Earth Science Club of Northern Illinois - ESCONI

ESCONI October 2020 General Meeting - October 9th, 2020 at 8:00 PM via Zoom - "The Blue Forest of Ancient Lake Gosiute” #fossils #paleontology #PetrifiedWood #chalcedony

The speaker is Mike Viney. Mike is a Teacher in Residence at Colorado State University and a long-time collector and researcher into petrified wood. The title of his talk is "The Blue Forest of Ancient Lake Gosiute: Sweetwater County, Wyoming". The Blue Forest is a famous source of petrified wood known for its blue chalcedony. Lake Gosiute was one of the lakes in the Green River region during the Eocene.

Here's a link to Mike’s web page called "The Virtual Petrified Wood Museum"  http://petrifiedwoodmuseum.org/

The Digging Science Youtube channel has a great video of collecting petrified wood in the Blue Forest in Wyoming.

 

Phys.org: New evidence suggests it was matter ejected from the Chicxulub crater that led to impact winter #dinosaurs #impact #MassExtinction #Cretaceous #Meteor #Chicxulub

A large asteroid (~12 km in diameter) hit Earth 66 million years ago, likely causing the end-Cretaceous mass extinction. Credit: Southwest Research Institute/Don Davis

Phys.org has a story on new research about the extinction of the non-avian dinosaurs.  Since it's discovery 40 years ago by Walter and Luis Alvarez, this mass extinction, which occurred approximately 66 million years ago, has been a source for much research.  The cause is generally thought to be the large meteor that struck the Earth and created the Chicxulub crater in Mexico.  Now, some new evidence suggests that the ejecta from that strike caused the post event "Nuclear Winter", not widespread wildfires as had previously be suggested. A paper in the Proceedings of the National Academy of Sciences has the details.

A team of researchers from the U.S., Australia and the U.K. has found evidence that suggests material thrown into the atmosphere by the asteroid that struck the Earth approximately 66 million years ago, and not massive wildfires, led to a mass extinction event. In their paper published in Proceedings of the National Academy of Sciences, the group describes their study of sediment from the Chicxulub crater and other ocean areas and what it showed them.

Over the past several decades, Earth scientists have come to believe a large asteroid slammed into the Earth just off the coast of what is now Mexico's Yucatán Peninsula approximately 66 million years ago. The impact of the asteroid strike was so great that it led to a mass extinction event that killed off the dinosaurs. Evidence of the asteroid strike has been found around the globe, and so-called K–Pg boundary records have been identified. They are evidence of material in the atmosphere circling the globe after the asteroid strike, blocking out the sun, which resulted in plants and animals dying. But one area of contention has remained: the source of the material in K–Pg boundary records. Prior research has suggested it came from material that was burned by massive wildfires that were set off by the asteroid strike. In this new effort, the researchers suggest that while some of the material in K–Pg boundary records is likely from such burnt material, most of it came from material ejected from the crater at the impact site.

Trilobite Tuesday #25: Fossils of New Trilobite Species Found in Tasmania #trilobite #fossils #TrilobiteTuesday #Tasmania

SciNews has a piece about a new species of trilobites from Tasmania.  A new species of the genus Gravicalymene has been named.  It's called Gravicalymene bakeri after the actor Thomas Stewart Baker, the fourth actor to play the title character in the television series "Doctor Who".  This animal lived about 450 million years ago during the late Ordovician Period.  This animal is very similar to the many Calymenid species across Europe and North America from the Ordovician through the Devonian Periods.  All the details are in a paper that appeared in the journal Alcheringa: An Australasian Journal of Palaeontology.

Gravicalymene is a small genus of calymenid trilobites that flourished from the Ordovician to the Devonian period.

It includes at least seven species and is relatively well-known from the ancient continents of Avalonia, Baltica and Laurentia (i.e., Europe and North America).

The newly-discovered species, named Gravicalymene bakeri, lived during the Late Ordovician epoch, approximately 450 million years ago.

“During this time, Australia was part of the great landmass Gondwana, when complex marine ecosystems were starting to develop,” said Dr. Patrick Smith from the Australian Museum Research Institute and Macquarie University and Dr. Malte Ebach from the University of New South Wales.

“It was also a time when the first primitive plants were appearing on land.”

Several specimens of Gravicalymene bakeri were collected from the Late Ordovician shales of the Gordon Group in northern Tasmania.

“This is the first record of the genus Gravicalymene from the Ordovician of East Gondwana (Australasia),” the paleontologists said.

Mazon Monday #27: Care and Feeding of Your Mazon Creek Concretions #fossils #MazonCreek #concretions #MazonMonday #HowTo

This is Mazon Monday post #27.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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Now that you have collected some concretions at Braceville (and maybe other places) this year, here are some notes on how to process them to maximize your chances for something good.

Care and Handling of Mazon Creek Concretions 

Storage 

• Concretions should be stored out of the sun in a cool place. 
• Sunlight and heat changes the chemical composition and makes them harder to open 

Opening Concretions 

• Most concretions, 90%, do not break on the plane of the fossil when hit with a hammer unless they are ready to open (micro fraction already present on the plane of the fossil)
• Concretions ready to open will sound and feel dull when tapped by a hammer.
• If the concretion rings and the hammer bounces well, the concretion is not ready. Set it aside for freeze thaw treatment.
• Tap all around the edge of a concretion that is ready to open until a visible crack develops. If you see a crack, keep tapping until the concretion opens.
• If the concretion does not open after a while, set it aside for freeze thaw. Do not strike a concretion hard with a hammer until you are ready to give up on it. 

Freeze Thaw Method of Opening Concretions - Highly Recommended 

Most concretions can be opened by frost action. The water-saturated concretion is stressed differentially when it is frozen, creating weakness along the plane of the fossil, wherever in the concretion that may be. It may take many cycles of freeze thaw to succeed in developing a fracture along the plane of the fossil, and some concretions never do succumb. At least 10-15 freeze thaw cycles are recommended before giving up on a concretion. Most concretions that are going to open will open by 40 cycles. The upper limit of cycles is bounded by your patience. Once you reach your limit, go ahead and pound it open with a hammer, knowing that it will probably fracture in many pieces. The alternative is to give it away, or throw it out. 

• Place concretions in a watertight container. The smaller the container, the more freeze thaw cycles that you will get.
• Fill the container with water and let it soak for a couple of days. 
• In the winter, place the container in a sunny place outdoors to promote more freeze thaw  cycles, and/or bring the container into a warm place to thaw periodically. 
• In the spring, empty the container onto a screen and wash down the concretions. 
• Let the concretions dry 
• Tap each concretion with a hammer and follow the directions for opening concretions above.
• Return unopened concretions to a container and store in a cool, dark place until cold weather sets in again. 

Concretions may be frozen open in a freezer as well

• Place the concretions in a container that will fit into the freezer 
• Fill the container with water and let soak for a couple of days .
• Place the container in the freezer for at least two days 
• After two or more days. remove the container and let thaw for a day.
• Examine the concretions for cracks. wash off and remove debris
• Tap with hammer to test. open concretions per instructions above.
• Place concretions back into water filled container. let soak for a day 
• Place concretions back into freezer and repeat cycle
• Every fourth or fifth cycle let the concretions dry out partially, which takes a few hours. Then examine and test for readiness. Concretions often develop a crack when they dry
• It is important that the concretions be fully saturated with water before freezing.
• Some people place a little detergent into the water to aid saturation of the concretion. This practice lowers the freezing point of the water, however. 

Cleaning Concretions 

Concretions sometimes have dirt or a whitish mineral stain that can be removed by a brief soaking in dilute vinegar. Soaking in dilute vinegar can help remove some light mineral coatings as well. 

• Place the specimen in a container and cover it with a solution of 1 part white vinegar to 4 parts water. 
• Let the specimen soak for 10 or 15 minutes. 
• Remove the specimen from the solution and brush the dirt, or mineral stain gently with a finger tip or cotton ball 
• Do not use a tooth brush. that will scratch the specimen
• Be careful not to let grit picked up the cotton ball to scratch the specimen. Flush the specimen with water for 15 minutes to remove any residual vinegar solution 

Care of Specimens

• Do not coat them with anything 
• Store in a cool. dry, dark place. Sunlight and heat will damage them. 
• Keep in an acid free environment. No newspaper. 

 

'Giant impact' theory of moon's formation gets another boost #space #moon #impact #geology

Space.com has a story about the formation of the moon.  A recent paper in the journal Proceedings of the National Academy of Scieces lends more evidence for the "Giant-Impact  Hypothesis" of the creation of the moon.  

Scientists have found fresh evidence in lunar rocks showing that the moon was likely formed after a Mars-sized planet crashed into the proto-Earth more than 4 billion years ago.

A NASA-led team examined moon rocks brought back to Earth by Apollo astronauts more than 50 years ago. Investigating the samples with advanced tools not available to researchers in the 1960s and 1970s, the team found further evidence of the "giant impact theory" by focusing on the amount and type of chlorine in the rocks, a new study reports.

The researchers discovered the moon has a higher concentration of "heavy" chlorine compared to Earth, which sports more "light" chlorine. The terms "heavy" and "light" refer to versions of the chlorine atom, known as isotopes, that contain different numbers of neutrons in their nuclei.

BBC: Spinosaurus dinosaur was 'enormous river-monster', researchers say #dinosaurs #spinosaurus

Spinosaurus dental remains accounted for 45% of those discovered in a prehistoric river, researchers said

BBC has a story about Spinosaurus.  Some researchers believe they have settled the argument around Spinosaurus being an aquatic.  This new evidence, which appeared in the journal Cretaceous Research, stems from over 1200 teeth discovered in a prehistoric river deposit.  And, it backs up another paper which was published in April.  That research looked at the tail of Spinosaurus.

Palaeontologists believe they have settled a debate surrounding the largest ever carnivorous dinosaur.

 

The researchers at the University of Portsmouth say their discovery of 1,200 dinosaur teeth "proves beyond reasonable doubt" that Spinosaurus was an "enormous river-monster".

Its dental remains accounted for 45% of those found in a prehistoric river, they said.

 

The findings have been published in the Cretaceous Research journal.

 

Spinosaurus fossils were found in large numbers at the site of an ancient river bed in Morocco, which flowed through the Sahara Desert 100 million years ago.

 

The scientists said their discovery meant the 15-metre (49ft) long, six-tonne dinosaur was not a land-based predator but a largely aquatic one.

Fossil Friday #24: Euphoberia from the Mazon River #fossils #fossil #FossilFriday #MazonCreek #millipede

This is the "Fossil Friday" post #24.  Expect this to be a somewhat regular feature of the website.  We will post any fossil pictures you send in to [email protected].  Please include a short description or story.  Check the #FossilFriday Twitter hash tag for contributions from around the world!

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Today, we have an excellent specimen of a Euphoberia millipede from Mazon Creek. Actually, it's literally from Mazon Creek, or at least the Mazon River.  This awesome fossil was found by Connor Puritz at the annual I&M Canal Corridor Fossil Trip in late August 2020.  This thread on the Fossil Forum has pictures and discussion about the trip.  By the way, we did a Species Spotlight on Euphoberia a few weeks ago.

Throwback Thursday #26: 1815 Eruption of Mount Tambora #TBT #history #volcano

This is Throwback Thursday #26.  In these, we look back into the past at ESCONI specifically and Earth Science in general.  If you have any contributions, (science, pictures, stories, etc ...), please sent them to [email protected].  Thanks!

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If you are looking for an interesting history channel on Youtube, give the History Guy a chance.  A recent episode is about the 1815 eruption of Mount Tambora in the East Indies.  There's a good account of how this, the largest volcanic eruption in modern times, impacted climate, warfare, agriculture, and the course of European history.  The ultimate effect led to 1816 being termed "the year without a summer".

In 1815, the volcano Mount Tambora on the island of Sumbawa in the Dutch East Indies erupted in the most explosive volcanic eruption in human history. The explosion affected the world's climate, changing history in surprising ways. The History Guy recalls the forgotten history of the year without a summer. This is original content based on research by The History Guy. Images in the Public Domain are carefully selected and provide illustration. As very few images of the actual event are available in the Public Domain, images of similar objects and events are used for illustration.

 

PBS Eons: When Rodents Had Horns #archaeology #paleontology #rodents #fossils

 

PBS Eons has a new episode.  This one is about horned rodents, more specifically horned gophers.  When originally described, they were likened to miniature rhinoceros.

These odd rodents belong to a genus known as Ceratogaulus, but they’re more commonly called horned gophers, because, you guessed it, they had horns. And it turns out the horns probably had a purpose - one that rodents would likely benefit from today.

Trilobite Tuesday #24: Fossils In Millard County, Utah #trilobite #fossils #TrilobiteTuesday #Utah

While doing some research during my recent trip to Utah, I ran across an very interesting page on the fossils of Millard County, Utah.   It's a great report of a couple field trips in this area of Utah.

We stayed in Delta, Utah, which is a great place to stay to explore this area.  The area is chock full of fossils from the Cambrian and the Ordovician Periods.  The two main places to visit are the Wheeler Amphitheater and Fossil Mountain.  The Wheeler Amphitheater is named for the legendary Wheeler Shale, from which Elrathia kingii spring by the absolute millions (billions?).  Elrathia kingii is probably the most recognizable trilobite species with literally thousands sold every year.  I have this one sitting on my desk.

An excellent place to begin a Millard County paleontology adventure is of course Wheeler Amphitheater in the House Range, or as many fossil aficionados prefer to call the rich region: Antelope Spring. That's where the fabulous middle Cambrian Wheeler Shale attains its ultimate geological and paleontological development, where quite conveniently that successful commercial fossil dig allows visitors to come on in and collect for a reasonable fee any number of whole, perfect trilobite carapaces.

The history of fossil collecting at Wheeler Amphitheater probably begins with the prehistoric Ute Indians, who archaeologists aver used not a few of the extinct arthropod trilobites as amulets to help repel injury during battle. But there is no doubt that a Henry Engelmann, who accompanied geologist J. H. Simpson on the very first earth science expedition to Millard County in the mid 19th Century, made the initial historic recorded trilobite find at Antelope Spring in 1859. Simpson eventually provided paleontologist/geologist Fielding Bradford Meek with the Wheeler Amphitheater trilobites Engelmann had collected during the Utah explorations--specimens that Meek described for the first time in a peer-reviewed scientific paper in 1876, shortly before his death. In the early 1870s geologist G. K. Gilbert, aware of Engelmann's fossil discoveries, visited Antelope Spring and measured upwards of 2,300 feet of middle Cambrian strata, collecting in the process numerous trilobites subsequently identified and described by famous Cambrian paleontologicst C. D. Walcott, who during expeditions to Wheeler Amphitheater in 1903 and 1905 not only recovered additional abundant fossil material, but also measured the entire middle to late Cambrian sequence exposed in the general vicinity--a sedimentary succession now known to contain the following geologic rock formations: middle Cambrian Howell Limestone; middle Cambrian Dome Limestone; middle Cambrian Swasey Limestone; middle Cambrian Wheeler Shale; middle Cambrian Marjum Formation; middle Cambrian Weeks Limestone; upper Cambrian Orr Formation; and upper Cambrian Notch Peak Formation (uppermost part is lower Ordovician). Walcott officially named what's now universally recognized as the world-famous middle Cambrian Wheeler Shale in a scientific paper in 1908. After Walcott's contributions, the proverbial paleontological flood gates open on scientific exploration of the House Range and its incomparable middle to late Cambrian geologic section; scientific research papers now abound.

At Wheeler Amphitheater, only a rather narrow 17-foot thick section in the upper portions of the middle Cambrian Wheeler Shale produces significant concentrations of fossil remains. This is the precise interval that's presently mined commercially for paleontologic specimens, having operated more or less continuously since the late 1960s when an enterprising entrepreneur recognized that, fortuitously, the richest trilobite horizon occurred in an easily accessible valley or "amphitheater" on Utah state-owned lands, which could legally be leased for natural resource exploitation.

Another place to visit is Fossil Mountain.  This locality exposes Ordovician layers, specifically the heavily fossiliferous Kanosh Shale.

The abundant fossil organisms at Ibex and Fossil Mountain occur in the roughly 485 to 470 million year-old lower Ordovician Pogonip Group, an association of six distinct and easily identifiable geologic rock formations. This major stratigraphic succession can be traced throughout western Utah and extreme eastern Nevada (the Pogonip Group of eastern California is composed of several different formations), but nowhere is it as fossiliferous as in the Ibex area, where silty carbonate beds several feet thick often consist of nothing but exceptionally well preserved brachiopods, gastropods, ostracods, trilobites, or echinoderms--each animal type characteristically contributing its specific remains solely to an individual shell bed, to the exclusion of all other invertebrate varieties. Such technically termed monotypic shell beds are extensively developed in the Pogonip at Ibex's Fossil Mountain, and the fossil-saturated ledges can be followed for considerable distances.

I had long heard reports of the remarkable paleontologically prolific formations of the Ibex District--had even viewed stunning brachiopod specimens from the lower Ordovician Kanosh Shale exposed there. Nevertheless, I was dutifully skeptical of the reportedly extensive, bountiful fossil occurrences. Many times in the past I'd been given "reliable" information about a rave-review region, only to find out that it could not live up to its advance billing. A fossil dealer at a mineral show once touted Ibex, talking on and on about the unbelievable abundance of fossils available there, but at the time I was busy researching another specific locality and his credible recommendations went over my head.

At a rock shop in Calico Ghost Town, in California's Mojave Desert a few miles east of Barstow, the proprietor made a special point of showing off his Millard County specimens, including chunks of brachiopod material from Ibex that were beyond belief. By now my interest in the region was solidifying, but there just didn't seem to be any spare time to get away and properly explore the place.

When at last I finally made the trip to Ibex, I was not disappointed. As the well-worn saying goes, you have to see it believe it. The rocks are relatively flat-lying, in a horizontal bedding orientation, and erosion has created natural ledges along these bedding planes. Fossil hunters can simply hike along the strike of the strata--in other words, along the horizontal direction of the rock layers--and pick of free-weathered fossils at will, in addition to innumerable quality chunks of fossil-bearing limestones and shales.

In a coming post, I will post highlights of our own trip to collect trilobites in the Great Basin of Utah.  Until then, here are a few photos.

 

Mazon Monday #26: Braceville Field Trip Report #fossils #MazonCreek

This is Mazon Monday post #26.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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The weather could not have been better for the annual Fall trip to Braceville, IL for Mazon Creek concretions this past weekend.  For both days, we had lows in the 50s and highs around 70 degrees.  There were 51 participants on Saturday and 42 on Sunday, with 9 of those on Sunday from the Kalamazoo Geological and Mineral Society (KGMS).  Thanks for joining us!

We had several donations of fossils.  Most notable was the donation from Ralph Jewell, Thanks!  He donated several buckets of concretions, Mississippian fossils, Ordovician fossils, Pliocene fossils, and some fossils from Morocco.  Hopefully, people won't be too confused with their findings!  Everyone went home with something... be it finds from the spoil pile or the donated fossils.

There is a great field trip report by Ralph Jewell on the Fossil Forum.  If you aren't a member over there, you are really missing out on some great information and discussions.  Sign up... it's free!  You will learn more than you ever imagined about fossils and their place in the natural world!

Here are a couple videos of the distribution of donated material on Saturday.

Sunday.

Here is a photo of the hill... it's shrunk since my first visit in 2004.

A view from the top

Various photos from the day

SciTechDaily: Discovery of a New Mass Extinction – Carnian Pluvial Episode – 233 Million Years Ago #dinosaurs #extinction #massextinction #evolution #paleontology

Summary of major extinction events through time, highlighting the new, Carnian Pluvial Episode at 233 million years ago. Credit: D. Bonadonna/ MUSE, Trento

SciTechDaily has a story about the identification of a new mass extinction.  This one called the "Carnian Pluvial Episode".  It occurred about 233 million years ago during the Triassic Period. The cause is believed to be flood basaltic volcanic eruptions in western Canada.  Some of the outcomes was the rise of the dinosaurs and the arrival of the very first mammals and turtles.  You can find more details in a paper, which appeared in the journal Science Advances.

It’s not often a new mass extinction is identified; after all, such events were so devastating they really stand out in the fossil record. In a new paper, published today in Science Advances, an international team has identified a major extinction of life 233 million years ago that triggered the dinosaur takeover of the world. The crisis has been called the Carnian Pluvial Episode.

The team of 17 researchers, led by Jacopo Dal Corso of the China University of Geosciences at Wuhan and Mike Benton of the University of Bristol’s School of Earth Sciences, reviewed all the geological and palaeontological evidence and determined what had happened.

The cause was most likely massive volcanic eruptions in the Wrangellia Province of western Canada, where huge volumes of volcanic basalt was poured out and forms much of the western coast of North America.

“The eruptions peaked in the Carnian,” says Jacopo Dal Corso. “I was studying the geochemical signature of the eruptions a few years ago and identified some massive effects on the atmosphere worldwide. The eruptions were so huge, they pumped vast amounts of greenhouse gases like carbon dioxide, and there were spikes of global warming.” The warming was associated with increased rainfall, and this had been detected back in the 1980s by geologists Mike Simms and Alastair Ruffell as a humid episode lasting about 1 million years in all. The climate change caused major biodiversity loss in the ocean and on land, but just after the extinction event new groups took over, forming more modern-like ecosystems. The shifts in climate encouraged growth of plant life, and the expansion of modern conifer forests.

PBS Eons: The Sea Monster from the Andes #archaeology #paleontology #pliosaur #fossils #Andes #Cretaceous

 

There's a new episode of PBS Eons.  This one is about a giant sea monster called Kronosaurus.

In 1977, a farmer was plowing his field on a plateau high in the Andes mountains when he stumbled upon a giant fossilized skeleton. How did this giant marine reptile end up high in the Andes Mountains?

Zoom Link: ESCONI September 2020 Paleo Meeting - September 19, 2020 - Brag Night! #fossils #paleontology

September 19, 2020, Paleontology Study Group Meeting

John A. Catalani

We are going to have a Paleo Study Group meeting on Saturday Sept. 19 beginning at 7:30 p.m on Zoom. The plan is to have members present their fossil finds collected since the last “Brag Night” meeting of Sept. 2019. It would be best to present your finds in photograph form. The photos should be collected in a folder for ease of access. You can then show the photos in order by advancing to each in turn. Please limit the number of photos to 20 for each participant, so all can be seen. Instructions for joining the Zoom mtg will be on the ESCONI web site. Additionally, an invitation via e-mail will be sent the day before the meeting.  Zoom link.

After all photos have been presented, we will discuss future Paleo meetings. Please think about presenting a program to the group.

Fossil Friday #23: Animals from Braceville #fossils #fossil #FossilFriday #MazonCreek #Jellyfish #shrimp

This is the "Fossil Friday" post #23.  Expect this to be a somewhat regular feature of the website.  We will post any fossil pictures you send in to [email protected].  Please include a short description or story.  Check the #FossilFriday Twitter hash tag for contributions from around the world!

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There is a field trip to Braceville to collect Mazon Creek concretions on September 19th and 20th, 2020.  Last week, we did plant fossils from Braceville.  This week, we will highlight some of the animal fossils that can be found there.

Octomedusa pieckorum (Jellyfish)

Mazonomya mazonensis (Clam)

Aviculopecten mazonensis (Scallop)

Mazopherusa prinosi (Fan worm)

Paucijaculum samamithion (Arrow worm)

Palaeoxyris sp. (Shark egg case)

Essexella asherae (Jellyfish)

Dryptoscolex matthiesae (Rat worm)

Kallidecthes richardsoni (Shimp)

Throwback Thursday #25: Hunting Ghosts, Blobs, and Assorted Monsters in Illinois' Coal Age Nodules #TBT #history #fossils #MazonCreek #TullyMonster #Jellyfish

This is Throwback Thursday #25.  In these, we look back into the past at ESCONI specifically and Earth Science in general.  If you have any contributions, (science, pictures, stories, etc ...), please sent them to [email protected].  Thanks!

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The following is an article by Cecilia Duluk about the fossil blobs (and monsters) found in Mazon Creek concretions.  This article appeared in the July/August 1968 issue of Earth Science.  I like how she refers to Pit 11 as the new area.  It's interesting to read what was thought about the "blobs" 50+ years ago.  And while we understand more now, there is still so so much to research and understand!!!!

 

 

Reminder: ESCONI September 2020 Paleo Meeting - September 19, 2020 - Brag Night! #fossils #paleontology

September 19, 2020, Paleontology Study Group Meeting

John A. Catalani

We are going to have a Paleo Study Group meeting on Saturday Sept. 19 beginning at 7:30 p.m on Zoom. The plan is to have members present their fossil finds collected since the last “Brag Night” meeting of Sept. 2019. It would be best to present your finds in photograph form. The photos should be collected in a folder for ease of access. You can then show the photos in order by advancing to each in turn. Please limit the number of photos to 20 for each participant, so all can be seen. Instructions for joining the Zoom mtg will be on the ESCONI web site. Additionally, an invitation via e-mail will be sent the day before the meeting.  Zoom link.

After all photos have been presented, we will discuss future Paleo meetings. Please think about presenting a program to the group.

 

Trilobite Tuesday #23: AMNH: Trilobites on Land #trilobite #fossils #TrilobiteTuesday

It's been generally accepted that trilobites were marine animals, living only in the ocean.  However, there are some specimens that might hint that some of them crawled out of the sea.  The American Museum of Natural History (in New York) has a page about this.  Here is a paper from Nature that also proposes that trilobites ventured beyond the ocean.  Maybe way back in the Cambrian, trilobites became some of the first land animals.

These Olenellus romensis are from the Rome Formation. Similar examples may have crawled out of the sea and onto adjacent tidal flats. 

Despite the long-standing, and well-established notion that trilobites were strictly-and-solely marine inhabitants, back in 2014, scientists investigating a series of Lower Cambrian deposits in the Appalachian Mountains of Tennessee discovered something they had not anticipated. Within outcrops of the 515 million-year-old Rome Formation, a team from the University of Saskatchewan found unmistakable fossil evidence which indicated that soon after beginning their lengthy crawl through Deep Time, some olenellid trilobites had already started journeying onto dry land – or at least onto sea-adjacent tidal flats.

The early Paleozoic rocks emerging from that expedition revealed two distinct types of trace fossils:  cracks and tracks. The former were indicative of a shallow sea floor habitat that upon being exposed to direct sunlight, began to rapidly bake and crack.

The latter, however, were a decidedly different matter. These particular trilobite trackways, also known as Cruziana rugosa, presented telltale signs that more than half-a-billion years ago those highly adaptable animals were exploring the surrounding shoreline and taking advantage of the resource-filled tidal flats which bordered their aquatic home.

 

Mazon Monday #25: Species Spotlight: Mazonomya mazonensis #MazonCreek #fossils #MazonMonday #clam #clamclam

This is Mazon Monday post #25.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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The species spotlight falls on Mazonomya mazonensis, known mistakenly as Edmondia for a long time.  It was also called affectionately clam-clam.

Preserved in the "death position" from Chowder Flatts.

Here is the text from the  Mazon Creek Fossil Fauna by Jack Wittry.

Mazonomya mazonensis Bailey, 2011

Found in numbers that exceed the combined total of all other clams, Mazonomya mazonensis, commonly called Clam-Clam, is ubiquitous in the Mazon Creek Biota. Concretions containing numerous individuals are frequently found in collections. This species is equivalved. with rather smooth shells lacking valve ornamentati1on except for growth lines. It has an elliptical out line and a valve width that is about one-half of the average 30 mm length. It is usually found in the death position: both valves opened. butterfly-like. The flexible hinge ligament is often preserved and seen stretched between the valves. (See Figure 105.2 and 105.4 below.) As they moved through the substrate, M. mazonensis produced many of the fossil trails that appear in concretions. (See Trails, page 157.)

Misidentified as an Edmondia years ago, recent studies show that this species is a solemyid, a group today found living in the mud of oxygen-poor and sulfide-rich waters, such as present-day salt marshes.

Here is the text from Creature Corner.

The Bivalve Edmondia

Early researchers of the Mazon Creek Biota considered the fauna discovered in the nodules of that strata to be transients, non-resident creatures which had been trapped by some storm or other natural disturbance, carried out to the delta front and buried. Sealed in an iron concretion, siderite to be exact. The finding of bivalvia in nodules crippled that idea. Here we had creatures that burrowed .* into the mud or limey silt; a bottom dwelling resident of the delta front. As a class, bivalvia are tolerant of slight changes in salinity, water temperature, and water quality. A creature able to adapt to slight changes or at least tolerant of conditions around the delta front. Concretions holding bivalves sometimes had indications of the clam trying to burrow out and up (?) from its enclosing media. What sort of mechanism or condition could seal a bivalve in its burrow? Encase it in an iron carbonate nodule? 

The members of the genus Edmondia found in the Mazon Creek area are under study at the present time. At this date it is felt that all belong to one species. It is one of the more abundant bivalves in the northern part of Pit 11, Morris and Ottawa. In life it is believed to have been a shallow burrower. Edmondia are egg-shaped or nearly so, from a side view. Edmondia are equivalved, with a nearly smooth surface. Some specimens are found in life position with valves closed, others with valves open, denoting burial after death.

From Chowder Flatts

From Braceville

PBS Eons: How Ancient Art Captured Australian Megafauna #archaeology #paleontology #mammals #art #australia #fossils

 

There's a new episode of PBS Eons.  This one connects archaeology, paleontology, and ancient art.

Beneath layers of rock art are drawings of animals SO strange that, for a long time, some anthropologists thought they could only have been imagined. But what if these animals really had existed, after all?