Night is falling as a mother Tarchia and her young calf get ready to sleep. The ankylosaurs feel a little out of place, as they usually live in the deserts of Mongolia. They are not used to the lush forests of Cretaceous Grande Prairie. In their native Mongolia, the tyrannosaur Tarbosaurus is the greatest threat to Tarchia. The mother dinosaur is complacent, knowing that this huge predator is not a component of this new forested world.
Her sense of safety is unfounded, however. The closest relative of the Tarbosaurus in North America is T. rex; an animal that is well adapted to these lush forests. And, at this moment, there happens to be a T. rex watching the pair of ankylosaurs from the shelter of some nearby trees. It has been several days since the T. rex feasted on the fallen Anchiceratops, and she is hungry again. Because of their great size, T. rexes need a lot of food.
The T. rex knows from experience that ceratopsian parents can be very protective of their young, and she knows her sneak attack will have to be swift and deadly. Despite being a 13-m long, 8-ton animal, the T. rex is master of camouflage, and specializes in ambush predation. She creeps slowly closer to the pair of Tarchia, inch by inch, careful to not let even the tiniest twig snap under her great feet. Her eyesight is very keen, even in the muted moonlight.
She waits until she’s sure the two Tarchia are asleep before almost silently launching herself out of the woods. The T. rex has snapped up the baby in her massive jaws before the young animal had even awoken. The mother Tarchia, jolted awake, staggers to her feet. She sees the limp body of her baby hanging from predator’s mouth and lets out a loud, mournful bellow of anger and grief. Although the T. rex has already claimed her prize, she knows the bereaved mother could still be a dangerous foe.
The T. rex tries to make a hasty exit, but the dead Tarchia calf is heavier than she’d expected. Before she quite makes it back into the shelter of the forest, the mother Tarchia swings around and aims a devastating blow at the T. rex’s leg with her formidable tail club. The T. rex is too slow to dodge and the club smashes into her lower leg, shattering the bone. The pain is so intense that the T. rex almost drops her prey, but she just manages to hold on as he continues to stagger away. She has won her hard-earned meal, but it has come at a cost. She knows she will now need to eat and then rest, giving her grievous injury time to heal.