Myliobatiformes are an order belonging to the subclass of Elasmobranchs, characterized as all species of Chondrichthytes, by a cartilaginous body. They are closely related to the order of the Rajiformes, with whom they share the extremely flattened dorsal-ventral body shape. In fact, for many years the species of Myliobatiformes were included within the order of the Rajiformes. Recent phylogenetic studies have shown that Myliobatiformes are an independent order of the Rajiformes, despite their similarity.
As can be seen in the image, the body scheme of the Rajiforms (left) and the Myliobatiformes (right) is quite similar. Among the differences we find between both orders, we highlight that Myliobatiformes have pelvic fins formed by a single lobe, while Rajiforms are usually bilobulated (red circle). The tail of the Myliobatiformes is usually relatively thin and elongated. It usually has a spine in a dorsal position and positioned in the first third of the tail. Also, Myliobatiformes generally lack a dorsal fin (blue circle) and in species that do have one, the dorsal fin is usually unique and located closer to the base of the tail rather than to the end of it. Finally, Myliobatiformes lack spines on the midline of their tail (pink circle), a feature present however in Rajiformes.
Beyond the differences between the Myliobatiformes and Rajiformes mentioned above, the similarities in behavior and feeding habits are many.
Due to the body conformation of the Myliobatiformes, as we can easily deduce, they go very easily unnoticed on sandy/muddy bottoms, since the extremely flattened shape, together with some movements of their undulating pectoral fins, allows them to cover their whole or part of their body with the same bottom. In this way the Myliobatiformes go completely unnoticed by possible prey that may pass through their vicinity.
At present, all species of Myliobatiformes are organized into 10 families, which contain 29 genera, and in which there are a total of 221 species of Myliobatiformes.
