200 years of dinosaur discoveries –a visual portrayal of their geographic and historical origins

Background The first dinosaur to be formally named was Megalosaurus in 1824. Over the subsequent 200 years more than 1,200 different species of dinosaur have been discovered and named. The discoveries come from every continent, but different regions are characterized with different species from different geological time periods. Given this multi-generational collection history, from a wide variety of geographic areas, and representing a huge diversity of animals, it was felt that a new type of visual summary of the current state of our knowledge of dinosaur diversity and discovery history would be much more informative and revealing than a simple list comprised of words and numbers. Methods Using recently published, comprehensive surveys of all known Mesozoic, non-avian dinosaurs, a series of computer-generated, horizontal, stacked, bar-type graphs are used to graphically show how our knowledge of dinosaur diversity has developed over the past 200 years at the decade level. The graphs use clusters of coloured boxes, with individual boxes scaled to the numbers of dinosaurs from a region, to enable comparisons of counts of dinosaur discoveries from different regions within and between decades. The colours are used to identify the countries and regions on an accompanying global map. This analysis of the historical growth in our knowledge of dinosaur diversity is presented in two ways: at the high level of the clades Theropoda, Sauropodomorpha and Ornithischia; and at a lower one with many detailed monophyletic and paraphyletic sub-group levels. Results As of end of 2025 this survey finds that there are 1,259 reliably known dinosaur species: 428 ornithischians, 366 sauropodomorphs and 465 theropods. From the entire 19th century only 58 dinosaur species can be viewed as having been discovered and still be considered valid today. These 19th century discoveries came from Europe and the United States of America with just three exceptions. Dinosaur discovery and naming rates were very low, typically no more than 10 per decade per major clade, until the 1970s when the decadal counts began to exceed the total 19th century counts for the first time. Discoveries from 1920s began to fully reveal to the true global extent of dinosaur occurrences. The early 2000s saw Argentina and China become the leading countries for new dinosaurs, but Europe and the United States continue to produce new discoveries up to the present.