Tag: MazonCreek
-
Fossil Friday #316: Asterophyllites longifolius
Recently, Marie Angkuw mentioned that she had required a large, and very sweet example of Asterophyllites longifolius. She found this specimen at an antique mall. The fossil was part of an old collection. I wonder if it was the “oldest” antique at the mall?
-
Mazon Monday #320: A shoot at the root? Unique development and evolution of the stigmarian apical meristem
Our friends at the Field Museum have been busy… this time it’s paleobotany. The paper “A shoot at the root? Unique development and evolution of the stigmarian apical meristem” was published in the journal Proceedings of the Royal Society B a few days ago. The authors should be familiar… Michael P. D’Antonio, C. Kevin Boyce,…
-
Fossil Friday #315: Eubleptus danielsi
Eubleptus danielsi belongs to the Palaeodictyoptera an extinct order of medium-sized to very large, primitive Palaeozoic paleopterous insects. E. danielsi was described by Anton Handlirsch in 1906. Handlirsch (1865 – 1935) was an Austrian entomologist, who worked extensively on many insect orders. He did significant work studying of fossil insects. Handlirsch described E. danielsi in “Revision of American Paleozoic insects. Proceedings of…
-
ESCONI Field Trip to Braceville, IL for Mazon Creek Fossils – Saturday, May 30th and Sunday, May 31st, 2026
The ESCONI field trips to Braceville for Mazon Creek fossils are set for May 30th and 31st, 2026 from 9 AM to 3 PM. You can attend one or the other, but not both days. There is an attendance limit of 50 people each day. You must register to go on this trip. See rule…
-
Mazon Monday #319: ESCONI Braceville Trip Spring 2005
Our spring trip to Braceville Spoil Pile is coming up in May. The sign-up will kick off very soon. We have been going there for many years. For the spring trip in 2005, Barbara Brotman, a reporter for the Chicago Tribune was there to talk to a few ESCONI members and talk about ESCONI.
-
Fossil Friday #314: Kellibrooksia macrogaster
For today’s fossil, we have a beautiful specimen of Kellibrooksia macrogaster, which was a species of mantis shrimp (see Mazon Monday #105). This rare animal was described by Frederick Schram in 1973. It was named in honor of Harold Kelly Brooks, who published the first well-illustrated modern account of Mazon Creek crustaceans. A pdf of his work is…
-
Mazon Monday #318: Eusphenopteris neuropteroides
Eusphenopteris neuropteroides is an extinct seed fern species that is relatively uncommon, though it is primarily known from the terrestrial deposits of Mazon Creek. It was originally described as Pseudopecopteris anceps by Leo Lesquereux, but its classification has shifted over time as its relationships to other taxa became better understood. Over the years, it has…
-
Fossil Friday #313: Mazonomya mazonensis
George Witaszek sent us this breathtaking plate platter of Mazonomya mazonensis (see Mazon Monday #25). This animal was called “clam-clam” by collectors. Mazonomya mazonensis was known incorrectly as Edmondia for a long time. It was redescribed by Jack Bailey in the book “Paleobiology, Paleoecology, and Systematics of Solemyidae (Mollusca: Bivalvia: Protobranchia) from the Mazon Creek…
-
Mazon Monday #317: Pohlsepia Revisited — Not an Octopus After All
A new paper “Synchrotron data reveal nautiloid characters inPohlsepia mazonensis, refuting a Palaeozoic origin for octobrachians” in the journal Proceedings of the Royal Society B Biological Sciences refutes the classification of Pohlsepia mazonensis as an octopus and reclassifies it as a soft-bodied nautiloid with the new name Paleocadmus pohli.
-
Fossil Friday #312: Sublepidophloios protuberans with a spray of Cyperites bicarinatus
At first glance, today’s fossil might look like a cone. But, closer examination reveals it to be a nice specimen of Sublepidophloios protuberans with a spray of Cyperites bicarinatus at the top. Sublepidophloios protuberans is a species of lycopsid branch (see Mazon Monday #316) and Cyperites bicarinatus was the sterile leaves for the Lycopsida (see Mazon…
-
Throwback Thursday #312: Ron Schinderle Donation
Barb Schinderle stopped by ESCONI Show last month to drop off a donation of her late husband Ron’s fossils. Ron passed away in 2021. He was a long time ESCONI member and an avid fossil collector . He went on many ESCONI field trips. A group of us remember him fondly from our many trips…
-
Mazon Monday #316: Sublepidophloios protuberans
Today, we have Sublepidophloios protuberans, which is a species of lycopsid branch. It’s very common, actually the most common form of lycopsid bark in the Mazon Creek fossil flora.
-
ESCONI Field Trip to Danville Shale Pile Fossils – Saturday, May 2nd, 2026
An ESCONI field trip to the Danville IL Shale Pile for Pennsylvanian fossils is scheduled for Saturday May 2nd, 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…
-
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.
-
Fossil Friday #310: Mazon Creek Scallop
Another small concretion with a treasure inside… this one has a scallop (see Mazon Monday #35). This one is Aviculopecten mazonensis. There’s no information about where this concretion was collected, but Pit 11 is very likely. We ran across it while preparing for the 2026 ESCONI Show. Do you think these were as tasty as…
-
Mazon Monday #314: Smithixerxes juliarum
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.
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #40: Mazon Creek Asterophyllites and a Sphenopterid in a Riker Mount
Last preview… a Riker Mount with a Mazon Creek Asterophyllites and a Sphenopterid… both are beautiful fossils. Today is the day… come out at 10 AM and see all the auction items for yourself!
-
2026 ESCONI Gem, Mineral, and Fossil Show – Preview #38: Reticulopteris munsterii var. dawsonii from Mazon Creek
How about another Mazon Creek seed fern? This one is Neuropteris jacksonii (see Mazon Monday #250). If you are reading this… today is the day!
-
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 #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!
-
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 #18: Lepidostrobus, sp. Cone
Here’s a beautiful Lepidostrobus, sp. cone (see Mazon Monday #202) from Mazon Creek. These cones were the reproductive organs of lepidodendron trees.
-
Mazon Monday #313: Mazon Creek Studies – the first 120 years
For this week, we have an article from the September 1978 edition of the Field Museum’s Bulletin. The full edition, which includes Jaunary thru December, is available on the Biodiversity Heritage Library (BHL) website.
-
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…
-
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.
