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Fossil Friday #337: A Different View of Lepidostrobus
Read more: Fossil Friday #337: A Different View of LepidostrobusLepidostrobus is a cone from lepidodendron tree. It was named in 1828 by Adolphe-Theodore Brongniart (1801 – 1876), who was a French paleontologist, considered by many to be the father of paleobotany. He also named Lepidostrobophyllum which are the individual cone bracts of which Lepidostrobus is the whole reproductive organ. See Mazon Monday #202.
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ESCONI Events for October 2026
Read more: ESCONI Events for October 2026Field trips require membership, but visitors are welcome at all meetings! Friday, October 9th General Meeting – 8:00 PM via Zoom. Lazaro Vinola from The Field Museum will be presenting live from the field in the Dominican Republic. Saturday, October 10th Junior Study Group Meeting – 2:00 PM at College of DuPage, TEC, Room 1038A Earthquakes! Junior members will watch videos about earthquakes, make seismographs and test them. Specifics of this meeting are available from Scott Galloway, 630-670-2591, gallowayscottf@gmail.com. Saturday, October 10th Mazon Creek Fossil Day Details are here. Saturday, October 17th Field Trip to Danville for Carboniferous Fossils Details…
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Throwback Thursday #337: Looking Back At ESCONI for October 2026
Read more: Throwback Thursday #337: Looking Back At ESCONI for October 2026ESCONI highlights from 25, 50, and 70 years ago
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Reminder: Mazon Creek Fossil Day 2026 – Saturday, October 10th, 2026 – Coal City Library
Read more: Reminder: Mazon Creek Fossil Day 2026 – Saturday, October 10th, 2026 – Coal City LibraryThe 2026 Mazon Creek Fossil Day will be held on Saturday, October 10th, 2026 at the Coal City Library from 10 AM to 3 PM. See you there! Previous events
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T. Rex, King of the Dinosaurs, Had a Body Temperature of 97 Degrees
Read more: T. Rex, King of the Dinosaurs, Had a Body Temperature of 97 DegreesThe New York Times has a story about recent T. rex research. There’s been a long running debate about whether dinosaurs were warm or cold blooded – endothermic or exothermic. New research, published recently in the journal Science Advances, adds a little evidence to the warm blooded side. Scientists at the University of California, Los Angeles, used a geochemistry techniques on fossilized teeth, including two from “Thomas”, a T. rex at the National History Museum of Los Angeles County. They looked at carbon and oxygen bonds in a the T. rex teeth. Bonds of the heavier isotopes act as a…
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Mazon Monday #342: Jeanerpeton mazonensis – A new Mazon Creek tetrapod!
Read more: Mazon Monday #342: Jeanerpeton mazonensis – A new Mazon Creek tetrapod!The Mazon Creek fossil biota has a new member… a tetrapod, which are quite rare. Jeanerpeton mazonensis, which means “Jean’s crawler from Mazon Creek”, was named by two student-scientists from the Field Museum. The name honors their mothers, who are both named Jean.
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A strange circle on satellite maps turned out to be a 390-million-year-old impact crater
Read more: A strange circle on satellite maps turned out to be a 390-million-year-old impact craterScience Daily has a story about a recently discovered impact crater. The crater was hidden in the Quebec wilderness near Lake Marsal in eastern Quebec. The impact that formed the crater dates to about 390 million years ago during the Devonian Period. It was found by an amateur astronomer, who noticed the structure while planning a camping trip in 2024. In 2024, Joël Lapointe was preparing for a trip to the remote Côte-Nord region when a circular feature near Lake Marsal caught his attention on online satellite imagery. He wondered whether the depression could have been formed by an impact…
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A Feather Found in Dinosaur Poop Might Explain How Birds Beat Extinction
Read more: A Feather Found in Dinosaur Poop Might Explain How Birds Beat ExtinctionThe New York Times has a story about an amazing, chance discovery. In 2016, a researcher in the Hell Creek Formation in Montana picked up a small rock that turned out to be a small piece of fossilized dinosaur dung. Fossilized dung is called a coprolite and this one had a “big” surprise. It had broke in half and revealed a tiny, well-preserved feather alongside fragments of avian bones. This was likely the leftovers from a bird’s final meal before being eaten. An extremely well-preserved bird feather from the age of dinosaurs has been found inside a fossilized piece of…
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Fossil Friday #336: Shark Egg Case from Chowder Flats
Read more: Fossil Friday #336: Shark Egg Case from Chowder FlatsHere’s a beautiful Palaeoxyris prendeli from Chowder Flats. It’s a shark egg case thought to have been produced by hybodont sharks. P. prendeli was named by Leo Lesquereux in 1870. At that time, it was believed to be a plant part, maybe a seed pod. The name palaeoxyris comes from the the flowering plant genus Xyris, which grows in swampy environments in the tropics and subtropics. There are a number of species found in India. There, they are commonly known as yellow-eyed grasses and are characterized by their grass-like leaves and yellow iris-like flowers.
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Throwback Thursday #336: Vacation Trip to Oregon
Read more: Throwback Thursday #336: Vacation Trip to OregonThe October 1959 edition of the ESCONI newsletter included this little burb from the newsletter editor, George Darrow, about his vacation to Oregon during the summer of 1959.
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Recap of the ESCONI “Brag Night” 2026
Read more: Recap of the ESCONI “Brag Night” 2026ESCONI held our annual “Brag Night” 2026 on September 19th, 2026. 20 members braved the torrential rains to share fossils (and a few minerals) with their fellow members. Here’s a quick photo recap…
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PBS Eons at the Field Museum!
Read more: PBS Eons at the Field Museum!View this post on Instagram A post shared by Eons (@eonsshow) PBS Eons posted this video a few days ago on Instagram. In making Life and Death on Pangea, not only did we get to tell the story of one of the most dramatic times in Earth’s history, but we got visit places that were dreams come true for our natural-history-loving hearts!
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Mazon Monday #341: Titanoscorpio douglassi
Read more: Mazon Monday #341: Titanoscorpio douglassiTitanoscorpio douglassi is known from just three specimens, but the holotype is a breathtaking three-inch claw on display at the Prehistoric Life Museum in the basement of Dave’s Down to Earth Rock Shop (see Throwback Thursday #94) in Evanston, Illinois. And yes, it really is breathtaking!
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PBS Eons: Did the Ozone Collapse 252 Million Years Ago?
Read more: PBS Eons: Did the Ozone Collapse 252 Million Years Ago?PBS Eons has a new video. This is another one about the Great Dying about 252 million years ago. What was it about the Great Dying that caused a global age of mutant plants? And could figuring it out help us avoid triggering the next one? Watch Eons: Life and Death on Pangea on the free PBS App: https://to.pbs.org/EonsApp or on the web here: https://pbs.org/eons ← use this link if you are outside of the U.S.
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10,000-year-old fossilized mastodon tooth found in Bay Area creek
Read more: 10,000-year-old fossilized mastodon tooth found in Bay Area creekABC Eyewitness News has a story about an “exceptionally preserved fossilized tooth.” The tooth of an American mastodon was found in a creek in California’s Bay Area. It was found by a scientist doing a survey for an environmental restoration project. The fossil may be more than 10,000 years old. A fossilized Pacific mastodon tooth that scientists say is at least 10,000 years old and in “immaculate condition” was discovered recently in a creek bed in California, according to local officials. The “exceptionally preserved fossilized tooth” was discovered during field surveys for a habitat enhancement project in a Midpeninsula (Midpen)…
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Fossil Friday #335: A Couple of Beautiful Rhacophyllum
Read more: Fossil Friday #335: A Couple of Beautiful RhacophyllumLong-time member Marty Houdek recently sent me a couple photos of Rhacophyllum from Mazon Creek. The first one is a sweet Rhacophyllum clarkii (see Mazon Creek #170), from one of the Braidwood pits (2, 3, or maybe 4?). It’s beautiful. It opened this past summer via freeze/thaw… after being collected 30 years ago!
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Throwback Thursday #335: A Look Back At “Brag Night” in the 1960’s
Read more: Throwback Thursday #335: A Look Back At “Brag Night” in the 1960’sWe hope you’ll come out to “Brag Night” this Saturday, September 19th, 2026! We are sure there will be some very nice treasures to see! “Brag Night” on the first meeting after summer vacation has been an ESCONI tradition for a long time. The first one seems to be 1952. Here is the announcement.
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ESCONI Field Trip to Danville Shale Pile Fossils – Saturday, October 17th, 2026
Read more: ESCONI Field Trip to Danville Shale Pile Fossils – Saturday, October 17th, 2026Danville Field Trip Rules for Saturday, October 17th, 2026 An ESCONI field trip to the Danville, IL Shale Pile for Pennsylvanian fossils is scheduled for Saturday October 17th, 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. You must register to go on this trip. See rule 6 below for instructions. This is the only way to register. Those…
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ESCONI “Brag Night” 2026 – Saturday, September 19th, 2026 at 7:30 PM at the College of DuPage, TEC 1038B
Read more: ESCONI “Brag Night” 2026 – Saturday, September 19th, 2026 at 7:30 PM at the College of DuPage, TEC 1038BCome on out and show off your finds for 2026! “Brag Night” has been a ESCONI tradition since the very beginning!
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Mazon Monday #340: Neuropteris thompsoniana
Read more: Mazon Monday #340: Neuropteris thompsonianaThis is Mazon Monday post #340. What’s your favorite Mazon Creek fossil? Tell us at esconi.info@gmail.com. Neuropteris thompsoniana was described by William Culp Darrah (1909-1989), in 1969. Darrah was an American professor of biology at Gettysburg College, in Pennsylvania. He was a specialist in paleobotany. In addition to paleontology, Darrah had a deep interest in 19th century photography, and published several works on the subject. His daughter, Elsie, wrote and edited book “Historical Perspective on Early Twentieth Century Carboniferous Paleobotany in North American”, which was dedicated as a memorial volume to her father. N. thompsoniana is a very rare variety of Neuropteris. It is…
Mazon Creek Fossil Day – October 10th, 2026!
Most Recent Post
- Fossil Friday #337: A Different View of Lepidostrobus
Lepidostrobus is a cone from lepidodendron tree. It was named in 1828 by Adolphe-Theodore Brongniart (1801 – 1876), who was a French paleontologist, considered by many to be the father of paleobotany. He also named Lepidostrobophyllum which are the individual cone bracts of which Lepidostrobus is the whole reproductive organ. See Mazon Monday #202.
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Field trips require membership, but visitors are welcome at all meetings!
| Friday, October 9th | General Meeting – 8:00 PM via Zoom. Lazaro Vinola from The Field Museum will be presenting live from the field in the Dominican Republic. |
| Saturday, October 10th | Junior Study Group Meeting – 2:00 PM at College of DuPage, TEC, Room 1038A Earthquakes! Junior members will watch videos about earthquakes, make seismographs and test them. Specifics of this meeting are available from Scott Galloway, 630-670-2591, gallowayscottf@gmail.com. |
| Saturday, October 10th | Mazon Creek Fossil Day Details are here. |
| Saturday, October 17th | Field Trip to Danville for Carboniferous Fossils Details are here. |
| Saturday, October 17th | Paleontology Study Group – 7:30 PM via Zoom Enrique Clark will be presenting “Depositional and Lithostratigraphic Characterization of the Lower Maysvillian Calloway Creek Formation.” |
| No meeting this month | Mineralogy Study Group |