Earth Science Club of Northern Illinois

Fossil Friday, Mazon Creek

Fossil Friday #313: Mazonomya mazonensis

George 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.
Read more: Fossil Friday #313: Mazonomya mazonensis
Throwback Thursday

Throwback Thursday #313: Who Was DuPage? How the River and County Were Named

The BeHistoric channel on Youtube has a fascinating video about the history behind the name of the DuPage River and DuPage County.
Read more: Throwback Thursday #313: Who Was DuPage? How the River and County Were Named
Calendar of Events

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.
Read more: ESCONI April 2026 Paleontology Meeting via Zoom and in-person – “Digging the Marl of the Lance Formation”
Around the Web, Calendar of Events

49th Annual CGMA Show – May 23rd and 24th, 2026

The 49th Annual CGMA Show will be held May 23rd and 24th, 2026 at the Expo Center of the Kane County Fairgrounds.
Read more: 49th Annual CGMA Show – May 23rd and 24th, 2026
Mazon Creek, Mazon Monday

Mazon Monday #317: Pohlsepia Revisited — Not an Octopus After All

A 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.
Read more: Mazon Monday #317: Pohlsepia Revisited — Not an Octopus After All
Around the Web

Ancient bees found nesting inside fossil bones in rare cave discovery

Science 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.
Read more: Ancient bees found nesting inside fossil bones in rare cave discovery
Around the Web

PBS Terra: The Cascadia Megaquake Is Inevitable. And It Will Reshape America Forever

PBS Terra has an interesting new video. This one covers the history, science, and future of the Cascadia Subduction Zone in the Pacific Northwest.
Read more: PBS Terra: The Cascadia Megaquake Is Inevitable. And It Will Reshape America Forever
Fossil Friday, Mazon Creek

Fossil Friday #312: Sublepidophloios protuberans with a spray of Cyperites bicarinatus

At 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.
Read more: Fossil Friday #312: Sublepidophloios protuberans with a spray of Cyperites bicarinatus
In Memoriam and Honorarium, Mazon Creek, Throwback Thursday

Throwback Thursday #312: Ron Schinderle Donation

Barb 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.
Read more: Throwback Thursday #312: Ron Schinderle Donation
Field Trips

ESCONI Field Trip to the Winfield Mounds “Walking with the Ancestors” – Saturday, May 9th, 2026

There 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.
Read more: ESCONI Field Trip to the Winfield Mounds “Walking with the Ancestors” – Saturday, May 9th, 2026
Calendar of Events

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!
Read more: ESCONI April 2026 General Meeting via Zoom – “Life in the Devonian Period, The Age of Fishes”
Mazon Creek, Mazon Monday

Mazon Monday #316: Sublepidophloios protuberans

Today, 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.
Read more: Mazon Monday #316: Sublepidophloios protuberans
Around the Web

Fossil of Pincer-Wielding Crawler Reveals Origins of Spiders, Scorpions and Others

The Trilobites column over at the New York Times has a interesting story about the origin of chelicerates – spiders, scorpions, mites, horseshoe crabs, and others. Chelicerates are a diverse group of arthropods that consists of more than 120,000 known species. Member of this group are classified by having a pair of appendages called chelicerae. These appendages are adapted for various purposes like snatching prey, injecting venom, and even spinning silk.
Read more: Fossil of Pincer-Wielding Crawler Reveals Origins of Spiders, Scorpions and Others
Uncategorized

PBS Eons: The Chaotic Race to Name T. rex

PBS Eons has a new episode. This one is about the controversial history of the name Tyrannosaurus rex.
Read more: PBS Eons: The Chaotic Race to Name T. rex
Fossil Friday

Fossil Friday #311: Dung Beetle Balls from the Oligocene

Today’s contribution comes from our old friend Ralph Jewell. Back in the 1990s, Ralph was interested in the Oligocene fossils of the Brule Formation, which dates to 34-40 million years ago. This region is sometimes referred to as the White River as the Brule Formation is a member of the White River Group.
Read more: Fossil Friday #311: Dung Beetle Balls from the Oligocene
Calendar of Events

ESCONI Events for April 2026

Event schedule for April 2026
Read more: ESCONI Events for April 2026
Throwback Thursday

Throwback Thursday #311: Looking Back At ESCONI For April 2026

A look back at 25, 50, and 70 years ago
Read more: Throwback Thursday #311: Looking Back At ESCONI For April 2026
Calendar of Events, Field Trips, Mazon Creek

ESCONI Field Trip to Danville Shale Pile Fossils – Saturday, May 2nd, 2026

An ESCONI field trip to the Danville IL Shale Pile for Pennsylvanian fossils is scheduled for Saturday May 2nd, 2026 starting at 10 AM. This is on private property and there is an attendance limit of 25 people. The gate will be secured once we are in and locked when we leave. Plan on being off the hill at 3 PM to give time for specimen identification and pictures.
Read more: ESCONI Field Trip to Danville Shale Pile Fossils – Saturday, May 2nd, 2026
Calendar of Events, ESCONI Gem, Mineral & Fossil Show

2026 ESCONI Gem, Mineral, and Fossil Show Recap – Photos from the Show

Here is an assortment of the friendly, smiling people from the show! Thanks to the volunteers, thanks to the vendors, thanks to the ESCONI members , thanks to everyone that came out. There’s lots of familiar faces in these. It was great seeing old and meeting new friends… we hope everyone had a good time!
Read more: 2026 ESCONI Gem, Mineral, and Fossil Show Recap – Photos from the Show
Mazon Creek, Mazon Monday

Mazon Monday #315: Another Langford Book Inscription

From time to time, we run across some old book inscriptions. Back in Mazon Monday #18, we highlighted a few… Well, here’s another interesting inscription.
Read more: Mazon Monday #315: Another Langford Book Inscription

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

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