The ESCONI June 2026 Paleontology Study Group Meeting was held on Saturday, June 20th, 2026 at 7:30 PM via Zoom. Lincoln Shoemaker presented “Factors controlling the distribution of Late Ordovician – Silurian crinoids.”

Lincoln Shoemaker is currently a master’s student at the University of Cincinnati where he is involved in multiple projects regarding the Late Ordovician Mass Extinction along with minor work involving Mississippian crinoids. Prior to pursing a master’s Lincoln worked as a freelance fossil preparator and commercial dealer of invertebrate fossils. 

Description: Many crinoid genera well represented in rocks of the Illinois Basin similarly occur in the Appalachian Basin during the Sandbian and lower Katian (lower portion of the upper Ordovician). However, during the late Katian crinoid faunas of the eastern US and Ontario show little similarity to those of the Illinois Basin. What drives this separation of crinoid faunas when in the preceding interval the faunas were broadly indistinguishable? This talk will discuss elements of crinoid biogeography and preliminary evidence suggesting that these faunas may be separated by water – temperature differences.