Which of the following characteristics is likely to be present in a recently discovered species with amniotic eggs and a four-chambered heart?

The presence of amniotic eggs and a four-chambered heart indicates a high level of evolutionary adaptation associated with certain groups of animals. A four-chambered heart is typically found in birds and mammals, facilitating efficient circulation and oxygen transport, which is vital for sustaining higher metabolic rates and aiding flight in birds.

The presence of amniotic eggs allows for the development of embryos in a protected environment, an adaptation that enables reproduction on land without reliance on water bodies, which is characteristic of both birds and mammals.

Feathers for flying are a defining feature of birds, which also possess a four-chambered heart and lay amniotic eggs. This makes the option concerning feathers for flying the most appropriate characteristic associated with this species as it aligns with the evolutionary features known for birds—specifically adaptations related to flight.

In contrast, ectotherms generally refer to organisms that rely on external sources to regulate their body temperature, which does not align with the warm-blooded nature of birds and mammals. External fertilization is typically found in amphibians and many fish, not in species that possess amniotic eggs and a four-chambered heart, as these characteristics are more closely associated with internal fertilization methods. Mammary glands, while