Paleocene Plant Fossils of North Dakota (A Visual Post)

[Thomas.Dodson]

Paleocene plants in Central North Dakota are among the first fossils I've collected. Despite this I haven't given them the attention they are due lately. The preservation is very nice but due to various reasons they've taken a back seat to other outcrops in the state like the Cretaceous ones and I haven't thought about them for awhile. I am now reorganizing some of my Paleocene collection and a spark was reignited in me. I've decided to post some of the best examples here as a result. Come spring hopefully I can collect in additional Fort Union sites.

 

The terrestrial Paleocene deposits I've collected in all belong to the Fort Union Group, mostly the Sentinel Butte Formation and the Bullion Creek Formation. I see that some sources now list the Fort Union Group as a formation and the Sentinel Butte and Bullion Creek as members but for the purposes of this post I'll treat it as a group.

 

First, petrified wood is a common constituent of the Fort Union Group. Some of the wood is rather spectacular though. Silicified patterns are often striking. This piece is Sentinel Butte Formation.

[Thomas.Dodson]

Even basic plant structure is often well preserved and striking. The following are also Sentinel Butte Formation fossils.

Cercidiphyllum genetrix (Cercidiphyllum arcticum) is highly variable in the leaves.

More common than the leaves in my experience are the seeds.

 

[Thomas.Dodson]

A malformed example of the fruit of Cercidiphyllum genetrix.

Originally described as Carya antiquorum by Roland W. Brown in his report on Paleocene Folora of the Rocky Mountains and Great Plains, a revision states that most are in fact Aesculus hickeyi. I still see many examples online listed as Carya and for a long time these sat in my collection labeled as such.

More typical leaf mash where it is difficult to identify the species. Most of these appear to be Corylus insignis and Aesculus hickeyi.

[Thomas.Dodson]

Various single leaf examples of Corylus insignis.

[Thomas.Dodson]

While searching for Fox Hills Formation outcrops in Morton County I decided to stop by some roadcut exposures. These ended up being exposures of the Bullion Creek Formation. While most leaves and seeds were partial and unidentifiable aside from more Aesculus hickeyi and Carya antiquorum there were a couple species new to my collection.

A partial Sapindus affinis.

I believe this to be a partial Viburnum, maybe antiquum.

Hopefully I will find more to add here come spring but even if this isn't as large and diverse as my Cretaceous North Dakota stuff I thought someone might find some of these interesting.

[jpc]

nice stuff.  

[Fossildude19]

Definitely cool looking fossils. 

Thanks for posting them.  

[FossilNerd]

Very cool! The leaves are great and that piece of pet wood is a beauty! 

[badeend]

Very nice plant fossils, thanks for showing.

 

greetings Walter

[Petalodus12]

Amazing finds! I love Cretaceous/Paleocene plants.

[Jeffrey P]

GREAT SPECIMENS! Impressive collection there. I have some Paleocene petrified wood I found in New Mexico, but I would love to expand my collection and collect in the Fort Union Group someday. Plans to do so last summer in Wyoming unfortunately got cancelled. But there will be more summers hopefully. Thanks for sharing what you've got.