|
|
||||||||
Paleobotany |
L. H. Bailey Hortorium, Department of Plant Biology, 228 Plant Science Building, Cornell University, Ithaca, New York 14853 USA
Fossilized flowers and fruits from the Upper Cretaceous (Turonian, ca. 90 million years [my] before present) Raritan Formation of New Jersey are described as the new genus Divisestylus with two species, D. brevistamineus and D. longistamineus. The fossils are fusainized and three-dimensionally preserved. Morphological characteristics suggest affinities with extant Saxifragaceae and Iteaceae, two closely related families in Saxifragales. Similarities include a pentamerous perianth, calyx fused below into a hypanthium with free sepal lobes above, haplostemonous androecium with stamens situated opposite the calyx lobes, inferior ovary, bicarpellate gynoecium, numerous ovules on axile placentas, conspicuous intrastaminal nectary ring, and capsulate fruit opening apically. The unique fusion of the gynoecium, with carpels and stigmas fused but styles free, indicates closer affinities with extant Iteaceae, whereas other characters, such as basifixed anthers in D. brevistamineus, tricolpate and striate pollen grains, and anomocytic stomata, indicate closer affinities to Saxifragaceae. Cladistic analyses utilizing molecular data from a previously published analysis and morphological data as well as morphological data alone demonstrate the fossils share a more recent common ancestor with Iteaceae than Saxifragaceae, thereby making Divisestylus the oldest fossils known with clear affinities to Iteaceae.
Key Words: angiosperm Cretaceous fossil Itea Iteaceae Raritan Formation, New Jersey Saxifragaceae Turonian
This article has been cited by other articles:
![]() |
C. L. Anderson, K. Bremer, and E. M. Friis Dating phylogenetically basal eudicots using rbcL sequences and multiple fossil reference points Am. J. Botany, October 1, 2005; 92(10): 1737 - 1748. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. L. Crepet, K. C. Nixon, and M. A. Gandolfo An extinct calycanthoid taxon, Jerseyanthus calycanthoides , from the Late Cretaceous of New Jersey Am. J. Botany, September 1, 2005; 92(9): 1475 - 1485. [Abstract] [Full Text] [PDF] |
||||
![]() |
W. L. Crepet, K. C. Nixon, and M. A. Gandolfo Fossil evidence and phylogeny: the age of major angiosperm clades based on mesofossil and macrofossil evidence from Cretaceous deposits Am. J. Botany, October 1, 2004; 91(10): 1666 - 1682. [Abstract] [Full Text] [PDF] |
||||
| HOME | HELP | FEEDBACK | SUBSCRIPTIONS | ARCHIVE | SEARCH | TABLE OF CONTENTS |