They did not fight dinosaurs.

The scene depicts Pygmies fighting a hippopotamus and a crocodile at the Nile. For another scene much like it, see this Fresco depicting Nilotic landscape with pygmies at the Museo Archeologico Nazionale di Napoli. As the text with the picture explains:

The whole cycle depicts pygmies fighting crocodiles and hippopotamuses, a theme frequently used in depictions of this type, of which there are examples in mosaics and pottery. Pygmies were depicted from Archaic times in scenes of combat with cranes and, in Hellenistic times, represented the symbol of a remote exotic world, portrayed in its most grotesque and comic guises.

For the record, neither Moeritherium nor Sphenacodon are dinosaurs.

The images are almost certainly depictions of a hippopotamus and a crocodile, made by someone who had only heard descriptions of such animals. The suggestion that they are dinosaurs seems to have been put forward by Christian fundamentalists searching for evidence of a "short earth" theory of the world. I'm not a mod, but in future I recommend that you ask somewhat more plausible questions.

This submission has been removed because it is soapboxing, promotion of a political agenda, or moralizing. We don't allow content that does these things because they are detrimental to unbiased and academic discussion of history.