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Stonerose fossils


Sycamore Tree 
Family Platanaceae

Leaves and fruits related to the sycamore family are found in many fossil localities of western North America. The leaf type illustrated in the accompanying photograph was assigned to a new genus named Macginitiea in honor of Harry D. MacGinitie, who sepent over 50 years researching fossil plants.

Macginitea is found in many sites. Besides leaves, other parts of the plant are also found in these sites, including flowers with pollen, and seed pods with seeds. Because these were not originally found together with the leaves they were given different names. The small fossil flowers, called Platananthus, are arranged in dense round clusters along a stem, and their shapes shows that they were pollinated by insects. The fossil seeds are called Macginicarpa.

macginitiea
The fossil genus Macginitiea was named after one of the pioneering paleobotanist in the west, Harry D. MacGinitie. 15.5 cm wide.

macginicarpa_glabra
The fossil sycamore seed pods Macginicarpa glabra are often well preserved in the ancient lake beds. 2.5 cm wide.
Photo by Ron Eng

Macginitiea was likely a very large spreading tree, much like living sycamores. There are only three species of sycamore trees (genusPlantanus) native to North America today, living in the warm southeastern and southwestern regions.