THE LOST WORLD by VICTOR MENDOZA

Edward Malone was a young journalist who wanted to marry Gladys , but Gladys wanted an adventurous husband. The boss of Edward invited him to meet the famous scientist Professor Challenger. The Professor Challenger hated journalists and when he discovered that Edward was a journalist, he tried to hit him, but then he was able to speak with him. The Professor Challenger told Edward a story in which another scientist called Mister White travelled to South America to discover if dinosaurs existed or not. Professor Challenger, Edward and two more scientist travelled to America to investigate the history of dinosaurs and discover The Lost World.
Once there they used a tree to build a bridge to The Lost World, but then the tree fell and they were trapped there. In The Lost World they discovered prehistoric creatures and other beings half-humans half-ape.
Suddenly, one night Edward woke up and saw that his companions had disappeared.
He finally got to find them and then the half-ape captured them and suddenly a few Indians appeared and fought against the half-ape to help scientists. The Indians won the battle and Edward and his friends returned to London turned into heroes.

The Professor Challenger had inside his bag a baby dinosaur to prove that dinosaurs exist in The Lost World.