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Fossil Friday #314: Kellibrooksia macrogaster
Read more: Fossil Friday #314: Kellibrooksia macrogasterFor today’s fossil, we have a beautiful specimen of Kellibrooksia macrogaster, which was a species of mantis shrimp (see Mazon Monday #105). This rare animal was described by Frederick Schram in 1973. It was named in honor of Harold Kelly Brooks, who published the first well-illustrated modern account of Mazon Creek crustaceans. A pdf of his work is available. Have a look as it has some amazing illustrations! This contribution comes from Alan Keith. Alan is a very serious Mazon Creek collector. He travels up here from Texas multiple times each year to collect concretions he can process back home. Thanks for sharing,…
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Throwback Thursday #314: Collecting from 1954
Read more: Throwback Thursday #314: Collecting from 1954We are in the midst of the spring field trip season and this article by Roy Beghtol from the May 1954 edition of the ESCONI newsletter seemed appropriate.
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Happy Earth Day 2026!
Read more: Happy Earth Day 2026!For more information see the Earth Day website.
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Video for ESCONI April 2026 Paleontology Meeting – “Digging the Marl of the Lance Formation”
Read more: Video for ESCONI April 2026 Paleontology Meeting – “Digging the Marl of the Lance Formation”The April 2026 Paleontology Study Group Meeting featured Keith Robitschek and his presentation “Digging the Marl of the Lance Formation”.
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Video for ESCONI April 2026 General Meeting – “Life in the Devonian Period, The Age of Fishes”
Read more: Video for ESCONI April 2026 General Meeting – “Life in the Devonian Period, The Age of Fishes”The April 2026 General Meeting was held on April 10th, 2026 at 8:00 via Zoom. At the meeting, Jessica Hull presented “Life in the Devonian Period, The Age of Fishes.”
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Mazon Monday #318: Eusphenopteris neuropteroides
Read more: Mazon Monday #318: Eusphenopteris neuropteroidesEusphenopteris neuropteroides is an extinct seed fern species that is relatively uncommon, though it is primarily known from the terrestrial deposits of Mazon Creek. It was originally described as Pseudopecopteris anceps by Leo Lesquereux, but its classification has shifted over time as its relationships to other taxa became better understood. Over the years, it has been reassigned among several genera, including Sphenopteris and Mariopteris, before being placed in its current genus.
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The revolution in dinosaur science started 50 years ago—here’s what we have learned
Read more: The revolution in dinosaur science started 50 years ago—here’s what we have learnedPhys.org has a story about the dinosaur renaissance that started about 50 years ago. Before the research that led to the revolution in dinosaur science, dinosaurs were thought to dumb, slow, lumbering animals that went extinct because mammals were faster and smarter. Bone histology, birds as dinosaurs, feathers, lifespan, diet, and behavior are just a few of the advances we now understand to a greater extent than before the change in view that led to the renaissance.
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Reminder: MAPS Expo XLVII – April 24-26, 2026 in Springfield, IL
Read more: Reminder: MAPS Expo XLVII – April 24-26, 2026 in Springfield, ILThe Mid-America Paleontology Society (MAPS) 2026 Expo XLVII is being held from April 24th to 26th, 2026 at the Joe Orr Building on the Illinois State Fairgrounds in Springfield, Illinois. The topic for the show is “Fossil Preparation and Archiving”.
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Fossil Friday #313: Mazonomya mazonensis
Read more: Fossil Friday #313: Mazonomya mazonensisGeorge Witaszek sent us this breathtaking plate platter of Mazonomya mazonensis (see Mazon Monday #25). This animal was called “clam-clam” by collectors. Mazonomya mazonensis was known incorrectly as Edmondia for a long time. It was redescribed by Jack Bailey in the book “Paleobiology, Paleoecology, and Systematics of Solemyidae (Mollusca: Bivalvia: Protobranchia) from the Mazon Creek Lagerstätte, Pennsylvanian of Illinois” in 2011.
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Throwback Thursday #313: Who Was DuPage? How the River and County Were Named
Read more: Throwback Thursday #313: Who Was DuPage? How the River and County Were NamedThe BeHistoric channel on Youtube has a fascinating video about the history behind the name of the DuPage River and DuPage County.
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ESCONI April 2026 Paleontology Meeting via Zoom and in-person – “Digging the Marl of the Lance Formation”
Read more: ESCONI April 2026 Paleontology Meeting via Zoom and in-person – “Digging the Marl of the Lance Formation”The April 2026 Paleontology Study Group Meeting will feature Keith Robitschek and his presentation “Digging the Marl of the Lance Formation”. You can attend in-person at the College of DuPage, TEC, Room 1038B (Map). The meeting will also be available via Zoom.
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49th Annual CGMA Show – May 23rd and 24th, 2026
Read more: 49th Annual CGMA Show – May 23rd and 24th, 2026The 49th Annual CGMA Show will be held May 23rd and 24th, 2026 at the Expo Center of the Kane County Fairgrounds.
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Mazon Monday #317: Pohlsepia Revisited — Not an Octopus After All
Read more: Mazon Monday #317: Pohlsepia Revisited — Not an Octopus After AllA new paper “Synchrotron data reveal nautiloid characters inPohlsepia mazonensis, refuting a Palaeozoic origin for octobrachians” in the journal Proceedings of the Royal Society B Biological Sciences refutes the classification of Pohlsepia mazonensis as an octopus and reclassifies it as a soft-bodied nautiloid as Paleocadmus pohli.
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Ancient bees found nesting inside fossil bones in rare cave discovery
Read more: Ancient bees found nesting inside fossil bones in rare cave discoveryScience Daily has a post about a recent paper that looked at novel bee nesting behavior. Researchers working on the Caribbean island of Hispaniola discovered a rare and unusual fossil interaction in a cave, ancient bees used fossilized bones as nesting sites.
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PBS Terra: The Cascadia Megaquake Is Inevitable. And It Will Reshape America Forever
Read more: PBS Terra: The Cascadia Megaquake Is Inevitable. And It Will Reshape America ForeverPBS Terra has an interesting new video. This one covers the history, science, and future of the Cascadia Subduction Zone in the Pacific Northwest.
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Fossil Friday #312: Sublepidophloios protuberans with a spray of Cyperites bicarinatus
Read more: Fossil Friday #312: Sublepidophloios protuberans with a spray of Cyperites bicarinatusAt first glance, today’s fossil might look like a cone. But, closer examination reveals it to be a nice specimen of Sublepidophloios protuberans with a spray of Cyperites bicarinatus at the top. Sublepidophloios protuberans is a species of lycopsid branch (see Mazon Monday #316) and Cyperites bicarinatus was the sterile leaves for the Lycopsida (see Mazon Monday #69). Lycopsids were giant club mosses that existed during the Carboniferous Period. Lycopsids are still around, just not the giants.
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Throwback Thursday #312: Ron Schinderle Donation
Read more: Throwback Thursday #312: Ron Schinderle DonationBarb Schinderle stopped by ESCONI Show last month to drop off a donation of her late husband Ron’s fossils. Ron passed away in 2021. He was a long time ESCONI member and an avid fossil collector . He went on many ESCONI field trips. A group of us remember him fondly from our many trips to Pit 11 and Fossil Rock Campgrounds to collect Mazon Creek fossils.
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ESCONI Field Trip to the Winfield Mounds “Walking with the Ancestors” – Saturday, May 9th, 2026
Read more: ESCONI Field Trip to the Winfield Mounds “Walking with the Ancestors” – Saturday, May 9th, 2026There will be a field trip to the Winfield Mounds on Saturday, May 9th, 2026. Meet at Hedge’s Station in Winfield, IL. at 1:00 PM. We will be departing from the meeting spot at 1:15 PM. The field trip ends around 3:00 PM. This guided nature-and-culture hike offers participants an immersive journey through the Winfield Mounds—one of DuPage County’s most significant Indigenous archaeological landscapes—situated along the dynamic ecotones of the West Branch of the DuPage River. Blending natural history with archaeological insight, the experience highlights how ancient peoples selected, shaped, and understood this riverine environment.
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ESCONI April 2026 General Meeting via Zoom – “Life in the Devonian Period, The Age of Fishes”
Read more: ESCONI April 2026 General Meeting via Zoom – “Life in the Devonian Period, The Age of Fishes”The April 2026 General Meeting will be held on April 10th, 2026 at 8:00 via Zoom. At the meeting, Jessica Hull will present “Life in the Devonian Period, The Age of Fishes.” The Devonian Period was a crucial moment in the history of life. In this presentation, Jessica Hull will bring fossils to life by describing how they would have lived based on the most up to date research. Dunkleosteus fans won’t want to miss this!
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Mazon Monday #316: Sublepidophloios protuberans
Read more: Mazon Monday #316: Sublepidophloios protuberansToday, we have Sublepidophloios protuberans, which is a species of lycopsid branch. It’s very common, actually the most common form of lycopsid bark in the Mazon Creek fossil flora.
ESCONI Gem, Mineral, and Fossil Show
Most Recent Post
- Fossil Friday #314: Kellibrooksia macrogaster
For today’s fossil, we have a beautiful specimen of Kellibrooksia macrogaster, which was a species of mantis shrimp (see Mazon Monday #105). This rare animal was described by Frederick Schram in 1973. It was named in honor of Harold Kelly Brooks, who published the first well-illustrated modern account of Mazon Creek crustaceans. A pdf of his work is available. Have a look as it has some amazing illustrations! This contribution comes from Alan Keith. Alan is a very serious Mazon Creek collector. He travels up here from Texas multiple times each year to collect concretions he can process back home. Thanks for sharing, Alan!
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Field trips require membership, but visitors are welcome at all meetings!
| Friday, April 10th | General Meeting – 8:00 PM via Zoom. Jessica Hull will present “Life in the Devonian Period, The Age of Fishes.” |
| Saturday, April 11th | Junior Study Group Meeting – 2:00 PM, in person at the College of DuPage Technical Education Center (TEC) Building – Room 1038A (Map). Katherine Howard will present on Sand and Sediment Collecting. Specifics of this meeting are available from Scott Galloway, 630-670-2591, gallowayscottf@gmail.com. |
| Saturday, April 18th | Paleontology Study Group – 7:30 PM via Zoom and in person at the College of DuPage, TEC, Room 1038B (Map). Keith Robitschek will present “Digging the Marl of the Lance Formation.” |
| Friday, April 24th | MAPS Expo XLVII – Springfield, IL. |
| Saturday, April 25th | MAPS Expo XLVII – Springfield, IL. |
| Sunday, April 26th | MAPS Expo XLVII – Springfield, IL. |
| No meeting this month | Mineralogy Study Group |