Dinosaurs come from the evolution of early primitive organisms approximately 230 million years ago and it is unknown why these organisms evolved into dinosaurs. Scientists have been able to trace dinosaurs back 228 million years ago to one of the first species known as the "eoraptor" that was the size of a dog and was carnivorous.Know More
Although dinosaurs are now extinct, there are many living examples of the dinosaur through its descendants in the bird kingdom. Alligators and other reptiles are also descendants of dinosaurs, but they are later descendants and evolved from other animals that evolved from dinosaurs. It is believed that birds evolved from dinosaurs directly. There are many similarities between dinosaurs and birds including hollow bones, walking upright and closely related skulls.
When the dinosaurs were alive, people were not yet living. Humans came into existence approximately 2.5 million years ago, which is approximately 127.5 million years after the dinosaurs first evolved and 62.5 million years after the dinosaurs disappeared. Scientists base their findings about dinosaurs on the fossils they left behind and on the study of their closet relatives including the birds and reptiles living in the modern world. Through these studies, scientists have concluded that most dinosaurs laid eggs, provided parental care for their young and protected their eggs once they had been laid.Learn more about Dinosaurs
There are a few well-researched theories about why dinosaurs are extinct; one of the most prominent theories hypothesizes that a massive asteroid impact killed off the dinosaurs. Another states that heavy volcanic eruptions across the Earth may have been responsible.Full Answer >
Scientists believe that the earth looked much different during the dinosaur's lifetime than it does today; at the advent of dinosaur life, all of the landmass on earth made up one single super continent known as Pangea. Dinosaurs likely did not live on every part of Pangea, instead concentrating in certain areas, including the land that is now known as Argentina, which is the home of the oldest known dinosaur fossil. Certain dinosaur species may have been localized to certain parts of the world, including the T.Rex, which has only been discovered in fossils found in North America.Full Answer >
The purported mass dinosaur die off known as the K-Pg extinction event took place during the end of the Cretaceous Period (K) during the Mesozoic Era some 65 million years ago. This scientific theory is based on the study of the fossil record, which shows evidence for the existence of dinosaurs during the Mesozoic Era but not during the proceeding Cenozoic Era. There is a clear line of demarcation, an actual line found in sedimentary rock layers known as the K-Pg Boundary, with the majority of the fossilized remains found below this line belonging to the "Age of Dinosaurs" not appearing in the space above the line, which marks the beginning of the Paleogene Period (Pg), the Cenozoic Era and the "Age of Mammals."Full Answer >
Dinosaurs lived during the Mesozoic era, between 250 and 65 million years ago. The earliest discovered dinosaur species, Nyasasaurus parringtoni, dates from 245 million years ago. Dinosaur fossils are most common between rock strata that are 225 to 65 million years old.Full Answer >