Charcoalified homoxylous woods from the Cenomanian of the Bohemian Cretaceous Basin (Czech Republic)
Abstract
Three types of charcoalified fossil homoxylous woods are described from the Upper Cretaceous of the Bohemian Cretaceous Basin: Podocarpoxylon sp.,?Podocarpoxylon vel Taxodioxylon sp. and Protocupressinoxylon sp. They come from the uppermost part of the Peruc-Korycany Formation, which is mid-Cenomanian in age.
Podocarpoxylon sp. shows distinct growth rings, uniseriate rays of medium height. 1-2 podocarpoid cross-field pits, and abietinean pitting on radial tracheid walls. Wood of ?Podocarpoxylon vel Taxodioxylon sp. differs in its indistinct growth rings, its rays which are uniseriate with medium height to multiseriate with horizontal resin duct, 1-2 podocarpoid cross-field pits per field, and mixed type of pitting on its radial tracheid walls.
Protocupressinoxylon sp. also displays indistinct growth rings, and its rays arc either uniseriate of medium height or multiseriate with horizontal resin ducts, but it has 1, occasionally 2-3 cupressoid cross-field pits per field, and abietinean to mixed pitting on radial tracheid walls. One of the three woods shows wood with growth rings, suggesting seasonally dry climate.
The composition of the wood assemblage and its comparison with plant megafossils, sporomorphs and sedimentology suggest that there are two paleoenvironments in Unit 5 of the Peruc-Korycany Formation in the Pecinov quarry: a swampy coniferous forest in the coastal lowlands, and a mesophytic forest in the uplands.