Discipline-based education research (DBER) conducted by faculty within geoscience departments can address identified needs in undergraduate geoscience education. This study explores the evolution of undergraduate geoscience education research (GER) from 1985 to 2016, primarily in terms of the types of published research and secondarily in terms of the insights this literature offers on the evolution of GER as a scholarly discipline. Stokes' (1997) quadrant model of research types is used as a theoretical framework for the former and Kuhn's (1970) model of disciplinary paradigm for the latter. An exploratory sequential mixed-methods approach to a systematic literature review of 1,760 articles is utilized. The period 1985-2000 is characterized by proto-research as evidenced by the abundance of instructive and informational education articles rather than research articles. From 2000 to 2011, GER underwent a growth period characterized by the presence of applied, use-inspired, and pure basic research. The period 2011-2016 appears to be a period of relative steady-state conditions in the normalized number of GER publications per year. Existing gaps in knowledge about geoscience education, the evident unfamiliarity with education and social science research methodologies among authors of GER articles, and efforts to build consensus about what GER is and how to conduct it suggest that GER is preparadigmatic or at a low paradigm state. That is, GER is an immature discipline as far as the evolution of a discipline goes. A path forward is proposed for the continued evolutionary growth of GER. This study provides new perspectives on the emergence of GER as a discipline that can be used as a basis for studies on cross-disciplinary DBER comparisons.