Retodus is an extinct genus of prehistoric sarcopterygian or lobe-finned fish from North Africa and Nebraska.These reached lengths of approximately 3.5 m, roughly as much as a larger modern crocodile. However, lived in that very area still significantly larger crocodile, namely Sarcosuchus imperator, and Spinosaurus, which is why one can strongly assume that even part of this giant fish prey to even bigger predators. Here lungfish are themselves predators that feed on fish, amphibians, worms, insect larvae, as well as hard-shelled mollusks such as crustaceans, mussels and snails. Partly also plants are eaten, but these seem to be at least partially mitgefressen unintentionally when entangling prey. Most likely the food of giant lungfish will have been geared more towards larger prey, and especially the huge massive tooth plates (which will be discussed further below exact times), indicate a certain specialization in hard-shelled food. But which hard-shelled prey will probably have eaten a three and a half meters large lungfish? Most likely not only small mussels, snails or crustaceans. Presumably stood for turtles frequently on the menu, and especially smaller specimens may have not been a problem for the jaw. Turtles can partially amazing form large biomass, which is why it will not appear too far-fetched that they can be an important part of the diet of certain large predators in aquatic ecosystems. Also in some types of modern Crocodilia play at least locally turtles an important role in the diet. Considering the fact that lung fish are generally quite aggressive predators, can well assume that they recorded and all sorts of other vertebrates in their diet when the opportunity arose, whether floating in water reptiles, birds or even small dinosaurs.
A lungfish of three and a half meters is pretty huge, but there was even greater . Only recently , namely in 2011 , a huge Ceratodus tooth from Nebraska was described . This mandibular was 117 mm long , and thus 17 mm longer than the largest Retodus tuberculatus tooth from Africa . From this giant lungfish is no longer known as one of the giant tooth plates, so of course is not entirely sure how they actually looked like during his lifetime. However, the tooth plates are those of modern Australian extremely similar lungfish, which are also in their body shape other better-known archaic style still so similar that it is certainly not resorted to far to use it as a direct reference. How extremely large these giant lung fish such Retodus tuberculatus and even more species in North America were, is also evident when one considers their weight. Based on the mentioned at the beginning the average weights of modern Australian lungfish I come for the former to a weight of about 437 kg, which is far more difficult than almost all of today's freshwater fish, and is only surpassed by some anadromous sturgeon, but in a large part of their lives spend sea. For the giant lungfish from Nebraska I'm at 4 m length even on a weight of 652 kg. That is more than four times as heavy as the largest documented European catfish, about three times as much as the heaviest South American Piraibas and more than twice as heavy as the largest Mekong giant catfish. As previously known only as extremely little fossils, of course you must also assume that individual specimens of giant lungfish have also become even greater. It is amazing that a freshwater ecosystem has enabled the development so huge fish.