I don't blame those artists. They may be and usually are, fine artists, but they are not interested in dinosaurs or any other extinct animal. That is because they don't know enough about them to make a proper restoration. The next way requires a certain level of interest and knowledge of the subject. Most skeletal reconstruction is made only in profile, but Paul does some of his dinosaur reconstruction showing front and top views, thereby giving a three-dimensional perception of the animal which makes it more appealing to draw.
Artists devoted to their subjects have the right approach.
It doesn't start with a commissioned job and then the search for a reference in panic to meet a deadline. It doesn't start with a commissioned job and then the search for a reference in panic to meet a dead-lines. It starts with an obsession and a drive to study the subject and extensively collect the reference material which can take years. In fact, when you know a lot about the subject, you have completed only half of the job, before you even start to illustrate. Nevertheless, you will have to refresh your memory and find all the media you can where the subject has been described and featured.