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Extinct genus of cycads
Ticoa
Scientific classification
Kingdom:
(unranked):
(unranked):
Order:
Genus:
†Ticoa
Species
†T. harrisii (
type species )
†T. magnipinnulata
†T. lamellata
†T. magallanica
†T. jeffersonii
†T. lanceolata
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]
Taxonomy
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
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
^
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 .
^ 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 .
^ 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 .
^ 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 .
^ Gee, Carole T. (May 1987).
"Revision of the early Cretaceous flora from Hope Bay, Antarctica" .
^ 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 .