Overview

Jennifer Alice "Jenny" Clack FRS (née Agnew; 3 November 1947 – 26 March 2020) was an English palaeontologist best known for her work on the early evolution of tetrapods. She served as curator at the Cambridge University Museum of Zoology and as Professor of Vertebrate Palaeontology at the University of Cambridge. Her research integrated fossil discovery, anatomical description and evolutionary interpretation to address how lobe‑finned fishes gave rise to the first four‑limbed vertebrates. See a general profile.

Research focus and methods

Clack concentrated on Late Devonian and early Carboniferous material that records the transition from fin to limb. She combined careful preparation and description of fossils with comparative anatomy and modern imaging where appropriate, and emphasised the importance of functional and ecological interpretation. Her publications placed fossil anatomy in a broad evolutionary framework; further context is available at palaeontological summaries.

Major contributions

  • Detailed anatomical studies of early tetrapods clarified the sequence of changes in skulls, vertebrae and limbs that accompanied terrestrialisation.
  • She popularised the informal term "fishapod" for transitional Devonian forms, highlighting the mosaic nature of evolutionary change.
  • Her work linked morphology to habitat, arguing that many important changes occurred in freshwater and marginal environments rather than in fully marine settings.

Her synthesis of anatomy, ecology and phylogeny remains a cornerstone for studies of tetrapod evolution.

Career, fieldwork and curation

Clack combined curatorial duties with active fieldwork and academic teaching. As a long‑term curator at the Cambridge University Museum of Zoology she helped manage collections and make specimens available for research; see the museum curatorial role. She held the university post of Professor of Vertebrate Palaeontology and contributed to training students and early‑career researchers; details of her academic role are summarized at academic post.

Historical and scientific significance

Working within the geological framework of the Devonian and the subsequent Carboniferous, Clack emphasised how environmental settings such as freshwater habitats and marginal wetlands provided ecological contexts that favoured the evolution of weight‑bearing limbs and air‑breathing adaptations. Her studies showed that the origin of tetrapods was a complex, stepwise and regionally variable process rather than a single sudden event.

Recognition and legacy

Clack was widely respected for rigorous descriptive work, clear synthetic writing and mentorship of younger scientists. She was elected a Fellow of the Royal Society and is remembered for establishing durable anatomical and ecological frameworks for understanding the fish‑to‑land transition. For institutional and further reading links see profile and research summaries at palaeontology resources.