Gastornis evolving into modern birds

Scenario: In our alternate timeline, the Gastornis, an impressive bird from the Eocene era, did not go extinct. Instead, it managed to survive and adapt to changing environments over millions of years, gradually evolving into a myriad of fascinating forest-dwelling species that inhabit various forests around the world today. The pivotal point came during the early Oligocene epoch, when Gastornis found itself competing with some of the first forest-dwelling mammals. With survival on the line, these birds began to adapt in order to make better use of forest resources. One branch of Gastornis evolved into a large, ground-dwelling species known as the Sylvornis, named for their forest homes (from Latin "sylva", forest). These birds exhibit a brilliant adaptation: they are incredible burrowers. The Sylvornis utilize their beaks, which have evolved to be strong and shovel-like, to burrow into the forest floor for insects, tubers, and small mammals. This adaptation has allowed them to access food sources unavailable to many competing species. Another offshoot of the Gastornis evolved into smaller, tree-dwelling birds called Arbornis. Over millions of years, Arbornis developed sleek bodies and powerful talons allowing them to navigate swiftly amongst the tree branches, unlike their heavy-built ancestors. They've also acquired long, sharp beaks perfect for piercing tree bark to reach insects or sipping nectar from flowers, behaving much like modern-day woodpeckers or hummingbirds. Another notable evolution is the Noctornis, a branch of Gastornis that adapted to a nocturnal lifestyle to evade daytime predators and exploit the nighttime niche. These birds have large, sensitive eyes for low light conditions, and a nearly silent flight similar to modern owls. Noctornis primarily eat small mammals and insects. These adaptations not only facilitated the survival of Gastornis descendants but greatly diversified the species and made them some of the most unique forest birds. In this parallel evolution, these descendants from the prehistoric Gastornis become an integral part of forest ecosystems across the world. Their survival story is a testament to the power of natural selection and adaptability in the face of changing environments, competitors, and predators.