measured the evolutionary fitness of these simulated carnivores and found that, when large sources of sauropod carrion were available, scavenging was more profitable than hunting, suggesting that carnivores in such ecosystems might have evolved specialized traits to help them detect and exploit large carcasses.”

The research team, whose findings were published in the journal PLoS One, stressed that the model represents a “simplified abstract” of a complex system.

They believe that the results might be altered with the inclusion of more variables, such as more dinosaur species or features of the life history of the simulated dinosaurs.

However, they noted that models might improve understanding of how the availability of carrion can influence the evolution of predators.

Prof Ruedas, of Portland State University, said: “Our evolutionary model demonstrates that large theropods such as Allosaurus could have evolved to subsist on sauropod carrion as their primary resource.

“Even when huntable prey was available to them, selection pressure favored the scavengers, while the predators suffered from lower fitness.

“So we think allosaurs probably waited until a bunch of sauropods died in the dry season, feasted on their carcasses, stored the fat in their tails, then waited until the next season to repeat the process.”

He added: “This makes sense logically too, because a single sauropod carcass had enough calories to sustain 25 or so allosaurs for weeks or even months, and sauropods were often the most abundant dinosaurs in the environment.”

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