Definition: The term "Apelognathiformes" refers to a family of birds in the order Apalognathidae, which belong to a group of bird species known as the apelognaths, a family that includes echinoderms, crustaceans, and arachnids. These families are characterized by having a series of legs or wings on their heads, similar to those found in reptiles. The term "Apelognathiformes" is derived from the Greek word "apellus," which means "head." This term is commonly used to refer to any species within this group that has the ability to fly, such as echidna (a family of birds), or parrots and cockatiels (birds with two tails), or other animals that have wings. The definition of "Apelognathiformes" is broad and encompasses a wide range of birds with unique features including wings, feathers, and flight. They are classified into different groups based on the presence of these characteristics: echinodermans (which include echidna and parrot), crustaceans (which have two tails), arachnids (including cockatiels), reptiles (including the flying parrots and cockatiels), and other animals that have wings or have been adapted to flight. In summary, "Apelognathiformes" refers to a group of birds with wings, while their family members are characterized by having heads with legs or wings.

Aepyornithiformes