fossils having been found worldwide. Notable locations include North America, Europe, Israel, and Kazakhstan. Cretoxyrhina mostly occurred in temperate and subtropical zones. It has been found in latitudes as far north as 55° N, where paleoclimatic estimates calculate an average sea surface temperature of . Fossils of Cretoxyrhina are most well known in the Western Interior Seaway area, which is now the central United States and Canada. In 2013, Mikael Siverson and colleagues noted that during the Turonian or early Coniacian, Cretoxyrhina individuals living offshore were usually larger than those inhabiting the Western Interior Seaway, with some of the offshore C. mantelli fossils like one of the syntypes yielding total lengths of up to , possibly . HabitatCretoxyrhina inhabited mainly temperate to subtropical pelagic oceans. A tooth of Cretoxyrhina found in the Horseshoe Canyon Formation in Alberta (a formation where the only water deposits found consist of brackish water and no oceans) suggests that it may have, on occasion, swum into partially fresh-water estuaries and similar bodies of water. However, a rework from an underlying layer may be a more likely explanation of such occurrence. The climate of marine ecosystems during the temporal range of Cretoxyrhina was generally much warmer than modern day due to higher atmospheric levels of carbon dioxide and other greenhouse gases influenced by the shape of the continents at the time. The interval during the Cenomanian and Turonian of 97–91 Ma saw a peak in sea surface temperatures averaging over and bottom water temperatures around , about warmer than modern day. Around this time, Cretoxyrhina coexisted with a radiating increase in diversity of fauna like mosasaurs. This interval also included a rise in global δ13C levels, which marks significant depletion of oxygen in the ocean, and caused the Cenomanian-Turonian anoxic event. Although this event led to the extinction of as much as 27% of marine invertebrates, vertebrates like Cretoxyrhina were generally unaffected. The rest of the Cretaceous saw a progressive global cooling of earth's oceans, leading to the appearance of temperate ecosystems and possible glaciation by the Early Maastrichtian. Subtropical areas retained high biodiversity of all taxa, while temperate ecosystems generally had much lower diversity. In North America, subtropical provinces were dominated by sharks, turtles, and mosasaurs such as Tylosaurus and Clidastes, while temperate provinces were mainly dominated by plesiosaurs, hesperornithid seabirds, and the mosasaur Platecarpus. CompetitionCretoxyrhina lived alongside many predators that shared a similar trophic