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 ( http://www.amjbot.org/content/102/5/725.abstract). 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.

DSC_3600_edited_leafblog Combined-counterparts-15761N_57228_leafblog DSC_3589_edited_leafblog

Allen_14_edited2_fruitblog Stacked-classic_51997_edited_fruitblog



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!


And finally….!

July 30th, 2014
By Allen,Sarah E

Thanks to everyone who helped me this summer in the field: Sahale Casebolt, Dr. Steve Manchester, Jim Barkley, Dr. Ellen Currano, Dr. Mike Smith, Dr. Paul Murphey, Terry Lott, and Xiaoyan Liu. I must add additional thanks to Steve for allowing me to use his van and to Sahale and Terry for help in driving to and from Florida.

Also, thank you to Hongshan Wang, the Paleobotany Collections Manager, who will be of great assistance in curating all of the specimens we found.

Financial support for my fieldwork (this summer and 2012) was generously provided by: The Paleontological Society, The Evolving Earth Foundation, National Science Foundation (NSF), and the University of Florida Department of Biology Mildred Mason Griffith Botany Grant.

Thank you also to the FLMNH and Department of Biology fiscal staff, especially Ashley Gazich. Sarah Fazenbaker, FLMNH webmaster, helped to get my blog up and running before the start of the field season.

Finally, thank you to my Mom, who has provided many last minute proofreading sessions of my posts!

I hope you have all enjoyed reading my updates from the field. Be sure to check back occasionally because I will continue to provide updates about my project! Thanks for reading!


Final days

July 30th, 2014
By Allen,Sarah E

Steve, Terry Lott, and Xiaoyan Liu arrived in Rock Springs on Wednesday July 23rd after driving from Florida. Terry is the paleobotany lab manager at the Florida Museum of Natural History. Xiaoyan Liu is a visiting student from Sun Yat-Sen University in Guangzhou, South China. They helped me collect at three more sites. We found more fossils and I documented the leaf specimens for my census data.


Here Steve is graciously showing off one of the quarries.



Xiaoyan and Terry are working at a locality that Greg Stull (another graduate student in paleobotany at the FLMNH) found two years ago.



I hiked over to my stratigraphic section to document a few more details, but Steve, Terry, and Xiaoyan kept fossiling!


I was fortunate to have Dr. Paul Murphey take time from his busy schedule to help in the field for a day. He has worked extensively in the Bridger Formation documenting the geology and vertebrate paleontology. He is now the Vice President of Rocky Mountain Paleo Solutions. We walked around two areas of Blue Rim to both look for vertebrate fossils and to discuss the stratigraphy. Paul noticed many tiny bone fragments that I had overlooked in my quest for plant fossils. It is nice to know what animals may have been living in the same area as the plants I have been studying!


Paul is searching for bones weathering out of the sandstone.



This photo shows a bone fragment of a Brontothere. Brontotheres are extinct herbivorous mammals that are most closely related to modern rhinos and horses. Other bone fragments in the Blue Rim section are from turtles, fish, crocodiles, and rarely, from small mammals.

As I close out my journey at Blue Rim for 2014, I leave you with some scenic photos.




Playing tourist

July 22nd, 2014
By Allen,Sarah E

I ended up with a few unexpected days in Rock Springs, WY and visited several of the local tourist stops.

Here are some of the young wild horses that have been rounded up. They can be adopted by the general public.


I took a short trip northeast of town to visit two unique geological features.  First, I saw the Killpecker Sand Dunes. A large quantity of sand has accumulated in this area and created dunes up to 150 feet tall after being funneled through a gap in the nearby volcanic Leucite Hills. Some areas of the dunes are protected, but other areas are open for recreation. This is the largest active dune field in North America and is more than 100 miles wide.

IMG_0507_dunes2           IMG_0499_dunes1

I passed a volcanic remnant called Boar’s Tusk. It is about 400 feet high and is similar to Devil’s Tower in northeast Wyoming.


My drive would not be complete without some cattle blocking the road!


I completed a circuit of the local museums including Rock Springs Historical Museum, the Community Fine Arts Center, and the small Natural History Museum at Western Wyoming Community College.

Rock Springs Historical Museum is located downtown in the former City Hall. It has information about life in a coal town and a small exhibit about WWII. The old jail is still there and open for the public to explore.  I will take my tent and a strong wind over those accommodations any day!


Nearby, the Community Fine Arts Center was another nice, free place to stop. The building is a former church that houses more than 400 pieces of American art including pieces by Norman Rockwell and Grandma Moses.

Western Wyoming Community College is on top of a hill in the middle of town. It has a small natural history exhibit that includes five full size dinosaur replicas. It also has some other fossil exhibits including this palm frond and fish (the well-known Knightia)  from the Green River Formation.  If you ever buy a Green River fish fossil, that is usually what you get.

IMG_0530_trex     IMG_0528_palm

Finally, I leave you with an image of the Green River cutting through rocks of the formation of the same name.  The Green River Formation spans areas in Wyoming, Colorado, and Utah and represents a massive interior lake that was present from about 53.5 to 48.5 million years ago.


Searching for tuffs

July 20th, 2014
By Allen,Sarah E

I also met up with Mike Smith, a professor at Northern Arizona University. He studies the stratigraphy and geochronology of the Green River Formation and the surrounding areas. We searched for tuffs in the Blue Rim section and also reviewed the local geology.  Tuffs are rocks that contain a significant amount of material derived from a volcanic eruption.  The crystals within a tuff are formed when the volcano erupts and can be used to date the rock by a method called radiometric dating.   Luckily, we found some tuffs to sample and hope to get better age estimates for the Blue Rim section than we have now.


Mike with his dog Nebula examining a tuff.


A close up view of a tuff with bits of pumice preserved. Pumice is a light colored volcanic rock. It is an unusual rock because it usually floats due to the high concentration of gas that forms hollow cavities.


The bowl-shaped darker brown rocks near the top of the cliff preserve a large river channel from ~49 million years ago.


A view looking south toward the area we worked in for most of the day. It was very windy with gusts up to 35 mph!

Moving Rock

July 20th, 2014
By Allen,Sarah E

The last few days, Ellen Currano and Jim Barkley helped me in the field. Ellen Currano is a professor at the University of Wyoming who studies climate change by looking at fossil plant and insect interactions. Jim Barkley is an amateur paleobotanist from western Colorado. I significantly added to my leaf census data at three different sites with their help. We moved a lot of rock in order to find lots of fossils!

Ellen on the left and Jim on the right.
It was pretty hot one of the days we were working and there was no breeze. Ellen found that her fossil quarry also made a nice couch – especially with Jim fanning her!
There is not a lot of wildlife at Blue Rim, but I have heard coyotes and seen lots of rabbits, ground squirrels, various birds, and horny toads. Horny toads are a type of lizard that most often feed on ants. Even though horny toads do not look appetizing, they are a food source for other semi-desert carnivores. You can observe two of their defense mechanisms in the photo below: camouflage and numerous spines.

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