Ever since they were first identified in the 1800s, dinosaurs have sparked the imagination of kids and adults alike. It's the perfect beginner's reference book for children aged 7-9 who are curious about all things dinosaurs. Main-stream palaeontologists have followed this view for small theropods, but not for larger herbivores. [21] Since we know that the size of a Stegosaur's brain was about the size of a walnut, there is good reason to think its intelligence was limited. For 150 million years, dinosaurs were the undisputed rulers of the Earth. This book profiles the creatures who lived during the great Age of Reptiles, the real-life giants and monsters such as the Tyrannosaurus rex and Stegosaurus who once dominated our planet.

There were larger dinosaurs, but knowledge of them is based entirely on a small number of fragmentary fossils. Most of the largest herbivorous specimens on record were discovered in the 1970s or later, and include the massive Argentinosaurus, which may have weighed 80 000 to 100 000kilograms (90 to 110short tons) and reached lengths of 30 to 40 meters (98 to 131ft); some of the longest were the 33.5-meter (110ft) long Diplodocus hallorum [143] (formerly Seismosaurus), the 33-to-34-meter (108 to 112ft) long Supersaurus, [150] and 37-meter (121ft) long Patagotitan; and the tallest, the 18-meter (59ft) tall Sauroposeidon, which could have reached a sixth-floor window. The heaviest and longest dinosaur may have been Maraapunisaurus, known only from a now lost partial vertebral neural arch described in 1878. Extrapolating from the illustration of this bone, the animal may have been 58 meters (190ft) long and weighed 122 400 kg ( 270 000 lb). [143] However, as no further evidence of sauropods of this size has been found, and the discoverer, Cope, had made typographic errors before, it is likely to have been an extreme overestimation. [151] New revelations were supported by an increase in dinosaur discoveries. Major new dinosaur discoveries have been made by paleontologists working in previously unexplored regions, including India, South America, Madagascar, Antarctica, and most significantly China. Across theropods, sauropodomorphs, and ornithischians, the number of named genera began to increase exponentially in the 1990s. [21] As of 2008, [update] over 30 new species of dinosaurs were named each year. [66] At least sauropodomorphs experienced a further increase in the number of named species in the 2010s, with an average of 9.3 new species having been named each year between 2009 and 2020. As a consequence, more sauropodomorphs were named between 1990 and 2020 than in all previous years combined. [67] These new localities also led to improvements in overall specimen quality, with new species being increasingly named not on scrappy fossils but on more complete skeletons, sometimes from multiple individuals. Better specimens also led to new species being invalidated less frequently. [66] Asian localities have produced the most complete theropod specimens, [68] while North American localities have produced the most complete sauropodomorph specimens. [67] a b c d e f g Weishampel, Dodson & Osmólska 2004, pp.210–231, chpt. 11: "Basal Avialae" by Kevin Padian. Zhou, Zhonghe (October 2004). "The origin and early evolution of birds: discoveries, disputes, and perspectives from fossil evidence" (PDF). Naturwissenschaften. Berlin: Springer Science+Business Media. 91 (10): 455–471. Bibcode: 2004NW.....91..455Z. doi: 10.1007/s00114-004-0570-4. ISSN 0028-1042. PMID 15365634. S2CID 3329625. Archived from the original (PDF) on July 21, 2011 . Retrieved November 6, 2019.Distinct proximodistally oriented (vertical) ridge present on the posterior face of the distal end of the tibia (the rear surface of the lower end of the shinbone)

MacLeod N.; etal. (1997). "The Cretaceous–Tertiary biotic transition". Journal of the Geological Society. 154 (2): 265–292. Bibcode: 1997JGSoc.154..265M. doi: 10.1144/gsjgs.154.2.0265. S2CID 129654916.

Plot, Robert (1677). The Natural History of Oxford-shire: Being an Essay toward the Natural History of England. LCCN 11004267. OCLC 933062622 . Retrieved November 13, 2019. {{ cite book}}: |work= ignored ( help) Create a list of articles to read later. You will be able to access your list from any article in Discover. Matthew G. Baron; Megan E. Williams (2018). "A re-evaluation of the enigmatic dinosauriform Caseosaurus crosbyensis from the Late Triassic of Texas, USA and its implications for early dinosaur evolution". Acta Palaeontologica Polonica. 63. doi: 10.4202/app.00372.2017. Sarjeant, William A.S., ed. (1995). Vertebrate Fossils and the Evolution of Scientific Concepts: Writings in Tribute to Beverly Halstead, by Some of His Many Friends. ISBN 978-2-88124-996-9. ISSN 0026-7775. LCCN 00500382. OCLC 34672546. {{ cite book}}: |journal= ignored ( help) "Reprint of papers published in a special volume of Modern geology [v. 18 (Halstead memorial volume), 1993], with five additional contributions.--Pref." Rupke, Nicolaas A. (1994). Richard Owen: Victorian Naturalist. New Haven: Yale University Press. ISBN 978-0-300-05820-8. LCCN 93005739. OCLC 844183804 . Retrieved November 5, 2019.

Dinosaurs diverged from their archosaur ancestors during the Middle to Late Triassic epochs, roughly 20million years after the devastating Permian–Triassic extinction event wiped out an estimated 96% of all marine species and 70% of terrestrial vertebrate species approximately 252million years ago. [104] [105] The oldest dinosaur fossils known from substantial remains date to the Carnian epoch of the Triassic period and have been found primarily in the Ischigualasto and Santa Maria Formations of Argentina, and the Pebbly Arkose Formation of Zimbabwe. [106] Concave articular surface for the fibula of the calcaneum (the top surface of the calcaneum, where it touches the fibula, has a hollow profile) a b Farlow & Brett-Surman 1997, pp. 3–11, chpt. 1: "The Earliest Discoveries" by William A.S. Sarjeant.Currie, Philip J.; Padian, Kevin, eds. (1997). Encyclopedia of Dinosaurs. San Diego, CA: Academic Press. ISBN 978-0-12-226810-6. LCCN 97023430. OCLC 436848919 . Retrieved October 30, 2019.

Currie, Philip J.; Koppelhus, Eva B.; Shugar, Martin A.; Wright, Joanna L., eds. (2004). Feathered Dragons: Studies on the Transition from Dinosaurs to Birds. Life of the Past. Bloomington, IN: Indiana University Press. ISBN 978-0-253-34373-4. LCCN 2003019035. OCLC 52942941.

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Restoration of four macronarian sauropods: from left to right Camarasaurus, Brachiosaurus, Giraffatitan, and Euhelopus While recent discoveries have made it more difficult to present a universally agreed-upon list of their distinguishing features, nearly all dinosaurs discovered so far share certain modifications to the ancestral archosaurian skeleton, or are clearly descendants of older dinosaurs showing these modifications. Although some later groups of dinosaurs featured further modified versions of these traits, they are considered typical for Dinosauria; the earliest dinosaurs had them and passed them on to their descendants. Such modifications, originating in the most recent common ancestor of a certain taxonomic group, are called the synapomorphies of such a group. [30] Labeled diagram of a typical archosaur skull, the skull of Dromaeosaurus The tallest and heaviest dinosaur known from good skeletons is Giraffatitan brancai (previously classified as a species of Brachiosaurus). Its remains were discovered in Tanzania between 1907 and 1912. Bones from several similar-sized individuals were incorporated into the skeleton now mounted and on display at the Museum für Naturkunde in Berlin; [145] this mount is 12 meters (39ft) tall and 21.8 to 22.5 meters (72 to 74ft) long, [146] [147] and would have belonged to an animal that weighed between 30 000 and 60 000kilograms ( 70 000 and 130 000lb). The longest complete dinosaur is the 27 meters (89ft) long Diplodocus, which was discovered in Wyoming in the United States and displayed in Pittsburgh's Carnegie Museum of Natural History in 1907. [148] The longest dinosaur known from good fossil material is Patagotitan: the skeleton mount in the American Museum of Natural History in New York is 37 meters (121ft) long. The Museo Municipal Carmen Funes in Plaza Huincul, Argentina, has an Argentinosaurus reconstructed skeleton mount that is 39.7 meters (130ft) long. [149] An adult bee hummingbird, the smallest known dinosaur Curry Rogers, Kristina A.; Wilson, Jeffrey A., eds. (2005). The Sauropods: Evolution and Paleobiology. Berkeley: University of California Press. ISBN 978-0-520-24623-2. LCCN 2005010624. OCLC 879179542.