We report here a series of fossil flowers, collected in the outcrops of the Raritan Formation, New Jersey (Turonian age (ca. 90 mybp)), exhibiting a mosaic of characters present in the extant monocot family Triuridaceae. The three-dimensional structure of the organs and the exquisite morphological and cellular details allow observation of a wide array of floral characters in these fossils. Flowers are unisexual (only staminate flowers are known), actinomorphic, with a perianth composed of six basally fused tepals. Tepals are triangular in shape, and valvate in bud. The androecium consists of three stamens placed in a single whorl. The anthers are sessile, dithecal, and longitudinally dehiscent with a one-layered endothecium. The connectives are thick and well developed and extend beyond the anther sacs in some specimens. Clusters of pollen grains found within the anther sacs are monosulcate with a rugulate exine; columellae are apparent in some broken grains. There is no indication of a gynoecium or pistillode(s). Based on observed variation in tepal and stamen connective morphology, we estimate that these fossils represent at least four species of related plants with affinities to modern Triuridaceae.
Gandolfo, M. A., K. C. Nixon, W.L. Crepet, and E. M. Friis. 1997. American Journal of Botany 84 (6 supp.): 196.
|Fossil bud||Open fossil Triuridaceae|
Gandolfo, M. A., K. C. Nixon, W.L. Crepet, D. W. Stevenson, and E. M. Friis. 1998. Oldest known fossil flowers of monocotyledons. Nature 394: 532-533.
Gandolfo, M. A., K. C. Nixon, and W. L. Crepet. 1998. Species diversity of Triuridaceae flowers from the Late Cretaceous of New Jersey. American Journal of Botany 85 (6 supp.): 73.
Gandolfo, M. A., K. C. Nixon, W. L. Crepet, and D. W. Stevenson. 1998. Phylogenetic analysis of modern and cretaceous Triuridaceae. American Journal of Botany 85 (6 supp.): 1.