Prehistoric Wild: Life in the Mesozoic

Carried By the Current (118 MYA)

Paja Formation, Colombia, 118 Million Years ago

The mid-day sun casts a steady light across the sky, illuminating the upper west coast of South America. In our modern day, this land will be where the Colombian Andes would grow and further bleed into other parts of the continent. Even parts of the Amazon Rainforest would be eclipsed by this same mountain range.

However, such mountains have yet to form. Instead, higher sea levels have resulted in much of Colombia being flooded, turning even the central parts of the country into a coastal environment. Small parts of the westernmost sections of the country remain as dry land, but are separated into islands. Although the land bridge between North and South America is still present, it's in a different position than it is today.

Steady waves continuously splash and recede on the white sands of the Colombian shore. This beach acts as a border between the ocean blue and the humid forests on the land. Much of it is made up of ancient Conifer trees, towering over a bed of ferns and cycads.

Bits of these plants are also scattered across the seaside, having been blown away by storms of the past. Some lay hidden by the sand, occasionally sticking out along with the various seashells and bones of dead animals. The rest is carried away by the tide, drifting it out to sea.

The movement of the waves also reveals the many rocks that line the shallows and even rest at the shoreline. Many of them are merely small pebbles towered over by the occasional larger stone. More minuscule ones are often smooth and rounded while the much bigger ones are pointed and jagged. They are also home to barnacles and algae, the white shells and green slime standing out against the black craigs they cling onto.

Other ones are seen much farther away from many of the other sea stones, only surrounded by the white sands submerged by the ocean current. Curiously, some of these rock shapes are slowly moving. Inch by inch, they gently grow closer to dry land.

However, moving past the receding tide reveals much more to these perceived rocks. Limbs swing upward, repeatedly dragging them across the sand. Heads at the front poke up, letting out a deep gasping noise as it inhales air amidst the crash and splashes of the tides they emerge from.

These are not rocks but merely Desmatochelys, the earliest sea turtles. Water-dwelling terrapins have been around even before these evolved. It's only now in the Early Cretaceous that these shelled animals are taking the form we recognize in our modern day. Despite this, their relatives that permeate today's oceans are directly descended from these ancient reptiles.

Unlike what's seen in most sea turtles, Desmatochelys have a thick, leathery shell akin to that of the modern leatherback. These carapaces covering their 6-foot-long bodies are flexible yet tough, with a surface that is slightly ridged. Four large, paddle-shaped flippers stick out from these shells, adapted for swimming yet also effective in dragging the turtles across land. Short tails stick out from the back but are hidden by the turtles' carapace. Protruding from the front of the shells are sleek, slightly elongated heads with pointed snouts. These heads end in sharp, strong beaks built for grasping and tearing soft prey. The rubbery skin of these turtles is primarily charcoal gray with faint, irregular deep, blue spots covering it and the shell. This coloration is only interrupted by the occasional small barnacles that have latched themselves to many parts of the turtles.

From the foaming tides, the Desmatochelys emerge onto the sandy Colombian shores. Such actions are a grueling effort for animals adapted for life in the ocean. On land, they feel every ounce of their massive weight fastening them to the earth. Even their massive flippers can only carry them across shifting sands in short, repeated bursts.

Despite such difficulties, many Desmatochelys haul themselves onto the shore. What initially appears as a handful quickly turns into the 10s before building up to hundreds. Each one gasps for air as they shift the sands beneath them.