Illinois’ 300-million-year-old fossil octopus turns out to be a different creature A fossil octopus from Illinois’ Mazon Creek fossil beds turns out to be a nautiloid.

#ScienceNews #Paleontology #Illinois #Cephalopod #MazonCreek

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Fossil Friday #312: Sublepidophloios protuberans with a spray of Cyperites bicarinatus #fossils #paleontology #MazonCreek #FossilFriday…

esconi.org/2026/04/fossil-friday-31...

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Throwback Thursday #312: Ron Schinderle Donation #TBT #history #MazonCreek #ThrowbackThursday

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Mazon Monday #316: Sublepidophloios protuberans #fossils #paleontology #MazonCreek #MazonMonday #lycopsid #carboniferous #pennsylvanian #illinois

esconi.org/2026/04/mazon-monday-316...

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.

Mazon Monday #315: Another Langford Book Inscription #fossils #paleontology #history #MazonCreek #MazonMonday

A scientific poster about a collection from an understudied lagerstätte framed by stylized art of some of its flora like an illuminated manuscript.

Related to this morning's musings, this is the last scientific poster I ever did. It was an attempt to get the word out about an amazing collection that someone else needed to study because I was leaving the field.
#paleobotany #paleontology #MazonCreek

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Fossil Friday #310: Mazon Creek Scallop #fossils #paleontology #MazonCreek #FossilFriday #scallop #pennsylvanian #carboniferrous

esconi.org/2026/03/fossil-friday-31...

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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #38: Neuropteris jacksonii from Mazon Creek #fossils #paleontology #MazonCreek…

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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #28: Coelocanth Scale from Pit 11 #fossils #paleontology #MazonCreek #coelocanth #pit11…

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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #25: Calomostachys Cone #fossils #paleontology #MazonCreek #ESCONIShow #carboniferous #pennsylvanian

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Fossil Friday #309: Acanthotelson stimpsoni #fossils #paleontology #MazonCreek #FossilFriday #shrimp #MazonRiver #carboniferous #pennsylvanian

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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #30: Mazon Creek Achistrum, sp. Colony #MazonCreek #fossils #paleontology #carboniferous…

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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #23: Macroneuropteris scheuchzeri terminal pinnule #fossils #MazonCreek…

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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #18: Lepidostrobus, sp. Cone #fossils #paleontology #MazonCreek #ESCONIShow #lepidodendron #cone…

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Mazon Monday #313: Mazon Creek Studies - the first 120 years #fossils #paleontology #MazonCreek #MazonMonday #history #pennsylvanian #carboniferous #FieldMuseum

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2026 ESCONI Gem, Mineral, and Fossil Show – Preview #15: Macroneuropteris scheuchzeri #fossils #paleontology #MazonCreek #seedfern #ESCONIShow

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

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

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

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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

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

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

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

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

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

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

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

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

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

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