Ticoa is an extinct genus originally assigned to the Cycadales[1] from the Early Cretaceous of Argentina, Chile, and Antarctica. Other authors view this genus as a member of the polyphyletic "seed ferns".[2]

Ticoa
Temporal range: Aptian
Scientific classification
Kingdom:
(unranked):
(unranked):
Order:
Genus:
Ticoa

S.Archang.[1]
Species
  • T. harrisii (type species)
  • T. magnipinnulata
  • T. lamellata
  • T. magallanica
  • T. jeffersonii
  • T. lanceolata

Taxonomy

edit

The genus was erected by Sergio Archangelsky based on material from the Anfiteatro de Ticó formation.[1] The genus first comprised two species, T. harrisii and T. magnipinnulata, with T. lamellata being described from the Bajo Grande locality in Patagonia, Argentina.[3] The species T. magallanica was described from the Springhill formation in Chile.[4] T. jeffersonii was described from Hope Bay in Antarctica.[5] T. lanceolata was described much later from the Anfiteatro de Ticó formation .[6]

Description

edit

Ticoa includes large, bipinnate or tripinnate leaves with pecopteroid pinnules and a robust rachis. The cuticle, either hypostomatous or amphistomatous, presents large stomata sunken in a pit formed by multiple subsidiary and encircling cells.

References

edit
  1. ^ a b c Archangelsky, Sergio (1963). "A new Mesozoic flora from Ticó, Santa Cruz Province, Argentina". Bulletin of the British Museum (Natural History), Geology. 8 (2): 45–62. doi:10.5962/p.313876.
  2. ^ McLoughlin, Stephen (2001). "The breakup history of Gondwana and its impact on pre-Cenozoic floristic provincialism". Australian Journal of Botany. 49 (3): 271–300. doi:10.1071/bt00023. ISSN 1444-9862.
  3. ^ Archangelsky, Sergio (1966). "New gymnosperms from the Tico Flora, Santa Cruz Province, Argentina". Bulletin of the British Museum (Natural History), Geology. 13 (5): 259–295. doi:10.5962/p.313841.
  4. ^ Archangelsky, Sergio (1976). "VEGETALES FOSILES DE LA FORMACION SPRINGHILL, CRETACICO, EN EL SUBSUELO DE LA CUENCA MAGALLANICA, CHILE". Ameghiniana (in Spanish). 13 (2): 141–158. ISSN 1851-8044.
  5. ^ Gee, Carole T. (May 1987). "Revision of the early Cretaceous flora from Hope Bay, Antarctica". {{cite journal}}: Cite journal requires |journal= (help)
  6. ^ Villar De Seoane, Liliana (2005-08-01). "New cycadalean leaves from the Anfiteatro de Ticó Formation, Early Aptian, Patagonia, Argentina". Cretaceous Research. 26 (4): 540–550. Bibcode:2005CrRes..26..540V. doi:10.1016/j.cretres.2005.02.004. ISSN 0195-6671.