New data on the geographic and stratigraphic range of the Mesozoic fossil wood genera Protocedroxylon and Xenoxylon in the Arctic region

Abstract

Protocedroxylon Gothan and Xenoxylon Gothan are two biogeographically important Mesozoic fossil wood genera. They are the witnesses of a boreal flora whose periodic extensions towards the south characterize Mesozoic climatic oscillations. However, previously documented Arctic records of these taxa are known mostly by poorly dated specimens. A new well-preserved and well-dated fossil wood material is described from the Upper Jurassic deposits of Franz Josef Land Archipelago (Russian Arctic). We studied this new material and evidenced two taxa, Protocedroxylon araucarioides Gothan and Xenoxylon phyllocladoides Gothan. We re-examined the fossil woods of Xenoxylon with the same provenance described by Shilkina (1967) as X. barberi (Seward) Kräusel and re-assigned them to the X. phyllocladoides-group. A review of Protocedroxylon and Xenoxylon from northern high palaeolatitudes allows us to better understand the spatial and temporal extension of the flora that yielded to the Protocedroxylon and Xenoxylon fossil wood assemblage.