Vojnovskyales

The Vojnovskyales, are a bizarre, short-lived group of Late Paleozoic gymnosperms" (Mamay 1976). They possess a stem with prominent leaf scars and fan-shaped leaves with parallel veins. Reproductively, they produced an umbrella-like cone with seeds proximally, and elongate microsporophylls at the apex. The affinities of this group are unknown and debated, with some thinking they are related to the Cordaitales (Meyen 1984) and others thinking they are related to Angiosperms (Krassilov & Burago 1981)

Ecology & Form

Stems

  • Vojnovskya paradoxa: axes 2cm wide and 13cm long

  • Prominent leaf scars on the surface of the stem

Leaves

  • Fan-shaped leaves of the Nephropsis type

  • Venation parallel on leaves

  • Flabelliform leaves from the Early Permian, resembling Nephropsis, are described as Sandrewia texana

Roots

  • Unknown

Reproduction

  • Fertile cones are about 3cm long and scattered along the stem

  • Each cone contains both ovules and pollen organs, which is uncommon for gymnosperms

    • Seeds are attached to the basal region of the cone

    • The apical region produces structures that have been interpreted as microsporophylls

Paravojnovskya (formerly Gaussia)

  • Neuberg 1934; Doweld 2004

  • Carboniferous-Early Permian from southwestern Siberia, Russia

  • Umbella-like female strobili [seeds fallen], consisting of a shortened cylindrical axis of numerous (ca. 40) spirally arranged elongated seed stalks with a terminal seed scar

  • The lower part of umbella sometimes might bear reduced sterile seed appendages

P. cristata (formerly Gaussia cristata)

  • Neuberg 1934; Doweld 2004

  • Late Carboniferous of southwestern Siberia, Russia

P. imbricata (formerly Gaussia imbricata)

  • Naugolnykh; Doweld 2004

  • Early Permian of the Sverdlovsk Oblast and Perm Krai in Russia

P. scutellata (formerly Gaussia scutellata)

  • Late Carboniferous of southwestern Siberia, Russia

Geologic Age

Archaeopetalanthus progressus

  • Naugolnykh 2020

  • Middle to Upper Carboniferous of Siberia, Russia

  • Bisexual reproductive organs consist of an axis of obconic shape, with narrow base and widening upper part.

  • Central part/central area of upper (abaxial) surface of the axis bears numerous microsporangia producing anasulcate pollen.

  • Peripheral margins of abaxial surface bear radially orientated long and narrow appendages.

  • Most of appendages sterile.

  • Some of appendages have terminal winged seeds.

  • Small glands between microsporangia and basal parts of appendages

Above: Reconstruction of the bisexual reproductive organ of Archaeopetalanthus progressus. Scale bar = 1 cm.