You are in the swamplands of Europe, 240 million years ago.

The air was thick and humid, tasting of sulfur and decaying ferns. You knelt on the marshy bank, taking notes on the sprawling forest of conifers when the water nearby erupted. It wasn't a crocodile, but something far older and more bizarre.

A massive, triangular head—easily the size of an office desk—swung toward you, its eyes fixed on the bank.

A Mastodonsaurus.

It was colossal, nearly six meters from its massive jaw to its tapering, muscular tail. The creature looked like a nightmare hybrid of a giant newt and a crocodile, yet it moved with a languid grace in the shallow river, armored skin glistening in the hazy, prehistoric sun.

It didn't roar. Instead, it opened its vast, flat mouth, revealing a row of sharp, needle-like teeth alongside enormous tusks that protruded from its lower jaw. The scent of brackish water and wet, armored scales filled the air. Seeing its peculiar eyes—a mixture of cold aquatic stillness and reptilian focus—you felt an absolute sense of wonder.