Peter Andreas Hochuli (1946–2018)

Peter Andreas Hochuli, a dedicated, eminent and highly talented palaeobotanist and palynologist with comprehensive expertise in palaeoclimatology, palaeoecology and stratigraphy, sadly died of cancer on 27 March 2018. He was only 71 years old. Peter Hochuli was born on 25 October 1946 in the small village of Unterentfelden in the Canton of Aargau, northern Switzerland. He attended primary school in Unterentfelden; however, his mother and sisters convinced him to continue his education in the boarding school at the Cistercian monastery in the nearby city of Wettingen, in the Limmat Valley, district of Baden. The monastery school stimulated and reinforced his curiosity for nature, and Peter became fascinated by all the natural sciences, especially botany. Peter collected plants in and around Aargau for his own herbarium while he was at boarding school. His herbarium encompasses 2131 sheets, largely comprising very well-preserved flowering plants together with 67 specimens of lichens. It is now part of the collection of Naturama Aargau, a museum of natural history in Aarau, the capital of the Canton of Aargau. Following graduation from school, Peter began his studies in natural sciences at the University of Z€urich. At first he focused on botany, and subsequently developed an ever-increasing interest in palaeobotany. Die Urwelt der Schweiz [The primal world of Switzerland] by Oswald Heer, a professor of botany (Heer 1883), became one of his favourite books. This impressive early magnum opus on Earth history, with chapters on palaeoclimate and the use of fossil plants as climate proxies, taught Peter well that a background in geology is essential in order to better understand the evolution of plants. In 1976 Peter completed his PhD dissertation on Cenozoic aquatic and terrestrial palynomorphs from the Alpine Molasse basin, entitled Palynological investigations of the Oligocene and the Early Miocene of the Central and Western Paratethys (Hochuli 1978). He then continued his scientific career as a postdoctoral fellow at the Swiss Federal Institute of Technology (ETH), Z€urich, which included a sabbatical at the University of Saskatchewan, Canada, to work with Bill Sarjeant. In the late 1970s, Peter began his long-standing scientific collaboration with Helmut Weissert on Cretaceous oceanic anoxic events. Together with Judy McKenzie and Helmut Weissert, Peter successfully combined carbon isotope geochemistry with micropalaeontology and palynology in order to reconstruct the palaeoclimate of the Barremian (Weissert et al. 1979). Peter Hochuli demonstrated his adaptability and versatility when he completed his habilitation on Palynostratigraphy of the Permo–Carboniferous of northeastern Switzerland in 1985 at the University of Zürich. The same year, he left university for the oil industry to work as a stratigrapher for Esso Production Research European, later Esso REP, Bègles, Bordeaux, France. For 10 years at Esso, he worked as part of a team on material from the entire Phanerozoic of the northern hemisphere from northern Norway to Central Africa. In 1995 Peter moved from France back to Switzerland and rejoined academia. He was appointed senior lecturer at the universities of Fribourg and Z€urich. In addition to his university career, he continued to work as a consultant on biostratigraphy. At this time Peter and Helmut Weissert resumed their collaboration on Cretaceous palaeoclimatology and palaeoceanography, and so this long-lasting and extremely productive cooperation was reestablished. Helmut and Peter co-authored several influential articles, for example on the floral response to mid-Cretaceous oceanic anoxic events (Hochuli et al. 1999). During 2002 Peter joined Hugo Bucher’s research group at the Palaeontological Institute and Museum, University of Zürich, and in 2008 he was appointed professor. In the early 2000s, Peter worked on Cretaceous palaeoclimates and the early evolutionary history of the angiosperms, from material collected in Brazil and Portugal in collaboration with Helmut Weissert and his two PhD students Stefan Burla and Ulrich Heimhofer (e.g. Hochuli et al. 2006; Heimhofer et al. 2007, 2012; Heimhofer and Hochuli 2010). With Hugo Bucher and others, he also undertook multidisciplinary research projects on palaeoclimate and vegetational changes across the Permian–Triassic transition (e.g. Galfetti et al. 2007a, 2007b; Hochuli and Vigran 2010; Hochuli et al. 2010a; Schneebeli- Hermann et al. 2015). Peter and his co-workers, including PhD students Elke Hermann and Anna Sanson-Barrera, succeeded in demonstrating that plants responded in much more complex ways than previously thought to changing environmental conditions during mass extinctions, with shifts due largely to environmental changes rather than evolutionary phenomena and/or paced by volcanic pulses (e.g. Hermann et al. 2010, 2011; Hochuli et al. 2010b; Schneebeli- Hermann et al. 2013; Romano et al. 2013; Sanson-Barrera et al. 2015). Despite Peter’s interest in unravelling the palaeoecological aspects of plant evolution and its intimate link to palaeoenvironmental change, he never lost interest in the stratigraphical value of palynomorphs. He continued, for example, to work on material from the Barents Sea that he first examined during his time in the oil industry (Hochuli et al. 1989; Mørk et al. 1990). He did this in close collaboration with Norwegian colleagues, in particularly the palynologist Jorunn Os Vigran. This work resulted in a series of pioneering publications from this region and, in one of his last research projects, he returned to the Triassic palynostratigraphy of the Barents Sea region (Vigran et al. 2014). Peter was best known for his work on terrestrially derived palynomorphs (e.g. Hochuli 1981); however, he also had significant experience with Mesozoic and Cenozoic dinoflagellate cysts (e.g. Hochuli 1978; Hochuli and Kelts 1980; Jan du Ch^ene et al. 1986; van Veen et al. 1998; Hochuli and Frank 2000). Furthermore, Peter was never afraid of presenting provocative ideas, so long as they were based on robust evidence. An example of this is his discovery, together with Susanne Feist-Burkhardt, of early angiosperm pollen grains from the Middle Triassic (Hochuliand Feist-Burkhardt 2004; Hochuli and Feist-Burkhardt 2013). Peter was one of the few scientists who managed to develop an integrated approach by combining his broad palaeobotanical expertise with his deep knowledge of geology and sedimentology. This effortless polymathy enabled him to successfully tackle some of the big questions in the evolutionary history of plants. Peter Hochuli was an outstanding scientist and research partner. One of the aspects of his character, so often missing in the world of science, was his ability to listen to others and to argue with colleagues in an utterly respectful way. Both his colleagues and his students appreciated Peter’s willingness to share his enthusiasm, experience and passion for the twin sciences of palaeobotany and palynology. In his 40 years of palynological research, Peter published over 120 articles, as well as numerous unpublished technical reports. Many of his papers are highly cited, extensively read, and published in high-profile journals. Despite his declining health, he was scientifically active right to the end of his life. Peter Hochuli will always be remembered as an extremely dedicated scientist, and an amiable, cheerful and helpful colleague. He was a dedicated and inspiring teacher and mentor with a fantastic sense of humour. Furthermore, he was always very gentle, hardworking, modest, perceptive, polite and supportive. For many younger colleagues, Peter’s scientific guidance was of outstanding value. He is deeply missed