Tag: fossils
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #28: Coelocanth Scale from Pit 11
Here’s beautiful example of a Coelocanth scale Mazon Creek’s Pit 11 locality. Look closely, the preservation is very detailed. Did we mention the tomorrow is the show… see you there!
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #27: Rare Wisconsin Jellyfish from Marathon County, Wisconsin
Jellyfish, which have no hard parts, are very rare in the fossil record. This species Hiemalora stellaris was found in the Cambrian rocks of the Blackberry Hill Deposit of Marathon County, Wisconsin. Come on out tomorrow and it can be yours!
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #25: Calomostachys Cone
We have a bunch of Mazon Creek fossils this year… here’s another nice cone – Calomostachys, sp. One day away from the show… are you coming?!?
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Fossil Friday #309: Acanthotelson stimpsoni
Today, we have a cute little Acanthotelson stimpsoni (see Mazon Monday #52) from the Mazon River. Acanthotelson stimpsoni is a syncarid shrimp. It’s the most common shrimp found in the Braidwood fauna.
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #23: Macroneuropteris scheuchzeri terminal pinnule
Preview 23 is a nice terminal end of a Macroneuropteris scheuchzeri from Mazon Creek. To learn more see Mazon Monday #39. Saturday will be here before you know it…
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #21: Thalassina anomala from Gunn Point, N. T., Australia
The next preview is a fossil mangrove lobster, Thalassina anomala, from Gunn Point, N. T., Australia. This is a very detailed fossil with superb preparation. Come on out and check it out at the show… less than 2 days away!
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #18: Lepidostrobus, sp. Cone
Here’s a beautiful Lepidostrobus, sp. cone (see Mazon Monday #202) from Mazon Creek. These cones were the reproductive organs of lepidodendron trees.
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PBS Eons: Did Ancient Storms Kill These Pterosaurs?
PBS Eons has a new episode. This one is about the pterosaur diversity of the Solnhofen formation in Germany.
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Mazon Monday #313: Mazon Creek Studies – the first 120 years
For this week, we have an article from the September 1978 edition of the Field Museum’s Bulletin. The full edition, which includes Jaunary thru December, is available on the Biodiversity Heritage Library (BHL) website.
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #16: Calamostachys Cone
A the rarer side, we have a nice Calamostachys cone for preview #16. Calamostachys was one of the cones of Calamites (see Mazon Monday #99). Less than 6 days left until the show… how quickly time flies!
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #15: Macroneuropteris scheuchzeri
For this preview, we have a beautiful Macroneuropteris scheuchzeri (see Mazon Monday #39). This was collected from one of the Morris localities.
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Fossil Friday #308: Beautiful things in small packages…
For this week, we have a nice and detailed orbicular pinnule from a Macroneuropteris scheuchzeri. The concretion is very small., but the “hairs” are there. Unfortunately, they may not show up in the photos. This concretion was collected from Pit 2 and opened via freeze/thaw. Check out the last photo to see the size and…
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #12: Crinoids from the Bangor Formation in Alabama
Here’s a gorgeous plate of crinoids from the Bangor Formation of Western Alabama. These fossils date to the Upper Mississippian Chestertian Series. There are a couple other fossils on the piece, including Archimedes bryozoans and other crinoid calyxes. Come on out and check it out in less than two weeks!
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Mazon Monday #312: Sigillaria tessellata
Sigillaria tessellata is an extinct species of spore bearing, arborescent (tree-like) lycophyte from the Mazon Creek fossil deposit. Arborescent lycophytes (or scale trees) belong to the group Lepidodendrales. Sigillaria is known from as early as the Middle Devonian. It went extinct during the Early Permian Period.
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Des Plaines Valley Geological Society’s 61st Annual Jewelry, Mineral, Gem & Fossil Show, March 28-29, 2026
Des Plaines Valley Geological Society’s 61st Annual Jewelry, Mineral, Gem & Fossil Show, March 28-29, 2026. Des Plaines Park District Leisure Center, 2222 Birch St., Des Plaines, IL. Sat. 9-5, Sun. 10-4. Adults $3, seniors $2, students over 12 or with school ID $1, children under 12 free when accompanied by an adult. Dealers, demonstrators,…
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PBS Eons: Why Evolution Made Your Teeth Hurt
There’s a new episode of PBS Eons. This one is about the evolution of teeth.
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Fossil Friday #307: Euphoberia sp. From Pit 11
For today, we have a very nice Mazon Creek millipede. Euphoberia is an extinct genus of millipede found in both Europe and North America. The genus was erected by Fielding Bradford Meek and Amos Henry Worthen when they described Euphoberia armigera as a centipede in 1868.
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #10: Merycoidodon (Oreodon) Jaw
For today’s preview, we have a nice Merycoidodon (Oreodon) Jaw from the Brule Formation near Chadron, Nebraska. The Brule Formation dates to the Oligocene about 34 and 30 million years ago. This jaw is in nice shape with six complete teeth. Show details can be found here
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Mazon Monday #311: Strip mining begins in Braidwood on May 23, 1928
Yesterday marked opening day for fossil collecting at the IDNR Mazonia–Braidwood State Fish and Wildlife Area. I hope you were able to make it out… or are planning a trip soon. This is prime season for collecting at Pit 11, the name many collectors still use for Mazonia–Braidwood.
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #8: A Tully Monster on Pit 11’s Opening Day!
Today is opening day of fossil collecting season at the Mazonia-Braidwood State Park. So, it’s only fitting that the preview for today is a Tully Monster. Here it is… we hope you get out, enjoy some fresh air, and find a Tully today!
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Report for the Junior’s Study Group Meeting February 2026
The meeting began with the Juniors Chair handing out the tradeable earth science specimens. Then he introduced the speaker, Finn Lutz. Finn is a senior at Oak Park River Forest High School. He talked about the display that he brought, which was his Eagle Scout project for ESCONI. The project began years ago with a…
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ESCONI Books and Items for Sale
ESCONI actively sells our Club’s new books on Mazon Creek fossils that were written by Jack Wittry (an Honorary Club member). We also sell other ESCONI-branded items such as T-shirts, hats, mugs, ornaments, memory sticks, etc., in addition to used books that are donated to the Club. These items are for sale at ESCONI’s annual…
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Reminder: Chicago Rocks & Minerals Society’s Annual Silent Auction, Saturday, March 14, 2026
Chicago Rocks & Minerals Society’s Annual Silent Auction Saturday, March 14, 2026 6 to 9 p.m. St. Peter’s United Church of Christ 8013 Laramie Ave., Skokie, IL (Across the street from the public library on Oakton) Plus a special live auction of high-end specimens during the last half-hour! The first table closes at 6:30 p.m.…
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2026 ESCONI Gem, Mineral, and Fossil Show – Vendor List
The 2026 ESCONI Gem, Mineral, and Fossil Show will be here before you know it! Here is the vendor list. Exclusive Inspirations Wisconsin Janski Designs Illinois Rock’s Rocks Illinois Rock Stars Illinois Michael’s Mineral Exchange Illinois Fossil Hut Illinois Grab Your Rocks Illinois Lavin’s Gems Illinois KP Rocks and Minerals Michigan RockhoundMike Minerals Illinois Joe’s…
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Fossil Friday #306: Cyclus obesus
Just earlier this week, Mazon Monday #310 was about Cyclus obesus. That post was triggered by Mike Monteith’s recent find. On one of the nice days last week, Mike was going through his freeze/thaw from this winter and found this very nice Cyclus obesus. Thanks for sharing, Mike!
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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #7: Paleoctopus newbolti from Lebanon
This is the preview post #7 for the 2026 ESCONI Gem, Mineral, and Fossil Show Live Auction. The ESCONI Gem, Mineral, and Fossil Show for 2026 will be held on March 21th and 22nd at the DuPage Fairgrounds in Wheaton, IL, which is the same location as last year. All details can be found here. We…
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Paleontologist Dr. Hans-Dieter Sues RIP (1956-2026)
We are sad to hear of the sudden passing of Dr. Hans-Dieter Sues, Curator of Vertebrate Paleontology at the Smithsonian National Museum of Natural History. Here is the Smithsonian’s announcement on Facebook. It is with profound sadness that we share the news that our friend and colleague Dr. Hans-Dieter Sues, Curator of Vertebrate Paleontology, unexpectedly…
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Mazon Monday #310: Cyclus obesus
This is Mazon Monday post #310. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Cyclus obesus is one of four species of Cycloidea found in Mazon Creek. It was described in the paper “Mazon Creek Cycloidea” by Frederick Schram. The paper was published in the Journal of Paleontology in 1997. In that paper,…
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ESCONI at the Ranch View STEAM Event in Naperville
For the second year, ESCONI was asked to participate in the Ranch View Elementary STEAM event in Naperville. Represnting the club were Jodi Gosain, Rusty Grenier, and Jim Bigler. The club had three tables of fossils, rocks, geodes, magnetic stones and our popular dig box. Over 300 parents and children attended our booth. In addition,…
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New ‘scimitar-crested’ Spinosaurus species discovered in the central Sahara
Phys.org has a story about a new species of spinosaurus. Spinosaurus mirabilis was found in Niger at a remote locale in the central Sahara by a team of 20 researchers led by Paul Sereno, Ph.D., Professor of Organismal Biology and Anatomy at the University of Chicago. The animal is described in the paper “Scimitar-crested Spinosaurus species from…
