What is "alectrosaurus"

Alectrosaurus (; meaning "alone lizard") is an extinct genus of tyrannosaurid theropod dinosaur that lived approximately 83 to 74 million years ago during the latter part of the Cretaceous Period in what is now Inner Mongolia. It was a medium-sized, moderately-built, ground-dwelling, bipedal carnivore, with a body shape similar to its much larger relative, Tyrannosaurus rex, and could grow up to an estimated long.