Article: An unusual bennettitalean leaf from the Upper Triassic of the south-western United States
Sidney R. Ash
Eoginkgoites davidsonii sp. nov. is a large pinnately compound bennettitalean leaf which has wedge-shaped pinnae. It is unusual because the pinnae are aggregated near the top of a short rachis and not arranged laterally on a long rachis as in other pinnate bennettitalean leaves. The veins radiate from the base of each pinna and divide and anastomose several times before reaching the margins and apices. The cuticle of the new species shows paracytic (syndetocheilic) stomata. Typically E. davidsonii sp. nov. is larger than the other species of the genus. E. davidsonii sp. nov. occurs at seven localities in the basal strata of the Upper Triassic Chinle Formation in Arizona and southern Utah and appears to be confined to the lowest unit (Shinarump Member) of the formation.