Prehistoric Wild: Life in the Mesozoic

Don't Leave the Wilderness (154 MYA)

Lourinha Formation, Portugal, 154 Million Years Ago

The late-morning sun rests in the blue sky above what is now Portugal. Its shining rays in addition to a lack of wind and rain create an intense, sweltering heat. This marks one of the harshest times of the Jurassic, the dry season.

Only a month in, the effects of this arid period can be seen in the thick forests. Bristles of the conifer trees have started to turn brown or fall off entirely. The parched drought has begun draining the green from the many ferns and cycads, leaving the same decayed bits of brown.

Many kinds of bugs litter this wooded land. The beige, dirt ground and bark of the trees are swarming with millipedes, cockroaches, crickets, termites, and aphids. In the air, flying insects including beetles, cicadas, dragonflies, damselflies and mosquitoes fill the wilderness with droning buzzing sounds.

Other bigger organisms reside here, clinging to survival in their way. Early arboreal mammals run across the tree branches to eat whatever greenery remains, adding their chirps and squeaks to the forest ambiance. Quieter residents in the form of ancient skinks scurry across the ground, gobbling any insect they can find. In terms of size, they are eclipsed by another form of life that calls these woods home: dinosaurs.

The smallest of these is a type of 10-foot-long herbivore named Draconyx. Their thick bodies are carried by two strong, slender legs and a long, thick tail. A pair of forelimbs are also present, much shorter and held closer to their bodies. It's only when the Draconyx reaches low to the ground during foraging that these front limbs ever touch the ground. A narrow-elongated neck supports their small heads which have beaks at the front of their mouths, hiding flat-topped cheek teeth. This arrangement in dentition greatly helps them in grinding up the low-lying vegetation, on which they feast. Large, keen eyes serve them well in scanning the environment around them. Their scaly skin is primarily sheen green with vertical, dark green streaks on their back and body as well as a white underbelly.

Accompanying them is a smaller herd of one of the most well-known dinosaurs of this time. Their footsteps thud into the ground imprinting large tracks into it. Snaps and rustles follow in their wake as they move to and from larger batches of foliage.

These are Stegosaurus, the namesake of the stegosaur family. At up to 30 feet long and 6 tons in weight, each of these females is among the largest members of their well-known group. Their heavily built bodies are supported by four legs, each ending in a different arrangement of toes. The front limbs are shorter and have five toes with short, stout claws while the hindlegs are much longer with larger, three-toed, hooved feet. Long, u-shaped necks hold up their proportionately small heads. Their beak-like mouths conceal an array of rounded, peg-like teeth. Combined with the strength of their jaws, this dentition greatly serves them in stripping plant matter.

Resting atop their backs are two rows of one of their most recognizable features, their bony plates. Each one has a hexagonal, leaf shape and is covered in a sheath of keratin. Primarily, they are colored in burnt umber with a bright, orange oval at the center. These plates start small on top of their necks before growing larger on their backs before shrinking back down along their high-held tails. These lengthy appendages terminate in their other iconic feature: their thagomizers. This is a name for the two pairs of keratinous sideways-held spikes at the end of their tails. They grow as long as baseball bats and are as heavy as a small sledgehammer. Their bumpy, pebbly skin is made up of a series of small, mossy green scales occasionally interrupted by black, irregularly shaped plates. Phthalo green, vertical streaks also decorate this skin in addition to a creamy, beige underbelly.

Each of these two herbivores adds very different noises to the symphony of the forest ambiance. Between the snaps and nibbles of their feeding, Draconyx makes various, pigeon-like coos and trills. The Stegosaurs produce deep rumbles, grunts, and hums amidst the sheering of the vegetation in their mouths.