• Adjunct Professor, Northwestern University
• Lecturer, Committee on Evolutionary Biology, University of Chicago
• Research Associate, The Field Museum

• American Society of Plant Taxonomists, International Association for Plant Taxonomy, Botanical Society of America
• President, International Association for Plant Taxonomy
• Chair, International Association of Botanical and Mycological Societies

My research is directed at understanding the evolutionary history of plants, and is focused in two broad areas: study of Mesozoic age fossil plants to document their evolutionary history, and systematics of the legume family. Graduate students working with me have the opportunity to participate in these projects, or focus on other research topics. In my research I am working to understand present and historical patterns of diversity and details of morphological evolution using both living and fossil plants. Paleontological data provide unique insights into phylogeny, biogeography, and taxonomic and structural diversity that are not available in studies that include only living organisms.

Paleobotanical Research on Mesozoic Age Fossil Plants

The Mesozoic was a period of great change. Ancient lineages of seed plants were disappearing and other lineages were taking their place. Some of these would go on to dominate modern ecosystems, such as the conifers and angiosperms. Jurassic and Early Cretaceous age rocks from Mongolia and Inner Mongolia, China, are the source for a remarkable diversity of fossil plants and animals. The Early Cretaceous of Mongolia in particular is well known for its fossil dinosaurs and other vertebrates, but fossil plants from Mongolia are very poorly studied. Together with an international group of collaborators we are studying diverse assemblages of fossil plants from Mongolia and China that are yielding new, exceptionally well-preserved fossil seed plants. Our goal is to understand the diversity and evolutionary implications of these fossil plants. The fossils are studied primarily using scanning electron microscopy and high-resolution X-ray microtomography. The excellent preservation provides a rare opportunity to reconstruct extinct Jurassic and Cretaceous age “whole plants” from multiple co-occurring fossil organs. Our research is adding significantly to knowledge about extinct seed plants during the Jurassic and Early Cretaceous, an interval of major and rapid evolutionary and vegetational change, immediately prior to the major diversification of angiosperms.

In Mongolia we are studying well-preserved seed plants from multiple Early Cretaceous age localities. The fossils are mainly mummified leaves, shoots, cones, seeds and other plant parts preserved three-dimensionally as lignified mesofossils. In addition, there are also well-preserved compression fossils from several localities. From the Tevshiin Govi lignite mine we have described multiple genera of the pine and redwood families, as well as several very interesting representatives of extinct seed plant lineages. From Inner Mongolia we are studying fossil plants from several coal mines, including Huolin Gol where a chert deposit provides exceptional anatomical preservation of a diverse assemblage of fossil plants. Several of the plant species preserved in chert at Huolin Gol are also present in the lignite at Tevshiin Govi. This gives us the exciting opportunity to combine morphological and anatomical information from two different modes of preservation to maximize our knowledge of structural details for these plants and to provide more detailed reconstructions of “whole fossil plants.”

We are also conducting research on the early fossil record of flowering plants. The angiosperms are the largest group of land plants, yet their origin and early diversification have long been poorly understood. Flowering plants diversified rapidly during the Cretaceous when they became abundant and diverse and dominated nearly all terrestrial ecosystems. Materials for these studies, which include fossil flowers, fruits, and seeds that have been preserved as charcoal or as mummified remains, are derived from numerous fossil localities in North America, Europe and Japan. In addition to flowering plants, these fossil sites yield diverse assemblages of fossil conifers, ferns, and bryophytes that are in need of detailed study.

Systematics of the Leguminosae

As the third largest family of flowering plants, the Leguminosae is extremely diverse taxonomically, biologically, and in vegetative and reproductive morphology and anatomy. One of my primary areas of research is working to understand the evolutionary history of this large and important family. This research has been focused on the critically important early branching lineages within the family, which traditionally were recognized as the subfamily Caesalpinioideae. This project involves several international collaborators, including A. Bruneau (Montréal) and G. Lewis (Kew). Our primary goal has been to produce a comprehensive phylogeny for caesalpinioid legumes based on phylogenetic analyses of morphological and molecular data. In addition, graduate students have conducted revisionary monographic studies on particular caesalpinioid genera or groups of genera that needed detailed study.

Our phylogeny for basal legume relationships reinforced the view that the traditional Caesalpinioideae subfamily was paraphyletic and required revision. Several caesalpinioid lineages have more basal positions in the family than either the Mimosoideae or Papilionoideae, and some lineages are more closely related to Mimosoideae or Papilionoideae than they are to other caesalpinioids. With these results we worked with the Legume Phylogeny Working Group (LPWG) to develop a new subfamily classification for the family. How many distinct lineages are there in the “Caesalpinioideae,” at what level should they be recognized relative to mimosoids and papilionoids, and how many subfamilies would be required to produce a phylogenetic classification at the subfamily level? Some of these questions had multiple possible answers and therefore we decided that it would be advantageous to engage the legume systematics community in the process of developing a new classification that would be acceptable to the community as a whole. This process took several years, but the result was a well thought out classification, and a strong collaborative relationship among numerous specialists in the family (Legume Phylogeny Working Group 2013a, 2013b, 2017). Ongoing work is now focused on tribal classifications within the individual subfamilies.

Pan, A.D., B.F. Jacobs, E.D. Currano M. de la Estrella, P.S. Herendeen, X.M. van der Burgt. In Press. A fossil Anthonotha (Leguminosae: Detarioideae: Amherstieae) species from the Early Miocene (21.73 Ma) of Ethiopia. American Journal of Botany.

Herendeen, P.S. and A. Bruneau. In Press. Tribe Gleditsieae. In Advances in Legume Systematics 14. Classification of Caesalpinioideae. Part 2. Higher level classification. A. Bruneau, L. Paganucci de Queiroz, J.J. Ringelberg, eds. PhytoKeys.

Pan, A.D., B.F. Jacobs, R.T. Bush, M. de la Estrella, F. Grímsson, P.S. Herendeen, X.M. van der Burgt, E.D. Currano. 2023. First evidence of a monodominant (Englerodendron, Amherstieae, Detarioideae, Leguminosae) tropical moist forest from the Early Miocene (21.73 ma) of Ethiopia. PlosONE. https://doi.org/10.1371/journal.pone.0279491

Shi, G., F. Herrera, P.S. Herendeen, E.G. Clark, P.R. Crane. 2022. Silicified cupulate seed-bearing structures from the Early Cretaceous of eastern Inner Mongolia, China: rethinking the corystosperm concept. Journal of Systematic Palaeontology http://dx.doi.org/10.1080/14772019.2022.2133644.

Gravendyck, J., R.A. Fensome, M.J. Head, P.S. Herendeen, J.B. Riding and N.J. Turland. 2022. (142–148) Proposals to improve the definition, utility, and curation of (type) specimens of fossil algae, fungi, and plants. Taxon 71: 705-706.

Herendeen, P.S., M.A. Bickner, E. Bugdaeva, S. Naugolnykh, and E. Kostina. 2022. The problematic genus Problematospermum. Taxon. https://doi.org/10.1002/tax.12722

Herendeen, P.S., D.B.O.S. Cardoso, F. Herrera, and S.L. Wing. 2022. Fossil papilionoids of the Bowdichia clade (Leguminosae) from the Paleogene of North America. American Journal of Botany 109: 130-150. DOI: https://doi.org/10.1002/ajb2.1808  

Dong, C., G. Shi; F. Herrera; Y. Wang; Z. Wang; B. Zhang; X. Xu; P. S. Herendeen; P. R. Crane. 2021. Leaves of Taxus with cuticle micromorphology from the Early Cretaceous of eastern Inner Mongolia, Northeast China. Review of Palaeobotany and Palynology 298: 104588. https://doi.org/10.1016/j.revpalbo.2021.104588

Herrera, F., Testo, W., Field, A., Clark, E., Herendeen, P.S., Crane, P.R., and Shi, G. 2021. A permineralized Early Cretaceous lycopsid from China and the evolution of crown clubmosses. New Phytologist. https://doi.org/10.1111/nph.17874  

Herrera, F., G. Shi, M. Bickner, N. Ichinnorov, A. Leslie, P.R. Crane, and P.S. Herendeen. 2021. Early Cretaceous abietoid Pinaceae from Mongolia and the history of seed scale shedding. American Journal of Botany 108: 1483-1499.

Li, X., S.R. Manchester, J.E. Correa-Narvaez, and P.S. Herendeen. 2021. An extinct fruit species of Fabaceae from the Early Eocene of northwestern Wyoming, USA. International Journal of Plant Sciences 182: 730-746. https://doi.org/10.1086/715634

Gravendyck, J., R.A. Fensome, M.J. Head, P.S. Herendeen, J.B. Riding, J.B. Bachelier, and N.J. Turland. 2021. Taxonomy and nomenclature in palaeopalynology: basic principles, current challenges and future perspectives. Palynology 45: 717-743. https://doi.org/10.1080/01916122.2021.1918279

Shi G., Tan T., Li J., Dong C., Zhang B., Wu Q., Yin S., Herrera F., Herendeen P. S., Crane P. R. 2021. Age of the Huolinhe Formation, eastern Inner Mongolia, China: evidence from U-Pb zircon dating and palynological assemblages. Journal of Stratigraphy 45: 69-81. DOI: 10.19839/j.cnki.dcxzz.2021.0001.

Shi, G., F. Herrera, P.S. Herendeen, E.G. Clark and P.R. Crane. 2021. The cupules of Mesozoic seed plants and the origin of the angiosperm second integument. Nature 594: 223-227. https://doi.org/10.1038/s41586-021-03598-w

Matsunaga, K.K.S., P.S. Herendeen, F. Herrera, N. Ichinnorov, P.R. Crane and G. Shi. 2021. Ovulate cones of Schizolepidopsis ediae sp. nov. provide insights into the evolution of Pinaceae. International Journal of Plant Sciences 152: 490-507. DOI: https://doi.org/10.1086/714281

Takahashi, M. P.S. Herendeen, F. Herrera, R. Hirayama, H. Ando, K. Sasaki, and P.R. Crane. 2021. A new assemblage of plant mesofossils (late Coniacian – early Santonian; Upper Cretaceous) from the Tamagawa Formation, Kuji Group, in northeastern Japan. Paleontological Research 25: 120-126. https://doi:10.2517/2020PR015.

Koenen, E.J.M., D.I. Ojeda, F. Bakker, J.J. Wieringa, C. Kidner, O.J. Hardy, R.T. Pennington, P.S. Herendeen, A. Bruneau and C.E. Hughes. 2020. The origin of the legumes is a complex paleopolyploid phylogenomic tangle closely associated with the Cretaceous-Paleogene (K-Pg) mass extinction event. Systematic Biology. https://doi.org/10.1093/sysbio/syaa041

Gravendyck, J., J.B. Bachelier, W.M. Kürschner, and P.S. Herendeen. 2020. A proposal to solve a paradox when neotypifying names of fossil-taxa. Taxon 69: 628.

Herrera, F., G. Shi, C. Mays, N. Ichinnorov, M. Takahashi, J.J. Bevitt, P.S. Herendeen, and P.R. Crane. 2020. Reconstructing Krassilovia mongolica supports recognition of a new and unusual group of Mesozoic conifers. PLoS ONE 15(1): e0226779. https://doi.org/10.1371/journal.pone.0226779 

Herrera, F., M.R. Carvalho, S.L. Wing, C. Jaramillo, and P.S. Herendeen. 2019. Middle to Late Paleocene fruits and leaves from Colombia. Australian Systematic Botany 32: 385-408. https://doi.org/10.1071/SB19001  

Herendeen, P.S. and F. Herrera. 2019. Eocene fossil legume leaves referable to the extant genus Arcoa (Caesalpinioideae, Leguminosae). International Journal of Plant Sciences 180: 220–231. https://doi.org/10.1086/701468

Shi, G., P.R. Crane, P.S. Herendeen, N. Ichinnorov, M. Takahashi and F. Herrera. 2019. Diversity and homologies of corystosperm seed-bearing structures from the Lower Cretaceous of Mongolia. Journal of Systematic Palaeontology. https://doi.org/10.1080/14772019.2018.1493547

Herrera, F., G. Shi, G. Tsolmon, N. Ichinnorov, M. Takahashi, P.R. Crane, and P.S. Herendeen. 2018. Exceptionally well-preserved leaves of Nilssoniopteris from the Early Cretaceous of central Mongolia. Acta Palaeobotanica. https://doi.org/10.2478/acpa-2018-0016   

Herrera, F., R.C. Moran, G. Shi, N. Ichinnorov, M. Takahashi, P.R. Crane, and P.S. Herendeen. 2017. An exquisitely preserved filmy fern (Hymenophyllaceae) from the Early Cretaceous of Mongolia. American Journal of Botany 104: 1370–1381. https://doi.org/10.3732/ajb.1700246

Redden, K.M., P.S. Herendeen and G.P. Lewis. 2018. Understanding Paloue (Leguminosae: Detarioideae): revision of a predominantly Guiana Shield endemic. Smithsonian Contributions to Botany, no. 109.

Radosavljevic, A., B.A. Mackinder, and P.S. Herendeen. 2017. Phylogeny of the detarioid legume genera Cynometra and Maniltoa (Leguminosae). Systematic Botany 42(4): 670-679. https://doi.org/10.1600/036364417X696465. 

Zimmerman, E., P.S. Herendeen, G.P. Lewis, and A. Bruneau. 2017. Floral evolution and phylogeny of the Dialioideae, a diverse subfamily of tropical legumes. American Journal of Botany 104: 1019-1041. https://doi.org/10.3732/ajb.1600436.

Takahashi, M., P.S. Herendeen and X. Xiao. 2017. Two early eudicot fossil flowers from the Kamikitaba assemblage (Coniacian, Late Cretaceous) in northeastern Japan. Journal of Plant Research. http://doi.org/10.1007/s10265-017-0945-1

Herrera, F., G. Shi, N. Ichinnorov, M. Takahashi, E.V. Bugdaeva, P.S. Herendeen, and P.R. Crane. 2017. The presumed ginkgophyte Umaltolepis has seed-bearing structures resembling those of Peltaspermales and Umkomasiales. Proceedings of the National Academy of Sciences 114(12): E2385–E2391. www.pnas.org/cgi/doi/10.1073/pnas.1621409114.

Herendeen, P.S., E.M. Friis, K. Raunsgaard Pedersen, and P. R. Crane. 2017. Palaeobotanical redux: revisiting the age of the angiosperms. Nature Plants 3, 17015. http://doi.org/10.1038/nplants.2017.15   

Legume Phylogeny Working Group. 2017. A new subfamily classification of the Leguminosae based on a taxonomically comprehensive phylogeny. Taxon 66: 44-77. https://doi.org/10.12705/661.3  

Shi, G., F. Herrera, P. S. Herendeen, A. B. Leslie, N. Ichinnorov, M. Takahashi and P. R. Crane. 2017. Leaves of Podozamites and Pseudotorellia from the Early Cretaceous of Mongolia: stomatal patterns and implications for relationships. Journal of Systematic Palaeontology. http://dx.doi.org/10.1080/14772019.2016.1274343

Herrera, F., G. Shi, P. Knopf, A. B. Leslie, N. Ichinnorov, M. Takahashi, P. R. Crane, and P. S. Herendeen. 2017. Cupressaceae conifers from the Early Cretaceous of Mongolia. International Journal of Plant Sciences 178:19–41. http://doi.org/10.1086/689577  

Herrera, F., A. B. Leslie, G. Shi, P. Knopf, N. Ichinnorov, M. Takahashi, P. R. Crane, and P. S. Herendeen. 2016. New evidence from the Lower Cretaceous of Mongolia on the early history of Pinaceae. Botany 94: 885-915. http://doi.org/10.1139/cjb-2016-0042

Herendeen, P.S. J. A. Doyle, P. K. Endress, and M. Takahashi. 2016. A novel multiparted flower from the mid-Cretaceous Rocky Point locality, Maryland. Botany 94: 787-803. http://doi.org/10.1139/cjb-2016-0039   

Shi, G., A.B. Leslie, P.S. Herendeen, F. Herrera, N. Ichinnorov, M. Takahashi, P. Knopf, and P.R. Crane.  2015. Early Cretaceous Umkomasia from Mongolia: implications for homology of corystosperm cupules. New Phytologist. http://doi.org/10.1111/nph.13871

Herrera, F., G. Shi, A.B. Leslie, P. Knopf, N. Ichinnorov, M. Takahashi, P.R. Crane, and P. S. Herendeen. 2015. A new voltzian seed cone from the Early Cretaceous of Mongolia and its implications for the evolution of ancient conifers. International Journal of Plant Sciences 176: 791-809. http://doi.org/10.1086/683060  

Shi, G., A. B. Leslie, P. S. Herendeen, N. Ichinnorov, M. Takahashi, P. Knopf, and P. R. Crane. 2014. Whole-plant reconstruction and phylogenetic relationship of Elatides zhoui sp. nov. (Cupressaceae) from the Early Cretaceous of Mongolia. International Journal of Plant Sciences 175: 911-930.

Takahashi, M. P. S. Herendeen, X. Xiao, and P. R. Crane. 2014. Lauraceous Fossil Flowers from the Kamikitaba Assemblage (Coniacian, Late Cretaceous) of Northeastern Japan. Systematic Botany 39: 715-724.

Leslie, A.B., I. Glasspool, P.S. Herendeen, N. Ichinnorov, P. Knopf, M.Takahashi, and P.R. Crane. 2013. Pinaceae-like reproductive morphology in Schizolepidopsis canicularis sp. nov. from the Early Cretaceous (Aptian-Albian) of Mongolia. American Journal of Botany 100: 2426–2436.

International Association for Plant Taxonomy (https://www.iaptglobal.org/)