Amargasaurus vs. Irritator
125 Million years ago in Early Cretaceous Argentina, braided rivers flow across the landscape, emptying into lakes. On the banks of one such lake, Irritator arrives from 15 million years in the future.
As a contemporary neighbor in Early Cretaceous South America, Irritator hasn’t wandered too far from home for this battle. As the sun reaches its zenith at high noon, its rays begin to beat down, leaving Irritator uncomfortably hot and feeling rather exposed on the bank.
Irritator finds coverage among the tall aquatic plants that grow just offshore of the lake. At 8 meters in length, it is no small animal, but only his nose, eyes, and sail can be seen with sharp eyes among the thick foliage. From tip to tail, the adaptations of his high-sitting nostrils and eye sockets, short legs comparative to body length, and fish-catching teeth make the water a very agreeable place to hide out (Arden et al. 2018).
Amargasaurus, slightly larger than Irritator at 10 meters in length, wanders out of the tree line and approaches the water’s edge. This is his usual watering hole, and he is none the wiser that Irritator watches him warily in the deceptively placid silence. Wading deeper into the lake, Amargasaurus can access the clearer undisturbed water for drinking, while cooling its legs and belly at the same time. Unfortunately, this move takes the larger animal too close for Irritator’s comfort.
Not willing to abandon his new hideaway, Irritator rises from the water, showing his full height, made even taller by the sail on his back. Water drips from his long claws and pointed teeth.
This unexpected show of force certainly shakes the sauropod. Startled, Amargasaurus responds by pointing the domineering spikes along the back of his neck towards the aggressor in his own display of intimidation. Irritator stands his ground, going so far as to advance part way out of the plant cover, hissing. Without a backup defense like the serious threat of Irritator’s sharp claws, Amargasaurus concedes the lake to the newcomer, retreating at speed. Satisfied, Irritator sinks back into plant coverage to wait for his next ill-fated challenger.