History of Dinosaurs

History of Dinosaurs

    

               Dinosaurs first appeared between 247 and 240 million years ago. They ruled the Earth for about 175 million years until an extinction event 65.5 million years ago wiped out all of them, expect for the avian dinosaurs. Scientists don't agree entirely on what happened, but the extinction likely was a double or triple whammy involving an asteroid impact, choking chemicals from erupting volcanoes, climate change and possibly other factors.

Dinosaurs are a varied group of animals from taxonomic, morphological and ecological standpoints. Birds, at over 10,000 living species, are the most diverse group of vertebrates besides perciform fish. Using fossil evidence, paleontologists have identified over 500 distinct genera and more than 1,000 different species of non-avian dinosaurs. Dinosaurs are represented on every continent by both extant species (birds) and fossil remains. 

Through the first half of the 20th century, before birds were recognized to be dinosaurs, most of the scientific community believed dinosaurs to have been sluggish and cold-blooded. Most research conducted since the 1970s, however, has indicated that all dinosaurs were active animals with elevated metabolisms and numerous adaptations for social interaction. Some were herbivorous, others carnivorous. Evidence suggests that all dinosaurs were egg-laying; and that nest-building was a trait shared by many dinosaurs, both avian and non-avian. 

https://www.livescience.com/3945-history-dinosaurs.html

In the above link explained about the Flying on, Hip check, Ornithischia, Family tree update, Marine reptiles, Dinosaur cloning. 

In the 20th Century, most people thought that all dinosaurs were lizard-like and extinct. We now know that dinosaurs are not lizards and that birds are a type of dinosaur. Scientists now refer to modern birds as avian dinosaurs and to extinct dinosaurs as non-avian dinosaurs, many of which had feathers and beaks

http://www.thestargarden.co.uk/History-of-Dinosaurs.html

From the above website we can clearly  identity types, classification and the following useful identifications.  

1. Non-avian dinosaurs
2. Avian dinosaurs
3. How do we know?