Earth Science Club of Northern Illinois

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
Around the Web

A large tyrannosaurid from the Late Cretaceous (Campanian) of North America

The journal Nature Scientific Reports has a paper about a new large tyrannosaur from the Late Cretaceous (Campanian) in North America. The unnamed animal lived from about 74 to 75 million years ago in what is now New Mexico, USA. Abstract The Tyrannosauridae emerged as the dominant large predators in Laurasia during the Late Cretaceous. Their evolution in North America culminated with the replacement of Albertosaurinae, Daspletosaurinae, and Teratophonei, with masses of 2-3 tonnes, by the giant Tyrannosaurus in the late Maastrichtian, with a mass approaching or exceeding 10 tonnes. The origin of Tyrannosaurus remains enigmatic, but fossils suggest an origin in the Campanian—Maastrichtian…
Read more: A large tyrannosaurid from the Late Cretaceous (Campanian) of North America
Around the Web, Calendar of Events

MAPS Expo XLVII – April 24-26, 2026 in Springfield, IL

The 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”.
Read more: MAPS Expo XLVII – April 24-26, 2026 in Springfield, IL
Fossil Friday, Mazon Creek

Fossil Friday #310: Mazon Creek Scallop

Another small concretion with a treasure inside… this one has a scallop (see Mazon Monday #35). This one is Aviculopecten mazonensis. There’s no information about where this concretion was collected, but Pit 11 is very likely. We ran across it while preparing for the 2026 ESCONI Show. Do you think these were as tasty as modern day scallops?
Read more: Fossil Friday #310: Mazon Creek Scallop
Throwback Thursday

Throwback Thursday #310: History of the Thornton Quarry

Ran across this interesting episode of “It’s History” on Youtube…. “Why This Highway Runs Through Chicago’s Biggest Hole”. It’s about the Thornton Quarry and one of the founders of Chicago, Gurdon Saltonstall Hubbard, who is the namesake of Hubbard Street in Chicago.
Read more: Throwback Thursday #310: History of the Thornton Quarry
Around the Web

This crocodile ran like a greyhound across prehistoric Britain 200 million years ago

Science Daily has a story about a newly discovered Triassic reptile from the UK. The animal, Galahadosuchus jonesi, lived about 215 million years in what is now Gloucester, UK. It was probably a fast, land-dwelling predator.
Read more: This crocodile ran like a greyhound across prehistoric Britain 200 million years ago
Calendar of Events, ESCONI Gem, Mineral & Fossil Show

2026 ESCONI Gem, Mineral, and Fossil Show Recap – Displays and Demonstrators

Well, that sure went by fast! We put in quite a bit of work to get ready and then it was over in a flash. The results and photos are still coming in, so we’ll do the recap in a few posts. We hope you made it out and had a great time. Please, send feedback to esconi.info@gmail.com or esconiclub@gmail.com.
Read more: 2026 ESCONI Gem, Mineral, and Fossil Show Recap – Displays and Demonstrators
Mazon Creek, Mazon Monday

Mazon Monday #314: Smithixerxes juliarum

Smithixerxes juliarum is among the rarest animals found in the Mazon Creek fossil deposit. It belongs to an extinct group of arthropods known as the euthycarcinoids, which ranged from the Cambrian to the Triassic periods. Some researchers believe euthycarcinoids may have been amphibious, capable of venturing between water and land.
Read more: Mazon Monday #314: Smithixerxes juliarum

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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