Earth Science Club of Northern Illinois - ESCONI

Mazon Monday #29: Species Spotlight Achistrum sp./Holothurians #MazonMonday #MazonCreek #fossils #seacucumbers #echinoderms

This is Mazon Monday post #29.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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This week's "Mazon Monday" is a species (or class) spotlight on the Holothurians otherwise known as Sea Cucumbers.  They belong to the phylum Echinodemata, which includes starfish, sea urchins, sand dollars, and seal lilies.  Current feeling is there were two species of holothurian in Mazon Creek. The most common, and maybe only, one is called Achistrum sp.

There's a nice page about Sea Cucumbers over on wikipedia.

Sea cucumbers are echinoderms from the class Holothuroidea. They are marine animals with a leathery skin and an elongated body containing a single, branched gonad. Sea cucumbers are found on the sea floor worldwide. The number of holothurian (/ˌhɒləˈθjʊəriən,ˌhoʊ-/^[2][3]) species worldwide is about 1,717^[4] with the greatest number being in the Asia Pacific region.^[5] Many of these are gathered for human consumption and some species are cultivated in aquaculture systems. The harvested product is variously referred to as trepang, namako, bêche-de-mer or balate. Sea cucumbers serve a useful role in the marine ecosystem as they help recycle nutrients, breaking down detritus and other organic matter after which bacteria can continue the degradation process.^[5]

Like all echinoderms, sea cucumbers have an endoskeleton just below the skin, calcified structures that are usually reduced to isolated microscopic ossicles (or sclerietes) joined by connective tissue. In some species these can sometimes be enlarged to flattened plates, forming an armour. In pelagic species such as Pelagothuria natatrix (Order Elasipodida, family Pelagothuriidae), the skeleton is absent and there is no calcareous ring.^[6]

Sea cucumbers are named for their resemblance to the fruit of the cucumber plant.

Here's how modern day sea cucumbers look.

Chiridota heheva, abyssal species.  By n - n, Public Domain, https://commons.wikimedia.org/w/index.php?curid=11363281

Holothurians appeared in Andy Hay's Creature Corner in May 1986.  Here is the text.

Holothurians (sea cucumber)

As has been noted previously in these articles, the not uncommon fossil finds of Pit 11 are a great rarity in the fossil record of the rest of the world. So it is with the "sea cucumbers", more accurately the members of the class HOLOTHUROIDEA which are found at this location.

Ina recent journal it is stated "complete fossil Holothurians are rare". During the last 100 years only a few such specimens have been found. Following a page describing the complete specimens known, a paragraph much further on makes note of Dr. Eugene S. Richardson, Jr.'s study of "entire specimens of apodus holothurians" from Pit 11.

Holothurians possess leathery to gelatinous body walls, which are strengthened by Ossicles and spicules -tiny bone-like structures of various shapes. The body is more or less cylindrical, mouth at one end, anus at the other. Feeding tentacles surround the mouth. These tentacles are usually retractable. Some holothurians are burrowing creatures, ingesting the bottom sediment and filtering it for food.Others feed on tiny animals swimming by ensnaring them in the fan like tentacles. A calcareous ring of calcite plates joined together (often called radula by fossil collectors) is a support for the esophagus and body muscles. This ring plus the tiny "fish-hooks" (ossicles) are the field marks of Pit 11 sea cucumbers. During preservation, the sac-like body dries and cracks. Spaces being filled by calcite give the fossil body a septarian or mud-crack appearance. The various genera and species, one dozen plus or minus, are under study and will be described by S. Sroka (personal communication). Gelatinous body with few skeletal elements that could be preserved make the study of fossil holothurians difficult. Pit 11 holothurian specimens may change this condition.

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

Achistrum sp.

This holothurian,or Sea Cucumber, is a member of the echinodermsand has a worm-like, soft and leathery body. Like most echinoderms, the body is divided into five sections. They are not uncommon in the Essex Fauna, but are extremely rare in the overall fossil record. It was assumed at one time that about a dozen species existed in the Mazon Creek Biota. Today, it is felt that, at most, two species are found.

Achistrum has a cylindrical form that is sac-like, and dries during preservation, leaving dessication cracks. These cracks are replaced with calcite, giving the fossil a septarian or mud-crack appearance. A ring of approximately 15 small calcareous plates at the head end is a prominent feature of Achistrum. (See Insets on pages 122 and 170.) This ring of plates forms the mouth support ing the esophagus, and serves as the anchor point for five radial body elements that run the length of the animal. Radial symmetry is a uniting feature of all echinoderms and is occasionally seen in Achistrum such as the one shown in Figure 122.1 on page 122. Embedded throughout the body wall are small fish-hook shaped Figure 121 after Shab Scale bara supports called sclerites

Though found in modern species, no feeding tentacles surround-ing the mouth have been observed in the Mazon Creek forms. The calcareous mouth rings, fish-hook structures, and body cracks are the field marks of this genus.

Care must be taken when cleaning Achistrum specimens. Using any form of acid, such as vinegar, will quickly destroy any traces of the mouth ring plates and sclerites.

Stan the T. rex just became the most expensive fossil ever sold #dinosaurs #trex

LiveScience has a story about the sale of Stan the T-rex on October 6th, 2020.  Stan sold for $32 million and set a new record for the sale of a fossil.  SUE the T-rex, which went on sale back in 1997, had the previous record as it sold for $8.36 million.

Many paleontologists are dismayed that Stan sold for so much to an unknown buyer, especially now that many scientific institutions don't have the money to purchase such fossils and keep them in the public domain. However, unlike other dinosaur specimens, Stan had no choice but to go to the auction block, so how did it end up there?

Normally, the Society of Vertebrate Paleontology (SVP) opposes the auction of such fossils. In 2018, for instance, SVP asked the Aguttes auction house in Paris to pull the plug on auctioning off an Allosaurus, a type of meat-eating dinosaur, that had been found on private land in Wyoming. In contrast, Stan came to the auction house not because its owner wanted to turn a profit, but through a court order, which complicated SVP's response. 

Amateur paleontologist Stan Sacrison found Stan in 1987 in the Hell Creek Formation, near the town of Buffalo, South Dakota, according to the Black Hill Institute of Geological Research (BHI), a company that supplies fossils for research, teaching and exhibit. After learning about the specimen, BHI scientists spent more than 300,000 hours excavating and preparing the nearly 40-foot-long (12 meters) T. rex, which they named after its discoverer. 

The T. rex became famous, headlining at the T. rex World Exposition, a yearlong tour that opened in Japan in 1995. In 2005, the BBC TV show "The Truth About Killer Dinosaurs" created a replica of Stan's skull and jaws to learn about T. rex bite force; and researchers reported in 2009 in the journal PLOS One how they had studied Stan to better understand how dinosaurs moved. 

PBS Eons: How Plants Became Carnivores #paleontology #plants #carnivorousplants

 

There's a new episode of PBS Eons on Youtube.  This one is about how carnivorous plants evolved.

Go check out Overview on PBS Terra: https://www.youtube.com/watch?v=NHMZw... Deep Look’s episode on Sundews! https://youtu.be/D4kBrsyWhS4

How and why does botanical carnivory keep evolving? It turns out that when any of the basic things that most plants need aren’t there, some plants can adapt in unexpected ways to make sure they thrive.

Fossil Friday #26: Elrathia kingii from the Cambrian of Utah #fossils #fossil #FossilFriday #trilobite #Utah #Cambrian

This is the "Fossil Friday" post #26.  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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Here is an Elrathia kingii trilobite.  It was collected from A New Dig, Inc. near Delta, Utah, in September 2020. The amimals lived in the middle Cambrian, about 407 million years ago.  These trilobites are found in extremely high concentrations in the Wheeler Shale in the area of the Wheeler amphitheater.  If you vacation in Utah, bring a hammer and bag some trilobites!

This guy popped right out of the matrix.  Both top and bottom are well preserved.

 

 

 

 

Reminder with Zoom Link: 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.  Zoom link.

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.

 

Throwback Thursday #28: Photos of Braidwood Coal Mining 1960 #TBT #history #coal #MazonCreek

This is Throwback Thursday #28.  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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Here are a few photos of the Braidwood coal mines in 1960.  Some very large drag lines and and cranes were used to remove the coal.

NatGeo: This small dinosaur had a marvelous sense of touch, detailed fossils reveal #dinosaurs #germany

Preserved scales from the tail of Juravenator—a small predatory dinosaur that lived 150 million years ago in what is now Germany—contain small bumps that scientists believe are sensory organs.  ILLUSTRATION BY JAKE BAARDSE

National Geographic has a story about Juravenator starki.  This animal lived about 150 million years ago, during the Jurassic Period, in what is now Germany.   A new paper, in the journal Current Biology, proposes that it might have used sensory scales on its tail to sense fish when it foraged at night.

A CHICKEN-SIZE DINOSAUR that lived in what is now Germany about 150 million years ago might have used sensory scales on its tail as it foraged for fish at night. These sensory organs, remarkably similar to those found on a crocodile, likely helped the animal suss out its environment as it waded across the shallow lagoons of a prehistoric archipelago that once covered Europe.

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“Skin only rarely preserves in the fossil record, so when we try to imagine living dinosaurs from just bones, details about their external body coverings are often speculative,” says Stephanie Drumheller-Horton of the University of Tennessee, Knoxville, who was not involved with the new research. “Soft tissues can really flesh out our interpretations of these groups.”

 

Trilobite Tuesday #26: Trilobite Enrollment #trilobite #fossils #TrilobiteTuesday #AMNH

As we've said previously, the AMNH has an awesome Trilobite website.  Today, we want to highlight the one about Trilobite Enrollment.  It is generally accepted that trilobites enrolled to protect themselves from predators and other potentially other events in the surrounding environment.  This page has a good discussion about the history and the usefulness of enrollment.

There is a story that has become part of trilobite folklore. It tells of how back in the early 1970s, a Berber tribesman living on the edge of Morocco's Sahara Desert was walking near the mountains that encircled his home. As he was strolling past one, he heard the distressing sound of falling rocks and noticed a particular fist-sized piece that was cascading in his direction down the mountainous slope. 

Out of curiosity, he bent to investigate what the mountain had yielded, and much to his surprise, he found a perfectly enrolled Drotops trilobite lying at his feet. The unexpected discovery intrigued the Berber and empowered him to seek the spot from which this “strange rock” had originated. For weeks he searched, climbing and exploring, until finally he found the fossil-bearing layer upon the Magic Mountain that would soon ignite the entire Moroccan trilobite explosion.

This tale serves as a somewhat roundabout means for us to broach the subject of trilobite enrollment and ask some very basic questions… why did these primitive arthropods enroll… and when did they begin to do so? Of course, many modern creatures from isopods to armadillos enroll for safety, and it can be logically surmised that trilobites assumed such a defensive position for much the same reason. With their thick calcite shells, an enrolled trilobite could present quite the daunting challenge for any predator seeking an easy meal. In addition, the compact shape provided by enrolling may have also aided them in battling unfavorable conditions during the heights of oceanic storms.

The discovery of an enrolled Drotops megalomanicus similar to this sparked the Moroccan trilobite explosion of the 1970s

Hundreds of enrolled Eldredgeops crassituburculata specimens have been found in the 400 million year old rocks of Ohio.

As proven by this large Paraomalonotus calvus, not only small trilobites enrolled.

Mazon Monday #28: Species Spotlight - Cyclus americanus #fossils #MazonCreek #MazonMonday #Arthropods

This is Mazon Monday post #28.  What's your favorite Mazon Creek fossil?  Tell us at email:[email protected].

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Today, we have a species spotlight on Cyclus americanus.  It's one of my favorite Mazon Creek animals.  Cycloids form an order of fossil arthropods that lived from the Carboniferous to the Cretaceous periods.  

Here is the text from the Creature Corner column, which was published in March 1987.

Cyclus americanus (crustacean)

Cyclus is indeed a most "vexing animal". Discovered as a fossil in Europe in 1836, it was classified among the trilobites. In ensuing years, the Carboniferous limestones and ironstones of Europe yielded several more specimens. Cyclus was discovered in an ironstone nodule at Morris, llinois 45 years later, named species -americanus.

A short chronology will explain the opening sentence.

• 1836 Cyclus discovered labeled a Trilobite
• 1884/5 Cyclus discovered at Morris, described and labeled limulid/Xiphosuran ("horseshoe crab")
• 1894 Numerous species studied; "suckers" described on Cyclus.
• 1902 Cyclids discovered in Pn. Limestone at Kansas City, Missouri
• 1925 Cyclidae described. Cyclus classified with the Branchiura - "fish lice".

Most recently Cyclus is classified thus - Subphylum: Crustacea; Class: Maxillopoda; Subclass: Branchiura; Order: ? (F. Schram personal communication).

A quick field identification of Cyclus - if it looks like an apple hanging from a twig, it's Cyclus. Straight, bar-like antennae at 90 degrees to the center line of the circular body, give it the appearance of a hanging object. The six pairs of "legs" and the telson (tail) are not always visible on the fossil specimens. Location of the eyes is a matter for conjecture. A circular, low profile carapace is the shape of an animal living in a swift water environment. As noted by early workers,Carboniferous swamps are not envisioned as swift water environments. Discovery of "suckers" on the animal, coupled with body shape, led to the conclusion it may have been a parasite. Hence the "fish lice designation. Despite the fine preservation of certain Mazon Creek/Pit 11 Cyclus americanus, details of body parts are difficult to discern.

Mazon Creek/Pit 11 is the location for Cyclus americanus. The Cyclids found at Kansas City are of a different species.

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

Cycloids are an extinct group which wan first discovered in Europe in 1835 and assigned to the trilobites. Originally described from European specimens as a horseshoe crab by Packard (1883), Cyclus americanus was first found in the Mazon Creek area in 1884 in a single concretion from Morris, Illinois. Later in 1925, this group was assigned by A. T. Hopwood to the group known commonly as Fish Lice. These efforts were just some in a long history of confusion over the affinities of these enigmatic arthropods. Due to the fact that several features are not yet fully understood, its closest. taxonomic relation still remains a mystery. At present, the evidence points to Cycloids most likely being a sister group to Copopods.

C. americanus is common in Essex animal concretions.A round body (about 15 mm in diameter) and long, straight antennae located on the anterior of the body give the fossil the appearance of an apple hanging from a twig. At the posterior, there is a distinct notch where a pair of short, stout, flipper-like processes are seen. Leg appendages are seldom visible, and no internal details are known. Schram believes they filled a crab-like niche in Paleozoic shallow seas. Other members of the Cycloids have since been discovered at other locations in North America and Europe.

National Geographic goes big on dinosaurs — and big on Yale paleontology #dinosaurs #paleotology

YaleNews has a story about the latest issue of National Geographic.  The cover has a Deinonychus, discovered in the 1960 by Yale paleotologist John Ostrom.  This web page on the National Geographic site has links to numerous stories about recent dinosaur discoveries.  It includes the lead story in this issue of the magazine... "Reimagining Dinosaurs".

The latest cover of National Geographic magazine features a Yale discovery that stretches back … oh, about 115 million years. 

Deinonychus, a Cretaceous Period raptor that Yale paleontologist John Ostrom identified in the 1960s, peers at readers with a menacing eye while guarding a nest of blue-green eggs. A hatchling covered in feathery fuzz gazes up from below its father, who wields distinctive sickle-shaped claws. 

Crowned with feathers, the prehistoric beast makes a fitting — if frightening — cover model for the issue’s lead story, which highlights a few of the latest discoveries by scientists at Yale’s Peabody Museum of Natural History that, like Deinonychus, help us reimagine how dinosaurs looked and lived. 

PBS Eons: The First and Last North American Primates #paleontology #mammals #primates #NorthAmerica #evolution

There's a new episode of PBS Eons.  Did you know that primates actually evolved in North America?  All the details here!

Early primates not only lived in North America -- our primate family tree actually originated here! So what happened to those early relatives of ours?

 

ESCONI Events October 2020

Field trips require membership, but visitors are welcome at all meetings!

Fri, Oct 9th	ESCONI General Meeting 8:00 PM Zoom - Topic: "The Blue Forest of Ancient Lake Gosiute: Sweetwater County, Wyoming” by Mike Viney from Colorado State University.  Zoom link
Sat, Oct 10th	ESCONI Junior Meeting 7:00 PM Zoom - Topic: "Does your child like space and fossils?" Zoom link Your child only needs to have a butter knife and some play doh or clay for the hands on portion.  There will be something for kids ages 6 to 17 years old to enjoy at this junior meeting.
Sat, Oct 17th	ESCONI Paleontology Meeting 7:30 PM Zoom - Topic: "Fishing the Green River Formation: From Sites, To Tackle, To Fish, To Preparation", by ESCONI member Keith Robitschek. Zoom link.

 

 

Fossil Friday #25: Asaphicus wheeleri from the Cambrian of Utah #fossils #fossil #FossilFriday #trilobite #Utah #Cambrian

This is the "Fossil Friday" post #25.  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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Here is an Asaphiscus wheeleri trilobite from the Wheeler Shale in Utah.  The Wheeler Shale is a very fossiliferous shale in the Great Basin in Utah.  It's about 507 million years old, which is very close to the age (508 million years) of the Burgess Shale in British Columbia, Canada. Both strata were named and discovered by Charles Walcott.  Some of the same animals are found in both localities.

This specimen was collected from an exposure in the Drum Mountains this summer.

Positive

Negative

Here are photos from the quarry

Here is a photo from Wikipedia for reference.

Throwback Thursday #27: Field Trip to Morris for Mazon Creek Fossils September 1976 #TBT #history #MazonCreek #fossils

This is Throwback Thursday #27.  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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Here is a selection of photos from a field trip to Morris, IL to collect Mazon Creek fossils.  There were numerous localities around Morris for collecting fossils.  Unfortunately, there aren't any details as to where these photos were taken.  We can only dream of the treasures that were found that day!