The largest extant snakes live in the tropics of South America and southeastAsia where high temperatures facilitate the evolution of large body sizes among air-breathing animals whose body temperatures are dependant on ambient environmental temperatures (poikilothermy.
Links:
[1] http://admin.indiaenvironmentportal.org.in/feature-article/giant-boid-snake-palaeocene-neotropics-reveals-hotter-past-equatorial-temperatures
[2] http://admin.indiaenvironmentportal.org.in/category/author/jason-j-head
[3] http://admin.indiaenvironmentportal.org.in/category/author/jonathan-i-bloch
[4] http://admin.indiaenvironmentportal.org.in/category/author/alexander-k-hastings-et-al
[5] http://admin.indiaenvironmentportal.org.in/category/journal/nature
[6] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-change
[7] http://admin.indiaenvironmentportal.org.in/category/thesaurus/climate-science
[8] http://admin.indiaenvironmentportal.org.in/category/thesaurus/global-warming
[9] http://admin.indiaenvironmentportal.org.in/category/thesaurus/fossils
[10] http://admin.indiaenvironmentportal.org.in/category/thesaurus/colombia