In Jurassic: the Hunted, the first weapon you take is this one and it's called the .45 Pistol in the game. It has 8 rounds to 12 extended rounds and 200 ammo.
The .45 Pistol appeared in the first mission as the first weapon the player can equip. It also appears in this mission so the player can equip it for his ammo. In the PS2 version (PlayStation 2), it appeared in the fifth mission, two copies of it.