AllosauroideaAutomatic taxobox | name = Allosauroids | fossil_range = Middle Jurassic–Late Cretaceous, (Possible Late Toarcian and Late Maastrichtian records) | image = Allosaurus skull SDNHM.
AcrocanthosaurusAcrocanthosaurus (ˌækroʊˌkænθəˈsɔːrəs ; high-spined lizard) is a genus of carcharodontosaurid dinosaur that existed in what is now North America during the Aptian and early Albian stages of the Early Cretaceous, from 113 to 110 million years ago. Like most dinosaur genera, Acrocanthosaurus contains only a single species, A. atokensis. Its fossil remains are found mainly in the U.S. states of Oklahoma, Texas, and Wyoming, although teeth, a tibia, and vertebrae attributed to Acrocanthosaurus have been found as far east as Maryland, suggesting a continent-wide range.
PachycephalosaurusPachycephalosaurus (ˌpækᵻˌsɛfələˈsɔːrəs meaning "thick-headed lizard", from Greek pachys-/παχύς- "thick", kephale/κεφαλή "head" and sauros/σαῦρος "lizard") is a genus of pachycephalosaurid ornithischian dinosaur. The type species, P. wyomingensis, is the only known species, but some researchers argue that the genus Stygimoloch might be a second species, P. spinifer or a juvenile specimen of P. wyomingensis. It lived during the Maastrichtian age of the Late Cretaceous period in what is now western North America.
LythronaxLythronax () is a genus of tyrannosaurid dinosaur that lived in North America around 81.9-81.5 million years ago during the Late Cretaceous period. The only known specimen was discovered in Utah in the Wahweap Formation of the Grand Staircase–Escalante National Monument in 2009, and it consists of a partial skull and skeleton. In 2013, it became the basis of the new genus and species Lythronax argestes; the generic name Lythronax means "gore king", and the specific name argestes originates from the Greek poet Homer's name for the wind from the southwest, in reference to the specimen's geographic provenance in North America.
KritosaurusKritosaurus is an incompletely known genus of hadrosaurid (duck-billed) dinosaur. It lived about 74.5-66 million years ago, in the Late Cretaceous of North America. The name means "separated lizard" (referring to the arrangement of the cheek bones in an incomplete type skull), but is often mistranslated as "noble lizard" in reference to the presumed "Roman nose" (in the original specimen, the nasal region was fragmented and disarticulated, and was originally restored flat).
HadrosaurusHadrosaurus (ˌhædrəˈsɔːrəs; bulky lizard) is a genus of hadrosaurid ornithopod dinosaurs that lived in North America during the Late Cretaceous Period in what is now the Woodbury Formation about 78-80 Ma. The holotype specimen was found in fluvial marine sedimentation, meaning that the corpse of the animal was transported by a river and washed out to sea. They were large animals ranging from and . Most of the preserved elements are very robust, unusual traits in hadrosaurs.
Stress fractureA stress fracture is a fatigue-induced bone fracture caused by repeated stress over time. Instead of resulting from a single severe impact, stress fractures are the result of accumulated injury from repeated submaximal loading, such as running or jumping. Because of this mechanism, stress fractures are common overuse injuries in athletes. Stress fractures can be described as small cracks in the bone, or hairline fractures. Stress fractures of the foot are sometimes called "march fractures" because of the injury's prevalence among heavily marching soldiers.
AlligatorAn alligator, or colloquially gator, is a large reptile in the Crocodilia order in the genus Alligator of the family Alligatoridae. The two extant species are the American alligator (A. mississippiensis) and the Chinese alligator (A. sinensis). Additionally, several extinct species of alligator are known from fossil remains. Alligators first appeared during the Oligocene epoch about 37 million years ago. The name "alligator" is probably an anglicized form of el lagarto, the Spanish term for "the lizard", which early Spanish explorers and settlers in Florida called the alligator.
PhyloCodeThe International Code of Phylogenetic Nomenclature, known as the PhyloCode for short, is a formal set of rules governing phylogenetic nomenclature. Its current version is specifically designed to regulate the naming of clades, leaving the governance of species names up to the rank-based nomenclature codes (ICN, ICNCP, ICNP, ICZN, ICVCN). The PhyloCode is associated with the International Society for Phylogenetic Nomenclature (ISPN). The companion volume, Phylonyms, establishes 300 taxon names under PhyloCode, serving as examples for those unfamiliar with the code.
Kirtland FormationThe Kirtland Formation (originally the Kirtland Shale) is a sedimentary geological formation. The Kirtland Formation is the product of alluvial muds and overbank sand deposits from the many channels draining the coastal plain that existed on the inland seashore of North America, in the late Cretaceous period. It overlies the Fruitland Formation. It is found in the San Juan Basin in the states of New Mexico and Colorado, in the United States of America. The base of the Kirtland Formation and its lowest sub-unit, the Hunter Wash member, has been dated to 75.
