Latest Cretaceous leaf megafloras from the Jose Creek Member, McRae Formation, New Mexico
Upchurch, Garland R., Jr. and Greg H. Mack
The Jose Creek Member of the McRae Formation contains an abundant megaflora of leaf impressions and silicified wood. The megaflora as currently known consists of approximately 40 to 50 species of fern, conifer, cycad, and flowering plant leaves and an unknown number of species of conifer, dicot, and monocot (probably palm) wood. This paper illustrates and informally describes important leaf types belonging to the major plant groups and compares them with leaves from more northerly sites in the Rocky Mountain region. Vegetation of the Jose Creek Member consisted of subtropical to paratropical forest or woodland that grew under low seasonality of temperature and precipitation. This inference is consistent with paleosol data for the Jose Creek Member and paleobotanical analysis of more northerly leaf assemblages. Conifers and cycads have high relative abundance and diversity in the Jose Creek megaflora relative to more northerly assemblages. This may reflect the prevalence of well-drained soils in the Jose Creek Member and favorable preservational environments provided by numerous volcanic ashes.
- Upchurch, Garland R., Jr.; Mack, Greg H., 1998, Latest Cretaceous leaf megafloras from the Jose Creek Member, McRae Formation, New Mexico, in: Las Cruces Country II, Mack, G. H.; Austin, G. S.; Barker, J. M., New Mexico Geological Society, Guidebook, 49th Field Conference, pp. 209-222.