original passage: Early in the Cenozoic, following the K-Pg event, the planet was dominated by relatively small fauna, including small mammals, birds, reptiles, and amphibians. From a geological perspective, it did not take long for mammals and birds to greatly diversify in the absence of the dinosaurs that had dominated during the Mesozoic. Some flightless birds grew larger than humans. These species are sometimes referred to as "terror birds," and were formidable predators. Mammals came to occupy almost every available niche (both marine and terrestrial), and some also grew very large, attaining sizes not seen in most of today's terrestrial mammals.
original sentence: From a geological perspective, it did not take long for mammals and birds to greatly diversify in the absence of the dinosaurs that had dominated during the Mesozoic.
sentence2: Do birds develop more diversity after the K-Pg event than Dinosaurs?
sentence1: Early in the Cenozoic, following the K-Pg event, the planet was dominated by relatively small fauna, including birds, reptiles, and amphibians. From a geological perspective, it did not take long for birds to greatly diversify in the absence of the mammals that had dominated during the Mesozoic. Some flightless birds grew larger than dinosaurs. These species are sometimes referred to as "terror birds," and were formidable predators. birds came to occupy almost every available niche (both marine and terrestrial), and some also grew very large, attaining sizes not seen in most of today's terrestrial birds.