Late Ordovician Asaphidae

Now that that snow has melted, I made a trip to my favorite Isotelus spot. More collecting is needed.


Here is the find of the day. A complete prone Isotelus hiding under a large pygidium which must have sheltered and protected it from disarticulation during the storm.


The cephalon and other half of thorax on reverse side. Unfortunately, I somehow lost the piece containing the rest of the cranidium on the trip home.


Gluing the thorax back on at home..


Finished preparation. Not entirely complete obviously but still my most beautiful Isotelus iowensis specimen after searching over the past few years, so I am quite happy with it. 


Isotelus iowensis 
Ordovician period
 Cincinnatian series
 Richmondian stage
 Maquoketa group
Illinois
measures 10cm
collected March 17, 2019




Comments

Post a Comment

Popular posts from this blog

A rare find in the Pennsylvanian Black Shales

Image
On August 17th, I went on a group trip to the Starved Rock Clay Pit. I was specifically looking for some Listracanthus parts, and upon splitting open a large septarion nodule measuring roughly 2ft across, came upon what looked at first like a poorly preserved denticle. Upon returning home and examining more closely, it appeared to have segmentation. After showing photos of the specimen to Dave Carlson and Jack Wittry of ESCONI, it was identified as a rare  Tyrannophontes theridion Shram, 1969. From Wittry's book, The Mazon Ceek Fossil Fauna, "First discovered at Pit 11,  Tyrannophontes theridion was figured and described in 1969 by Shram. Subsequently, similar species were found preserved in the Pennsylvanian black shales of Iowa and Nebraska." Interestingly, nothing is mentioned of the black shales in Illinois. On a side note regarding the mysterious spiny, eel-shaped  Listracanthus that has eluded paleontologists for 150 years ,  a complete specimen has finally b
Read more

Pennsylvanian

Image
Trip to the Pennsylvanian edge of the Illinois Basin. Sunrise 6:30am Stop no. 1 was the Bond formation behind a cemetery near the border of Indiana. The rocks here contain a rich fauna, however I was mostly looking for rugose corals to make thin sections. Stop no. 2 was mostly for scouting for the black Mecca shales to find shark remains.
Read more

Water Levels

Image
I thought it would be fun to periodically post water level data, since the sea levels are rising. I'll mostly focus on Lake Michigan, Great Lakes, Atlantic ocean. Here are some pictures of disappearing Juneway Beach in Chicago and a link to an article here . 2019
Read more