Pteranodon longiceps is a species of genus Pteranodon which comprised some of the biggest flying reptiles, with wings spanning over 20 feet. It existed in North America during the late Cretaceous geological period. It existed in current day South Dakota, Wyoming, Nebraska, Alabama and Kansas. Pteranodon was a reptile, but not a dinosaur. The syrinx is the organ that produced vocal signals. The frequency of signals was on the basis of the vibrations of the tracheal muscles and the amplitude was determined by the air pressure. The mechanisms by which vibrations are perceived and processed for the Pteranodon longiceps is homoplastic as it had to adopt it based on its environment
Dunkleosteus terelli is a species of genus Dunkleosteus which is a genus of prehistoric fish, and among the largest arthrodire placoderms to have ever existed. It existed approximately 360 to 380 million years ago in the Late Devonian period. This predator, 3.6 tones in weight and measuring up to 33 feet long and was a hyper-carnivorous apex predator. They use a swim bladder to create sound. Based on research, they applied double muscle pairs to pivot a modified rib, ‘the wing-like process,’ frontwards. This action resulted in the stretching of the swim bladder. Restoration of the swim bladder to its initial position is then initiated by an antagonistic muscle pair. The mechanisms by which vibrations are perceived and processed for this organism is homologous as it the same that is used by organisms. The mechanisms by which vibrations are perceived and processed for the Dunkleosteus terelli is homologous as it is an ancestral feature for this species.
Stupendemys geographicus of the prehistoric genus Stupendemys is a prehistoric freshwater turtle. Its fossils were found in South America’s northern region. It was estimated to have existed approximately 5 to 6 million years ago in the late Miocene to the beginning of the Pliocene. Stupendemys’s carapace was 5.9 feet long and was also quite wide. With a probable total carapace length of up to 311 feet, it was the biggest turtle that ever lived, Closely related to the Stupendemys is the Podocnemis expansa (Arau Turtle) which presently is the largest fresh water turtle in existence today , however, only measures 30 inches. It had an underwater acoustic communication system comprising a repertoire of percussive and complex sounds with possibly long-range, medium and short propagation physiognomies. Complex structures comprised harmonically connected elements (sparsely or richly) and varying rates of frequency variation. Frequency use went beyond the sensitivity of in-air auditory. The mechanisms by which vibrations are perceived and processed for the Stupendemys geographicus is homoplastic as it had to adopt it based on its environment.