Only two alligator species survived—on two continents
Living alligators are just the American and Chinese species, a late-Eocene lineage about thirty-seven million years old. The English name likely twists Spanish el lagarto, the lizard. Unlike most crocodilians they push into cooler winters, and Louisiana plus Florida still hold more than a million American alligators between them.
Alligatoridae pairs Alligatorinae with caimans. Alligators and caimans split in North America roughly fifty-three to sixty-five million years ago; Chinese alligators parted from Americans about thirty-three million years ago, probably via a Bering crossing. An average American adult runs about three hundred sixty kilograms and four metres, sometimes past four point four metres and four hundred fifty kilograms; a Louisiana record stretched five point eighty-four metres. Chinese adults rarely exceed two point one metres or forty-five kilograms in males. Juveniles wear bright yellow stripes; adults darken to black or olive-brown.
Range is oddly split: only the United States and China still host native alligators. Americans occupy the southeast from the Carolinas to East Texas, with Louisiana holding the largest state population. Lifespans commonly reach fifty years and can exceed seventy; Saturn, hatched in Mississippi in nineteen thirty-six, died at Moscow Zoo in twenty twenty aged eighty-three or eighty-four. Cold tolerance lets northern animals survive winters that would ground tropical crocodiles.
Breeding peaks in late spring. April and May bellowing choruses boom after sunrise, males adding infrasound blasts. Females mound vegetation nests whose rotting heat incubates eggs; nest temperature in the first seven to twenty-one days sets sex—about thirty degrees Celsius or cooler yields females, thirty-four or hotter yields males. Maturity arrives near one point eight metres. The genus is iconic swamp royalty, yet its living diversity is a razor-thin remnant of a once wider crocodilian experiment.
Source: Alligator
