A man who swung his own hammer and built something real.
Their story
Yoshikazu Hasegawa (長谷川 善和) was a Japanese vertebrate paleontologist, university professor, and museum director. He was born on 12 March 1930 in Chiyo, then a village in Shimoina District, Nagano Prefecture, now part of Iida City. The Iida City Art Museum, where he later served as an adviser, recorded that…
Yoshikazu Hasegawa (長谷川 善和) was a Japanese vertebrate paleontologist, university professor, and museum director. He was born on 12 March 1930 in Chiyo, then a village in Shimoina District, Nagano Prefecture, now part of Iida City. The Iida City Art Museum, where he later served as an adviser, recorded that village birthplace. Yokohama National University's proud-alumni curriculum vitae lists the same birthday and names Iida as his birthplace. He finished Iida Takamatsu High School and in 1955 graduated from the Faculty of Liberal Arts at Yokohama National University. That November he became an assistant at the university and began the work that would fill the rest of his life: vertebrate fossils. Japanese press and students called him Hasegawa-sensei (長谷川先生). This profile is that paleontologist, not a namesake musician or athlete.
He stayed close to Yokohama as a part-time lecturer, then in 1965 joined the National Science Museum in Tokyo as a technical official of the education ministry. The museum job put him in the path of a schoolboy's find in Iwaki, Fukushima. In 1968, while Hasegawa was a museum researcher, high-school student Tadashi Suzuki found bones that Hasegawa judged to belong to a long-necked marine reptile, a plesiosaur. A first survey that year and a second excavation in 1970 recovered nearly one animal, later nicknamed Futabasuzukiryu, the Futaba Suzuki dragon, for the Futaba Group rocks and for Suzuki. Cleaning, reconstruction, and formal description took decades. In 2006 Tamaki Sato, Hasegawa, and Makoto Manabe published it as a new elasmosaurid genus and species, Futabasaurus suzukii. The Yomiuri Shimbun later wrote that the work overturned the idea that dinosaur-age marine reptiles of this kind were not found in Japan, and that it helped open a nationwide hunt for dinosaur fossils. Hasegawa himself identified other Japanese Mesozoic bones along the way, including the Iwate specimen nicknamed Moshiryu in August 1978, published in 1991 as a first paper on Japan's dinosaurs, and a Kumamoto fossil he identified in 1984 as Japan's first meat-eating dinosaur specimen, nicknamed Mifuneryu.
In 1972 he earned a Doctor of Science from the University of Tokyo for a study of the Naumann's elephant, Palaeoloxodon naumanni, from late Pleistocene deposits off Shakagahana, Shodoshima, in the Seto Inland Sea. The doctorate sat inside a much wider mammalian program. He described a new insectivore, Shikamainosorex, in 1957. He worked on Quaternary rodents and the large deer of Japan, studied Ryukyu cave faunas including deer, cats, and murids, and later helped name fossil whales and a fossil colobine monkey. The Mammal Society of Japan counted dozens of mammal papers and, when it gave him its prize and special prize, called him a dinosaur doctor in the public mind who in fact carried deep knowledge across vertebrate fossils. International trips listed on the YNU vitae took him to Madagascar in 1973 and 1975, Ethiopia in 1976, China, Europe including the United Kingdom, the United States, Mongolia, the former Soviet Union, South Korea, Australia, and South America, comparing bones, rocks, and museum collections.
He also built the rooms where the public met those bones. YNU records him helping plan or evaluate displays for the Mine City history museum, the Iwaki coal and fossil museum, the Iida City Art Museum, the Natural History Museum and Institute at Chiba, the Kitakyushu Museum of Natural History, and the Kanagawa prefectural museum. From 1979 until retirement in 1995 he was a professor in the Faculty of Education at Yokohama National University, and he lectured at the University of Tokyo, Hiroshima, Kyoto, Nagoya, Shizuoka, Tohoku, and the University of the Ryukyus. After leaving YNU he became an adviser to the new Gunma Museum of Natural History in 1995 and its first director in 1996, the year the Tomioka museum opened. The Yomiuri reported that from 2010 he continued as honorary director and kept giving lectures. He was still honorary director at his death. Popular books carried the same mission. He supervised Gakken dinosaur and fossil encyclopedias, wrote the children's book Nihon no kyoryu (1988) and Kyoryu hakkutsu-ki (1998), translated or co-translated popular dinosaur books, and in 2008 published Futabasukikiryu hakkutsu monogatari, the story of the Futaba excavation. The Iida museum named him an adviser in 1988 and said he guided exhibitions, research, and outreach for 38 years. A planned show of material he had given the museum, "A Genealogy of Paleontology: Tokio Shikama and Yoshikazu Hasegawa," overlapped his death.
Honours followed the long paper trail more than celebrity. In 2007 he was named among the "Nice Step" researchers for a notable contribution to science and technology, and he shared that year's MEXT Prize for Public Understanding of Science and Technology with Tamaki Sato for work on Futabasaurus. The Mammal Society of Japan awarded him its prize in 2011 and a special prize in 2012, citing two thousand years of Japanese mammal evolution through fossils, and noting that he had chaired the society's Tomioka meeting in 1998, the first to pass 350 participants. A flightless Pleistocene diving duck, Shiriyanetta hasegawai, was named for his contributions. In 2018 Yokohama National University named him a Proud Alumnus.
Private life stays mostly off the public page. Obituaries name his home only as Kanagawa Prefecture. They do not name a spouse, and they do not name his parents. They do name his eldest son, Shinichi (真一), as chief mourner. Other children are not named. The funeral and farewell service were set for 10:30 a.m. on 8 September 2026 at Kamakura Family Hall, 2-17-15 Ofuna, Kamakura. The Iida City Art Museum asked the public not to send condolence money, flowers, or offerings there. Kyodo, the Yomiuri, the Shinano Mainichi, and Sankei Sports agree that he died at home at 7:54 a.m. on 2 September 2026 of pancreatic cancer (膵がん), aged 96. Sankei Sports added that he had kept working on mammal fossils until just before his death. Yoshitsugu Kobayashi, a former student, wrote on X that morning that the news had just reached him. He and Manabe had visited Hasegawa at the start of the previous month and had planned to go to Mongolia together that summer. Hasegawa was 96. The YNU proud page also prints 享年97, the inclusive Japanese year-count. The age used here is 96, the count given by Kyodo, the Yomiuri, and Japanese Wikipedia.
Biography adapted from Kyodo via Kumamoto Nichinichi and Sankei Sports; Yomiuri; Shinano Mainichi; Iida City Art Museum; YNU Proud Alumni CV; Wikipedia (EN/JA); Mammal Society of Japan..
In their own words
“Paleoparadoxia was an animal he knew well. He had cleaned Toki City fossils as a student and supervised the pose of a replica at the Mizunami Fossil Museum. The new specimen had bones connected from head to tail and teeth in place. The skull was almost uncrushed. He thought it the best preserved Paleoparadoxia yet found in Japan, and he looked forward to the reconstructed skeleton as research and display material for Mizunami.”
English rendering of Yoshikazu Hasegawa's published comment on the Furusato Choice page for the Mizunami Paleoparadoxia full-skeleton restoration (project 1830). He is identified there as Yokohama National University emeritus professor and Gunma Museum of Natural History honorary director. Not a wor
“At their first meeting the teacher in a beret looked radiant. He wrote many books. I respected him. I am truly sorry.”
Tadashi Suzuki, 75, the Iwaki man who found the bones as a high-school student, to the Yomiuri Shimbun, 2026-09-05. English rendering paraphrased from the Yomiuri Fukushima report, not a verbatim transcript.
“He was full of vitality and dug with his own hammer. About ten years earlier he had still walked briskly up a slope.”
Satoshi Nabana, 65, honorary curator, Iwaki City Coal and Fossil Museum, to the Yomiuri, 2026-09-05. English rendering of the reported remarks.
“There was no wall around him. He was friendly and answered questions carefully.”
Chisato Suzuki, 77, amateur fossil researcher in Iwaki, to the Yomiuri, 2026-09-05. English rendering of the reported remarks.
“The news of his teacher Hasegawa's death arrived that morning. He had visited with Manabe-sensei at the start of the previous month. The three had planned to go to Mongolia together that summer. He would leave for Mongolia the day after next without them.”
Yoshitsugu Kobayashi, via the official book account @dino_mamire, X post 2026-09-02 13:07 UTC. English rendering of the posted tribute, not a word-for-word transcript. Source: https://x.com/dino_mamire/status/2095136599990554998

That's a beautiful way to remember him. He made science belong to everyone.