Crocodylians

Crocodylians and their relatives have lived on the water's edge in the same form for millions of years. Even among reptiles, Crocodylians are unique. This exhibition introduces Crocodylians in their various forms from around the world and their ecology, using taxidermy, skeletal, and other specimens, videos, and old drawings, highlighting the history of human and Crocodylians. Considering how these "waterside neighbors" have coexisted with humans for such a long time can help us understand the relationship between people and wild animals in the future.

Researchers have studied them from various angles―morphology, ecology, and evolutionary history. By studying living crocodylians, we can obtain clues to what ancient, extinct crocodiles and other large reptiles once looked like and how they lived. The basis of such studies is the specimens preserved in museums. At the National Museum of Nature and Science, crocodylians that had been kept and died in zoos and other facilities have been collected and preserved as specimens and used in various studies. In addition, surveys on wild individuals, carried out close to danger, are essential to understand their true nature. This section introduces the forefront of crocodylian research.

Crocodylia first appeared in the Late Cretaceous Epoch as predators on the water's edge. They survived the mass extinction event that killed off non-avian dinosaurs and spread across the world. Among the extant reptiles, crocodylians compose a relatively small group, consisting of 27 species in 3 families. However, they come in various forms and have a powerful presence in the local ecosystems. Recent genetic studies have led to a greater understanding of their previously unknown taxonomic diversity and evolutionary history. This chapter traces the history of crocodylians from around the world that are full of unique characteristics.

Living groups of crocodylians, which have survived since the Mesozoic, are reptiles that have adapted to the waterside environment. They range in total length from less than 2 meters to greater than 6 meters, although all share specialized characteristics for hunting in water, such as hard scales, strong and flexible body, and sharp and pointed teeth. They also display social behavior such as child-rearing and territoriality. This chapter focuses on the amazing body plan and life of living crocodylians and unravels their evolutionary history.

Skull of Saltwater crocodile (National Museum of Nature and Science)

The oil painting of a life sized (the full length is 5 meters long) Saltwater crocodile(painted by Takashi Oda)

Crocodylians that had survived on the earth from ancient times eventually encountered humans. People feared, respected, utilized, and engaged with them in various ways, viewing them as powerful and sometimes mystical creatures. Although there are no wild crocodylians in Japan now, their presence can be felt even today based on fossils, legends, and religious beliefs, as well as by very rare castaways. How have humans been dealing with crocodylians and embracing them as cultural components?

As human neighborhoods have expanded, our conflicts with crocodylians have also increased. Removal as threats to humans, overexploitation, and loss of habitat have led many crocodilian species to the brink of extinction. However, they have also contributed to fortifying human culture and natural resources. How can humans and crocodylians coexist? By examining their current conservation status and efforts toward our co-existence, we herein think of the harmonious future for humans and all wildlife, including crocodylians.