Gandolfo, M. A., K. C. Nixon, and W.L. Crepet. 2002. Triuridaceae fossil flowers from the Upper Cretaceous of New Jersey. American Journal of Botany 89 (12): 1940-1957.

Abstract: We report here a series of fossil flowers exhibiting a mosaic of characters present in the extant monocot family Triuridaceae. Phylogenetic analyses with extant taxa confirm the affinities of the fossils with modern Triuridaceae. The fossil flowers were collected from outcrops of the Raritan Formation (Upper Cretaceous, ~90 MYBP), New Jersey, USA. These are the oldest known unequivocal monocot flowers. Because other reports of "earliest" monocots are all based on equivocal character suites, the Triuridaceae fossils reported here should also be considered the oldest unequivocal early monocot based on any type of fossil organs. Flowers are minute, unisexual (only male flowers are known); their perianth is composed of six tepals lacking stomata. The unicyclic androecium is formed by three stamens with monothecal, bisporangiate extrorse anthers that open by longitudinal slits showing the endothecium with U-type thickenings. Pollen grains are monosulcate. The triurid fossil flowers can be separated into three distinctive species. Based on phylogenetic analyses of morphological characters, the fossil taxa are nested within a completely achlorophyllous saprophytic clade supporting the interpretation that the extinct plants were also saprophytic. If so, this represents the earliest known fossil occurrence of the saprophytic/mycotrophic habit in angiosperms.

FOSSIL PHOTOS

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Mabelia and Nuhliantha
Actual width in ( ) unless otherwise noted.

Mabelia connatifila, male flower,
top view
(1.8 mm)
Side view
(height= 833 µm)
Closed stamens, note small spines
on anther (arrows)
(height= 564 µm)



M. connatifila, pollen grain
(grain length= 13 µm)
Mabelia archaia,
top view male flower
(2.2 mm)
Side view
(height= 1.4 mm)




M. archaia, stamens
(height= 740 µm)
Pollen grain
(grain length= 11 µm)
Nuhliantha nyanzaiana,
male flower
(1.3 mm)
Side view
(height= 844 µm)



Stamen
(height= 472 µm)
Pollen
(grain length= 16 µm)
Pistilode
(height= 347 µm)