AlbertosaurusAlbertosaurus (ælˌbɜːrtəˈsɔːrəs; meaning "Alberta lizard") is a genus of large tyrannosaurid theropod dinosaur that lived in northwestern North America during the early to middle Maastrichtian age of the Late Cretaceous period, about 71 million years ago. The type species, A. sarcophagus, was apparently restricted in range to the modern-day Canadian province of Alberta, after which the genus is named, although an indeterminate species ("cf. Albertosaurus sp.") has been discovered in the Corral de Enmedio and Packard Formations of Mexico.
TroodonTroodon (ˈtroʊ.ədɒn ; Troödon in older sources) is a former wastebasket taxon and a potentially dubious genus of relatively small, bird-like theropod dinosaurs definitively known from the Campanian age of the Late Cretaceous period (about 77 mya). It includes at least one species, Troodon formosus, known from Montana. Discovered in October 1855, T. formosus was among the first dinosaurs found in North America, although it was thought to be a lizard until 1877.
Edmontosaurus regalisEdmontosaurus regalis is a species of comb-crested hadrosaurid dinosaur. Fossils of E. regalis have been found in rocks of western North America that date from the late Campanian age of the Cretaceous Period 73 million years ago, but it may have possibly lived into the early Maastrichtian. E. regalis was one of the largest hadrosaurids, measuring up to long and weighing around . It is classified as a genus of saurolophine (or hadrosaurine) hadrosaurid, a member of the group of hadrosaurids that lacked large, hollow crests, and instead had smaller, solid crests or fleshy combs.
BactrosaurusBactrosaurus (ˌbæktrəˈsɔːrəs; meaning "Club lizard," "baktron" = club + sauros = lizard) is a genus of herbivorous hadrosauroid dinosaur that lived in Asia during the Late Cretaceous, about 96-85 million years ago. The position Bactrosaurus occupies in the Cretaceous makes it one of the earliest known hadrosauroids, and although it is not known from a full skeleton, Bactrosaurus is one of the best known of these early hadrosauroids, making its discovery a significant finding.
