The Australian-filmed TV series, "Sir Arthur Conan Doyle's The Lost World" was better than the book. It added women characters and made all characters more interesting than in the book. The rub is that the series used actor Peter McCaulay's real wife for Challenger's wife the few times she apperared. I think she was also a director. She is actually older than Peter. (I think he's 64 this year.) In the book, Jessie Challenger seemed much younger than her husband, who treated her with contempt, as he did most people. The character was supposedly based on a medical professor that author Doyle knew. He must have been a real so-and-so!
McCaulay played Challenger as becoming more social and relating to his companions better, rather than just seeing Science as his god and having a vast ego. He mellowed in later seasons, as did the sharp-tongued Marguerite Krux, played by Rachel Blakley. I quite liked Finn, played by blonde actress Lara Cox. She was born in Canberra, but can fake a US accent well. Some of you have seen her in the DVD movie, The Marine 2. She played Robin, the hero's wife. The guy who played her boss is also Australian, and also appeared as a guest star on, The Lost World.
A fan fiction author got Finn and Challenger together, with the Jessie Challenger of the show dying of influenza. Some readers initially objected, mainly on the basis of Challenger being in his 50's. Finn was 22, the only character to actually mention her age. But each met emotional needs of the other and no other suitable mate for either was on hand on that remote jungle plateau. Finn needed a father figure who would also support her emotionally and financially when they left the Plateau. And her youth, curiosity, and wry humor revitalized Challenger. In a TV episode, Finn gave blood and told the others how to rig the transfusion equipment. She saved Challenger after he drank one of his experiments that went badly. Most fans were surprised to find the Jessie of the show so different from the younger one of the book. When seen in that light and the issue of their respective emotional and financial needs was explored, Finn and Prof. George Challenger made a quite plausibe couple.
That Fic author also had Finn replace her little crossbow from the show with guns, including a S&W M&P .38. (Five-inch bbl, Model of 1905, Fourth Change.) But even the TV show had mostly correct guns for the 1919-1922 time frame.
Sir Arthur C. Doyle had very limited knowledge of guns and no desire to learn. That's why he was so vague about arms in his Sherlock Holmes books, and what the characters had in, The Lost World was poorly chosen and described. The TV show did much better. And adding the girls helped, too.
The 1950 version of, "King Solomon's Mines" was pretty good, and the guns seemed logical. But the book was more specific about armament. Unlike Doyle, Sir Henry Rider Haggard knew something about guns and he was a veteran of the Second Zulu War of 1879. I have been unable to determine just what he did in the war, but suspect that he was a staff officer with Lord Chelmsford's column. He was definitely not killed at Isandlwana, nor was he at Rorke's Drift in that epic battle that produced 11 awards of the Victoria Cross!
Haggad included Colt and Winchester guns in his book, as well as heavier British Express double rifles. It's likely that he selected guns that he saw used in South Africa at that time. The book was published in 1883, and is, I believe, still in print. It is a real classic of adventure literature.
The 1950 movie is good, but I think the book is even better.
But of, The Lost World, the TV series and the movie version of the 1960's with Michael Rennie as Lord John Roxton and Jill St. John in a female role were both better than the book. This does not mean that TLW is a bad book, just that it could have easily been better. It is the sole case that I know of where the book was worse than the films or the TV versions.
However, the movie version of another Benchey book, "The Deep" was close to the book and was very well done. The only actor it shared with, "Jaws" was Robert Shaw, but not playing Quint. Did any of you see, "The Deep"? It was a very good film, and not just because of Jacque Bissett's wet tee shirt!

In that case, the book and the movie were about on par. That's rare.