Geography of the US in the Late Cretaceous Period

Late Cretaceous (100mya - 65mya) refers to the second half of the Cretaceous Period, named after the famous white chalk cliffs of southern England, which date from this time. Rocks deposited during the Late Cretaceous Period are referred to as the Upper Cretaceous Series. Image File history File links US_cretaceous_general. ... Image File history File links US_cretaceous_general. ... The Cretaceous Period is one of the major divisions of the geologic timescale, reaching from the end of the Jurassic Period (i. ... A geologic period is a subdivision of geologic time that divides an era into smaller timeframes. ... The Needles,situated on the Isle Of Wight, are part of the extensive Southern England Chalk Formation. ... Motto (French) God and my right Anthem God Save the Queen England() – on the European continent() – in the United Kingdom() Capital (and largest city) London (de facto) Official languages English (de facto) Unified  -  by Athelstan 967 AD  Area  -  Total 130,395 km²  50,346 sq mi  Population  -  2007 estimate 50...

This was a period of great success for dinosaurs, with many new types appearing and diversifying, such as the Tyrannosaurs, duck bills, Ankylosauridae, and horned dinosaurs in Asiamerica (Western North America and eastern Asia), and Titanosaurs and Abelisaurs in Gondwana. Orders & Suborders Saurischia Sauropodomorpha Theropoda Ornithischia Thyreophora Ornithopoda Marginocephalia Dinosaurs were vertebrate animals that dominated the terrestrial ecosystem for over 160 million years, first appearing approximately 230 million years ago. ... Genera See text. ... Genera Lambeosaurinae     Corythosaurus    Lambeosaurus    Parasaurolophus Hadrosaurinae    Anasazisaurus     Anatotitan     Edmontosaurus     Hadrosaurus    Maiasaura    Prosaurolophus    Saurolophus    Shantungosaurus Hadrosaurids or duck-billed dinosaurs are members of the family Hadrosauridae, and include ornithopods such as Edmontosaurus and Parasaurolophus. ... Ankylosauridae were a family of armored dinosaurs that evolved 125 million years ago (along with another family of ankylosaurs, the Nodosauridae) and died 65 million years ago at the Cretaceous-Tertiary Extinction Event. ... Genera Centrosaurinae    Achelousaurus    Centrosaurus    Einiosaurus    Styracosaurus    Pachyrhinosaurus Ceratopsinae    Chasmosaurus    Diceratops    Pentaceratops    Protoceratops    Torosaurus    Triceratops Ceratopsids, or members of the Ceratopsidae (or Ceratopidae), are a diverse group of marginocephalian dinosaurs like Triceratops and Styracosaurus. ... Asiamerica was a large island formed from the Laurasian landmass and separated by shallow continental seas from Eurasia to the West and eastern North America to the East. ... Genera Aegyptosaurus Andesaurus Antarctosaurus Argentinosaurus Argyrosaurus Bruhathkayosaurus Jainosaurus Paralititan Saltasaurus Titanosaurus For the Titanosaurus featured in the Godzilla film series, click here. ... Abelisauridae is a family (or clade) of theropod dinosaurs. ... Gondwanaland redirects here. ...

Birds became increasingly common and diverse, replacing the pterosaurs which retreated to increasingly specialised ecological niches. “Aves” redirects here. ... Suborders Pterodactyloidea Rhamphorhynchoidea * Pterosaurs (, from the Greek πτερόσαυρος, pterosauros, meaning winged lizard, often referred to as pterodactyls, from the Greek πτεροδάκτυλος, pterodaktulos, meaning winged finger ) were flying reptiles of the clade Pterosauria. ...

In the seas, mosasaurs suddenly appeared and underwent a spectacular evolutionary radiation. Modern sharks also appeared and giant-penguin-like polycotylid pliosaurs (3 meters long) and huge long-necked elasmosaurs (13 meters long) also diversified. These predators fed on the numerous teleost fishes, which in turn evolved into new advanced and modern forms (Neoteleostei). Subfamilies Mosasaurinae Plioplatecarpinae Tylosaurinae Mosasaurs (from Latin Mosa, the Meuse river where the fossils were first discovered + Greek sauros, lizard) were serpentine marine reptiles, more closely related to snakes than to monitor lizards (Lee 1997). ... Genera Dolichorhynchops Edgarosaurus Polycotylus Thililua Tinacromerum Procotylus Georgiasaurus Ceraumasaurus Polycotylidae is a family of large plesiosaurs from Cretaceous, sister group to the elasmosauridae. ... Families Cryptoclididae Elasmosauridae Plesiosauridae Pliosauridae Plesiosaurs (PLEE-see-oh-SORES) were large, carnivorous aquatic reptiles. ... Elasmosauridae was the taxonomic family of the most advanced plesiosaurs. ... Superorders Osteoglossomorpha Elopomorpha Clupeomorpha Ostariophysi Protacanthopterygii Sternopterygii Cyclosquamata Scopelomorpha Lampridiomorpha Polymyxiomorpha Paracanthopterygii Polymyxiomorpha Acanthopterygii Teleostei is one of three infraclasses in class Actinopterygii, the ray-finned fishes. ...

Near the end of the Cretaceous Period, flowering plants diversified and didelphid marsupials and primitive placental mammals also became common. Classes Magnoliopsida - Dicots Liliopsida - Monocots The flowering plants (also called angiosperms) are the dominant and most familiar group of land plants. ... Genera Several; see text Opossum fur is quite soft, and was once commonly used in the bathtub as a sponge. ... Orders Didelphimorphia Paucituberculata Microbiotheria Dasyuromorphia Peramelemorphia Notoryctemorphia Diprotodontia Sparassodonta (extinct) Marsupials are mammals in which the female typically has a pouch (called the marsupium, from which the name Marsupial derives) in which it rears its young through early infancy. ... Orders Afrosoricida Macroscelidea Tubulidentata Hyracoidea Proboscidea Sirenia Xenarthra Dermoptera: Scandentia Primates Rodentia Lagomorpha Insectivora Chiroptera Pholidota Carnivora Perissodactyla Artiodactyla Cetacea Placentalia and Eutheria are terms used to describe major groupings within the animal class of Mammalia. ... Subclasses & Infraclasses Subclass †Allotheria* Subclass Prototheria Subclass Theria Infraclass †Trituberculata Infraclass Metatheria Infraclass Eutheria Mammals (class Mammalia) are warm-blooded, vertebrate animals characterized by the production of milk in female mammary glands and the presence of hair, three middle ear bones used in hearing, and a neocortex region in the...

The period was ended by the Cretaceous-Tertiary extinction event. Badlands near Drumheller, Alberta where erosion has exposed the KT boundary. ...