Bj. Axsmith et al., A NEW SPECIES OF EOGINKGOITES FROM THE UPPER TRIASSIC OF NORTH-CAROLINA, USA, Review of palaeobotany and palynology, 85(3-4), 1995, pp. 189-198
The foliage genus Eoginkgoites represents a superficially ginkgoalean
bennettitalean leaf restricted to the Late Triassic of North America.
A new species, Eoginkgoites sydneyi is described from the Pekin Format
ion in North Carolina. The number of lateral pinna pairs is typically
four, but varies from three to five. Previously described species have
a maximum of three lateral pairs. The new form is most similar in mor
phology to E. gigantea from the upper Stockton Formation of Pennsylvan
ia. Eoginkgoites sydneyi and the Chinle Formation species E. davidsoni
i share several cuticular features unusual to the Bennettitales includ
ing straight anticlinal epidermal cell walls and radiating striations
on the stomata guard cell thickenings. The additional pinna pairs of t
he new species suggests support for the hypothesis that the Eoginkgoit
es leaf morphology was derived from a typical pinnate form by loss of
lower pinnae and shortening of the rachis. Recognition of this unusual
leaf morphology in the Triassic provides further evidence for an emer
ging picture of greater morphological diversity in the early Bennettit
ales.