is almost complete; a denticle is preserved on the predentary, various vertebrae indicate a very iguanodontian-like body shape, specially dorsal vertebrae. The two right metatarsals are classified as metatarsals III and IV based on Camptosaurus and Iguanodon. The right pubis shows derived and plesiomorphic features, seen on related iguanodontians. Classification Iguanacolossus was placed in the Iguanodontia, being a styracosternan, a basal subgroup containing the Hadrosauridae and all dinosaurs more closely related to hadrosaurids than to camptosaurids. Below are the results obtained in the phylogenetic analysis performed by its describers in 2010: Paleoecology Iguanacolossus was recovered in the Yellow Cat Member from the Cedar Mountain Formation. However, this Member is divided in two beds: Upper and Lower Yellow Cat; Iguanacolossus was unearthed from the Lower bed, where it shared its environment with Theropods: Falcarius, Geminiraptor and Yurgovuchia. The sauropod Mierasaurus and the turtle Naomichelys. There are also indeterminate Goniopholidids crocodiles known from the Lower Yellow Cat. The other paleofauna is from the Upper Yellow Cat, which includes: Aquatilavipes; Sauropods: Cedarosaurus and Moabosaurus; Iguanodontians: Cedrorestes and Hippodraco; Theropods: Martharaptor and Utahraptor; the nodosaurid Gastonia; Turtles: Glyptops and Trinitichelys; Fish: Ceratodus, Semionotus and indeterminate remains of Hybodontids and Polyacrodontids sharks. Lastly, the mammal Cifelliodon. Additional unnamed genera is known from this bed: U. Sail-backed Iguanodont, U. Eudromaeosaur and Velociraptorine, U. Goniopholidids, U. Mesoeucrocodylian and U. Neochoristodere. See also 2010 in paleontology Ornithopoda Cedar Mountain Formation References Iguanodonts Early Cretaceous dinosaurs of North America Fossil taxa described in 2010 Taxa named by James I. Kirkland Paleontology in Utah Ornithischian genera