All 8 Types of Alligators Living and Extinct! (Listed from A to Z)

There are only two types of alligators left in the world. These are the American alligator and Chinese alligator. There are 6 species of alligators 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 Alligators

Types of Alligators Still Alive

1. American Alligator

Scientific NameA. mississippiensis
Conservation Status Least Concern
Where it’s Found Southeastern United States

The American alligator is what people often refer to when they say “alligator.” It is endemic to the United States, and they are hunted down during the gator season. Alligators are different from crocodiles in the sense that they have U-shaped snouts.

2. Chinese Alligator

Scientific NameA. sinensis 
Conservation Status Critically Endangered
Where it’s Found Eastern China

The Chinese alligator is an endangered species. It is endemic to China, and it is revered as the muddy dragon. Some People call it the Yangtze alligator or China alligator.

The Chinese alligator is either dark grey or black, and its body is also fully-armored. Unlike its American cousin, it is smaller, growing only to seven feet and weighing up to 100 pounds.

During the summer, it burrows in the ground, and it brumates in the winter. It is a nocturnal hunter during summer, and it is an opportunistic feeder.

Related: All 27 Types of Crocodiles

Types of Extinct Alligators

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.

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.

See Alos: What Colors are Alligators?

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.

In China, it is now Class 1 endangered species. It has been this way since 1972. What Class 1 means is that it is receiving the highest degree of protection from the government. 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.

Were Alligators Dinosaurs?

No, alligators were not dinosaurs. In the evolution tree, the dinosaurs and alligators came from the same ancestor, the archosaur. It was a reptile.

The archosaur included non-avian dinosaurs and also extinct relatives of crocodilians.

Dinosaurs are more closely related to birds than crocodiles and alligators. While both of them are reptiles, they diverged in the evolution tree, and some even lived together. Some believe that crocodiles also hunted dinosaurs.


There are only a few alligators remaining today. The only two are the Americana and Chinese alligators. They have a sub-family which is comprised of the 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.

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