Had there been strong prepossessions against the progressive theory, it would probably have been argued that when these cephalopods abounded, and the siphonated gasteropods were absent, a higher order of zoophagous mollusca discharged the functions afterwards performed by an inferior order in the Secondary, Tertiary, and Post-Tertiary seas.
"The Antiquity of Man"
Charles Lyell
There are, for instance, long lists of birds arranged in accordance with their occurrence in one or more continents: by correlating the distribution of the birds with their food he concludes "that the countries of the East Indian flora have no vegetable feeders in common with America," and "that it is probably due to the great peculiarity of the African flora that Africa has few phytophagous kinds in common with other countries, whilst zoophagous birds have a far more independent, often cosmopolitan, distribution."
"Darwin and Modern Science"
A.C. Seward and Others