FOSSIL CLUSIACEAE FROM THE LATE CRETACEOUS (TURONIAN) OF NEW-JERSEY AND IMPLICATIONS REGARDING THE HISTORY OF BEE POLLINATION

Citation
Wl. Crepet et Kc. Nixon, FOSSIL CLUSIACEAE FROM THE LATE CRETACEOUS (TURONIAN) OF NEW-JERSEY AND IMPLICATIONS REGARDING THE HISTORY OF BEE POLLINATION, American journal of botany, 85(8), 1998, pp. 1122-1133
Citations number
51
Language
INGLESE
art.tipo
Article
Categorie Soggetti
Plant Sciences
Journal title
ISSN journal
0002-9122
Volume
85
Issue
8
Year of publication
1998
Pages
1122 - 1133
Database
ISI
SICI code
0002-9122(1998)85:8<1122:FCFTLC>2.0.ZU;2-L
Abstract
The Turonian flora from Sayreville New Jersey includes one of the worl d's most diverse assemblages of Cretaceous angiosperm flowers. This fl ora is made even more interesting by its association with a large inse ct fauna that is preserved by charcoalification as well as in amber Fl oral diversity includes numerous representatives of Magnoliidae, Hamam elididae, Rosidae, Dilleniidae, and Asteridae (Ericales sensu late). I ncluded are hypogynous, five-merous flowers with uniseriate hairs on t he pedicels and stamens in bundles most frequently borne opposite the petals. There is considerable variation in filament length, and some f ilaments are branched. On some anthers, strands of residue, suggesting the former presence of a liquid of unknown nature, partially occlude the apparent zone of dehiscence. In other casts, open anthers are full y occluded by an amorphous substance. Pollen is rarely found associate d with anthers, but is common on stigmatic surfaces. Pollen is prolate and tricolporate with reticulate micromorphology. The superior syncar pous ovary is five-carpellate with axile/intruded parietal placentatio n and numerous anatropous ovules/carpel. Ovary partitions have closely spaced, parallel ascending channels (secretory canals?), and there ar e apparent secretory canals/cavities in receptacles, sepals, and petal s. Individual stigmas are cuneiform with a central groove and eccentri cally peltate. Styles are short and fused. In aggregate, the stigmas f orm a secondarily peltate stigma. Seeds have a reticulate sculpture pa ttern, a pronounced raphe, and funicular arils with sculpture similar to the seeds. Phylogenetic analyses of several data matrices of extant taxa place this fossil in a monophyletic group with the modern genera Garcinia and Clusia within the Clusiaceae. As such, these fossils rep resent the earliest fossil evidence of the family Clusiaceae. Some mod ern Clusiaceae are notable, in particular for their close relationship with meliponine and other highly derived bee pollinators; the fossil flowers share several characters that suggest a similar mode of pollin ation. This possibility is consistent with other floral and insect dat a from the same locality.