With the exception of the Virgilian Kinney Brick Quarry, information available on Upper Paleozoic floras of New Mexico consists primarily of sporadic preliminary reports. Sites currently under study include El Cobre Canyon (Missourian?), Carrizo Arroyo (3 quarries - uppermost Pennsylvanian or Permian), and Placitas (Lower Permian); with focus on providing time-ordered documentation of the "great drying" of the Late Carboniferous. Historically, these "transition" floras were viewed as admixtures of relictual coal swamp elements and newly-evolved "upland" plants. In the absence of reliable taxonomic age indicators, tentative age estimates have been proposed based on relative abundances of swampy to dry-climate taxa. If such estimated ratios are to serve as a proxy for age, it is required that draining through lowered eustatic sea level was a continuous process and accompanied by regional shifts toward dryer climatic patterns without localized backsliding into temporary coal-swamp conditions. Resurgences of humid-indicator floras into the Permian indicates that global drying was not strictly progressive. In addition, the picture of depositional environments in New Mexico is complicated by elevational relief associated with tectonics of the Ancestral Rockies and progradation within fragmented north-south trending intermontane basins. Idiosyncratic depositional characteristic may possibly obscure a regional signal. A new neuropterid frond reconstructed from specimens from Carrizo Arroyo site L- 3431 indicates that "typical" coal swamp elements were also simultaneously evolving into dryer climate forms. As an alternative interpretation, DiMichele has proposed that "transition" floras are more accurately viewed as having been mixed by transport within fragmented habitats characterized by localized topographic highs and lows, a condition typified by the depositional characteristics of New Mexico. Analyses in progress show El Cobre Canyon as a Appalachian equivalent coal-measures flora, Carrizo Arroyo as a mixed conifer, Cordaites, medullosan flora, and Placitas as a streamside peltasperm flora.

Key words: , Carboniferous, Fossil plants, New Mexico, Peltasperms, Permian