A diverse charcoalified assemblage of Cretaceous (Santonian) angiosperm woods from Upatoi Creek, Georgia, USA. Part 1: Wood types with scalariform perforation plates

Abstract: This paper is the first in a series describing a diverse assemblage of charcoalified angiosperm woods from the Cretaceous (early to mid-Santonian) Eutaw Formation at Upatoi Creek, Georgia, USA. In our study, we separated ‘twigs’ from more ‘mature’ woods and further subdivided the latter material into specimens showing scalariform and simple perforation plates. Here, we report on thirteen ‘mature’ specimens with scalariform perforation plates. For such a small sample size, there is a remarkable diversity, with seven more or less distinct wood types present including two new taxa: Gregoryoxylon georgiaensis gen. et. sp. nov. and Chaloneroxylon pagei gen. et. sp. nov. The seven wood types are similar to most previously reported specimens from the Turonian–Santonian interval, i.e., they are diffuse porous, with predominantly solitary vessels, heterocellular rays, and only diffuse and/or scanty paratracheal parenchyma. None of the seven Upatoi wood types has a combination of features that allows unequivocal assignment to a single extant family. Chaloneroxylon may represent a record of the Magnoliaceae; of the other unnamed wood types, one has features found in the asterid orders Cornales and Ericales, while two possibly are referred to the Malpighiales. The affinities of the remaining three wood types, including Gregoryoxylon, are uncertain. The cryptic affinity of these woods is significant in itself, reflecting their Cretaceous age, a time when extant families were still rapidly diversifying. [Copyright &y& Elsevier]