A gentle rustle of gravel is the only sound made by a Sinocalliopteryx as it creeps toward its prey. Its mottled grey-brown feathery coat is perfectly suited to blend into the rocks it is slinking past. For the past 20 minutes it has been stalking, step by careful step, toward a cliff edge where a Tianyulong has been dozing in the shade of some dry bushes. This heterodontosaur is very small and uses its size to hide from predators and its speed to escape when needed. These also help it hunt small animals when it needs to supplement its mostly plant filled diet.
After a long day of hunting small lizards, the Tianyulongis exhausted but has a full belly. This combination has led it to hide in some bushes to nap off its recent meal, and it is less aware of its surroundings than it should be. Especially with a very stealthy Sinocalliopteryx moving within striking distance.
With a rustle of gravel and a heaving breath, the Sinocalliopteryx leaps forward and attempts to grasp its jaws around the Tianyulong’s neck. This last-second sound rouses the Tianyulong from its slumber and it dashes from the bush, trying to flee. The sudden movement is enough for the Sinocalliopteryx to miss its strike.
Pivoting on one foot, the Sinocalliopteryx chases the Tianyulong along the cliff, snapping at its heels. One of these bites is enough to trip up the Tianyulong, who tumbles and trips the pursuing Sinocalliopteryx. This tangle of dinosaur slides over the edge of the cliff, which is mercifully short at this point. The Sinocalliopteryx uses its feathered arms to grasp the scree slope and slow its decent down the 20-foot fall. The Tianyulong is not so lucky. With much shorter arms, it is not able to slow its fall and tumbles down the slope, hitting the ground hard at the bottom. With a sickening crunch, its leg bone cracks upon impact with a rock at the base of the slope. After reaching the bottom and shaking to clear its head, the Sinocalliopteryx sees the wounded Tianyulong and takes another leap to snap the neck of the dinosaur, this time biting down with deadly strength.