The Illinois State Geologic Survey (ISGS) has a page on the trilobites of Illinois. It has good information about time periods and has a few pictures of the species that can be found here in Illinois. There's even a paragraph on it's body structure.
Trilobites are so named because the segments on their upper (dorsal) surface usually possess longitudinal furrows that form a three (tri-) lobed division of the body. The central lobe is called the axial lobe, and the two lateral counterparts are called pleural lobes. The dorsal surface consisted of a hard, mineralized protective shield called a carapace; it is this part of the shell, or exoskeleton, that is most commonly preserved in the fossil record. The lower (ventral) surface bore a pair of antennae and numerous pairs of jointed appendages that served as walking, swimming, feeding, and respiratory organs. The ventral surface, however, consisted of relatively soft tissue and rarely is preserved. A typical trilobite is about 2 inches long, but some are less than half an inch in length and giants of the group measure fully 2 feet.
If you were missing March Madness, here's you chance to get in on Museum Madness! But hurry... your bracket has to be in tonight!
Get up close and personal with some well-known, and other little-known, Field Favorites. Create your brackets for Museum Madness at the Field and then vote for your favorite! After each round of voting, see how you rank against other players. Who will win? You decide!
The Tully Monster, or Tullimonstrum gregarium, has long been one of the most popular Mazon Creek fossil specimens. The reasons are unclear... maybe it's the strange shape of the animal, or that it's the State Fossil of Illinois, or the questions and controversy as to what type of animal it is. It is fairly rare, but not as much as most people believe. Oh, and by the way, it's only found in Illinois.
Francis Tully is credited with discovering it in a strip mine near Braidwood, IL, about 50 miles southwest of Chicago, in 1955. Mr. Tully was an amateur fossil collector. He brought it to the Field Museum in Chicago. There at the museum Eugene Richardson found the fossil interesting and described and named it in 1969. After a long effort, Tullimonstrum gregarium became the state fossil of Illinois in 1989. You can find more about him here.
An invertebrate, (an animal having no backbone), the beast had a dirigible-like body. On one end was a spade shaped tail which must have provided propulsion. At the opposite end of its body was a long trunk tipped by a toothy claw. Protruding from the torso were stalks that scientists suspect were its eyes. An indentation under these eye stalks may indicate the location of its mouth. Until the last few years, scientists did not know where to classify the Tully Monster.
Paul Mayer, Collections Manager of Fossil Invertebrates at the Field Museum, wrote a great blog post about the Tully Monster. It's now thought to be a vertebrate.
Last year, two papers in the journal Nature sought to resolve what group of animals Tully Monster fossils belong to; both papers concluded the vertebrates. Last week, Dr. Lauren Sallan and colleagues published a paper in the journal Palaeontology, "The Tully Monster is Not a Vertebrate..." And that's okay; it is part of how science works.
It's quite normal for new ideas, based on new scientific information and analyses, to raise questions. You might think of scientific discourse as a marketplace of ideas, backed up by data, analyses, and interpretations. Scientists sometimes disagree about one or more of these three components, and that's where the marketplace concept comes in. Other scientists (not just the ones who wrote the papers) are part of the marketplace, and they scrutinize the different perspectives, sometimes doing more research, critiquing, or adding to the discussion and building on the base of knowledge about whatever controversy is at hand. Most often, some sort of consensus is reached in the broader scientific community, though it might take years of back-and-forth discussions.
We are co-authors on one of the papers in Nature, and we took part in a long meticulous slog examining more than 1,000 Tully monster fossils in the Field Museum’s collection. We were looking for biologically informative characters to add to the ones that had been reported in the 50-plus year interval since the Tully monster was described as a bizarre beast that didn't fit into any known animal group. We also examined and looked for characters of other 307-million-year-old Mazon Creek fossils preserved in the same unusual ironstone concretions as the soft-bodied Tully monster.
We then took all these characters and compared them to ones present in living and fossil groups to which the Tully monster had been compared. Our preliminary conclusion: Tully monster wasn't close to the combination of characters found in Arthropods or Molluscs, but was closer to Chordates, the phylum of animals that includes vertebrates. Then, using characters of different living and fossil chordates, especially fishes, we conducted a quantitative analysis with statistical tools from biological systematics to reach our hypothesis. Given the data available, and the analytical methods we used, the Tully monster was categorized as a stem group vertebrate, likely related to the lineage containing lampreys.
Here are a couple videos for more information.
The Brain Scoop - "The tully monster SOLVED!"
PBS Eons - "The Tully Monster & Other Problematic Creatures"
There's a new episode of PBS Eons. This one is about eggs, the platypus, and of course birds! They tackle the endless question "What came first the Chicken or the egg?".
The story of the egg spans millions of years, from the first vertebrates that dared to venture onto land to today’s mammals, including the platypus, and of course birds. Like chickens? We’re here to tell you: The egg came first.
On course, this depends on how everything is going with the gobal Covid-19 pandemic... here hoping! This exciting presentation will be given by ESCONI member John Catalani.
The “Gonioceras Fauna”: Inhabitants of the Mohawkian Sea
The Upper Ordovician “Gonioceras Fauna” of the Mohawkian Sea is remarkably abundant, diverse, and often well-preserved. I will start with an introduction to the Platteville Formation of the Ordovician System, the paleogeography of the Ordovician focusing on Laurentia (North America), and characteristics of the Mohawkian Sea of Laurentia. A bit about nautiloids and a description of Gonioceras, the namesake of the fauna, will follow. The fossiliferous rock units and different facies of the Platteville will be described and compared using quarry sections and specimens. The remainder of the program will feature photos of the major components of the “Gonioceras Fauna” including molluscs, brachiopods, and trilobites. Remarks on the “extinction” of the Fauna will conclude the program.
Travel and Leisure has a piece on SUE at the FIeld Museum. A bunch a good facts and information plus some of SUE's recent tours of the museum as it is closed for the next few weeks.
Chicago’s Field Museum sent out its very own dinosaur ambassador, SUE, to check on the museum as it remains closed due to the coronavirus pandemic. They couldn’t let those rockhopper penguins at the nearby Shedd have all the fun, after all.
“Once SUE heard about the @shedd_aquarium penguins, we really didn't have a choice,” the Field Museum wrote in a tweet along with a video of SUE the tyrannosaurus rex waiving to the museum’s own penguin exhibit.
There's a new episode of PBS Eons. This one is about penguins and how they evolved from sea birds.
Today, we think of penguins as small-ish, waddling, tuxedo-birds. But they evolved from a flying ancestor, were actual giants for millions of years, and some of them were even dressed a little more casually.
Complete specimen in dorsal view. Scale bar, 1 m. b, Camera lucida drawing of the postcranial anatomy of the specimen; pectoral fins have been illustrated in their position, although they are only visible ventrally. c, Reconstruction. an.fi, anal fin; cau.fi, caudal fin; op, opercular; pec.fi, pectoral fin; pel.fi, pelvic fin. Credit: Nature
Phys.org has a story about the evolution of the human hand. A new complete specimen of a tetrapod-like fish, Elpistostege, reveals new clues in the evolution of the human hand from fish fins. The paper describing this discovery can be found in the journal Nature.
An ancient Elpistostege fish fossil found in Miguasha, Canada has revealed new insights into how the human hand evolved from fish fins.
An international team of palaeontologists from Flinders University in Australia and Universite du Quebec a Rimouski in Canada have revealed the fish specimen, as described in the journal Nature, has yielded the missing evolutionary link in the fish to tetrapod transition, as fish began to foray in habitats such as shallow water and land during the Late Devonian period millions of years ago.
This complete 1.57 metre long fish shows the complete arm (pectoral fin) skeleton for the first time in any elpistostegalian fish. Using high energy CT-scans, the skeleton of the pectoral fin revealed the presence of a humerus (arm), radius and ulna (forearm), rows of carpus (wrist) and phalanges organized in digits (fingers).
"Today we announce in the journal Nature our discovery of a complete specimen of a tetrapod-like fish, called Elpistostege, which reveals extraordinary new information about the evolution of the vertebrate hand," says Strategic Professor in Palaeontology at Flinders University Professor John Long.
The Chicago Tribune has a story about the temporary closing of Chicago Museums due to Covid 19. The Field Museum, Shedd Aquarium, Art Institute, Planetarium, and Lincoln Park Zoo have closed for 2 weeks, Watch their websites for updated status.
The Museum of Science and Industry, Art Institute of Chicago, Adler Planetarium and Field Museum have joined Shedd Aquarium in announcing Friday a coronavirus related temporary closure, less than a day after Lincoln Park Zoo was the first of the region’s major museums and nature parks to say it is closing.
MSI, which welcomed almost 1.4 million visitors last year, said it will close beginning Saturday through April 6 in order to help minimize the spread of COVID-19. Adler said its closure will begin Saturday and last “until further notice.” Field’s closure begins Saturday and is listed as lasting through March 29.
The Art Institute will shuts its doors beginning Saturday for two weeks “so that we can thoroughly and thoughtfully respond to the escalating impact of COVID-19. We plan to reopen the museum on Saturday, March 28,” said a museum statement.
Due to COVID-19, the MAPS Board has made the obvious, yet painful, decision to cancel the 2020 EXPO. As of now, plans are to postpone the topic and Digest until the 2021 Show on April 16-18, 2021. Our concern for the health of everyone associated with EXPO, from dealers to attendees, is, and always will be, our first priority.
ESCONI has been very involved in the identification of Mazon Creek fossils for many years. From the legendary George Langford books, to the keys to identify Mazon Creek fossils, to the books of Jack Wittry, we have provided useful resources. The Mazon Creek Fossil Fauna reference book was published in 2012 and is a complete and updated taxonomic guide that includes descriptions and color photos of species that collectors are likely to find in the field or see in most large collections. Now, Jack has finished the Comprehensive Guide to the Fossil Flora of Mazon Creek. It is the definitive reference guide to Mazon Creek fossil flora.
These books were created with the help, expertise, specimens and work of many members of the Earth Science Club of Northern Illinois.
A Comprehensive Guide to the Fossil Flora of Mazon Creek, by Jack Wittry (2020, hardcover)
A Comprehensive Guide to the Fossil Flora of Mazon Creek, by Jack Wittry (2020, softcover)
The Mazon Creek Fossil Fauna, by Jack Wittry (hard cover)
The Mazon Creek Fossil Fauna, by Jack Wittry (soft cover)
You can purchase the books at club functions like General Meetings, Study Group Meetings, Field Trips, etc. Or, look for our books on ebay and Amazon.
It is with a heavy heart that we are announcing that ESCONI is canceling the annual show slated for March 21 and 22, 2020 at the Dupage fairgrounds due to concerns about the corona virus. There is a possibility, we will reschedule later in the year. Please stay tuned for more details!
This is the preview post #8 for the 2020 ESCONI Gem, Mineral, and Fossil Show. The show is on March 21st and March 22nd, 2020. Show details can be found here.
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Here is a nice large specimen of fluorite, possibly from Colorado.
There's a new PBS Eons episode. This one is about the "Green Sahara" only a few thousand years ago.
The climate of the Sahara was completely different thousands of years ago. And we’re not talking about just a few years of extra rain. We’re talking about a climate that was so wet for so long that animals and humans alike made themselves at home in the middle of the Sahara.
This is the preview post #7 for the 2020 ESCONI Gem, Mineral, and Fossil Show. The show is on March 21st and March 22nd, 2020. Show details can be found here.
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Here's one of multiple Mazon Creek plant fossil set. Each set is slightly different. Sets include from 5 to 7 specimens of the following species.
Cosmos Magazine has a post about Mary Anning. Mary died on March 9th, 1847 at the age of 47. She made important contributions to paleontology back in the early 1800s. She was a very interesting person who found some of the first Ichthyosaurs, Plesiosaurs, and pterosaurs. There are a few biographies of her life (The Fossil Hunter) and even a few recent movies!
Anning was no ordinary palaeontologist. She made her first significant find when just 11 or 12 (details differ) years old when she discovered a complete skeleton of an Ichthyosaurus from the Jurassic period, which created a sensation and made her famous.
Anning's passion for fossils came from her father's interest in fossil hunting, and a need for the income derived from them to support her family after his death.
She lived and worked in the English town of Lyme Regis, unearthing and selling large fossils to noted palaeontologists of the day and smaller ones to the tourist trade.
In 1823, Anning discovered the first complete Plesiosaurus. Her discoveries became key pieces of evidence for extinction. Later in her life, the Geological Society of London granted her an honorary membership.
