Obituary: Professor Jennifer A. Clack FRS (1947–2020)

A close friend and colleague to many at the NHM and elsewhere, Jenny Clack, passed away after a long, brave battle with cancer in the early hours of Thursday 26^th March 2020. Jenny would have been a familiar figure to many of you, not least in her roles in the NHM as an Honorary Research Fellow, a Scientific Associate and a member of the NHM's Science Advisory Board. She was a confidant and collaborator of many in the Fossil Vertebrates team and had long friendships stretching back over decades with several current and former members of staff.

Jenny was at the cutting edge of palaeontological research for nearly four decades. She was, without doubt, the world’s leading expert on the fish-tetrapod transition and made numerous seminal contributions that significantly advanced our knowledge of this critical event in the history of life. This work set new benchmarks that have enabled the field to progress in new and unexpected directions and she has had a far-reaching influence on the subject.

Her interest began with detailed studies of Coal Measure amphibians from the UK (an interest she maintained throughout her career), which also led to important new insights into the evolution of tetrapod ears. Indeed, the evolution of hearing, as revealed by changes in braincase and stapedial anatomy, unravelling the various transformations that occurred in the evolution of the impedance-matching ear, was a major passion, as also displayed through her wide assortment of tetrapod-based, homemade jewellery.

However, Jenny is most famous for her exquisitely detailed anatomical work on the earliest tetrapods and, in particular, on Acanthostega. Following suggestions that East Greenland would be a rich hunting ground, she led several expeditions there to collect important new material of these animals and spent many years documenting the fundamental changes that occurred to jaws, ears, braincases and limbs across the fish-tetrapod transition. This relied on exceptional anatomical skills and Jenny also went on to integrate this morphological work with information from evo-devo to reveal the processes by which these changes took place.

Jenny & Rob Clack, pictured after Jenny was admitted as a Fellow of the Royal Society in 2009. Photograph courtesy of Andrew & Angela Milner, close friends of Jenny & Rob, who’ve both been working with Jenny since the 1980s. All were graduates of Alec Panchen’s group based at the University of Newcastle.

In addition to this work, Jenny continued detailed studies of the taxonomy and biology of a range of other Palaeozoic tetrapod groups (notably anthracosaurs and baphetids) and occasionally ventured into the world of sarcopterygian fish. Latterly, she had been doing important work to close ‘Romer’s Gap’ a mysterious period in tetrapod evolution with few fossils. Her last major project (nicknamed TWEED) found numerous new tetrapod localities in the Scottish Borders and placed them within rigorous chronostratigraphic and environmental contexts: work that is currently ongoing thanks to the extended team that she built.

Many of Jenny’s most impactful papers appeared in Nature, but these were only the tip of a productive iceberg and were accompanied by numerous other papers in more specialist venues, dealing with subjects ranging from taxonomy to evo-devo to biomechanics. Her book on tetrapod origins – Gaining Ground – has been translated into many languages and offers the broadest introduction to the subject available.

In addition to her academic contributions, Jenny mentored a large number of undergraduate and graduate students while she taught at Cambridge (me included). Although she did not produce many MSc/PhD students (a constraint of her curatorial, rather than academic, position) several went on to become leaders in the field (Per Ahlberg, Paul Upchurch, Michael Lee, Matthew Friedman), with others continuing work in either the museum sector or academic publishing.

Jenny’s achievements were recognized during her lifetime by the award of an honorary DSc from Cambridge, the Lapworth Medal of the Palaeontological Association and by election to the Royal Society. Indeed, Jenny was one of only two vertebrate palaeontologists to receive the latter honour over the past 20 years, confirming her preeminent international status.

Jenny is survived by her husband Rob, who is also well-known to many in the Department as a frequent presence on field trips and at conferences. Given current circumstances, the funeral will be small and private but a memorial service and celebration of her life is already being planned for a later date in Cambridge: more details will follow as they become available in future. Jenny will be greatly missed by all who worked with and knew her and we are all sending our collective sympathy to Rob at this difficult time.