#MazonCreek

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1 day ago

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Fossil Friday #308: Beautiful things in small packages... #fossils #paleontology #MazonCreek #Pennsylvanian #carboniferous #paleobotany #seedfern

esconi.org/2026/03/fossil-friday-30...

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ESCONI

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5 days ago

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Mazon Monday #312: Sigillaria tessellata #fossils #paleontology #MazonCreek #MazonMonday #lycopod #lycophyte #pennsylvanian #carboniferous

esconi.org/2026/03/mazon-monday-312...

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ESCONI

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1 week ago

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Mazon Monday #311: Strip mining begins in Braidwood on May 23, 1928 #fossils #paleontology #MazonMonday #MazonCreek #coalmining #history #Braidwood

esconi.org/2026/03/mazon-monday-311...

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ESCONI

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1 week ago

2026 ESCONI Gem, Mineral, and Fossil Show – Preview #8: A Tully Monster on Pit 11’s Opening Day! This is the preview post #8 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. Today is opening day of fossil collecting season at the Mazonia-Braidwood State Park.

2026 ESCONI Gem, Mineral, and Fossil Show – Preview #8: A Tully Monster on Pit 11's Opening Day! #fossils #paleontology #ESCONIShow #MazonCreek #Pit11 #TullyMonster

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ESCONI

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2 weeks ago

Fossil Friday #306: Cyclus obesus This is the “Fossil Friday” post #306. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! Mazon Monday #310 was about Cyclus obesus. That post was triggered by Mike Monteith's recent find.

Fossil Friday #306: Cyclus obesus #fossils #paleontology #FossilFriday #MazonCreek #pennsylvanian #carboniferous

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ESCONI

@esconi.bsky.social

2 weeks ago

Throwback Thursday #306: This is Life… This is Throwback Thursday #306. In these, we look back into the past at ESCONI specifically and Earth Science in general. If you have any contributions, (science, pictures, stories, etc …), please send them to esconi.info@gmail.com. Thanks! email:esconi.info@gmail.com. I received an interesting book from Bob Goss last November. You may remember him from a couple Fossil Friday's (Fossil Friday #284…

Throwback Thursday #306: This is Life... #TBT #history #ThrowbackThursday #nature #Naperville #MazonCreek #squirrel #gorilla

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ESCONI

@esconi.bsky.social

2 weeks ago

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, Schram established three new species of Cycloidea...

Mazon Monday #310: Cyclus obesus #fossils #paleontology #MazonCreek #MazonMonday #cyclid #Carboniferous #pennsylvanian #cycloidea

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ESCONI

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3 weeks ago

Mazon Monday #309: Herbivory is Older Than We Thought! This is Mazon Monday post #309. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. The Mann Lab at the Field Museum has been very busy. Their new paper "Carboniferous recumbirostran elucidates the origins of terrestrial herbivory" published in the journal Nature Ecology & Evolution has significant implications for the Mazon Creek ecosystem. This paper shows how even "old" ecosystems like the Sydney Mines and Mazon Creek are constantly being reinterpreted through new discoveries.

Mazon Monday #309: Herbivory is Older Than We Thought! #fossils #paleontology #MazonMonday #MazonCreek #SydneyMines #Canada #Carboniferous #Pennsylvanian #tetrapods

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ESCONI

@esconi.bsky.social

1 month ago

Fossil Friday #304: A Heartwarming Tully Reunion This is the “Fossil Friday” post #304. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! For Valentines Day, we have a nice heartwarming Tullymonster reunion story we received from long-time ESCONI member and Mazon Creek Collector Jim Alann.

Fossil Friday #304: A Heartwarming Tully Reunion #fossils #paleontology #MazonCreek #FossilFriday #Tully #Tullymonster

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ESCONI

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1 month ago

Mazon Monday #308: Acitheca polymorpha This is Mazon Monday post #308. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Fig. 8. Acitheca polymorpha (Brongniart) Schimper; proposed tripinnate-primary frond reconstruction with pinnule type placed at appropriate places. From Taxonomic revision of the Palaeozoic marattialean fern Acitheca" Acitheca polymorpha is an extinct species of the class Filcopsida. It is one of the rarer species of fern found in the Mazon Creek fossil localities.

Mazon Monday #308: Acitheca polymorpha #fossils #paleontology #MazonCreek #MazonMonday #fern #carboniferous #pennsylvanian

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ESCONI

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1 month ago

Fossil Friday #303: Mounted Pecopteris notata This is the “Fossil Friday” post #303. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! Today, we have one of the rarer forms, Pecopteris notata. It's not always present in Mazon Creek plant books, but Jack Wittry did include it in his latest flora book “A Comprehensive Guide to the Fossil Flora of Mazon Creek”.

Fossil Friday #303: Mounted Pecopteris notata #fossils #paleontology #history #MazonCreek #FossilFriday #fern #carboniferous #pennsylvanian #paleobotany

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ESCONI

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1 month ago

Mazon Monday #307: Arjan Mann on Fossil Nerds This is Mazon Monday post #306. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Episode #94 of the Fossil Nerds podcast is "The Marvelous Mini-Monsters of Mazon Creek with Arjan Mann". Arjan is the Assistant Curator of Early Tetrapods at the Field Museum. He discusses his lab's work, various ancient fish and tetrapods, gorganopsids, and (of course!) Mazon Creek.

Mazon Monday #307: Arjan Mann on Fossil Nerds #fossils #paleontology #FieldMuseum #ArjanMann #MazonCreek #MazonMonday #Onychodua #tetrapods

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ESCONI

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1 month ago

Fossil Friday #302: A Beautiful Macroneuropteris scheuchzeri from Braceville! This is the “Fossil Friday” post #302. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! For this week, we have a beautiful pyritized Macroneuropteris sheuchzeri (see Mazon Monday #39…

Fossil Friday #302: A Beautiful Macroneuropteris scheuchzeri from Braceville! #fossils #paleontology #FossilFriday #MazonCreek #seedfern #Braceville #pennsylvanian #carboniferous

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ESCONI

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1 month ago

Mazon Monday #306: Drevotella proteana This is Mazon Monday post #306. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Drevotella proteana is believed to be a hydrozoan. It lived during the Pennsylvanian Period. Fossils of this soft-bodied animal are known only from the Mazon Creek fossil deposit, where exceptional preservation allows such delicate organisms to be recorded. Hydrozoans are cnidarians and include jelly-like forms within the subphylum…

Mazon Monday #306: Drevotella proteana #fossils #paleontology #MazonMonday #MazonCreek #hydrozoa #cnidarian

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ESCONI

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1 month ago

Fossil Friday #301: French Palaeocaris This is the “Fossil Friday” post #301. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! In Mazon Monday #294, we highlighted the fossil site at Montceau-les-Mines in southeastern France.

Fossil Friday #301: French Palaeocaris #fossils #paleontology #MazonCreek #fossilFriday #Montceau-les-mines #stephanian #France #shrimp #carboniferous #pennsylvanian

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ESCONI

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1 month ago

Mazon Monday #305: Herdina mirificus This is Mazon Monday post #305. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Herdina mirificus is an extinct species of short-winged insect, currently classified in the order Protorthoptera. Protorthoptera is an extinct lineage of insects that lived during the middle to late Pennsylvanian Period some 318 to 299 million years ago. The order is a bit of a waste basket, containing a paraphyletic assemblage of basal neoptera.

Mazon Monday #305: Herdina mirificus #fossils #paleontology #MazonCreek #MazonMonday #insects #fossilinsects #carboniferous #pennsykvanian #protorthoptera

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ESCONI

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1 month ago

Fossil Friday #300: Orthotarbus robustus from the River This is the “Fossil Friday” post #300. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! Is there a better way to post our 300th Fossil Friday than with a Mazon Creek spider?

Fossil Friday #300: Orthotarbus robustus from the River #fossils #paleontology #spider #MazonCreek #FossilFriday #pennsylvanian #carboniferous #spiders

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ESCONI

@esconi.bsky.social

2 months ago

Mazon Monday #304: Field Museum… Illinois by the sea This is Mazon Monday post #304. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. In May 1970, the Field Museum opened an exhibit about Mazon Creek. It was called "Illinois by the sea: a coal age environment" and ran from May 25th until September 25th. It was a successful exhibit that featured Field Museum fossils and contributions from ESCONI members.

Mazon Monday #304: Field Museum... Illinois by the sea #fossils #paleontology #MazonMonday #MazonCreek #carboniferous #pennsylvanian #FieldMuseum

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ESCONI

@esconi.bsky.social

2 months ago

Fossil Friday #299: Annularia sphenophylloides This is the “Fossil Friday” post #299. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! Today, we have another beautiful contribution from George Witaczek. This time it's a beautiful…

Fossil Friday #299: Annularia sphenophylloides #fossils #paleontology #MazonCreek #FossilFriday #annularia #horsetail #carboniferous #pennsylvanian

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ESCONI

@esconi.bsky.social

2 months ago

Mazon Monday #303: Smithixerxes juliarum This is Mazon Monday post #303. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. 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.

Mazon Monday #303: Smithixerxes juliarum #fossils #paleontology #MazonCreek #MazonMonday #arthropod #Euthycarcinoid #carboniferous #pennsylvanian

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ESCONI

@esconi.bsky.social

2 months ago

Fossil Friday #298: Seed Fern Fiddlehead – Spiropteris This is the “Fossil Friday” post #298. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! This week’s Fossil Friday features a fiddlehead — the coiled frond of a young fern.

Fossil Friday #298: Seed Fern Fiddlehead - Spiropteris #fossils #paleontology #MazonCreek #FossilFriday #carboniferous #pennsylvanian #fiddlehead #seedfern

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ESCONI

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2 months ago

Mazon Monday #302: The Wreck of the 5560 This is Mazon Monday post #302. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. The Marion Power Shovel Company was an American company that designed, manufactured, and built steam shovels, power shovels, blast hole drills, excavators, and dragline excavators. The company was headquartered in Marion, Ohio and operated from 1884 to 1997, when it was acquired by its competitor…

Mazon Monday #302: The Wreck of the 5560 #fossils #paleontology #MazonCreek #MazonMonday #history #coalmining #coal #powershovel

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ESCONI

@esconi.bsky.social

2 months ago

Fossil Friday #297: Alethopteris serlii This is the “Fossil Friday” post #296. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! This week's Fossil Friday is a favorite of many Mazon Creek collectors. Alethopteris serlii…

Fossil Friday #297: Alethopteris serlii #fossils #paleontology #FossilFriday #MazonCreek #carboniferous #pennsylvanian #seedfern

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ESCONI

@esconi.bsky.social

2 months ago

Throwback Thursday #297: Season’s Greetings from the Langfords! This is Throwback Thursday #297. In these, we look back into the past at ESCONI specifically and Earth Science in general. If you have any contributions, (science, pictures, stories, etc …), please send them to esconi.info@gmail.com. Thanks! email:esconi.info@gmail.com. George Langford, Sr. (1876–1964) was a prolific collector of Mazon Creek fossils, assembling multiple significant collections over his lifetime. He sold or donated these collections to museums across the country, including the Illinois State Museum and the Denver Museum of Natural History.

Throwback Thursday #297: Season's Greetings from the Langfords! #history #TBT #ThrowbackThursday #fossils #paleontology #FieldMuseum #MazonCreek #carboniferous ##pennsylvanian

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ESCONI

@esconi.bsky.social

2 months ago

2026 ESCONI Gem, Mineral, and Fossil Show – Preview #1: Tully Monsters This is the preview post #1 for the 2026 ESCONI Gem, Mineral, and Fossil Show Live Auction. The ESCONI Gem, Mineral, and Fossil Show for 2025 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. Ok, how about an early Christmas present?

2026 ESCONI Gem, Mineral, and Fossil Show - Preview #1: Tully Monsters #fossils #paleontology #MazonCreek #ESCONIShow #TullyMonster #Carboniferous #Pennsylvanian

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ESCONI

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2 months ago

Mazon Monday #301: Cordaianthus ovatus This is Mazon Monday post #301. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Whole-plant reconstruction of Cordaites borassifolius (Sternberg) Unger (reconstruction by J. Svoboda). Cordaianthus ovatus is thought to be the fertile structure for Cordaites borassifolius (see Mazon Monday #299), an extinct genus of early gymnosperms. Cordaites probably grew to more than 100 feet tall in swampy conditions, forming forests similar to modern day mangroves.

Mazon Monday #301: Cordaianthus ovatus #fossils #paleontology #MazonCreek #MazonMonday #Pennsylvanian #carboniferous #gymnosperms #paleobotany

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ESCONI

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2 months ago

Fossil Friday #296: Roachoid Wing from the Creek This is the “Fossil Friday” post #296. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! This beautiful roachoid wing was collected from the Mazon River by Chris Berg... the esteemed president of ESCONI.

Fossil Friday #296: Roachoid Wing from the Creek #fossils #paleontology #roachoid #FossilFriday #insect #Carboniferous #MazonCreek #Pennsylvanian

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ESCONI

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2 months ago

Mazon Monday #300: Mazon Creek horseshoe crab fossil shows evidence of ancient algal or parasitic infestation This is Mazon Monday post #300. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. The Lauer Foundation just won't let the Mazon Creek horseshoe crabs alone... first it was Euproops danae remains in bromalites (see Mazon Monday #283), now they've found evidence of ancient algal or parasitic infestation in another Euproops danae fossil from the Mazon Creek biota.

Mazon Monday #300: Mazon Creek horseshoe crab fossil shows evidence of ancient algal or parasitic infestation #fossils #paleontology #MazonMonday #MazonCreek #horseshoecrab #Carboniferous #Pennsylvanian

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ESCONI

@esconi.bsky.social

3 months ago

Fossil Friday #295: Juvenile Amphibamid This is the “Fossil Friday” post #295. Expect this to be a regular feature of the website. We will post fossil pictures you send in to esconi.info@gmail.com. Please include a short description or story. Check the #FossilFriday Bluesky/Twitter hash tag for contributions from around the world! We have a particularly special Mazon Creek fossil to share this week, a juvenile amphibamid, possibly…

Fossil Friday #295: Juvenile Amphibamid #fossils #paleontology #MazonCreek #FossilFriday #amphibamis #tetrapod #evolution #FieldMuseum @FieldMuseum

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ESCONI

@esconi.bsky.social

3 months ago

Mazon Monday #299: Cordaites borassifolius This is Mazon Monday post #301. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Whole-plant reconstruction of Cordaites borassifolius (Sternberg) Unger (reconstruction by J. Svoboda). Cordaites borassifolius is an extinct genus of early gymnosperms. Cordaites probably grew maybe 100 feet tall in the drier areas of the Carboniferous swamps. They had stilt-like roots, forming forests similar to modern day mangroves.

Mazon Monday #299: Cordaites borassifolius #fossils #paleontology #MazonCreek #MazonMonday #Pennsylvanian #carboniferous #gymnosperms #paleobotany

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Posts tagged #MazonCreek