Lab Members

Interested students: Please contact Selena if you’re interested in becoming involved in the PEPPR lab! There are plenty of research opportunities for undergraduates and graduate students, especially for those who are interested in plant anatomy, evolution, plant paleoecology and/or the link between plants and climate.

Here are some descriptions of current and available projects we’re working on!

Current Lab Members


Dr. Selena Y. Smith, Principal Investigator. I am an Associate Professor in the Department of Earth & Environmental Sciences and the Program in the Environment at the University of Michigan, and Associate Research Scientist in the Museum of Paleontology. My interests are diverse, including plant evolution, anatomy & structure, paleoecology, and taphonomy…anything about plants and the past, and I’m there! I earned my B.Sc. (Hon.) in Evolutionary Biology and a Ph.D. in Systematics and Evolution from the University of Alberta. I was a Royal Society postdoctoral fellow with Margaret Collinson at Royal Holloway, University of London, and then a junior fellow in the Michigan Society of Fellows.


Dr. John Benedict, Lecturer, PitE. John was a postdoc in the lab for two years, and continues to be part of PEPPR in his “spare time.” He is helping to decipher the evolutionary history of the gingers, bananas, and relatives – the order Zingiberales, as well as leading his own projects on various plants including the fossil record of Alnus (alders) and the diversity of the Miocene Shimokawa Chert from Japan. John earned a B.S. and Ph.D. in Plant Biology from Arizona State University, and spent a year as an adjunct faculty member at University of Guam, before coming to UM.

Kelly Martin, Research Assistant/Lab Manager. Kelly earned his BS in Biology from Pennsylvania State University with a minor in Environmental Studies. He is interested in all things relating to paleontology and evolutionary biology.

Zachary Quirk, PhD candidate (2018–). Zack earned his BSc from the University of Rochester. He’s exploring leaf functional traits of the ginger family (Zingiberaceae), trying to better understand how these plants adapted and evolved through environmental and climatic changes in the geologic past, and what inferences we can make about living gingers reacting to anthropogenic climate change.  

Jerónimo Morales Toledo, Phd pre-candidate (2021–). Jerónimo earned his Bachelor’s degree in UNAM (National Autonomous University of Mexico) and later his Master’s Degree in the same university, both works got an Honorific Mention from the Synodal Committee, studying a Middle Jurassic Flora from Mexico. He is interested in plant evolution, taxonomy and extinct plant groups (such as pteridosperms and Bennettitales). Nowadays he is interested in integrating plant fossils into the plant tree of life. 

Kate Morrison, PhD pre-candidate (2021-). Kate earned her BS from the University of Idaho. She is interested in studying the diversification of Cretaceous angiosperms and interpreting paleoenvironments. She is particularly excited to be working with fossil wood from Antarctica and diving into the rich history of the supercontinent Gondwana.

Michael Machesky, MSc candidate (2021-2023). Mike earned his BS in Earth and Environmental Sciences from University of Michigan with a minor in East European Studies. He is studying the use of plant anatomy and isotope geochemistry for paleoclimatic and paleobotanical applications, co-advised with Dr. Nathan Sheldon.

Malinda Barberio, undergraduate (first in UROP program, now a research assistant) (2019-). Malinda is studying plant biology. At her home, she collects plants and specializes in aroids.

Katherine Harpenau, undergraduate (2022-).

Katherine is planning on majoring in Earth Science and PitE with a minor in Science, Technology, and Society. She enjoys getting coffee and going for long walks, many times simultaneously. She is excited to continue helping Zack in analyzing the effects of temperature and carbon dioxide on leaf traits.

Sarah Lindsey, undergraduate (2022 -). Sarah is studying Earth & Environmental Sciences and Program in the Environment. She enjoys hiking, identifying plants, and baking.

Dongsheng Yan, undergraduate (2022-). Dongsheng is a junior undergraduate student. He likes playing badminton and hiking, and is
interested in working on plants. He did a lot of anatomy and xylem analysis in the past. Now he’s helping Jeronimo collect data from microCT scans of monocot seeds and fruits.

Lab Alumns


  • Will Iles

Graduate Students

  • Bekah Stein (PhD 2020; postdoc at UC Berkeley and Agouron Institute Geobiology fellow), Carbon and Water Dynamics in Modern and Ancient Plants and Soils
  • Molly Ng (PhD 2020; Rea postdoc at Carnegie Museum of Natural History), Evaluation and Application of Leaf Anatomical Links to Climate in Metasequoia (Cupressaceae)
  •  Kelly Matsunaga (PhD 2019; postdoc at Chicago Botanical Garden; now Thomas N. Taylor Assistant Professor and Assistant Curator at University of Kansas), Fossils, fruits, and phylogeny: an integrative approach to understanding the evolutionary
    history of palms (Arecaceae).
  • Chelsea Mervenne (MSc. Fall 2015; co-supervised with Nathan Sheldon, Earth & Environmental Sciences), Isotope ecology of conifers.
  • Ethan Hyland (PhD 2014; co-supervised with Nathan Sheldon, Earth & Environmental Sciences), Reconstructing Eocene paleoenvironments.
  • Meredith Dennis (MSc. spring 2012; co-supervised with Nathan Sheldon, Earth & Environmental Sciences), Phytolith evidence for vegetation change across the Eocene-Oligocene transition in Montana
  • Lauren Miller (MSc., summer 2010; co-supervised with Nathan Sheldon, Earth & Environmental Sciences), Using phytoliths to reconstruct a high-resolution record of deep-time vegetation dynamics from the Eocene of Montana

Undergraduate Students

  • Lian Anderson (2020-2021) undergraduate research assistant, looking at trends in seed size in the Cretaceous and Cenozoic.
  • Seamus Callaghan (2020-2021) did an Honor’s thesis on a fossil Cornales fruit from the Cretaceous of Sucia Island. He’s now doing a PhD with Kevin Boyce at Stanford University.
  • Sarah Sturtz (2019-2021) undergraduate in UROP and research assistant, working with Bekah on stomatal features of Thuja and Populus.
  • Ashley Hamersma (2017-2020) was a research assistant with Selena working on various monocot projects. She’s now joined Steven Manchester’s lab at University of Florida for a PhD.
  • Kendall Rosevelt, undergraduate in UROP (2019-2020), worked with Selena on monocot leaf architecture and physiology.
  • Jen Wen (2019-2020) did an Honor’s thesis with John to look at aquatic plant ecology in relation to contaminants.
  • Jessie Agee, undergraduate research assistant and former UROP program (2017-2019), assisted Molly on her project linking functional traits in the redwood family.
  • Kaylie Charland, undergraduate research assistant and UROP program (2017-2019) who worked with Molly linking functional traits in the redwood family.
  • Tabitha Faber, undergraduate/senior thesis (2016-2019) who worked with John on Iris populations of Michigan. She’s now pursuing a PhD at University of Wisconsin.
  • Jasimine Ash, undergraduate in UROP program (2018-2019) who worked with Kelly on microCT analysis of palm fruit structure.
  • Leah Pifer, undergraduate in UROP program (2018-2019) worked with Selena on monocot leaf architecture and physiology.
  • Alice Hanlon, undergraduate research assistant (2018-2019) worked with John on ginger seed structure.
  • Stephanie Robinson, UROP student (2018-2019) worked with John on pollen analysis of a core from Northern Michigan.
  • Jenny Ruan, UROP 2017-2018 worked with John on ginger seed structure.
  • Serena Safawi UROP 2017-2018, Summer 2018 research assistant worked with Kelly on microCT analysis of palm fruit structure.
  • Lauren VanWagoner, Senior Thesis (2017-2018), Carbon Stable Isotopes of Palms
  • Mireille Farjo, Undergraduate Research Assistant (summer 2017), assisted with CT scanning palm fruits and Deccan Intertrappean Beds fossils.
  • Daniel Wu, Undergraduate Research Assistant 2016-2017, worked with Molly on investigating morphological and anatomical response of Taxodium distichum to environmental gradients.
  • Julian Hansen, UROP 2016-2017, on digital dissections of Zingiberales seeds.
  • Amanda Salvi, Undergraduate Research Assistant (2013–2016, UROP 2013). Amanda studied leaf architecture in Zingiberales, and doing an Honors thesis on why Costus (the spiral gingers) have a spiral arrangement to their leaves. In Fall 2016 she started a PhD in Botany at the University of Wisconsin-Madison!
  • Iris Partlan, Undergraduate Research Assistant (2015–2016, UROP student, 2014–2015). Iris worked on fossil ginger seeds from the Eocene of Vancouver Island.
  • Madelyn Celovsky, Undergraduate Research Assistant (2015-2016). Madelyn examined biodiversity of Zingiberales as recorded through the fossil record.
  • Chien Tan, Undergraduate Research Assistant (2015-2016; co-supervised with Nathan Sheldon). Chien is assisting with studies on a Late Cretaceous permineralized fossil flora from the Western Interior Seaway in Colorado.
  • Symone Bawol, Undergraduate Research Assistant, 2013-2015; UROP 2012-2013. Symone studied phytoliths from Zingiberales and for reconstructing paleovegetation in Montana.
  • Victoria Chrumka, Undergraduate Research Assistant, 2014-2015. Victoria looked at plant diversity preserved as permineralized plant material in the Cretaceous Western Interior Seaway.
  • Miles DeNudt, UROP student, 2014-2015. Miles will be looking at tomography data of ginger seeds, especially focusing on digitally dissecting out the operculum to look at its taxonomic significance.
  • Carli Balogh, Research assistant, 2012-2013. Phytolith and isotope based vegetation reconstruction in Montana. Carli has moved on to pursue graduate studies at the University of Nevada-Reno!
  • Alison Bradley, Research assistant 2013-2014. 3D visualization
  • Gabrielle Hodges, UROP 2013-2014. Paleobiodiversity and paleoecology of Pinaceae
  • Charlotte King, UROP 2013-2014. Diversity of seed structure in Zingiberales
  • Carter Reinke, UROP 2013-2014. Leaf architecture and vein density in monocots
  • Stephanie Chen, Research assistant, 2010-2013, UROP 2009-2010, resident phytolith expert, phytolith and isotope based vegetation reconstruction in Montana. Stephanie is now pursuing a PhD at North Carolina State University!
  • Catherine Hu, Independent study, 2012-2013; UROP student, 2011-2012, using seeds and x-rays to understand evolution in Zingiberales. Catherine recently finished her Master’s in Conservation from UW-Madison and is working as a nature reserve steward with Forest Park Forever in St. Louis, MO.
  • Germain Burchfield, UROP student, 2011-2012, biodiversity of monocots.
  • Tess Nugent, Research assistant, 2011-2012 (co-supervised with Nathan Sheldon, Earth & Environmental Sciences), relationship between Ginkgo carbon isotopes and climate
  • Bryana Boos, Research assistant, 2009-2012, Independent Study, 2011: conifer diversity from Late Cretaceous Pierre Shale nodules in Colorado.
  • Cameron Webley (Geosci 499, Winter 2010), depositional environment and paleoecology of Cretaceous Pierre Shale nodules from Colorado, USA
  • Xiang (Bill) Zhou (UROP 2009-2010), uses of 3D synchrotron tomography in understanding the fossil record of Zingiberales


  • Earth-RISE 2022 cohort: Aubrin Deyarmond, Eselohirere Izirein, Sofia Martinez-Lozoya
  • Cristina Squatriti, high school student volunteer (2018-2019). Cristina worked on a fossil cycad seed from the Cretaceous of South Dakota.
  • Monica Choi, high school student volunteer (2014–2016). Monica studied the opercula of ginger seeds by using synchrotron tomography data to digitally dissect out these tiny structures.