Voltziales †
Conifer-like gymnosperms
The Voltziales are an extinct group of conifer-like gymnosperms which appear in the Pennsylvanian and disappear during the Cretaceous extinction. There are generally two types of Voltziales: walchian and voltzian. The former had needle-like leaves and branches growth parallel to the ground; the latter with scale-like leaves and more upright branches. It is possible that the Voltziales were intermediate between the true conifers and the cordaites.
Ecology & Form
Two types of Voltiales: Walchian and Voltzian types
Walchian type
Plagiotropic branching (branches grow parallel to the ground)
Needle-like leaves
Dwarf shoots with radially-arranged scales
Pollen monosaccate
Voltzian type
Orthotropic branching (branches grow upright; perpendicular to ground)
Leaves are broad, dwarf shoots bearing flattened and partially fused scales
Pollen bisaccate
Fused female reproduction organs
Reproduction involves a pollen tube
Classification
└Voltziales †
Geologic Range
Reproduction
Mostly monoecious
Differentiated megasporangiate (♀) and microsporangiate (♂)
Ovuliferous scales
Highly-condensed, fertile shoot
Ovuliferous scales clustered into fertile area or cone
Diversity
Families
Utrechtiaceae
Thucydiaceae
Emporiaceae
Majonicaceae
Ullmanniaceae
Bartheliaceae
Ferugliocladaceae
Buriadiaceae
Krassiloviaceae
Select taxa
Pityocladus †
Vegetative branches
Pityophyllum †
Vegetative branches
Schizolepis †
S. daohugouensis (Zhang et al. 2011)
S. liasokeuperianus (Braun 1847)
Bilobate cone scales from the Late Triassic to Early Cretaceous of Europe & northern Asia
Tobleria bicuspis †
Jongmans & Gothan 1925, 1935
Early Permian (Asselian) from Sumatra
Cylindrical female cones with deeply split cone scales of a possible early Voltzian cone
Seed scales and bract scales are helically- and loosely-arranged on cone axis (Harris 1979)
Above: Reconstruction of Tobleria bicuspis (Van Wessen 2019)
