Zuiyo-maru carcass

The Zuiyo-maru carcass (ニューネッシー, Nyū Nesshii, literally "New Nessie") was a corpse, caught by the Japanese fishing trawler Zuiyō Maru (瑞洋丸) off the coast of New Zealand in 1977.

[2][3] Decomposing basking shark carcasses lose most of the lower head area and the dorsal and caudal fins first, making them resemble a plesiosaur.

On April 25, 1977, the Japanese trawler Zuiyō Maru, fishing east of Christchurch, New Zealand, caught a strange, unknown creature in the trawl.

The crew was convinced it was an unidentified animal,[4] but despite the potential biological significance of the curious discovery, the captain, Akira Tanaka, decided to dump the carcass into the ocean again so not to risk spoiling the fish caught.

However, before that was done, some photos and sketches were taken of the creature, nicknamed "Nessie" by the crew, measurements were taken and some samples of skeleton, skin and fins were collected for further analysis by experts in Japan (later the shipping company ordered all its boats to try to relocate the dumped corpse, but without apparent success).

He recalled other discoveries of similar dead marine creatures resembling plesiosaurs that on closer inspection revealed them to be just decomposed, unusually large sharks.

A team of Japanese scientists, Tadayoshi Sasaki and Shigeru Kimura from the Tokyo University of Marine Science and Technology, Ikuo Obata from the National Museum of Nature and Science, and Toshio Ikuya from the Atmosphere and Ocean Research Institute at the University of Tokyo, concluded jointly that, while the identity of the carcass could not be determined with certainty, the carcass was most likely that of a basking shark or some species closely related.