AP BIOLOGY

Detailed explanation-1: -A transitional fossil is any fossilized remains of a life form that exhibits traits common to both an ancestral group and its derived descendant group. This is especially important where the descendant group is sharply differentiated by gross anatomy and mode of living from the ancestral group.

Detailed explanation-2: -Archaeopteryx is a transitional fossil because of its characteristics of both reptiles (dinosaurs) and birds.

Detailed explanation-3: -The fossil record of horses provides other examples of transitional features. Modern horses (members of the genus Equus, which also includes donkeys and zebras) have just one toe-the hoof. However, the ancestors of modern horses, which lived more than 50 million years ago, had four toes.

Detailed explanation-4: -: a fossil that exhibits characteristics of both ancestral and derived forms. During the past 30 years, new discoveries and reinvestigations of long-forgotten specimens have coalesced into a flood of transitional fossils.

Detailed explanation-5: -Arguably one of the world’s most famous fossils, the first Archaeopteryx was discovered in Germany in 1861. It possesses a combination of traits that clearly place it as a transitional form between non-avian dinosaurs and birds. Its similarities to non-avian dinosaurs include a long feathered tail and small teeth.