I am honored to present Dr. Mary L. Droser as the recipient of the 2024 Paleontological Society Medal. Mary is without a doubt one of the most accomplished and impactful paleontologists of the past four decades. Her work is distinguished by clever and rigorous approaches to especially challenging fossil assemblages and the sedimentary rocks that contain them. Mary has an unrivaled understanding of sedimentary beds and surfaces and the ways in which they record physical information about biotic processes. She complements this insight with an exceptionally deep commitment to gathering new data from the field, putting in countless hours making detailed observations and developing new study areas.

Mary’s singular contributions began with her dissertation work with David Bottjer on bioturbation intensity through the Cambrian and Ordovician Periods. Previous examinations of the early Paleozoic record of animal–sediment interactions had been largely limited to compilations of trace fossil diversity. Recognizing that this approach could not capture the critical ecological and energetic dimensions of Cambro–Ordovician biotic change, Mary developed a new semi-quantitative Ichnofabric Index and spent thousands of hours in the field logging ichnofabric indices through many kilometers of section in the remote Basin Ranges of Utah, Nevada, and California. This allowed her to quantify patterns in the initial development of the infaunal realm, as a novel and informative counterpart to compendia of taxonomic diversity. The resulting papers consider evolutionary, paleoecological, and paleoenvironmental aspects of the early Phanerozoic escalation in bioturbation. Mary and her students built on this work with pioneering studies of trends in the distribution and composition of shell beds, the nature of marine substrates, the development of Burgess Shale-type preservation, and biogeochemical cycling and seawater chemistry that accompanied the colonization and expansion of the infaunal habitat. Mary’s early work also contributed critically to an emerging understanding of the paleoecological dimensions of the Great Ordovician Biodiversification Event.

For the past 25 years, Mary and her students and family have directed much of their effort into painstakingly excavating, studying, documenting, and preserving a unique set of extremely fossiliferous Ediacaran beds at Nilpena Station, in the Ediacara Hills of South Australia. Initially intending to work at Nilpena for only a few field seasons, Mary recognized the extraordinary potential of the site and redirected much of her research program toward realizing this potential. Over the course of many long field seasons, Mary has led the excavation and reconstruction of 40 beds representing a total of over 400 square meters of Ediacaran seafloor—a record unparalleled by any other Ediacaran section except the naturally exposed bedding planes on the Avalon Peninsula of Newfoundland. Mary and her students and collaborators have documented a rich variety of undescribed microbial textures and numerous newly discovered and reinterpreted metazoans with previously unknown body plans, ecologies, and phylogenetic affinities. Discoveries include the earliest evidence of sexual reproduction in metazoans, early records of pelagic lifestyles, early records of poriferan skeletonization, a candidate early bilaterian, the beginnings of mobility, and the early records and antecedent steps toward animal life below the seafloor. By changing the focus from cataloging enigmatic forms to understanding the lifestyles of specific taxa, Mary’s work has illuminated Ediacaran assemblages as ecosystems. Mary and her students and collaborators have also proposed a compelling new model for Ediacaran-style preservation and demonstrated that these assemblages have exceptionally high spatiotemporal fidelity.

While leading this research program, Mary has also invested a great deal of energy into a successful bid to have Nilpena designated a National Park and an ongoing bid for UNESCO World Heritage status to ensure that it will be protected and available to future researchers and the public. Characteristically, she has done this largely through bottom-up community organizing, bringing together the diverse and often conflicting private, tribal, and governmental stakeholders in the Ediacara Hills. This achievement may be the culmination of Mary’s organizing efforts, but it is hardly unique: Mary has always stood out in our field as both an energetic and inspiring community builder—most recently as the organizer of the highly successful 2019 North American Paleontological Convention at UC Riverside—and a thoughtful and ethical scientist who never prioritizes her own needs over those of others.

Finally, I know from my own experience as a former Ph.D. student of Mary’s that she is a truly extraordinary and exemplary advisor to graduate students, going well above and beyond to ensure that her students thrive. Mary points students toward interesting problems and invests a huge amount of time and effort in training them while also encouraging them to develop their own ideas and scientific identities. She is well known in the field for fostering a lab environment that is intellectually challenging but also deeply supportive, inclusive, and—not least—fun, and this is reflected in the number of her former students who have gone on to professional success. Mary was a strong voice and model for diversity, equity, and inclusion long before these values attained their current prominence, and she continues to lead by example.

To summarize, Dr. Mary L. Droser is an outstanding scientist who has devoted her career to unraveling the sedimentary and fossil record of the rise, diversification, and ecological expansion of animals. She is an innovator who develops new approaches and a careful and insightful observer who has set a very high bar for Ediacaran–Paleozoic field studies. She is an exemplary mentor and model for students and a community builder whose social and service contributions complement her scientific contributions. She is, in short, an ideal recipient for the Paleontological Society Medal.