Bonnethead began with a taxon that had a highly pronounced cephalofoil (most likely that similar to the winghead shark, "Eusphyra blochii"), and was later modified through selective pressures. Thus, judging by their smaller cephalofoils, bonnethead sharks are the more recent developments of a 25-million-year evolutionary process. This species occurs off the American coast, in regions where the water is usually warmer than . It ranges from New England, where it is rare, to the Gulf of Mexico and Brazil, and from southern California to Ecuador. During the summer, it is common in the inshore waters of the Carolinas and Georgia; in
What Is a Nation? and continues to be invoked. Political historian Karl Deutsch, in a quote sometimes mistakenly attributed to Renan, said that a nation is "a group of people united by a mistaken view about the past and a hatred of their neighbours". Benedict Anderson's 1983 work Imagined Communities, which states that a nation is an "imagined political community", argues that Renan contradicts himself when he says French people must have forgotten the St. Bartholomew's Day massacre, yet does not explain what it is. In other words, Renan assumes that all his readers will remember the very massacre he says they have forgotten.