Phylogenetic analysis of fossil stems in Yiwu Jurassic Forest, Hami, Xinjiang, Northwest China.

BACKGROUND: Permineralized fossil wood is frequently found in the Jurassic deposits of China. Many studies of fossil stems are based on anatomical descriptions, yet phylogenetic analyses could provide important insights for systematics studies of fossil wood. RESULTS: Here, we conducted a phylogenetic analysis of four fossil stems from Yiwu Jurassic Forest to elucidate their systematic relationships with extant gymnosperms. Phylogenetic trees were constructed using data from two nucleotide regions (trnK-matK, rbcL) and xylological characters of six extant gymnosperms. Tree Analysis Using New Technology under maximum parsimony revealed that the four fossil stems were basal to the Araucariaceae in the dataset that combined genetic and xylological characters. CONCLUSIONS: Our findings indicate that phylogenetic analysis combined with characterizations of wood anatomical characters are effective for taxonomic investigations of fossil wood from Yiwu Jurassic Forest.