Early Tertiary species of Azolla subg. Azolla sect. Kremastospora from western and arctic Canada

1976 ◽  
Vol 54 (3-4) ◽  
pp. 334-351 ◽  
Author(s):  
A. R. Sweet ◽  
L. V. Hills
Keyword(s):  
Phylogenetic Position ◽  
Arctic Canada ◽  
Banks Island ◽  
Early Tertiary

Species of Azolla subg. Azolla sect. Kremastospora Jain & Hall are described from samples of Early Tertiary age from the Ravenscrag Formation of Saskatchewan, the Paskapoo Formation of Alberta, and the Eureka Sound Formation of Banks Island, District of Franklin.Section Kremastospora is restricted to include only Azolla teschiana Florschütz, A. bulbosa Snead, A. stanleyi Jain & Hall, and A. areolata n. sp. The relative phylogenetic position and stratigraphic significance of these species are discussed.

scholarly journals A living fossil fig wasp (Hymenoptera, Agaoninae) developing in extant Neotropical fig species (Moraceae: Ficus, section Pharmacosycea)

2016 ◽  
Vol 64 (4) ◽  
Author(s):  
William Ramirez-Benavides
Keyword(s):  
World Wide ◽  
New World ◽  
Phylogenetic Position ◽  
Fig Wasp ◽  
Living Fossil ◽  
General Morphology ◽  
Early Tertiary ◽  
Sister Clade ◽  
The Family ◽  
Tropical America

The aim object of this work was to study five Tetrapus wasps, whose females have two mandibular appendages and hexapodous males, their fig host association and phylogenetic position in the family Agaonidae. The question of which group of fig pollinating wasps and associated figs are the sister to the rest of the pollinating agaonids and figs respectively remain open. I report about a group of New World extant Tetrapus wasps (Agaonidae:Agaoninae) assigned to Hexapus subg. nov. ined. Morphologically, ecologically, geographically and historically Hexapus seems to be the most ancestral clade of the extant Agaoninae, including Tetrapus s.s. It develops in fig species of subsection Petenenses (section Pharmacosycea). In the know extant Tetrapus s.s., the females have one mandibular appendage and the males have reduced one or two short-lobe atrophied non-functional midlegs (tetrapodous). On the contrary, Hexapus females have two functional mandibular appendages; while the males have five segmented functional mid-legs (hexapodous). Molecularly Hexapus seems to be the most ancestral clade of extant Agaoninae; e.g., Hexapus sp. of Ficus crassivenosa was molecularly placed as the most ancestral clade of 101 species, representing 19 recognized world-wide Agaoninae genera including four Tetrapus s. s. species, by other author. Two females (T. apopnus and T. delclosi) preserved in Early Miocene (Burdigalian) amber from the Dominican Republic, also have two mandibular appendages and the general morphology of extant Hexapus. It is suggested that Hexapus stands up as a living fossil and as the sister clade of Tetrapus s.s. The presence of extinct and extant Hexapus; and extant Tetrapus s.s. and their fig host species, especially in South America supports a southern Gondwanaland origin for both of them, a non-trans-Pacific migrating connection with tropical America for Pharmacosycea, long oceanic dispersal, high levels of stem extinction of Tetrapus s.s. and Atlantic land connections, as proposed by other authors. However lastly, it has been assumed that figs and their pollinators arose simultaneously in Eurasia during early Tertiary and spread southwards.

Ballast Brook and Beaufort Formations (late Tertiary) on Northern Banks Island, Arctic Canada

1994 ◽  
Vol 22-23 ◽  
pp. 141-171 ◽  
Author(s):  
J.G. Fyles ◽  
L.V. Hills ◽  
J.V. Matthews ◽  
R. Barendregt ◽  
J. Baker ◽  
...  
Keyword(s):  
Arctic Canada ◽  
Banks Island ◽  
Late Tertiary
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