Blue Rim Thanksgiving

November 24th, 2015
By Allen,Sarah E

Could you have a traditional Thanksgiving meal 50 million years ago in southwestern Wyoming using what is known about the flora and fauna at Blue Rim?

Here is the target “traditional” Thanksgiving meal: Turkey, Stuffing, Cranberry Sauce, Green Bean Casserole, Mashed Potatoes, Vegetables (carrots), Dinner Rolls, and Pumpkin Pie.

Various geologic time periods will be referenced throughout this post. Here is a geologic time scale for reference. Everything is in the Cenozoic or Mesozoic era.

Turkey: Turkeys (Meleagris gallopavo) appeared relatively recently. There are numerous fossil records of the genus Meleagris in the Pliocene and Pleistocene. However, fossil records assignable to the subfamily Meleagridinae (where turkeys are found) are known from the Early Miocene. The fossil record of birds in general is spotty because their bones are light, hollow, and do not preserve well. Since turkeys were not available, the alternate meat options at Blue Rim ~50 Ma likely would have included: local turtles, crocodiles, clams, and snails, and nearby fish and mammals. Bird fossils have been found, albeit rarely, in the Bridger Formation.

Stuffing & Dinner Rolls: The main ingredient in both is wheat or Triticum aestivum which is in the Poaceae (Grass) family. Poaceae is the fourth largest family in terms of number of species, but it covers the most land area of any plant family and is the most economically important today. Grasses evolved in the Late Cretaceous and were widespread by the Early Eocene, but were rare compared to today. Open, grass-dominated habitats did not spread in North America until the Middle-Late Miocene.

There is some evidence for grass-like plants at Blue Rim, but don’t start baking the rolls just yet!  Leaf fragments with parallel venation similar to grasses are present, but they do not preserve any diagnostic characters and could represent one of many other monocotyledonous families. There are some fruit clusters with characters in common with modern grasses, but pollen preserved in the stamens lacks the diagnostic single pore. In addition, grass pollen has not been observed in the sediment.  Since grasses are wind-pollinated, the pollen should be present if they were nearby; however, grass pollen often degrades over time, so it may not have preserved.  More information about the fossil history of grasses can be found in the following paper: Stromberg, 2011.

Sadly, it likely would have been difficult to gather enough grains from the local Blue Rim flora ~50 Ma to prepare stuffing or dinner rolls.

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Two grass-like fossils from Blue Rim.  Scale Bar = 1 cm.

Cranberry Sauce: Cranberries (Vaccinium macrocarpon) are in the Ericaceae or heath family along with rhododendrons and blueberries. Based on the evidence available, there were not any cranberries or their relatives present in the Blue Rim flora. The closest fossil relative is likely a specimen assigned to an extinct genus in the Polemoniaceae from the Eocene Green River Formation in Utah (Lott et al., 1998). The families Polemoniaceae and Ericaceae are related and both are found in the order Ericales.

Green Bean Casserole: Green beans (Phaseolus vulgaris) are in the Fabaceae or legume family. Fabaceae is the third largest family in terms of number of species and is the second most important plant family economically. The Fabaceae likely evolved in the mid to Late Cretaceous, but the fossil record is more extensive in the Paleogene, with diversification in the Eocene. No fossil beans have been recovered at Blue Rim. However, it is still possible that legumes were present as the leaf characters often mimic other families making them hard to identify. However, there are definitive fruits assignable to Fabaceae at the Kisinger Lakes site in northwest Wyoming. This fossil site is similar in age to Blue Rim, so if you were willing to take an extended walk (~150 miles) you might obtain some edible beans!  More information about the fossil history of legumes can be found in the following book: Herendeen, P.S. and D.L. Dilcher eds. (1992). Advances in Legume Systematics Part 4: The Fossil Record. United Kingdom: The Royal Botanic Gardens, Kew.


Fossil legume from the Kisinger Lakes site in northwestern, Wyoming.  Scale bar = 1 cm.

Mashed Potatoes: Potatoes (Solanum tuberosum) are members of the Solanaceae or Nightshade family. This family also includes peppers, tomatoes, eggplants, and tobacco. No fossils assignable to Solanaceae have been observed at Blue Rim. The oldest fossils confidently assigned to the Solanaceae that are approximately the same age as the Blue Rim fossils are found in the United Kingdom. A molecular analysis (Särkinen et al. 2013) placed the stem of Solanceae at ~49 Ma and the crown group (the current suite of genera) at ~30 Ma. Therefore, true potatoes probably did not even exist in the Early Eocene and there would be no mashed potatoes for dinner.

Carrots: Carrots, scientifically known as Daucus carota, are in the Apiaceae or Carrot Family. Few Apiaceae fossils are known. Herbaceous plants, such as carrot do not preserve as easily as woody plants. No Apiaceae fossils or their relatives are known from the Blue Rim flora or any nearby floras of similar age.

Pumpkin Pie: Pumpkin or Cucurbita pepo is a member of the Cucurbitaceae family along with melons. Sadly there are no fossils assignable to Cucurbitaceae at Blue Rim either, so a familiar dessert would not have been served.

If Thanksgiving had begun 50 million years ago instead of the 1600s, the “traditional “ meal everyone looks forward to today would be much different if it were based only on the flora and fauna present in the Blue Rim area of Wyoming at that time.  Have a Happy Thanksgiving and enjoy your meal!

Botany 2015 in Edmonton

August 7th, 2015
By Allen,Sarah E

I recently returned from this year’s Botany conference in Edmonton, Alberta, Canada. It was held in the Shaw Conference Center overlooking the North Saskatchewan River. I presented on Monday during the Paleobotany student session. My talk focused on the leaf flora from the lower stratigraphic horizon at Blue Rim. This horizon has 20 non-monocot angiosperm leaf morphotypes. I used specific leaf characters that have been linked to climate to estimate the paleotemperature and paleoprecipitation. I also attended the Paleobotany Banquet, the ASPT (American Society of Plant Taxonomists) Banquet, and numerous talks. After the conference, I participated in a field trip exploring the post-glacial landscapes, history, and vegetation east of Edmonton. This excellent trip was led by Alwynne Beaudoin and Diana Tirlea from the Royal Alberta Museum.

My travel to Edmonton and participation in Botany 2015 was supported by the ASPT and NSF DEB award number 1404895.

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Two of the leaf morphotypes (species) from Blue Rim. The leaf on the left is compound and toothed. The leaf on the right is simple and untoothed. Notice the large size of the leaf on the right. Scale bar for both = 1 cm.


View of the Shaw Conference Center in downtown Edmonton.


Foliage of Populus tremuloides (aspen). Aspen is the dominant tree species in and around Edmonton.


A male bison in Elk Island National Park.


A shallow lake at Elk Island National Park.


The North Saskatchewan River to the east of Edmonton near the site of a former Victorian fort and settlement.

Palm Flowers

July 14th, 2015
By Allen,Sarah E

Fossil palm flowers have been found at Blue Rim and other sites in the Rocky Mountain region.  These flowers, representing a new species named Phoenix windmillis, are related to date palms.  Modern date palms are native to Africa and southeast Asia, but are found in the Eocene of Wyoming, Colorado, and Utah.  One of the flowers contained in situ pollen, which provided more characters to support the assignment of these specimens to Phoenix.  This new species is documented in a paper that was recently published in the International Journal of Plant Sciences.


Two Phoenix windmillis flowers from Blue Rim.  Scale bar = 5 mm


A flower from the Barrel Springs site in the Green River Formation.  This site is in southern Wyoming to the east of Blue Rim.  Scale bar = 5 mm


Pollen extracted from an intact anther of Phoenix windmillis and viewed using a scanning electron microscope (SEM).  Scale bar = 23.1 µm. (Note: there are 1,000 µm in 1 mm)

Plant Anatomy Short Course: Week 2

July 13th, 2015
By Allen,Sarah E

The second week focused on the secondary plant body or wood.  We studied the anatomical details of wood of both flowering plants and conifers.  We also touched on the development, function, evolution, ecology, variability, and uses of wood.  Week 2 was taught by Elisabeth Wheeler, Peter Gasson, and Pieter Baas – all experts in wood anatomy.

I would like to extend my thanks to all the instructors, the TA Becky Povilus, Faculty Assistant Jess Gard, and our awesome bus driver, Andrew Brown. Thank you also to Steve Manchester and Christine Davis who wrote letters of recommendation on my behalf.

Here are some photographs from the second week:


A cross or transverse section of Quercus robur (English oak) wood.  The annual rings are visible.  The larger vessels (for water conduction) are formed in the spring when resources are more plentiful.  This is termed “earlywood.”  Later in the growing season, when water is less plentiful the vessels are smaller and compose the “latewood.”


Rays and vessels in a tangential section of Dalbergia spruceana (rosewood).  Dalbergia is a genus in the pea family, Fabaceae.


Radial section of Ilex aquifolium (holly).


Tangential section of Pinus monticola (Western white pine) with a resin canal in one of the rays.  While angiosperms have vessels and tracheids, conifers only have tracheids to transport water and minerals.

When you walk by plants, think of them as living, breathing organisms.  Although they don’t move or behave like animals, they are interesting and complex, necessary for the ecosystem to function, and add incredible beauty to our world.


Leaves and fruits of Acer tataricum subsp. ginnala (Sapindaceae family).  This specimen, commonly known as the Amur Maple, arrived at the Arnold Arbortum in 1963 from the Kyoto Takeda Herbal Garden in Japan.

Plant Anatomy Short Course: Week 1

July 12th, 2015
By Allen,Sarah E

I recently attended a two week short course in Plant Anatomy at the Arnold Arboretum in Boston.  It was funded by the NSF microMorph program (More info here).  Week 1 was taught by Ned Friedman and Pam Diggle and focused on the primary plant body.  We squeezed weeks of material into 5 jam packed days!  We covered apical meristems, the epidermis, ground tissue, vascular tissue, secretory structures, stems, leaves, and roots.  In addition to learning about all these topics through engaging lectures, we spent our afternoons in the lab seeing and photographing various specimens.

Here are a few pictures from Week I:


Helical protoxylem from a celery (Apium graveolens) petiole.


Glandular trichomes (hairs) on Drosera capensis. The trichomes secrete mucilage that can be used to catch insects. Drosera is a genus of carnivorous plants commonly known as the sundews.


Water absorbing scales from a bromeliad. Pineapples and spanish moss are also in the bromeliad family.


Stellate (star-like) parenchyma in Juncus. Parenchyma is one of the ground tissues and can be found throughout a plant. Juncus is a genus of monocots commonly called the rushes.


A cross section of a mature root of Ranunculus (buttercup). The four “arms” of xylem (water conducting tissue) are visible in the center of the root.

As an aside, if you have never been to Boston or the Arnold Arboretum (More info here), they are both worth a visit!  The Arnold Arboretum is a beautiful park spanning 281 acres with 15,000 labeled primarily temperate woody plants.  There is no admission charge.  I also enjoyed visiting some of the Boston historic sites with several of the other students who were enrolled in the course with me.


The Hunnewell Visitor Center on the grounds of the Arnold Arboretum.

Icacinaceae at Blue Rim

June 15th, 2015
By Allen,Sarah E

The Icacinaceae* are found in tropical forests in Asia and Africa today. However, this family of woody trees, shrubs, and climbers is found in the Blue Rim flora along with other sites in the Eocene of western North America. At Blue Rim, I found two species of fruits assignable to Icacinaceae, along with one species of leaves. Two colleagues and I discussed our findings in a recent article which appeared in the American Journal of Botany ( Our paper also documents another new species of Icacinaceae based on fossil fruits and discusses the biogeographical and paleoclimatic significance of finding Icacinaceae in the Eocene of North America.

*There is no regularly used common name for this family. For example, the Fabaceae are also known as the bean family.

I have included a several images of the leaves, Goweria bluerimensis, and the more common of the two species of Icacinaceae fruit, Iodes occidentalis, below.  The leaves have a 1 cm scale bar, while the fruits have a 0.5 cm scale bar.

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Dickinson Hall Window Exhibit

February 24th, 2015
By Allen,Sarah E

The Paleobotany lab at the FLMNH has updated the east side display window in the Dickinson Hall courtyard on the University of Florida campus.  It contains four posters describing research by others in the lab, including work on lianas in Panama, leaf morphotyping, and fossil fruits of Anacardiaceae and Icacinaceae.  In addition, I had the opportunity to create a small exhibit about my fieldwork and research.  The display spans more than 20 feet in length so I was able to track a fossil’s journey from its discovery in the field to the lab through my own research experiences.  The exhibit includes a mock fossil quarry, panels on the benefits and hazards of fieldwork, information about curating and preparing fossils for study, case studies, and more.  If you are local, check it out!  For those of you who are not local, here are a few overview photos:




Behind the Scenes: Prepping the fossils in the lab

November 6th, 2014
By Allen,Sarah E

Once the fossils have been curated, they can be prepared.  Many specimens collected in the field will be only partially exposed. Rock layers or sediment may still cover more than half the fossil or maybe just a small part. Small needles, razor blades, and dental picks are used to uncover the buried fossil. It is best to do this detailed work in the lab rather than the field. The tools are more accurate, the lighting is better, a dissecting microscope is available, and most important, elements like wind, rain, and uncomfortable temperatures are non-factors!



Some fossils can be fully prepped in a minute or two, while others require hours of work. The time needed depends both on how much of the fossil is buried and the type of sediment it is in. Fossils preserved in soft sediments are more easily exposed than those in more resistant material.

IMG_0388_Mac_before_5cm   IMG_0390_Macginitiea_exposed_5cm

Macginitiea leaf before preparation on the left and after on the right.  Macginitiea is an extinct genus in the Platanaceae or Sycamore family.  Scale bar is 5 cm.

Behind the Scenes: Curating the fossils

November 4th, 2014
By Allen,Sarah E

After getting back from the field, specimens are sorted by locality based on their field labels and carefully unwrapped.  Most of the Blue Rim specimens survived the journey to Gainesville intact, but a few needed to be glued (we usually use Elmer’s) and repaired.  Individual specimens are placed in boxes (usually the top or bottom of a jewelry box).  Each fossil is giving a number composed of the locality ID number and then an individual specimen number.  This same number is also recorded on a label in the box that has additional information about the locality including GPS coordinates, geological formation, age, and collectors.


The fossils are then arranged into labeled drawers by locality (each quarry is given a locality number) and then into stackable, compressible cabinets.


In the Paleobotany Division of the Florida Museum of Natural History, most of this work is done by Collections Manager, Hongshan Wang.  His many hours of work and attention to detail help preserve a very organized collection.



August 29th, 2014
By Allen,Sarah E

This post is long overdue, but better late than never!  I attended my first BOTANY Conference in Boise, ID after I finished my fieldwork in WY.  The conference was interesting and had many engaging sessions.  I presented a poster.


A few of us visited the botanical garden that was near the convention center.


I also went on a three day field trip to Clarkia, ID after the conference. The drive north was beautiful and was certainly a change from the badlands of southwestern Wyoming.


We stopped at three Miocene aged plant fossil localities. The first was 12 million years old and had lots of legume or bean pods like the one seen here.


The next two sites were about 15 million years old.  Rather than go into much detail about the Clarkia sites, I suggest you watch this excellent video: Plants Are Cool Too! Episode 2: Fossilized Forests!   The Clarkia fossil leaves are extremely well preserved.  Many of the compressed leaves are still green or red when they are exposed and can be processed for ancient DNA!


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