The World’s Only Horseshoe Crab Museum
The museum faces the Kōnoshima Channel in Kasaoka, an area known as a breeding ground for horseshoe crabs and designated a National Natural Monument of Japan. The facility was established to support the breeding, display, and conservation of these animals. It opened in March 1990 and continues to be operated by Kasaoka City.
Why the Museum Was Established
Kasaoka, on the southwestern coast of Okayama Prefecture along the Seto Inland Sea, has long been known as a habitat for horseshoe crabs. However, large-scale land reclamation in Kasaoka Bay between 1966 and 1989 reduced their natural habitat and raised concerns about the species’ survival. The museum was established in response, providing a place to study and display horseshoe crabs while promoting their conservation.
Conservation and the Release of Young Horseshoe Crabs
The museum supports the protection of the designated horseshoe crab breeding grounds by releasing young horseshoe crabs into their natural habitat. This work helps sustain the local population and contributes to the conservation of the area’s coastal environment.
Exhibits and Educational Experiences
The museum features a wide range of exhibits about horseshoe crabs and their natural history. Highlights include a life-size model of a roaring Baryonyx, fossilized horseshoe crab tracks, and a live nautilus display. A quiz-based theater also makes learning about prehistoric life engaging for visitors of all ages.
Meet the Museum’s Mascots
The museum has its own family of horseshoe crab mascots. The best-known character, Kabuni-kun, was created when the museum opened in 1990. Inspired by the horseshoe crab, he has a distinctive shell and a pointed tail.
In 2009, a second character, Kabumi-chan, was introduced as part of the museum’s renewal. She also takes the horseshoe crab as her model, with a soft-looking shell and braided hair. Since female horseshoe crabs are generally larger than males, her body was designed to be bigger than Kabuni-kun’s.
On July 4, 2016, the museum announced that Kabuni-kun and Kabumi-chan were getting married. Their children were introduced in 2017: a boy named Kabuki-kun and a girl named Kabuno-chan. Their names were selected through a public naming contest. The mascot family has become a familiar symbol of the museum.
Observe Living Horseshoe Crabs
One of the museum’s greatest attractions is the opportunity to see living horseshoe crabs up close. Often called “living fossils,” horseshoe crabs have retained a body form remarkably similar to that of their ancient ancestors, which lived hundreds of millions of years ago. Large aquariums allow visitors to observe adult specimens, while a separate breeding and exhibition area introduces younger horseshoe crabs and their development.
Other Living Fossils
The museum also introduces other creatures commonly described as living fossils, including coelacanths and nautiluses. These displays offer an opportunity to explore the long history of life on Earth and consider how certain groups of animals have survived through immense changes in the planet’s environment.
The coelacanth first appeared during the Devonian Period of the Paleozoic Era and was once thought to have become extinct around 70 million years ago. In 1938, however, a living specimen was discovered off South Africa. Since then, close to 100 individuals have reportedly been caught. Its survival with many primitive characteristics has made it one of the world’s best-known living fossils.
Nautiluses first appeared during the Ordovician Period of the Paleozoic Era and flourished during the Mesozoic Era. Today, they survive in limited areas around the Philippines and Australia. Seeing these animals alongside horseshoe crabs helps visitors appreciate the diversity and endurance of ancient marine life.
Dinosaurs and Prehistoric Creatures
The museum also features extensive dinosaur and prehistoric-life exhibits. A ramp leading to the second floor, known as the Dino Slope, is lined with dinosaur skeletons and models, creating an immersive journey into the prehistoric world.
Highlights of the Dino Slope
At the entrance, visitors are greeted by a replica of a Plesiosaurus, a marine reptile that lived in the Mesozoic Era. The model measures 2.7 meters in length. Farther along the ramp stands a Baryonyx model that moves and roars, bringing the prehistoric predator vividly to life.
The Giant Camarasaurus
Another striking exhibit is a large Camarasaurus model. This dinosaur measured approximately 16 meters in length and is estimated to have weighed 18 tonnes. Its name means “chambered lizard,” referring to the hollow chambers within its vertebrae.
Hands-On Learning
Inside the exhibition area, a large aquarium measuring 2.95 meters wide, 1.04 meters deep, and 0.75 meters high allows visitors to observe living horseshoe crabs at close range. Younger specimens are also displayed in the breeding area, helping visitors understand the animals’ life cycle.
The museum encourages hands-on exploration as well as observation. At the touch exhibit, visitors can handle fossils of ancient creatures such as ammonites and trilobites. Another activity lets them use a brush to uncover fossils hidden in sand, offering a taste of the work carried out by paleontologists.
A horseshoe crab marionette provides another interactive experience. By operating its controls, visitors can move the animal’s legs and tail spine, making it easier to understand how its body moves.
Views of the Horseshoe Crab Breeding Grounds
The museum’s observation room has an open front that provides broad views of the horseshoe crab breeding grounds, which are designated a National Natural Monument. The sea breeze and scent of saltwater enhance the coastal atmosphere, offering a relaxing pause between exhibits.
Dinosaur Park
A Walk Among Life-Size Prehistoric Giants
Surrounding the museum is a dinosaur park featuring life-size models of dinosaurs and other prehistoric creatures. It was the first full-scale dinosaur park of its kind in Japan and contains eight life-size models representing seven species. The park is divided into three themed zones—Forest, Desert, and Sea—each recreating a different prehistoric environment.
Desert Zone
The Desert Zone depicts a dramatic encounter between a Tyrannosaurus and a Protoceratops. The Tyrannosaurus, armed with sharp teeth, is represented as a formidable predator measuring 15 meters long and weighing an estimated 10 tonnes. The Protoceratops, discovered in the Gobi Desert and dating to the Late Cretaceous, measured approximately 2.4 meters long and weighed an estimated 180 kilograms.
Sea Zone
The Sea Zone features an Elasmosaurus, a long-necked marine reptile that lived during the Late Cretaceous Period. Reaching approximately 10 meters in length, it is thought to have extended its long neck to catch fish and ammonites.
Forest Zone
The Forest Zone features Diplodocus, Iguanodon, and Apatosaurus among scenery designed to evoke a prehistoric woodland. The exhibits suggest how herbivorous dinosaurs may have fed on vegetation in environments resembling modern forests.
Diplodocus is particularly impressive, measuring approximately 27 meters in length and weighing an estimated 10–11 tonnes. Its body structure has often been discussed in connection with adaptations for life on land and in water.
Scientifically Supervised Dinosaur Models
The park’s dinosaur models were produced under the academic supervision of specialists, including Dr. Takashi Hamada, professor emeritus at the University of Tokyo. Details such as skin wrinkles and muscle contours were carefully reproduced to create scientifically informed representations of these prehistoric animals.
Adventure Playground
The museum grounds also include an athletic play area equipped with playground equipment decorated with horseshoe crab and dinosaur motifs. Children can climb and play while enjoying the prehistoric theme, making the museum and park a rewarding destination for families.