Ancient Forest Diversity
The Rocky Mountain region was much warmer 34 million years ago. The Florissant valley was forested with towering redwoods, false cypresses, pines, mixed hardwoods, and ferns surrounded by drier slopes with scrublands, shrubs, and low trees. Streams flowed through the valley, which provided additional moisture to the redwoods and riparian vegetation.
Leaf Adaptations
The lobed, toothed leaf of the fossil maple, Acer florissantii (below left [image]) indicates warm-temperate growing conditions. The smooth-edged Cape mahogany Trichilia florissantii (below right [image]) with its extended "drip tip" is a leaf form common to wetter, subtropical climates.
The warm climate had cooled by 33 million years ago. Today, extreme winter temperatures can reach [sic] -35°F (-37°C). As the climate changed, the plants of the Eocene then adapted, became extinct, or dispersed to other parts of the Earth.
Fossil leaves serve as ancient thermometers for reading the temperature of the past. By comparing fossil plants with modern floras, scientists estimate that the mean annual temperature at Florissant during the late Eocene was about 56°F (13°F), similar to San Francisco today.
Erected by National Park Service.
Topics. This historical marker is listed in these topic lists:
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Location. 38° 54.817′ N, 105° 17.155′ W. Marker is near Florissant, Colorado, in Teller County. Marker is west of the Florissant Fossil Beds National Monument Visitor Center, along the trail leading to the exposed petrified Redwood stumps. Touch for map. Marker is at or near this postal address: 15807 County Road 1, Florissant CO 80816, United States of America. Touch for directions.
Other nearby markers. At least 8 other markers are within walking distance of this marker. Stumps of Stone (a few steps from this marker); Making of a Monument (a few steps from this marker); Ancient Clones (within shouting distance of this marker); Is the Trio in Trouble? (within shouting distance of this marker); Reading the Rings (within shouting distance of this marker); Just One Piece at a Time (within shouting distance of this marker); Dawn of the Recent Past (within shouting distance of this marker); Layers of Time (within shouting distance of this marker). Touch for a list and map of all markers in Florissant.
Also see . . . Florissant Fossil Beds National Monument. (Submitted on October 21, 2020, by William Fischer, Jr. of Scranton, Pennsylvania.)
Credits. This page was last revised on October 21, 2020. It was originally submitted on October 21, 2020, by William Fischer, Jr. of Scranton, Pennsylvania. This page has been viewed 132 times since then and 9 times this year. Photos: 1, 2. submitted on October 21, 2020, by William Fischer, Jr. of Scranton, Pennsylvania.
