A small herd of Massospondylus arrive on the shores of the river early in the morning. The prosauropods amble out of the forest on four legs, having spent the night safe amidst the forest canopy. Among them are several babies born just weeks earlier, and the parent dinosaurs are weary of predators that might attack the youngsters.
The adults in the group are about six metres long, looking like a cross between a long-necked, plant-eating sauropod and a carnivorous theropod. These animals are omnivores. They begin to root through the low-growing vegetation on the riverbank with the sharp thumb claw on their front legs, looking for small lizards, frogs, and salamanders. The youngsters turn their attention to the green shoots growing along the shoreline, which are soft enough for their small, peg-shaped teeth to munch.
They are all oblivious to the nine-metre-long terror concealed in the murky water just metres away.
The Sarcosuchus, a gigantic crocodile, has been waiting for the herd, biding its time. It is the supreme ambush predator in this environment, easily hiding four tons of muscle and bulk in the muddy waters of rivers and streams, then launching itself out of the water at unsuspecting prey.
A juvenile Massospondylus comes within metres of where the Sarcosuchus is lurking in the water. The predator tenses.
When the rest of the Massospondylus herd hear the roar and splash, they look up in alarm to see the young dinosaur struggling and screaming, its hind quarters clamped in the powerful jaws of the giant crocodile. The baby dinosaurs scatter back into the safety of the forest. A few of the older individuals hesitate for a terrified second, wondering if they should try to save this unfortunate member of their herd.
But it is too late.
The crocodile has already pivoted to belly roll back into the water, dragging the struggling Massospondylus with it. The Sarcosuchus does not bother inflicting a fatal wound. It knows its prey will become exhausted struggling to reach the surface of the water and drown. Then it will be a substantial and tasty meal.