Ancient Giants on Display: Crocodilian Exhibition Opens in Tokyo

A special exhibition titled "Crocodilians," showcasing their remarkable diversity and little-known ecology through taxidermy and preserved specimens, has opened at the National Museum of Nature and Science in Tokyo's Taito Ward. It will run through March 1, 2026.

Crocodilians are the world's largest living reptiles. They have inhabited rivers and wetlands around the globe since ancient times and have changed little in appearance over millions of years. The group includes crocodiles, alligators, caimans, and gharials, with 27 recognized species worldwide.

By learning more about these powerful animals, which are sometimes known to attack humans, visitors are also encouraged to reflect on humanity's relationship with wildlife.

Inside the Exhibition

Unlike lizards and snakes, which belong to the squamate group, crocodilians are classified as archosaurs. This is the same evolutionary group as dinosaurs and birds. Fossils believed to be close to the common ancestor of today's crocodilians date to about 90 million years ago in the Cretaceous period.

In 2024, fossils discovered in Kuji City, Iwate Prefecture, along with their reconstruction images, showed just how little these animals have changed since prehistoric times.

The exhibition is divided into five sections and features specimens from 18 species. These include the New Guinea crocodile, which grows to more than three meters in length.

"It's rare to see this many crocodilian species gathered in one place," said researcher Natsuhiko Yoshikawa, who supervised the exhibition. "I hope visitors enjoy comparing their different features."

A Giant Centerpiece

One of the highlights is the saltwater crocodile, the largest living crocodilian. Some individuals are known to exceed six meters in length. Also on display is a five-meter-long oil painting of a saltwater crocodile by Takashi Oda, a professor at Kyoto Seika University.

"It really conveys the animal's true scale," Yoshikawa said. "It is also a photo spot, so we hope visitors will share it widely on social media."

*A five-meter-long oil painting of a saltwater crocodile by Takashi Oda, professor at Kyoto Seika University. (©Sankei by Hikaru Ichinosawa)*

Among the three families in the order Crocodylia, the Crocodylidae are the most widely distributed. In Asia and Oceania, familiar species include the saltwater and Siamese crocodiles. Africa is home to the Nile crocodile and the West African crocodile.

The Alligatoridae family is found mainly in North and South America. It includes the American alligator and several species of caiman, such as the spectacled caiman. In Asia, the Chinese alligator survives only in a very limited area of China.

The Gavialidae family is restricted to Asia and includes just two species: the Indian gharial and the Malayan gharial of Southeast Asia.

Telling Them Apart

These three families can be distinguished by the shape of their heads, especially the snout, and by the way their teeth fit together. Crocodiles have sharp, V-shaped snouts, with both upper and lower teeth visible when the mouth is closed. This gives them a strong balance of speed and power.

Alligators have broad, U-shaped snouts and powerful bites for crushing hard prey. Only the upper teeth are visible from the side. Gharials have long, narrow snouts adapted for catching fish with minimal water resistance.

Reclassifying Crocs

Recent DNA research has reshaped how crocodilians are classified. One notable example is the West African crocodile, which has been reclassified as a species distinct from the Nile crocodile.

Studies have also revealed that the four crocodile species found in the Americas are most closely related to Africa's Nile crocodile. This suggests that a small number of African crocodiles somehow crossed the Atlantic long ago.

While it seems unlikely they swam such vast distances, Yoshikawa points out that insects have been carried across oceans by tsunamis in the past. This raises the possibility that crocodilians, too, were transported by extreme natural events.

Humans and Crocodilians

Crocodilians have long played an important role in human culture. They were revered in ancient Egypt, China, and Southeast Asia and were often regarded as sacred beings. In Japan, a record from 1744 describes a crocodilian that drifted near Iojima in Kagoshima Prefecture. It was depicted in an illustrated scroll as a dragon-like creature.

In modern times, these animals have also become familiar through popular culture and fashion. The footwear brand Crocs takes its name from the amphibious nature of crocodiles. The famous crocodile logo of the clothing brand Lacoste comes from its founder, tennis player René Lacoste. Crocodilian leather has also long been used in luxury goods.

At the same time, heavy hunting for leather and widespread extermination as dangerous animals caused crocodilian populations to collapse. Today, seven species, including the Chinese alligator and the Siamese crocodile, are classified as critically endangered on the International Union for Conservation of Nature Red List.

From Overhunting to Protection

Conservation efforts have led to recoveries in some regions. In Australia, uncontrolled hunting from the 1940s reduced the saltwater crocodile population from more than 120,000 to fewer than 5,000 by the late 1960s.

After hunting bans were introduced in the 1970s and 1980s, numbers steadily rebounded. By around 2020, the population in the Northern Territory had reportedly returned close to pre-hunting levels.

However, as crocodilian populations increase, conflicts with humans have also grown. These include some fatal attacks on local residents. Authorities now remove problem animals and provide safety education. Still, how humans and crocodilians can safely coexist remains an ongoing issue.

(Read the article in Japanese.)

Author: Hikaru Ichinosawa, The Sankei Shimbun