Roger Thoma is a Research Affiliate of the Division of Invertebrate Zoology's Crustacean Collection, and is an expert on the taxonomy, evolution, and conservation of crayfish. 

Recent publications:

• R. F. Thoma, C. Hurt, C. Williams & D. Withers, 2023.  Insights on the evolution and conservation of Appalachian burrowing crayfishes, with the description of a new species of Cambarus Erichson, 1846 (Decapoda: Astacidea: Cambaridae). Journal of Crustacean Biology, Volume 43, Issue 1, ruac066
• R. F. Thoma & J. W. Fetzner Jr., 2023. A new species of crayfish (Decapoda: Astacidea: Cambaridae) from the Cumberland Thrust Block (eastern Kentucky and Tennessee, USA), with notes on the evolution of Cambarus Erichson, 1846 in the Ohio River Basin of the Appalachian Mountains. Journal of Crustacean Biology, Volume 43, Issue 2, ruad023
• R. F. Thoma, 2015. The crayfish fauna of Canada and The United States (North America). In Freshwater Crayfish: Global Review. Eds. T. Kawai, Z. Faulkes, and G. Scholtz. Science Publishers.