There is some similarities betwen dragon with dinosaur, pterosaur, and prehistoric marine reptiles. Just search it in Google. At least there is one report about dinosaur that spit fire in Niger. It's looks like a kind of spinosaur. The above image is interpretation of Mokele-Mbembe, or to be more precise is the adult version of it, the Le'kela-Mbembe (both are Congolese water dragon)