Many of the creatures featured in Darkwing were inspired by real species that existed during the Paleocene and Eocene Epochs.
The Felids of Darkwing were suggested by Miacids, of the genus Miacis, are considered to be the ancestors of all carnivorous (meat-eating) animals. A small, five clawed animal like a modern Pine Marten, they had long slender bodies, long tails and short legs. Their sharp claws and uniquely shaped teeth allowed them to tear meat from their prey. Their hindlegs were longer than their forelegs and their pelvis was like that of a dog. Some species of Miacids lived in trees while others lived on the ground. In either case the Miacid was a highly agile and successful hunter throughout the Paleocene and Eocene Epochs.
The Dyatryma was based upon Gastornis, a large flightless bird up to 2 metres in height. It had an extremely large hooked beak and strong legs with taloned feet and is thought to have been a n agressive and carniverous predator. Scientists believe that Gastornis was a pack hunter that may have also ambushed its prey amidst the dense forest in which it lived. Gastornis fossils have been found in both North America and Germany. Gastornis may been the largest living bird during the Paleocene & Eocene Epochs and likely had few predators or competitors. The first recorded fossil was discovered near Paris, France, in 1855.
The Equids of Darkwing were inspired by Phenacodus, a small, sheep-sized, hoofed animal that evolved during the Eocene Epoch. It had an elongated skull, arched back and long tail and is regarded as one of the evolutionary ancestors of the modern horse. The nature of its limbs suggest that it was a capable runner and the shape and structure of its teeth and jaw suggest that it was most likely a herbivore. The Phenocodus actually had five separate toes. The middle toe was the largest and along with the twio adjacent toes, was encased in a hoof. Complete skeletons of Phenocodus have been discovered in variety of locations in North America.