Tag: MazonMonday
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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. 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. Cordaianthus…
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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…
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Mazon Monday #299: Cordaites borassifolius
This is Mazon Monday post #299. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. 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. Cordaites is relatively rare in the Mazon…
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Mazon Monday #298: The Freeze/Thaw Method
With winter arriving this weekend, it’s the perfect time to set out a few containers of Mazon Creek concretions and let nature do the work. Many collectors take advantage of the season’s freeze/thaw cycles to speed up the opening process, by placing buckets or smaller containers of nodules gathered throughout the year outside to weather…
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Mazon Monday #297: Pit 11 Coal Mining Artifact
This is Mazon Monday post #297. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. We often focus on the beautiful fossils found in the Mazon Creek deposit, but sometimes overlook the rich history that surrounds them. Coal mining played a central role in shaping the Wilmington, Braidwood, and Coal City area, from the deep…
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Mazon Monday #296: Jim Turnbull in Pit 11
Jim Turnbull, namesake for Anthracomedusa turnbulli (see Mazon Monday #278), worked for Abbott Labs for many years. Abbott has/had an internal newsletter called “AbbotTopics”. In the October 8th, 1965 edition, Jim is the subject of an article titled “Prehistoric Insect Discovery May Bear Abbott Man’s Name”.
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Mazon Monday #295: Ida Thompson collecting in Pit 11 in 1968
Michele Micetich, curator of the Carbon Hill School Museum, provided the photos in this post. The photos are part of the Tom Testa collection at the museum. On the back of the photos, there are notes written by Ida Thompson to Melbourne McKee, a chemist for the Peabody Coal Company in the Coal City area.…
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Mazon Monday #294: Montceau-les-Mines
This is Mazon Monday post #294. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Montceau-les-Mines is a commune located in the Saône-et-Loire department of the Bourgogne–Franche-Comté region in eastern France. It lies southwest of the city of Dijon and today has a population of just under 20,000 people. The town was officially established on…
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Mazon Monday #293: Mazon Creek Project Slides
This is Mazon Monday post #293. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. The Mazon Creek Project was a program sponsored by Northeastern Illinois University. Founded in the 1960s, by the late Eugene Richardson Curator of Fossil Invertebrates at the Field Museum in Chicago Illinois. It was originally an attempt to encourage more…
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Mazon Monday #292: Mazon Creek Fossil Day 2025
This is Mazon Monday post #292. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. We had a nice turnout at the Mazon Creek Fossil Day event in the Coal City library a few weeks ago. There were multiple displays by members and people brought in some of their finds for identification. Last week’s Fossil…
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Mazon Monday #291: Dithyrocaris sp.
This is Mazon Monday post #291. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Dithyrocaris sp. is a genus of crustacean from the Carboniferous. The Mazon Creek fossil biota includes one undescribed species, although there are other described species from other fossil localities – Bear Gulch, Montana (Dithyrocaris rolfei). Danville, IL (Dithyrocaris carbonarius), Cane…
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Reminder: 2025 Mazon Creek Fossil Day, October 11th, 2025 at the Coal City Library
The 2025 Mazon Creek Fossil Day will be held on October 11th, 2025 at the Coal City Library from 10 AM to 3 PM. See you there! Previous events
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Mazon Monday #290: Danville Spoil Pile Trip Report for September 2025
This is Mazon Monday post #290. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. There was lots of fun on the field trip to the Danville Spoil Pile on Saturday, September 27th, 2025. The day was hot and dry with a clear sky and temperatures in the 80s… summer like weather in late September…
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Mazon Monday #289: Ctenerpeton remex at Mazon Creek
This is Mazon Monday post #289. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. More exciting Mazon Creek research is out. Featured here is a short paper in the journal Vertebrate Anatomy Morphology Palaeontology (VAMP), which details the first occurrence of the urocordylid Ctenerpeton remex in the Mazon Creek fossil deposit! Arjan Mann, a…
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Mazon Monday #288: Callipteridium neuropteroides
This is Mazon Monday post #288. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Callipteridium neuropteroides is one of the rarer seed ferns (Pteridospermatophyta) found in the Mazon Creek fossil deposit. Although, it is much more common in the Herrin Coal flora, if the Danville locality is truly representative of that deposit. Callipteridium jongmansi…
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Mazon Monday #287: Braceville Fall 2025 Report
This is Mazon Monday post #287. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. The Braceville Fall 2025 Field Trip was held on the weekend of September 6th and 7th, 2025. We had perfect weather… sunny with temperatures in the mid-70s. There was nearly 100% attendance. It was two days of fun in…
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Mazon Monday #285: Etacystis communis
This is Mazon Monday post #285. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. One of the more problematic animals from Mazon Creek is Etacystis communis, known as the Aitch or “H” animal by amateur collectors. It was described by Matthew Nitecki and Frederick Schram in “Etacystis communis, a fossil of uncertain affinities…
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Mazon Monday #284: Mayomyzon pieckoensis
Mayomyzon pieckoensis is an extinct species of lamprey found in the Mazon Creek fossil biota. Pipiscius zangerli (see Mazon Monday #253) is also a lamprey from Mazon Creek. Lampreys are a group of jawless fish known for its funnel-like sucking mouth. There are about 38 modern species with maybe 7 extinct species currently classified. Genetic…
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Mazon Monday #283: Mazon Creek bromalites evidence a specialized, xiphosurid-rich diet for Pennsylvanian predators
This is Mazon Monday post #283. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Another week, another new Mazon Creek paper,.. “Mazon Creek bromalites evidence a specialized, xiphosurid-rich diet for Pennsylvanian predators” was published in the journal Palaios. It was authored by Russell Bicknell, Julien Kimming, Andew Young, Bruce Lauer, Rene’ Lauer, and…
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Mazon Monday #282: Pit 11 Shutdown in 1974
This is Mazon Monday post #282. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. For the Braidwood, Wilmington, and Coal City area, 1974 marked the end of an era with the closure of the last operating coal mine—Peabody Coal Company’s Pit 11. The mine had been in operation since 1951, originally opened by…
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Mazon Monday #281: 283,821 concretions, how do you measure the Mazon Creek?
This is Mazon Monday post #281. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. There’s quite a bit of Mazon Creek fossil research happening. Last week, we posted a paper that redescribed Palaeocampa (see Mazon Monday #280), some of our friends at the Field Museum had a paper about Sphenophyllales in June (see…
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Mazon Monday #280: Palaeocampa anthrax Redux
This is Mazon Monday post #280. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. The classification of Palaeocampa anthrax has long been controversial. The animal was first described as a catepillar in 1865 by Fielding Bradford Meek (1817-1876) and Amos Henry Worthen (1813-1888) in “Notice of some new types of organic remains from the…
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Mazon Monday #279: Prehistoric paradise hiding just outside Chicago
This is Mazon Monday post #279. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. When Arjan Mann and his lab at the Field Museum held a field trip to the Braceville spoil pile back in May 2025, he invited a ESCONI. Here is the story on Reuters. Near a riverbank in central Illinois,…
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Mazon Monday #278: Anthracomedusa turnbulli
This is Mazon Monday post #278. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Lacking hard parts, jellyfish are rare in the fossil record. Mazon Creek has a few species of them. One of the most common animal fossils found in Mazon Creek is Essexella asherae, which only recently was reclassified as a…
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Mazon Monday #277: Sphenophyllales from the Mazon Creek flora (Upper Moscovian: Illinois, USA)
This is Mazon Monday post #277. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Here’s a new paper “Sphenophyllales from the Mazon Creek flora (Upper Moscovian: Illinois, USA)” by some of our friends at the Field Museum, Yale, and the Smithsonian. It was published in the Biological Journal of the Linnean Society in…
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Mazon Monday #276: Video for Cal So’s “Taxonomic diversity and development of Late Carboniferous amphibamiforms from the Mazon Creek Lagerstätte”
This is Mazon Monday post #276. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Cal So, Postdoctoral Scientist in the Research & Collections Department of The Field Museum, Chicago, gave us an informative presentation in June 2025. The title of his presentation was “Taxonomic diversity and development of Late Carboniferous amphibamiforms from the…
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Mazon Monday #275: Rhacophyllum molle
This is Mazon Monday post #275. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. After Lesquereux (1870) Rhacophyllum molle is a wispy plant, underfined plant species described by Leo Lesquereux in 1870 as Hymenophyllites mollis. Later, he reclassified it as Rhacophyllum molle. He thought it was a type of aquatic plant. He reported…
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Mazon Monday #274: George Langford Sr. Passes Away on June 16th, 1964
This is Mazon Monday post #274. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Recently, I ran across the letter from George Langford Jr. upon the death of his father – George Langford Sr. The letter is the subject of this post and follows below. George Langford Sr. is giant in the history…
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Mazon Monday #273: Neuropteris fimbriata
This is Mazon Monday post #273. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Neuropteris fimbriata is a seed fern. It has by found associated with Neuropters ovata and is considered a growth form of it. N. fimbriata was described in 1866 by one the founders of American paleobotany Leo Lesquereux (1806-1889). Lesquereux…
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Mazon Monday #272: Annularia radiata
This is Mazon Monday post #272. What’s your favorite Mazon Creek fossil? Tell us at email:esconi.info@gmail.com. Annularia radiata is a very commonly found species of Annularia. Annularia was the foliage for Calamites sp., which is related to modern day horsetails. It is very similar to the larger Annularia inflata (Mazon Monday #60). It was named…
