Alvarezsaurus is a genus of alvarezsaurid dinosaur that lived between 86 and 83 million years ago in the Santonian stage of the Cretaceous. It appears as a minor antagonist in an episode of Dinosaur Planet.
Alvarezsaurus appear near the beginning of the episode, one attacking a Saltasaurus nest, eating one of the eggs before a Notosuchus appears and chases it off to have the nest to itself. After the eggs hatch and move into the forest, hordes of Alvarezsaurus and Notosuchus attack them throughout the night and into the day, until a herd of adult Saltasaurus encounter the young and begin protecting them.
- Alvarezsaurus is actually five millions years older than shown in the series.
- In the episode it's shown picking up a Saltasaurus hatchling, however the animal probably didn't have the strength to do so.
- The model of Alvarezsaurus, aside from color, is the exact same model of the Shuvuuia.