Hans-Dieter Sues, a distinguished German-born American paleontologist, passed away on February 21, 2026, in Washington, D.C., at the age of 70. Known for his extensive research on Mesozoic terrestrial vertebrates, particularly early dinosaurs and archosauromorph reptiles, Dr. Sues made profound contributions to our understanding of evolutionary transitions in continental ecosystems. His career was marked by a deep commitment to scientific inquiry and a passion for uncovering the ancient past.

Dr. Sues earned his Ph.D. in biology from Harvard University in 1984, laying the groundwork for a prolific career that spanned several prestigious institutions. He held significant curatorial and senior management positions, including Curator of Vertebrate Paleontology at the Royal Ontario Museum in Toronto and the Carnegie Museum of Natural History in Pittsburgh. He later returned to the Smithsonian Institution's National Museum of Natural History, where he served as Senior Research Geologist and Curator of Vertebrate Paleontology, a role he held until his passing.

Throughout his career, Dr. Sues was a prolific author, co-authoring over 150 scientific articles and several influential books on vertebrate paleontology and paleoecology. His work significantly advanced knowledge of the rise of herbivory among reptiles, faunal changes across the Permian-Triassic boundary, and the early diversification of archosaurs. He was also a dedicated science communicator, engaging with the public through various outreach initiatives and inspiring a new generation of paleontologists.

His exceptional contributions to the field were widely recognized through numerous honors and awards. Dr. Sues was elected a Fellow of the American Association for the Advancement of Science in 1997 and a Fellow of the Royal Society of Canada in 2003. He received the prestigious Alexander von Humboldt Prize for Excellence in Research and Teaching in 2010 and the Joseph T. Gregory Award in 2017. In a testament to his impact, the dome-headed dinosaur genus Hanssuesia was named in his honor in 2003.

Dr. Sues's leadership extended to serving as President of the Society of Vertebrate Paleontology from 2002 to 2004, where he championed the advancement of the discipline. His colleagues and peers remember him not only for his profound scientific intellect but also for his great sense of humor and infectious laugh. His legacy will continue to influence studies on vertebrate paleontology and paleoecology for years to come.