Spence Gulch Trilobite Trip

John has had trilobites on the brain recently. Seriously.

I realize that I never really wrote about our trilobite collecting trip to Spence Gulch, Idaho, so I thought I would fill you in. We did find the site. As I mentioned before, Spence Gulch is located in southeastern Idaho (see map below) near the town of Liberty, Idaho. We originally found out about the site from the Geo-Tools website. We knew the land is on National Forest Service property, so that was one good thing to find out, as far as invertebrate fossil collecting goes (you do not need a permit as long as you are collection common invertebrate fossils for non-commercial purposes only). Google earth showed us where we wanted to go (also see below), thanks to someone else marking the map. Once we found the right road to turn off of, it was reasonably easy to find.


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The Spence Shale (Lead Bell Shale Member of the Langston Formation) is exposed in a stream cutbank. While we were there the stream was dry. It is easy to see from an aerial photo but is not visible from the road. Once you see it though, you know you are there.
We collected for two days and did pretty well. All of the fossils we collected are now housed in the Museum of Western Colorado's paleontology collections. The trilobites we collected include:

• Peronopsis sp.
• Pagetia clytia
• Zacanthoides idahoensis
• Zacanthoides serratus
• Athabaskia bithus
• Oryctocare geikei
• Amecephalus idahoensis
  
• Achlysopsis sp.
  

The agnostoid trilobites Peronopsis and Pagetia dominated our finds (over 75% of what we found). The non-agnostoid Zacanthoides idahoensis (picture below right) was the most abundant, followed by Amecephalus idahoensis (picture above right))

Other fossils collected include:

• Brachiopods -
  Lingulella eucharis, Acrotreta sp., and Wimanella sp.
• Hyoliths - Hyolithes sp.
• Echinoderm - Gogia palmeri
  

Feel free to take a look at my pictures from that trip here.

















A big thanks to my husband who identified all of these bugs and did the bulk of the work!

Trilobites!

John and I are going trilobite hunting this week at Spence Gulch (Langston Formation, Spence Shale Member, Middle Cambrian), Idaho! Walcott even collected these agnostid trilobites from this location and named the Spence Shale. Its is always fun to be where he has been. It should be fun to spend a few days outside and get to camp one more time at least before the weather gets cooler. Spence Gulch is located in southeastern Idaho near the town of Liberty and we originally found out about the site from the Geo-Tools website. We contacted the owners of the website and a few others, but either no one returned our emails or did not know where the site was, so we decided to wing it. The land is on National Forest Service property, so that was one good thing to find out. Google earth showed us where we wanted to go so we tried to locate the site on our way back from our honeymoon last month. Unfortunatly we could not find it using the Google maps instructions we had (which reminded us of this). We stopped off at Fossil Butte and spoke with a friend we knew would be in the know, and he was able to draw us a map. So off we go! Hopefully we will come home with a nice Achlysopsis (pictured, link) or Zacanthoides idahoensis!