Short answers, pulled from the story.
Sir Richard Owen coined the term dinosaur in April 1842 during a revised version of his talk at the British Association for the Advancement of Science. He grouped three genera, Megalosaurus, Iguanodon, and Hylaeosaurus, together under this new name to evoke their fearsome characteristics and majestic size.
In 2017, researchers Matthew Baron, David Norman, and Paul Barrett published a radical revision proposing that Ornithischia was more closely related to Theropoda than to Sauropodomorpha. This study overturned the traditional view based on hip structure and resurrected the term Ornithoscelida to describe the union of these groups.
Dinosaurs diverged from archosaur ancestors approximately 233 million years ago during the Middle to Late Triassic epochs. Radiometric dating of the Santa Maria Formation in Brazil supports this timeline for early forms such as Eoraptor and Herrerasaurus.
Mary Higby Schweitzer discovered mineralized structures resembling red blood cells within a Tyrannosaurus femur in 1991. Her team reported in 2005 that soft tissues including blood vessels and connective fibers retained microscopic structure after sixty-six million years.
Mary Ann Mantell reportedly discovered Iguanodon remains in 1822, though historical records suggest her husband Gideon may have acquired them earlier. William Buckland described Megalosaurus bones collected from a limestone quarry in 1824, marking the first formal recognition of a non-avian dinosaur in a scientific journal.