What does the early presence of specialized marine birds like Waimanu indicate about their environment?
Answer
Robust food webs supported specialized predators
The existence of large, highly specialized birds like Waimanu shortly after the mass extinction event indicates that the marine food web was already stable and productive. This allowed the environment to support large, warm-blooded, predatory divers, suggesting that the pressures driving evolutionary specialization in the marine environment were intense and immediate.

Related Questions
During which geological epoch did the Waimanu genus thrive in New Zealand?What is the maximum estimated height for the species Waimanu manneringi?What physical trait regarding limb structure distinguishes Waimanu from modern penguins?What does the size variation between Waimanu manneringi and Waimanu tuatahi suggest?Which modern penguin species is mentioned to provide a size comparison for Waimanu?What is the primary order to which the genus Waimanu belongs?How likely was the swimming method of Waimanu different from modern penguins?Where is the geographical location that shares its name with the Waimanu genus?What does the early presence of specialized marine birds like Waimanu indicate about their environment?What observation is made about the head size of the larger Waimanu species?