Albertosaurus vs Kentrosaurus
Albertosaurus finds herself in a lush, humid rainforest of palms and conifers, in the eastern part of what will one day be the American state of Montana. She is used to cooler and drier conditions, but still feels more or less at home in these dense woods, and her sensitive nostrils (Witmer and Ridgely, 2009) detect the familiar smell of a fresh kill not far off to her left.
Although her belly is still full of Therizinosaurus, she moves unhurriedly in that direction, motivated by curiosity rather than by real hunger. Long experience has taught her that no creature on Earth can keep her from a tasty carcass she wishes to sample, and she anticipates a pleasant little snack.
Following her nose, she emerges into a small clearing, jaws already parted expectantly – and stops in her tracks, confused and intimidated. Splayed on the ground is a partly eaten Triceratops, similar enough to Anchiceratops from her own environment but considerably larger. Looming over the dead ceratopsian is a fully grown Tyrannosaurus, the only flesh-eating dinosaur much bigger and more powerful than herself that she has ever seen. Two smaller individuals, juveniles perhaps, are tearing at the carcass as well.
The Tyrannosaurus raises its head and gives a low, rumbling growl, the sort of sound Albertosaurus herself might make to warn some interloper away from her prey. Fighting such a monster would be suicidal, and Albertosaurus turns and dashes off through the trees.
She blunders onto a broad strip of flat, open sand and loose rocks, beside what appears to be a slow, winding river. Hearing no sounds of pursuit, she relaxes and takes a deep breath, unsure whether to retreat back into the forest or begin to explore the riverbed.
Kentrosaurus has also appeared in the Montana rainforest, and indeed is making her way along the bank of that same river, pausing now and then to bite at a plant that seems more or less edible. She is far from starvation and her injured forelimb is nearly healed, but she feels uncomfortable in this inland region full of strange trees. Her unease is compounded when she spots Albertosaurus a short distance in front of her, looking disoriented but clearly still dangerous. Kentrosaurus has recently learned that the larger theropod dinosaurs pose a formidable threat to her survival.
Determined to remove the threat, she attacks! Kentrosaurus charges along the riverbed, intent on killing. Albertosaurus realizes the danger and pivots towards Kentrosaurus, but a moment too late. Kentrosaurus is already turning, and swinging her spiked tail at the torso of Albertosaurus with lethal precision.
A clumsier foe would have been mortally wounded, but tyrannosaurs are agile (Snively and Russell, 2003), and Albertosaurus manages to skip aside. Nevertheless, the tail spikes of Kentrosaurus rip into her shoulder, instantly disabling her tiny left arm. Hurt and enraged, she bites at Kentrosaurus, managing to inflict a glancing wound on her flank. But Kentrosaurus turns nimbly and the two dinosaurs face each other, both hissing in fury.
Albertosaurus snaps at Kentrosaurus, but the plates and spines that sprout from the stegosaur’s body make her difficult to attack. Kentrosaurus whips around again, swinging her spiked tail, but this time Albertosaurus dodges out of the way entirely. Frustrated and hoping to surprise Albertosaurus, Kentrosaurus suddenly rears up on her hind legs, lashing out with her forelimbs. One of them catches Albertosaurus square in the snout, but the blow is hardly debilitating, and Kentrosaurus has committed a fatal error by exposing the front of her body. Albertosaurus lunges in, and her teeth close around the throat of the hapless Kentrosaurus. For a moment she struggles, but then she goes limp and subsides, collapsing helpless on the riverbank. Albertosaurus will be able to sample a dead dinosaur after all in this strange, steaming jungle.