Prehistoric Wild: Life in the Mesozoic

Trail of Opportunities (160 MYA)

Shaximiao Formation, China, 160 Million Years Ago

The morning sun peers down on what is now southern China. In place of the land we would recognize lies a subtropical forest. The floor is shielded by a vast canopy of trees, dark green conifers, and ginkgoes of varying shades of bright green, yellow, and gold. The floor was covered in a blanket of ferns and cycads. Even the dirt and moss are hidden by the near-endless covering of vegetation. The chirps and tweets of early birds fill the air, even if unseen in the countless trees.

But other sounds are creeping in. It starts with low-pitched, rumbling bellows echoing through the woods. Thunderous crashes can be heard too, which make the ground shutter and quake. Each crash grows louder and louder. Snaps and crackles start to fill the air as well. They accelerate in frequency till suddenly, a tree falls and slams into the bed of ferns below.

In the wake of this arboreal destruction, something large emerges from behind the tree. A leg steps down next to it. It's dark green, thick, pillar-like, and covered in countless small scales. Three more slowly step through, each one exceeding 6 feet in height. A large body attached to these legs crops up from the trees. It too is covered in millions of small scales, similar to those of snakes but dry. It has a wide bulbous stomach that jerks back and forth slightly. The ground continues to vibrate with each of this animal's steps as it arrives in a small clearing. The sunlight reveals a colossal sauropod reaching over 70 feet in length. Nearly 40% of its body length lies in its thick, muscular neck which alone is 30 feet long. The longest neck of any animal to ever live. It starts straight from its shoulders before curving up high above the trees and straightening just before its' comparatively small head. It also has a tail that only reaches half the length of its neck. This is a Mamenchisaurus, the largest animal in the land. It is also traveling in a herd, with over 20 others following behind it.

But a forest as thick as this leaves little room for even one of these giants to walk through. However, they have a simple solution. Every time they come across a tree in their way, the Mamenchisaurs simply push their shoulders against them. The weight of their 80-ton bodies is more than any tree around them can hold. Thus allowing them to knock down any tree in their way, just simply by walking into them. This process has created a miles-long trail of fallen trees behind them. Much of the cycads and ferns that blanket the forest floor now lay crushed under the fallen trunks of wood. Some are further crushed by the steps of the passing Mamenchisaur herd, causing shards of bark to be mixed in with the mess.

The traveling Mamemchisaurs have created what looks like a prehistoric logging field. To many of us, it looks like a disaster. But to other smaller animals, it creates welcome opportunities. The first of these lies within the stumps which are so broken, that the yellowish-white wood inside is exposed in broken spike-like shapes. This exposes the residents of these trees, termites. They crawl around, chewing at the bark inside, creating small tunnels to crawl through. Now their homes are broken and fallen apart, prompting them to retreat inside of their stumps. Suddenly, small-winged animals swoop in and start eating the termites. These are Jeholopterus, a 90cm wingspan pterosaur in the Anurognathid family. They are unique in that rather than having a mouth that is either long or beaked, it is instead short and broad. This and their covering of gray, fuzz-like feathers make them look like a cross between a lizard and a bat. Unlike many other pterosaurs who mainly feed on fish, Jeholopterus are insectivores. So, to them, stumps full of exposed termites are an all-you-can-eat buffet. That is if they can catch any before retreating further into the stump. Many succeed at this, despite others becoming nutritious snacks for a Jeholopterus.

These fallen trees also benefit another type of animal. A herd of up to 15 Chungkingosaurus arrives in the clearing. These are yellowish-brown skinned relatives of Stegosaurus with a few key distinctions. They grow no more than 15 feet long and weigh a little over 3 tons at most, half the size of their most well-known relative. The plates lining their backs, divided in rows of two, are narrow and pointed like blades. Their tails are adorned with 3 pairs of spikes as opposed to two like most other stegosaurs. However, the most glaring difference is at their shoulders which each had a long pointed spike jutting out. But much like other stegosaurs, Chungkingosaurs are herbivores. Thus they take pleasure in eating the conifer and ginkgo leaves that now lie on the ground. As low browsers, they are more accustomed to eating the various ferns and cycads. But now the travels of the Mamenchisaurs have given them a chance to vary their diet. They even eat some of the loose bits of bark which will greatly benefit their digestion, despite being a struggle to chew through.

For the Jeholopterus and Chungkingosaurs, this field of fallen trees has proven to be a mini paradise. But for one animal, it proves to be another opportunity. It stands still in the woods, hidden by the shadow of the tree canopy above. It is a Yangchuanosaurus. This female is a two-legged, 28-foot-long carnivore with a tail making up half of her body length. She has dark-brown skin on top of her body with a beige underbelly. Her head is thin and just under 3 feet long with a mouth filled with dagger-like teeth. She has two bony ridges above her nose as well as horn-like protrusions in front of her eyes. Although her clawed arms were short, her legs were large and muscular, allowing her to reach 10 feet in height. Her belly is also wider, making space for eggs that are forming inside of her. However, if they are to develop enough for her to lay them, she'll need to find food. Or else, her body will need to abandon the unborn young.

Lucky for this Yangchuanosaurus, the fallen trees have allowed her a perfect chance. With how much tougher the leaves and bark are, the Chungkingosaurs chew much louder than they otherwise would. And thus they have become oblivious to what's around them, a perfect time for an ambush predator to strike. She will still need to approach with caution. With one wrong move, she can risk one of the Chungkingosaurs spotting her or worse getting injured by a spike.

The Yangchuanosaurus takes one soft step forward, creeping ever so slowly. No sound occurs and the Chungkingosaurs remain unaware. She creeps in another step and the herbivores continue eating. Her steps become more frequent as she creeps up next to one of the Chungkingosaurs. She soon stops, just out of range of her prey's spiked tail. It swings back and forth, almost grazing the nose of the predator. She sidesteps, setting her sight on the herbivore's throat.

Suddenly, a loud crunching snap occurs as the Yangchuanosaurus steps on a branch near the herbivore. The Chungkingosaurus quickly jerks its head to its right side and lets out a squealing honk. The predator quickly bites down on the herbivore's back leg. The Chungkingosaurus struggles to break its leg free from the Yangchanosaurus' tightening jaws. It honks and squeals before swinging its tail against the predator's side, causing her to release her grip. The Yangchuanosaurus gives chase as her prey runs and limps. The herbivore looks back as its attacker approaches ever closer. Suddenly, the Chungkingosaurus trips and tumbles over a log, falling on its side. It looks up finding the predator standing over it. The herbivore lets out more squealing honks as the Yangchuanosaur bites down on its neck. She tightens her jaws, crushing and penetrating her prey's windpipe. The Chungkingosaur's cries fade as its head falls lifelessly to the ground. She lets go of her prey's neck before stepping one foot on its side and biting into the stomach. Squishing and crunching sounds occur as she feeds on the meat of the carcass. She rips out one large meat chunk before rearing her head up and gobbling it down.

The predator feeds on more of the carcass before hearing some footsteps. She lifts her head out, her mouth stained red with blood. A deep crocodile-like bellow is heard as she sets sights on its source, another Yangchuanosaurus. This one is a male and thus larger in every way. He stands three feet taller than the female, is 35 feet long, and weighs over three and a half tons. Even his skull is over half a foot longer, with its bony ridges and protrusions colored in bright reds and blues. The male lets out one more bellow, causing the female to bellow as well while slowly taking a few steps back. As the larger Yangchuanosaurus creeps in, she quickly snatches one more chunk of meat from the carcass. The male bellows again as he steps on top of the female's prey. Quickly, she runs back allowing the larger one to bite into the corpse and start feasting. The female stops and looks back, letting out one more bellow before running off. Sometimes, a predator's kill won't always be theirs for long, even in a trail of opportunities.