There are only two types of alligator left in the world. These are the American alligator and Chinese alligator. There are 6 species of alligator now extinct.
While the American alligator is still abundant, the Chinese alligator is considered vulnerable according to the IUCN red list. All 8 other types of alligators are now completely extinct. We only know about some of them because of fossil records!
Animals related to the alligator including the crocodile and caiman are excluded from this list.
Types of Alligator Still Alive
1. American Alligator
|Scientific Name||A. mississippiensis|
|Conservation Status||Least Concern|
|Where it’s Found||Southeastern United States|
American alligators are found across the southeastern United States, especially in the Florida Everglades and in the wetlands surrounding the Mississippi river.
American alligators are larger than Chinese alligators and are known to be quite dangerous to humans.
2. Chinese Alligator
|Scientific Name||A. sinensis|
|Conservation Status||Critically Endangered|
|Where it’s Found||Eastern China|
Chinese alligators live in the Yangtze River in China, and are known by the locals as muddy dragons.
The species is considered vulnerable to extinction and is classified as “Critically Endangered” by the IUCN. The species struggles with human settlements and agriculture and pollution resulting in habitat loss.
Chinese alligators are the smallest extant alligator, but can still grow up to 7 feet long (213cm).
Types of Extinct Alligator
1. Alligator hailensis
This alligator is one of the larger species, and it lived in Florida during the Pleistocene period. The name comes from the town of Haile, where it was first found.
Its age and fossil serve as an evolutionary intermediate between other species. Specifically, these species are the modern American alligator ad the extinct Alligator Mefferdi.
2. Alligator mcgrewi
The Alligator mcgrewi lived in the early Miocene period. Like the American alligator, it was only found in the United States, particularly in Nebraska. Based on scientific findings, it was a marine crocodile, and scientists tagged it this way based on its closeness to the Mesoeucrocodylia.
The average measurement of the skull was 145 x 96 millimeters. Based on the length of the fossil, the estimated body mass of this extinct alligator was three kilograms. If the hypothesis is correct, then this alligator is one of the shortest and lightest of all species.
3. Alligator mefferdi
The first Alligator mefferdi became known after Charles Craig Mook described it. They lived in the Miocene period, and their habitat spanned across Nebraska. The first specimen was discovered in the Ash Hollow Formation, which is also located in Nebraska.
The Alligator mefferdi is the closest relative of the modern American alligator. However, it has a shorter and blunter snout compared to the modern extant species. There is also a greater degree of cranial ornamentation compared to the modern alligator.
By taxonomy, the A. mefferdi belongs to the sub-family Alligatorinae, which is under the bigger family of Alligatoridae.
4. Alligator olseni
Also called Olsen’s Alligator, this species was named after Russel Olsen. Like the Alligator mcgrewi, it also lived during the Early Miocene period. Some scientists surmise that it lived between 20 and 15 million years ago.
Unlike the previous extinct alligators, this one lived in Florida, not Nebraska. There is a possibility that this alligator also expanded its territory as far as southeastern Texas.
It was Theodore E. White who first described it in 1942. However, it was named after its preparator, Russel Olsen. The first fossils were found at the Thomas Site Farm as early as 1931. The Alligator Olseni is small than its modern counterpart. Its maximum length was eight feet.
5. Alligator prenasalis
This one lived in the Late Eocene period. There are many fossils that have been collected, so there is a hefty amount of data about it.
The fossils came from the Chadron and Brule Formations located in South Dakota. The species’ name became official in 1940. However, it was originally thought of as a crocodile. It was in 1918 when it was re-assigned as an alligator.
The A. prenasalis has some similarities with the Allognathosuchus mooki, an alligatorine. Palaeontologists consider this species as ancestral to the A. mooki because of their physical similarities.
6. Alligator thomsoni
Little is known about the Alligator thomsoni, except that it lived in the Early Miocene period. The range of its habitat is also Nebraska.
What is the Largest Type of Alligator?
Since there are only two alligators living today, the largest is the American alligator. Of all the species of alligators, including the caimans, the black caiman is the only contender against the American alligator in terms of size.
It’s a common misconception that alligators grow forever, or that they are immortal. Like all animals, they eventually stop growing and die of old age.
Captive males can grow up to 13 feet and can weigh up to 770 pounds. Captive alligators may grow longer and weigh heavier because they have no predators.
The largest alligator caught was the one found on Marsh Island in Louisiana. Its length was 19.2 feet, and the weight was somewhere in the 2,000-pound range. The alligator was caught in 1890. However, there are some questions about the credibility of this claim.
Are Alligators Endangered?
The American alligator is not endangered. However, the Chinese alligator is now on the red list of the IUCN. It is critically endangered due to pollution and loss of habitat. As the rivers become poisoned and polluted, the fish that the alligator relies on for food die out.
In China, it is now a Class 1 endangered species. It has been this way since 1972. This means is that it receives the highest degree of protection from the Chinese government and killing it or capturing it from the wild is illegal.
People created the Anhui National Nature Reserve for Chinese Alligators in 1982. It is a reserve that aims to protect the habitat of the Chinese alligator. It spans 18,565 hectares of the wildlife reserve.
On top of the creation of this reserve, there are breeding centers for Chinese alligators. Right now, there are 15,000 Chinese alligators. These breeding centers were built in 1979 and were originally stocked with only 212 Chinese alligators.
In the wild, the estimate is only about 150 alligators left. A survey back in 1999 indicate that it is slowly recovering, but it is far from the risk of extinction. Today, it is the alligator that is in the top priority of conservation efforts.
There are only two alligators remaining today, the American and Chinese alligators. They have a sub-family which is comprised of caimans.
While alligators and crocodiles belong to the same class, they are different species. They cannot breed, and there is no successful interbreeding ever recorded between them.
The American alligator is not endangered and is part of the Least Concern list of the IUCN. The Chinese alligator, on the other hand, is critically endangered.
Stuart is the editor of Fauna Facts. He edits our writers’ work as well as contributing his own content. Stuart is passionate about sustainable farming and animal welfare and has written extensively on cows and geese for the site.