Randall, Lisa (2015). Dark Matter and the Dinosaurs: The Astounding Interconnectedness of the Universe. New York: HarperCollins: Ecco. ISBN 978-0-06-232847-2. LCCN 2016427646. OCLC 962371431. 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.

Foster, John R.; Lucas, Spencer G., eds. (2006). "Paleontology and Geology of the Upper Jurassic Morrison Formation". Bulletin of the New Mexico Museum of Natural History and Science. New Mexico Museum of Natural History and Science Bulletin. Albuquerque, NM: New Mexico Museum of Natural History and Science. 36. ISSN 1524-4156. OCLC 77520577 . Retrieved October 21, 2019. 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] Padian, Kevin, ed. (1986). The Origin of Birds and the Evolution of Flight. Memoirs of the California Academy of Sciences. Vol.8. San Francisco, CA: California Academy of Sciences. ISBN 978-0-940228-14-6. OCLC 946083441. OL 9826926M. This fantastic reference book for children includes fun facts about dinosaurs like the tallest dinosaur and who laid the largest dinosaur egg! It also includes:Chiappe, Luis M.; Witmer, Lawrence M., eds. (2002). Mesozoic Birds: Above the Heads of Dinosaurs. Berkeley: University of California Press. ISBN 978-0-520-20094-4. LCCN 2001044600. OCLC 901747962. Ornithopoda (various sizes; bipeds and quadrupeds; evolved a method of chewing using flexible skulls and many teeth)

The largest carnivorous dinosaur was Spinosaurus, reaching a length of 12.6 to 18 meters (41 to 59ft), and weighing 7 to 20.9 metric tons (7.7 to 23.0 short tons). [152] [153] Other large carnivorous theropods included Giganotosaurus, Carcharodontosaurus and Tyrannosaurus. [153] Therizinosaurus and Deinocheirus were among the tallest of the theropods. The largest ornithischian dinosaur was probably the hadrosaurid Shantungosaurus giganteus which measured 16.6 meters (54ft). [154] The largest individuals may have weighed as much as 16 metric tons (18 short tons). [155] Alvarez, Walter (1997). T. rex and the Crater of Doom. Princeton, NJ: Princeton University Press. ISBN 978-0-691-01630-6. LCCN 96049208. OCLC 1007846558 . Retrieved November 4, 2019. Alcober O.A & Martinez R.N. 2010. A new herrerasaurid (Dinosauria, Saurischia) from the Upper Triassic Ischigualasto Formation of northwestern Argentina. Zookeys. 63, 55–81. [4] Elasmaria (mostly southern ornithopods with mineralized plates along the ribs; may be thescelosaurids) In the skull, a supratemporal fossa (excavation) is present in front of the supratemporal fenestra, the main opening in the rear skull roofWorld War II caused a pause in palaeontological research; after the war, research attention was also diverted increasingly to fossil mammals rather than dinosaurs, which were seen as sluggish and cold-blooded. [60] [61] At the end of the 1960s, however, the field of dinosaur research experienced a surge in activity that remains ongoing. [62] Several seminal studies led to this activity. First, John Ostrom discovered the bird-like dromaeosaurid theropod Deinonychus and described it in 1969. Its anatomy indicated that it was an active predator that was likely warm-blooded, in marked contrast to the then-prevailing image of dinosaurs. [60] Concurrently, Robert T. Bakker published a series of studies that likewise argued for active lifestyles in dinosaurs based on anatomical and ecological evidence (see §Physiology), [63] [64] which were subsequently summarized in his 1986 book The Dinosaur Heresies. [65] Paleontologist Robert T. Bakker with a mounted skeleton of a tyrannosaurid ( Gorgosaurus libratus) Several other impact craters, and massive volcanic activity in the Deccan Traps in India, have been dated to about the time of the extinction event. These geological events may have reduced sunlight and hindered photosynthesis, leading to a massive disruption in Earth's ecology. [23] Earliest dinosaurs [ change | change source ] The early forms Herrerasaurus (large), Eoraptor (small) and a Plateosaurus skull

The extinctions at the end of the Cretaceous were caused by a catastrophic event: a massive meteorite hit the Earth (the Chicxulub impact). We now know where it hit: in the Yucantan peninsula in what is now Mexico. Dinosaurs began in the Upper Triassic, about 230 million years ago (mya). [3] The earliest date of a dinosaur fossil is that of Eoraptor and Herrerasaurus from Argentina, and Saturnalia from Brazil, 237 to 228 mya. [4] Arbour, V. (2018). "Results roll in from the dinosaur renaissance". Science. 360 (6389): 611. Bibcode: 2018Sci...360..611A. doi: 10.1126/science.aat0451. S2CID 46887409.Early saurischians were similar to early ornithischians, but different from modern crocodiles. Saurischians differ from ornithischians by keeping the ancestral configuration of bones in the pelvis (shown in a diagram above). Another difference is in the skull: the upper skull of the Ornithischia is more solid, and the joint connecting the lower jaw is more flexible. These features are adaptations to herbivory; in other words, it helped them grind vegetable food. Holmes, Thom (1998). Fossil Feud: The Rivalry of the First American Dinosaur Hunters. Parsippany, NJ: Julian Messner. ISBN 978-0-382-39149-1. LCCN 96013610. OCLC 34472600. Ferigolo, Jorge; Langer, Max C. (January 1, 2007). "A Late Triassic dinosauriform from south Brazil and the origin of the ornithischian predentary bone". Historical Biology. 19 (1): 23–33. doi: 10.1080/08912960600845767. ISSN 0891-2963. S2CID 85819339.