Despite over 120 years of fossil discoveries, the Florissant Fossil Beds are still producing new discoveries.

A new genus and species of fossil mole has been described from Florissant, published in September 2007 in Acta Palaeontologica Polonica. Karen Lloyd, who graduated in 2007 from the University of Colorado with an M.S. in Museum and Field Studies, discovered a partial jaw with three teeth among material collected from Florissant Fossil Beds National Monument.

Lloyd named the fossil mole Oreotalpa florissantensis, which means “mountain mole from Florissant” (oreo = mountain, talpa = mole). In addition to representing a new genus and species, Oreotalpa is the first evidence that moles lived around ancient Lake Florissant, as well as the oldest known specimen of a mole from North America. While moles were previously believed to have originated in Europe, Oreotalpa suggests the possibility of a North American origin for moles.

Research since 2003 by Lloyd, her advisor Dr. Jaelyn Eberle, and another Museum and Field Studies graduate and former park intern, Marie Worley-Georg, has more than tripled the number of known fossil mammals from Florissant.

The list now includes rodents (relatives of squirrels, mice, and the “mountain beaver” Aplodontia), rabbits, shrews and other insectivores, the small three-toed horse Mesohippus, deer-like Leptomeryx, sheep-sized oreodonts, a pigmy opossum, a rhinoceros-like brontothere, and a tapir-like ancestor of the rhinoceroses. Although less abundant at Florissant than fossil plants and insects, mammals are an important part of the ecological picture of ancient Lake Florissant.

You can read an abstract and download a copy of Lloyd and Eberle’s paper at Acta Palaeontologica Polonica.

-Melissa Barton

Image Credit: Walter Heubach (German, 1865-1923) (European mole, Talpa europaea)

With Deep Roots in Colorado: The Ponderosa Pine

by J.J. Huie

I like running in Colorado when the sound of my breathing is drowned out by a wind so violent it causes the arms of the ponderosa pines (Pinus ponderosa) to thrash about wildly. Hundreds of miles from the Pacific, in the foothills next to Rampart Range near Colorado Springs, I feel like I’m sailing through an ocean storm. In crossing this ocean, however, there is no salty scent or giant, looming swells; instead, I have the waving motion of the ponderosas and the rich aroma they exude.

In Colorado, the ponderosa pine ecosystem can be found at an elevation range of 5,600 feet to 9,000 feet on both sides of the Continental Divide, with ponderosas dominating on sunny, south-facing slopes. Throughout much of the elevation range of the ponderosa, Douglas-firs predominate on the shadier, north-facing slopes. Direct solar radiation is critical to the ponderosa, which germinates best on soils with unobstructed sunlight. Standing close to a mature tree, I enjoy the scent of vanilla that the orange-brown bark gives off as it’s warmed by the sun.

A distinctive feature of ponderosas is their long needles (up to 7 inches in length), which come in bundles of two or three needles. The needles of ponderosas are the longest among conifers in Colorado. Some ponderosas are among the largest trees in the Southern Rockies (the area from southern Wyoming through Colorado to northern New Mexico), growing up to 150 feet in height and more than 3 feet in diameter.

Mature trees usually have rounded crowns, while the oldest trees can have flat-topped crowns, unlike most other conifer species. Mature cones are globe shaped and can be up to 6 inches long; each of the cone’s thick scales is tipped with a sharp bristle.

We normally don’t see one of the most amazing features of the ponderosa: the tree’s extensive root system, an adaptation to frequent drought. Ponderosa pine forests typically receive from about 16 inches of precipitation in New Mexico and south-central Colorado to more than 25 inches in areas of Wyoming. While above average moisture in spring and early summer allows for seedling establishment, seedlings quickly develop a long taproot which helps them survive drought that dries out the topsoil. Mature ponderosas have taproots that can reach depths of up to 40 feet and lateral roots that extend through surface soils as much as 100 feet from the tree. I’ve marveled at how ponderosas stand up against Colorado’s sometimes vicious winds, but with such a wide-spreading root system, it’s difficult for a ponderosa to be shaken at its depths.

Low-intensity fires initiated by lightning during the summer were an important part of the ponderosa pine ecosystem before logging and wildfire suppression. Wildfires kill smaller plants and thin out dense stands of seedlings, decreasing competition for moisture. In addition, fires release nutrients in the litter of needles and twigs on the ground, thereby increasing the fertility of the soil. The thick bark of mature ponderosas provides protection against fires; nonetheless, the reduction in fuel loads that occurs with low-intensity fires is necessary to prevent catastrophic fires which could kill even mature trees. Since the beginning of the 1900s, fire suppression and logging have allowed other conifers to establish themselves in ponderosa forests or caused increased regeneration of ponderosas. The result has been overcrowded forests and smaller, less robust ponderosa pines.

The ponderosa pine’s affinity for sunny, south-facing slopes, extensive root system, and adaptations to the lightning-induced fires that spread more quickly under dry, windy conditions, reveal a high degree of adaptation. The species has even developed defenses against the pine beetle, including a higher concentration of limonene, a chemical toxic to the pine beetle, in ponderosas that survived infestations. Beyond its ability to withstand oftentimes harsh conditions, the ponderosa never ceases to bring pleasure to those who venture into the woods, whether we find a shady place under its sweeping branches, hear the music of its long needles fluttering against a cool breeze, or simply stand close for the scent of vanilla.

Photo Credits: Walter Siegmund (ponderosa needles and cones), Jamie Dwyer/public domain (ponderosa trunk)

It’s hard to forget the eerie sound of an American bull elk bugling–the sound is almost completely unlike a bugle, but rather a high, unearthly wail. Elk bugling is a common sound at Florissant Fossil Beds National Monument in the fall, when elk rut (seek mates).

American elk (Cervus canadensis*), which once numbered 10 million in North America and which lived in grasslands from coast to coast, today are mostly confined to last remaining wild spaces in the mountains. In Colorado, according to seasonal park ranger Harv Burman, wildland is developed at a rate of 4 acres per hour. That doesn’t leave much space for the elk, but in September and early October you still have a good chance of hearing or seeing elk at the park, particularly at the south end and along Lower Twin Rock Road.

During the rut, or mating season, cow elk focus on eating. They need the fuel to carry calves through the winter. The bulls, however, are often too busy to eat—the successful are busy gathering and keeping harems of 10-15 cows. They shed the velvet from their antlers in August, and polish them on trees. Struggles between males usually involve only pushing and shoving, and the antlers are more for display than combat. The bugling is also a warning to other males.

The Rocky Mountain elk (C. canadensis nelsoni) is the largest of the North American elk and the largest of the red deer species worldwide. In Europe, “elk” refers to the American moose (Alces alces), and “red deer” to C. elaphus, although European and Asian red deer are much smaller than American elk. There has been a largely unsuccessful push in North America to call C. canadensis by its Shawnee name, “wapiti,” meaning “white rump.” Like “buffalo” for the American bison (Bison bison), the name “elk” has centuries of inertia behind it.

Signs of elk–tracks, scat, scarred aspens, and broken ponderosa saplings–are common sights in the Front Range, but elk themselves are more elusive. Hundreds of elk graze and mate in the park in fall. In September and early October, park rangers at Florissant Fossil Beds National Monument lead evening programs to listen and look for elk. The chances of hearing the elk are very good, but elk sightings occur less often.

Many quaking aspen (Populus tremuloides) trunks in the park are scarred from elk eating the bark. Aspen bark is photosynthetic and a favorite of elk, especially in winter when nutritious grazing is hard to come by. Unfortunately for the aspens, elk chew makes them vulnerable to infection. Canker-invading fungi such as sooty-bark canker (Encoelia pruinosa) attack the trees, often killing them. Because aspens stands are “clones” with a common root system, fungus spreads rapidly from tree to tree. Sometimes a combination of overgrazing and fungus can kill an entire aspen clone.

The last elk walk this year will be on October 13, but you can always visit the park to listen and look for elk yourself. Nearby Mueller State Park is also a good place to spot elk.

ELK-SPOTTING TIPS

• Early morning and late evening in fall are the best times to see elk in the Front Range.
• Elk are color-blind, so it doesn’t matter what you wear, but try to stay in the cover of the trees.
• If you spot a herd, approach quietly and slowly from downwind. Elk have excellent senses of hearing and smell.
• Stop and listen frequently for the distinctive wailing bugles of the bulls. Elk herds can travel and change direction quickly.
• If you want a virtual guarantee of seeing elk and don’t mind them being practically tame, visit Rocky Mountain National Park. In this area, elk are so used to humans they have become pests.

-Melissa Barton

Photo Credits: PDPhoto.org/Jon Sullivan (elk at Yellowstone), Melissa Barton (broken sapling and Ranger Burman giving a talk)

*Some biologists classify American elk as belonging to the same species as European and Asian red deer, C. elaphus. Recent genetic studies suggest that American elk belong to a different species from red deer. Further studies will clarify the relationship of different species and subspecies of red deer and American elk (return to article).

Mountain mahogany (Cercocarpus) is a small genus of deciduous shrubs or small trees, currently placed in the rose family (not closely related to true mahoganies, in the Meliaceae family). In addition to growing throughout the Rocky Mountain region today, mountain mahogany is a relatively common Tertiary (65 to 1.8 million years ago, the time between the extinction of the dinosaurs and the first Ice Age) fossil found in the Florissant and Antero Formations, as well as at Creede, Webber Lake in the Sierra Nevada of California, the Desert Peak Formation of Nevada, Oligocene sediments in Mexico, and many other localities.

Mountain mahogany seeds are more common than leaves in the Florissant Formation (34.07 million years old), although the numerous hairs of the modern seeds (above) are not evident–seeds are generally preserved as a small oval seed with a long curling tail. In certain localities in the nearby Antero Formation (~33.76 million years old), mountain mahogany leaves are the most abundant fossil. At left you can see the well-preserved part and counterpart of a mountain mahogany leaf from the Antero.

We haven’t found any mountain mahogany seeds like the ones from Florissant in the Antero yet, only leaves. Further study will show whether the Antero mountain mahogany more closely resembles the species from Florissant or the species from the Oligocene Creede flora, which grew in a much colder climate than that of ancient Lake Florissant.

-Melissa Barton

Photo Credits: Melissa Barton

Student Conservation Association intern Lindsey Stecker pulling sweetclover.

Yellow sweetclover (Melilotus officinalis), an introduced European plant, grows profusely along roadways, trails, and in other disturbed areas throughout the plains and montane regions of North America, including Florissant Fossil Beds National Monument. Sweetclover is a hardy biennial that is used as fodder for livestock and for producing clover honey. Outside of cultivation, sweetclover can out-compete native plants, as well as overrun pastureland.  Sweetclover is aggressive and difficult to eradicate, and seeds can remain viable in the soil for up to 30 years.

Yellow sweetclover bushes can grow from 2 to 5 feet tall and have strong taproots. At right, sweetclover grows densely along the road to the Visitor Center. Park staff, particularly Student Conservation Association interpretive intern Lindsey Stecker (Boston University) and Chief Ranger Rick Wilson, have been working hard to control the spread of sweetclover this summer.

-Melissa Barton

Photo Credits: Melissa Barton

The fossil redwoods are the largest and, for many visitors, the most impressive fossils at Florissant. These are among the largest-diameter petrified trees known–the Big Stump, above, measures 3.7 meters in diameter at breast height, and another measures more than 4.1 meters.

Although now confined to California and Oregon (Sequoia sempervirens and Sequoiadendron gigenteum) and China (Metasequoia glyptostroboides), redwoods once grew throughout the temperate northern hemisphere, including Europe, North America, and Asia–there are even petrified Sequoia and Metasequoia trees from Iceland!

The fossil wood at Florissant, assigned to the fossil wood genus Sequoioxylon, almost certainly corresponds with the relatively abundant fossil cones and needles of Sequoia affinis found in the lake shales. Fossil pollen that resembles the pollen of living Sequoia has also been identified. S. affinis most closely resembles the living coastal redwood, S. sempervirens, although tree ring evidence suggests that the trees of Florissant grew in a more favorable climate than the California redwoods.

The Trio is the only known fossilized vegetative clone, commonly called a “fairy ring” or “family ring.” Vegetative clones occur when a tree is toppled or burned. Sprouts from exposed roots around the base can create rings of trees around the stump of the original tree, which eventually rots away. These new trunks share a root system, and so are considered to be a vegetative clone. Vegetative clones are common in modern coastal redwood forests. The Trio was dated to 500-700 years old at its time of death.

-Melissa Barton

Photo Credits: Melissa Barton (The Big Stump), Lee Snap (The Trio), Edward Z. Yang/public domain (living redwood clone), unknown photographer/public domain (sun shining through redwoods).

The northern flicker (Colaptes auratus) is one of the most commonly-seen members of the woodpecker family in Colorado. Flickers are unmistakable, with their large size (12-14 inches tall) and dramatic coloration, and they are the only woodpecker that regularly feeds on the ground.

Red-shafted flickers are the color variety most commonly seen in the western United States, named for the bright red or red-orange shafts of their wing feathers. In flight, the undersides of their wings are visible as a flash of red. Males and females have similar coloration, but males can be identified by their red cheek patches or “moustaches” (above). Like other woodpeckers, the primary food of the flicker is insects, although they will also eat fruits, seeds, and nuts.

Northern-dwelling flickers migrate in winter, unlike most other woodpecker species.  The red-shafted flicker also interbreeds with the yellow-shafted flicker where their ranges overlap.  Although formerly thought to be separate species, the red-shafted flicker is now considered a subspecies (Colaptes auratus cafer).

As you walk around Florissant Fossil Beds National Monument, watch for the undulating flight and red wings of the northern flicker, and listen for loud drumming or a “laughing” ki ki ki ki call.

 At the nearby Manitou Experimental Forest, abandoned flicker nesting cavities serve as nesting cavities for the sensitive flammulated owl (Otus flammeolus).

-Melissa Barton

Photo Credits: Elaine R. Wilson (male) & Alan D. Wilson (female)/NaturesPicsOnline.com (Creative Commons Attribution ShareAlike 2.5 license). Both photos taken in Oregon.

The “Florissant flower,” Florissantia speirii, is another iconic fossil from the Florissant Formation. Although more common in the Green River Formation and elsewhere, F. speirii was first described here at the Florissant Fossil Beds. The species is tentatively placed in the Sterculiaceae, the family which includes cocoa (Theobroma cacao), kola nuts, and tropical mahoganies.

The delicate petals of flowers are rarely preserved in the fossil record, but the sepals (modified leaves) of F. speirii formed a tough calyx that protected the flower and aided preservation. Features of the flower suggest that it was pollinated by insects or birds, and its fruits were probably wind-dispersed.

You can see a F. speirii fossil on display in the Visitor Center at the park.  The genus name, Florissantia, is also shared by an insect, the planthopper Florissantia elegans.

-Melissa Barton

Photo Credit: Herb Meyer/Florissant Fossil Beds National Monument

The bright red-orange and scarlet blooms of the scarlet paintbrush (Castilleja mineata, also called great red paintbrush, giant red paintbrush, and Indian paintbrush) are a common sight in the grasslands of Florissant Fossil Beds National Monument from about May through September. Paintbrushes are related to the garden snapdragon, and like snapdragons, their colorful “petals” are really bracts, or modified leaves. The actual flowers are much smaller, and in paintbrushes, fused into a long, greenish-yellow tube.

There are over 200 species of Castilleja in North America, and they frequently hybridize, making species identification difficult. Paintbrush species may have red, orange, pink, yellow, white, or purple bracts.

The genus is named for Domingo Castillejo (1744-1793), a Spanish botanist and Professor of Botany in Cadiz, Spain. In the late 1770s, Spanish-Columbian scientist Jose Celestino Mutis named a new genus “Castilleja” to honor his countryman. The common name comes from the plant’s resemblance to a paint-tipped brush.

 -Melissa Barton

Photo Credit: Melissa Barton

Palaeovespa was described in 1906 by University of Colorado professor T.D.A. Cockerell (learn more), a naturalist with wide-ranging interests. Cockerell collected extensively in the Florissant Formation during the summers of 1906 to 1908, and published over 130 papers on the fossils of Florissant, as well as numerous papers on living insects he collected there, particularly the bees. If you see a bee collecting pollen from a wildflower at the park, that bee was probably described and named by Cockerell–he described more than 900 species in Colorado alone!

A stylized image of Palaeovespa decorates the sign at the entrance of the Visitor Center parking lot, and Palaeovespa is also part of the Friends logo. You can buy replicas of this specimen at the Visitor Center gift shop.

“To a non-scientific person it seems highly illogical to say that an object is in one sense of priceless value, and in another only worth ten or fifty cents. The value of a new species of fossil fly or beetle, in a money sense, is of course very small, since neither museums nor naturalists can afford to give large sums for objects which “bake no bread,” and which at the time interest perhaps fewer than half a dozen persons in the world. On the other hand, such specimens form part of the material of science, and essential parts of the great structure of knowledge, and will continue for unknown generations to tell their humble but not insignificant tale of what has been. To lose or destroy them is like removing a brick from some splendid building; the building will not fall, but the offense is intolerable.”
-T.D.A. Cockerell, “Colorado A Million Years Ago,” Journal of the American Museum of Natural History (1916)

-Melissa Barton

Photo Credits: NPS/Florissant Fossil Beds National Monument (Palaeovespa), Michael Apel (living paper wasp and nest)