Similar Tree Ring pattern in the Gymnosperm woods from Late Permian of Antarctica and India

Abstract

Tree rings revealed in a newly described gymnosperm wood Araucarioxylon ghoshii sp. nov. from Raniganj Formation, Raniganj Coal field, India are similar to the tree rings described in the in situ gymnosperm fossil woods from the Late Permian of Antarctica.

The rings of the fossil woods from Antarctica and India have higher proportion of early woods compared to little amount of late wood. Characteristic zigzag pattern of early wood tracheids formed due to collapsing and crushing of tracheid files and false rings occur in the woods recorded from two distant areas. The characters suggest occurrence of rapidly growing young forest in both the continents during Late Permian. Quantitative analysis of growth rings in A. ghoshii reveals a CSDM curve with right skewedness +19% suggesting its possible evergreen nature with small to moderate leaf retention time.