Umkomasia

Umkomasia
Temporal range: Early Triassic–Late Triassic
Umkomasia macleanii ovulate structure, Late Triassic, Molteno Formation, Umkomaas, South Africa.
Scientific classification Edit this classification
Kingdom: Plantae
Clade: Tracheophytes
Order: †Corystospermales
Family: †Corystospermaceae
Genus: †Umkomasia
Thomas 1933
Species

Umkomasia is a genus of seed bearing organs produced by corystosperm seed ferns, first based on fossils collected by Hamshaw Thomas from the Burnera Waterfall locality near the Umkomaas River of South Africa.[3] He recognized on the basis of cuticular similarities that the same plant produced pollen organs Pteruchus and the leaves Dicroidium. Various other corystosperm seed bearing organs from the Jurassic and Cretaceous have been assigned to this genus, but recently have been given distinct genera, with Umkomasia being restricted to the Triassic.[4]

Umkomasia macleanii reconstruction with pollen organs (Pteruchus africanus) and leaves (Dicroidium odontopteroides) from the Late Triassic, Molteno Formation of South Africa
  1. ^ Gongle Shi; Andrew B. Leslie; Patrick S. Herendeen; Fabiany Herrera; Niiden Ichinnorov; Masamichi Takahashi; Patrick Knopf & Peter R. Crane (2016). "Early Cretaceous Umkomasia from Mongolia: implications for homology of corystosperm cupules". New Phytologist. 210 (4): 1418–1429. doi:10.1111/nph.13871. PMID 26840646.
  2. ^ However, Rothwell & Stockey (2016) transferred this species to the genus Doylea. See: Gar W. Rothwell; Ruth A. Stockey (2016). "Phylogenetic diversification of Early Cretaceous seed plants: The compound seed cone of Doylea tetrahedrasperma". American Journal of Botany. 103 (5): 923–937. doi:10.3732/ajb.1600030. PMID 27208360.
  3. ^ Thomas, H.H. (1933). "On some pteridospermous plants from the Mesozoic rocks of South Africa". Philosophical Transactions of the Royal Society B. 222 (483–493): 193–265. doi:10.1098/rstb.1932.0016.
  4. ^ Anderson, Heidi M.; Barbacka, Maria K.; Bamford, Marion K.; Holmes, W. B. Keith; Anderson, John M. (2019-01-02). "Umkomasia (megasporophyll): part 1 of a reassessment of Gondwana Triassic plant genera and a reclassification of some previously attributed". Alcheringa: An Australasian Journal of Palaeontology. 43 (1): 43–70. doi:10.1080/03115518.2018.1554748. ISSN 0311-5518. S2CID 134483119.