It is hot, it’s always hot. The stifling air rises off the hot ground, colliding in rippling waves with the slightly less sweltering air above. The only escape from the relentless sun is a puffy rainless cloud that occasionally makes its way across the vastness. In 145 million years, this expanse will be known as the Morrison Formation of the Bighorn Basin.
In the south and west there are mountains and some volcanos, the latter causing the airborne ash clouds lying just below the rainless cloud. To the north is a shallow inland seaway extending into Canada. Far to the east, the Appalachian Mountains are tall and sharp as erosion begins to wear down the edges and spires. Farther south past great sand dunes lies another sea where the Gulf of Mexico will one day be.
The sun bakes the ground until cracks form. Thin tendrils of water move across the surface of this forbidding land and evaporate in an instant. Plants cling to lower flows of seasonal and subsurface water. Cycads, conifers, gingko trees, horsetails, and ferns are the plants of the Morrison.
Also clinging to the water’s edge are frogs and salamanders like Enneabratrachus and Iridotriton and turtles Dinochelys and Uluops. Goniopholis, the ancient crocodilians, wait to explosively ambush whatever might wander too close. Mammals like Docodon and Amphidon skitter from fern to fern, always on the alert. The pterosaur Dermodactylus chases buzzing insects, distracting the predator Allosaurus, who swallows the last bit of a lizard. Most animals rest as they wait out the worst of the heat.
The sound of crushed ground under heavy feet and the belly rumble of a giant beast rolls across the flat ground. The head and long neck of a sauropod called Suuwassea break through dust and rippling air, like a ship out of a foggy dream. Slowly the massive body comes into focus. With each footfall comes the wave of a whiplash tail, followed by the next Suuwassea in the herd.
The herd is important to Suuwassea. At only about 50 feet, Suuwassea is not the largest of the Morrison’s dinosaurs. Suuwassea is easy prey for Allosaurus compared with the giants Brachiosaurus, Apatosaurus, or Seismosaurus, the spiky-tailed Stegosaurus, and the armored and weaponized Gargoyleosaurus. Safety in numbers works well for Suuwassea when food is plentiful. During long, dry seasons when food is scarce, desperate Allosaurus work together to conquer the herds.
Yet today, Allosaurus naps and small mammals drink water from the footprints of Suuwassea as the sun sets. The animals feed on the low lying ferns, their heads never stopping as they rake fern frond after fern frond into their mouths and throats. As evening falls, the heat persists, just as it will for the rest of the Jurassic in this place that we will one day call the Bighorn Basin.
Text and illustrations by Jason Poole, Dinosaur Hall Manager and Dig Leader, Bighorn Basin
This article originally appeared in the fall 2016 issue of Academy Frontiers.