Tag: fossil
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #37: Alethopteris serlii from St. Clair, Pennsylvania
This preview is of a chunk of shale from St. Clair, PA. This piece contains numerous examples of Alethopteris serlii, a seed fern also found in Mazon Creek localities. We are getting very close now… inside 12 hours away!
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #35: Priscacara, sp. from the Green River Formation in Wyoming
What fossil show is complete without a Green River fish? Here is a nice Priscacara, sp. These fish date to the Eocene, about 50 million years ago. We have other Green River fish, come on out and see them!
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #34: Giant Moroccan Trilobite
How about a giant Moroccan trilobite for something different? Come on out… we will have other trilobites at the show.
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #33: Laveineopteris rarinervis from Mazon Creek
This is a beautiful specimen of Laveineopteris rarinervis (see Mazon Monday #81) a seed fern commonly found in the Mazon Creek fossil deposit. Come on out and check it out tomorrow!
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #30: Mazon Creek Achistrum, sp. Colony
Another Mazon Creek beauty… this is a nice Achistrum, sp. colony, which is a sea cucumber. You can see at least three mouths in the fossil. See Mazon Monday #29. Come on out and see for yourself, tomorrow, yes, tomorrow! Less than a day away!
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #31: Crinoid Plate from the Bangor Formation in Northern Alabama
Another crinoid plate from the Bangor Formation in Northern Alabama. This plate has multiple crinoids and other fossils like Archimedes bryozoans. Tomorrow is the day!
-
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!
-
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?!?
-
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.
-
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…
-
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!
-
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.
-
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…
-
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!
-
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.
-
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.
-
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
-
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.
-
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!
-
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!
-
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,…
-
Fossil Friday #305: A Beautiful Receptaculites/Fisherites!
This is the “Fossil Friday” post #305. 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! Taking a little break from Mazon Creek fossils this week…
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #5: Large Archimedes sp. from Alabama
This is the preview post #5 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’s…
-
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…
-
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…
-
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. 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. The classification of Acitheca polymorpha (Pecopteris polymorpha) has been problematic. Leo Lesquereux figured Pecopteris…
-
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.…
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #3: Acanthotelson stimpsoni
This is the preview post #3 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. For…
-
Mazon Monday #307: Arjan Mann on Fossil Nerds
This is Mazon Monday post #307. 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,…
-
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…
