Williamsoniaceae

Williamsoniaceae
Temporal range: Triassic–Cretaceous
Restoration of Wielandiella
Diagram of Weltrichia, a male reproductive structure
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Order: †Bennettitales
Family: †Williamsoniaceae
(Carruthers) Nathorst, 1913
Genera
  • Zamites (leaf, in partim)
  • Anomozamites (leaf)
  • Ischnophyton
  • Kimuriella (whole plant)
  • Pterophyllum (leaf)
  • Otozamites (leaf)
  • Wielandiella (whole plant)
  • Williamsonia (female reproductive structure)
  • Williamsoniella (bisexual reproductive structure)
  • Weltrichia (male reproductive structure)
  • Bucklandia (axes)
  • Bennettistemon (male pollen organ)
  • Vardekloeftia (female seed cone)

Williamsoniaceae is a family within the Bennettitales, an extinct group of seed plants. Members of this family are believed to have been around two meters tall and with widely serrate leaves along a central stem. Reproductive organs of the Williamsoniaceae have varied widely in the fossil record but almost all have been found to be borne on stalks emerging from a ring of leaves.[1]

Pterophyllum fossil from Shamshak Formation, Middle Jurassic, Iran

Reproduction

This family is different from Cycadeoidaceae by having the presence of cones leaving the major axis and lateral branches associated with a long peduncle covered by bracts. Some of this family reproduce by sporangia and others only produce ovule or pollen sacs.[2]

References

  1. ^ Meyen, Sergei V. (1984). "Basic Features of Gymnosperm Systematics and Phylogeny as Evidenced by the Fossil Record". Botanical Review. 50 (1): 1–111. doi:10.1007/BF02874305. JSTOR 4354028. S2CID 38485693.
  2. ^ Paleontologia Paleovertebrados e Paleobotânica Autor : Ismar de Souza Carvalho. Editora Interciência. Archived 2016-03-04 at the Wayback Machine