Most artwork depicts ammonites as floating free in the ocean. Unlike the modern nautilus, which lives far down where there is little light, ammonites seemed to have thrived closer to the surface. Ammonites were more closely related to squid and cuttlefish than to nautilus. Many species of ammonites were little larger than your hand. Only a few grew to 4.5 and 6.5 feet in diameter. For the larger numbers, those smaller than a dinner plate, hiding would have been the better option than hanging out in the open. It may be that ammonites are an indication of wider spread mats of sea plants like floating sargassum (S. natans and S. fluitans). That would explain why so many fossils of these shellfish appear to have dropped to a basically sterile ocean bottom after death. During the Cretaceous period, the Atlantic and Pacific Oceans were connected through several large straits. Cutting through the lower half of Central America, the North Equatorial Current simply flowed through the Caribbean into the Pacific Ocean. The global oceans were warm and provided the perfect environment for sargassum. The ancient Gulf of Mexico may have acted as a trap for free floating seaweed. The coastlines of any islands, which remained above the tides, may have had scattering of ammonites along with the strong sulfur smell of rotting seaweed. But out in the Gulf, below the drifting mats, millions of fish would have swarmed. And, hunting them from the tangle above ammonites with the lightning fast reach of modern squid.