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Credit...Chip Clark/Smithsonian
It's a few years old... March 3rd, 2014, but trilobites are even older! The New York Times has an great article called "When Trilobites Ruled the World" by Natalie Angier, who does excellent science writing on many, many subjects from geology to paleontology to genetics to neuroscience. You name it and she's written about it.
This article is all about Trilobites. What they are, when they lived, who studies them... there's even a trilobite song! Check out the article, it's a great diversion from the current shelter in place!
"The Lament for the Passing of the Trilobites" by Nigel Hughes. a professor at the University of California.
She even speaks with Carlton Brett of the University of Cincinnati, who was the keynote speaker at MAPS for the 2017 program "The Silurian Period".
Other researchers have found evidence that some trilobites were highly social, migrating long distances in a head-to-tail procession as they searched for food, or gathering together during molting season at a kind of Trilo’s Retreat, where the trilobites could simultaneously shuck off their carapaces and seek out mates.
“It looks like a lot of trilobite mating behavior happened when they were in a soft-shelled form,” said Carlton E. Brett, a professor of geology at the University of Cincinnati, who has presented research on trilobite assemblages to the Geological Society of America and elsewhere. “They did it in the nude.”
To investigate trilobite social life, Dr. Brett and his colleagues analyzed numerous examples of mass burial sites, where congregations of trilobites had been trapped in place by the sedimentary upheavals from violent sea storms, just as the residents of Pompeii were smothered in midscream by Vesuvian ash.
“You feel a little bad for the trilobites, but it’s incredible seeing these things preserved in the act of life processes,” Dr. Brett said. “It’s frozen behavior.”
This is Mazon Monday post #7. This is about one of the favorite Mazon animals, the Tully monster.
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A reconstruction of the Tully Monster as it would have looked 300 million years ago, swimming in the Carboniferous seas. Notice the jointed proboscis, the multiple rows of teeth, and the dorsal eye bar. Credit: Sean McMahon / Yale University
Phys.org has an article about some new research about the Tully Monster. The Tully Monster was first discovered by Francis Tully in 1955. He was fossil hunting in Pit 11 of the old Peabody Coal Company's strip mines near Braidwood, IL., when he came across a strange looking fossil. He brought the fossils to Eugene Richardson at the Field Museum, who had never seen anything like it. The animal was quickly dubbed "My Tully's Monster". In 1966, Richardson formally described it and gave it its proper scientific name... Tullymonstrum gregarium. Even though it was originally designated an invertebrate, No one knew exactly where it belonged on the tree of life.
In 2016, Victoria McCoy, along with a bunch of other researchers including Scott Lidgard and Paul Mayer of the Field Museum, coauthored a paper called simply "The 'Tully Monster' is a vertebrate". The study detailed in that paper analyzed 1200 specimens. Looking at eyes, teeth, gills, ... literally the whole body and found enough evidence to place it with lampreys.
Abstract
Problematic fossils, extinct taxa of enigmatic morphology that cannot be assigned to a known major group, were once a major issue in palaeontology. A long-favoured solution to the ‘problem of the problematica’1, particularly the ‘weird wonders’2 of the Cambrian Burgess Shale, was to consider them representatives of extinct phyla. A combination of new evidence and modern approaches to phylogenetic analysis has now resolved the affinities of most of these forms. Perhaps the most notable exception is Tullimonstrum gregarium3, popularly known as the Tully monster, a large soft-bodied organism from the late Carboniferous Mazon Creek biota (approximately 309–307 million years ago) of Illinois, USA, which was designated the official state fossil of Illinois in 1989. Its phylogenetic position has remained uncertain and it has been compared with nemerteans4,5, polychaetes4, gastropods4, conodonts6, and the stem arthropod Opabinia4. Here we review the morphology of Tullimonstrum based on an analysis of more than 1,200 specimens. We find that the anterior proboscis ends in a buccal apparatus containing teeth, the eyes project laterally on a long rigid bar, and the elongate segmented body bears a caudal fin with dorsal and ventral lobes3,4,5,6. We describe new evidence for a notochord, cartilaginous arcualia, gill pouches, articulations within the proboscis, and multiple tooth rows adjacent to the mouth. This combination of characters, supported by phylogenetic analysis, identifies Tullimonstrum as a vertebrate, and places it on the stem lineage to lampreys (Petromyzontida). In addition to increasing the known morphological disparity of extinct lampreys7,8,9, a chordate affinity for T. gregarium resolves the nature of a soft-bodied fossil which has been debated for more than 50 years.
Now in 2020, the new paper looks at chemical signatures of soft tissues in the fossils to provide further evidence that the 'Tully Monster' is indeed a vertebrate.
Abstract
The chemical composition of fossil soft tissues is a potentially powerful and yet underutilized tool for elucidating the affinity of problematic fossil organisms. In some cases, it has proven difficult to assign a problematic fossil even to the invertebrates or vertebrates (more generally chordates) based on often incompletely preserved morphology alone, and chemical composition may help to resolve such questions. Here, we use in situ Raman microspectroscopy to investigate the chemistry of a diverse array of invertebrate and vertebrate fossils from the Pennsylvanian Mazon Creek Lagerstätte of Illinois, and we generate a ChemoSpace through principal component analysis (PCA) of the in situ Raman spectra. Invertebrate soft tissues characterized by chitin (polysaccharide) fossilization products and vertebrate soft tissues characterized by protein fossilization products plot in completely separate, non‐overlapping regions of the ChemoSpace, demonstrating the utility of certain soft tissue molecular signatures as biomarkers for the original soft tissue composition of fossil organisms. The controversial problematicum Tullimonstrum, known as the Tully Monster, groups with the vertebrates, providing strong evidence of a vertebrate rather than invertebrate affinity.
Credit: University of Wisconsin Oshkosh
Phys.org has a story about one the most favorite raptor dinosaurs. Raptors became popular after appearing in the 1993 blockbuster movie Jurassic Park. In that movie, where they were incorrectly called Velociraptors instead of Deinonychus antirrhopos, they are portrayed as hunting in packs similar to wolves. Because behavior doesn't fossilize, there has been little evidence for this hunting style. This study, published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology, compared the composition of teeth from young and adult specimens. Teeth are a good predictor of both what and where an animal eats.
"The problem with this idea is that living dinosaurs (birds) and their relatives (crocodilians) do not usually hunt in groups and rarely ever hunt prey larger than themselves," he explained.
"Further, behavior like pack hunting does not fossilize so we can't directly test whether the animals actually worked together to hunt prey."
Recently, scientists have proposed a different model for behavior in raptors that is thought to be more like Komodo dragons or crocodiles, in which individuals may attack the same animal but cooperation is limited.
"We proposed in this study that there is a correlation between pack hunting and the diet of animals as they grow," Frederickson said.
In Komodo dragons, babies are at risk of being eaten by adults, so they take refuge in trees, where they find a wealth of food unavailable to their larger ground-dwelling parents. Animals that hunt in packs do not generally show this dietary diversity.
"If we can look at the diet of young raptors versus old raptors, we can come up with a hypothesis for whether they hunted in groups," Frederickson said.
This is the "Fossil Friday" post #5. 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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For this week's Fossil Friday, we have some pictures of a great example of Esconites zelus from ESCONI member Chris Berg. There are some interesting close ups of the body and jaws, which are very well defined! This specimen was found in Pit 11 and opened fairly recently. Chris is a firm believer in the Freeze/Thaw method of opening Mazon concretions.
Chris usually joins us on Braceville trips in the Spring and Fall. Additionally, he's one of the people wading through the Mazon River during the August Canal Corridor trip, And, as if he needed more to prove he's a diehard Mazon Creek collector, I can verify that he spends a good amount of time collecting concretions in the wilds of Pit 11. Check out other outstanding specimens in his collection on TheFossilForum!
Thanks for your contribution, Chris!
There was a Species Spotlight on Esconites zelus for Mazon Monday this week... if no one minds, let's refer to this week as Esconites Week!
Full Body
Body close ups
Close up of the jaws!
More jaws
This is Throwback Thursday #6. 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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At one time, ESCONI had a yearly field trip to the old Lone Star Quarry near Oglesby, IL. And, in some years, we had both a spring and fall field trip there. The quarry provided a very rich fossil deposit, which included brachiopods, crinoids, sponges, trilobites, cephalopods, and even shark teeth. The exposed rock layers date to the Pennsylvanian Period. The State of Illinois purchased the quarry in October 2018, and there is now a proposal to turn it into a Fossil Park.
Here are some pictures from years past, many are from one of our last field trips in 2008.
With very little effort, brachiopods could be collected in the hundreds!
And, in June 2000, an amphibian fossil was found, by junior member Matthew Galloway!
Don Auler, Jim Fairchild, and David Bergman in a photo that is likely from the 1990s.
ESCONI members gather on a chilly morning before descending into the quarry.
Dramatic late-summer skies over the parking area.ESCONI members gather on a chilly morning before descending into the quarry.
LaSalle limestone provides abundant marine fossils.
Sharing a find. (Marie Angkuw and Deborah Lovely)
Some fossils are just millimeters in width. (Andrew Young)
Taking a careful look.
Collecting can be a solitary, meditative act.
A lucky collector with a nautiloid and a shark's tooth.
Everyone finds fossils in this rich site.
Three treasures: a crinoid calyx, a large Juresania brachiopod, and a rare nautiloid.
Sorting the treasure from collecting bags.
A good haul: Spirifer and Juresania brachiopods, gastropods, crinoid stems and calyx, and several nautiloids.
For over 100 years scientists thought that Brontosaurus and Apatosaurus were the same dinosaur as their bones look very similar © Daniel Eskridge/Shutterstock
The NHM in London has an article about the reinstatement of Brontosaurus as a valid species name. Both animals we discovered in the American west in the 1970, during a period of time referred to as the "Bone Wars" or the "Great Dinosaur Rush". Apatosaurus ajax was named by Othniel Charles Marsh in 1877 from bones found in Colorado. He named Brontosaurus excelsus a few years later from bones discovered in Wyoming. Both we found in rocks dated to the Jurassic Period, about 156 to 145 million years ago.
Brontosaurus is one of the world's most beloved dinosaurs, unusual, perhaps, for a reptile whose validity was doubted for more than 100 years.
Brontosaurus was a large sauropod, a group of typically large dinosaurs with long necks and long tails. It lived during the Late Jurassic Period, from about 156 to 145 million years ago.
The first recorded evidence of Brontosaurus was discovered in the 1870s in the USA. But by the early 1900s, scientists had started to question whether the fossils used to name Brontosaurus actually came from another dinosaur, the remarkably similar Apatosaurus.
Due to the rules of scientific naming - the first name published gets priority - Brontosaurus was relegated to scientific history and the fossils reassigned to Apatosaurus. That was until a study in 2015 unexpectedly found evidence that Brontosaurus was distinct from Apatosaurus all along, signalling the reinstated status of this iconic dinosaur.
If you're interested in the largest trilobites, have a look over at this page on "A Guide to the Orders of Trilobites" or this page at the American Museum of Natural History. The following quote is from the AMNH page.
The size variance shown among trilobite species is nothing less than astonishing. Generally when one considers these long-extinct arthropods, images of small, hard-shelled creatures scurrying across ancient sea floors spring readily to mind. And for the most part, such a perception is accurate. The vast majority of the more than 25,000 scientifically recognized species that existed during the trilobites' 270 million year reign from the Lower Cambrian to the end of the Permian were diminutive -- an inch, or smaller in length. By no means, however, should such information be interpreted as indicating that trilobites didn't grow bigger than that… much bigger!
Perhaps the most notable of these large trilobite species are the Ordovician-age Isotelus maximus from the mid-western United States, a type that grew up to 16 inches in length and became recognized as the State Fossil of Ohio back in 1985. In addition, impressively sized Silurian-age trilobites have been found in western New York State, with species such as Trimerus delphinocephalus attaining lengths up to eight inches. And a variety of species, including Hungoides bohemicus, that on rare occasion exceed 12 inches from head to tail, have been found in the prolific Ordovician quarries near Volongo, Portugal, marking the entire formation as one filled with mega-fauna.
The list of largest trilobites includes:
The largest complete trilobite ever found resides at the Manitoba Museum in Manitoba, Canada. It is a specimen of Isotelus rex and is almost twice as big as then next largest specimen. It is over 27 inches long and lived during the Ordovician Period 455 million years old . If we were living in the Ordovician period, we would find these creatures while scuba diving. This individual specimen was found in Churchill, Manitoba, which is a city in northern Manitoba. In it's display, you see it's fossilized track, called Cruziana.
This is Mazon Monday post #6. A fellow member sent me some pictures of some recently opened Esconites zelus. Got interested in where and when it was first described, here are some highlights.
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| Esconites Temporal range: Carboniferous
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| Scientific classification | |
| Kingdom: | Animalia |
| Phylum: | Annelida |
| Class: | Polychaeta |
| Order: | Eunicida |
| Family: | Eunicidae |
| Genus: | †Esconites |
| Species: |
†E. zelus
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| Binomial name | |
| †Esconites zelus Thompson & Johnson 1977
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Esconites zelus is a species of polychaete worm. It is part of the Mazon Creek biota, Essex fauna. It was described in 1977 in a paper by Ida Thompson and Ralph Johnson, which appeared in Volume 33 No. 25 of Fieldiana a journal of the Field Museum of Natural History in Chicago, IL. It was dedicated to the Earth Science Club of Northern Illinois (ESCONI). Here is the acknowledgments section of the paper.
The resurrection of the species described above has been greatly aided by two groups: collectors in the northern Illinois area and colleagues at Field Museum. We dedicate this new species, Esconites zelus, to the members of the Earth Sciences Club of Northern Illinois (ESCONI) in gratitude for their valuable co-operation in making their collections available for study, in lending specimens to Field Museum, and in donating particularly valuable specimens. Special thanks go to Mr. and Mrs. Ted Piecko, Mr. and Mrs. Francis Wolff, and Mr. and Mrs. Calvin George for generous donations of specimens. At Field Museum, Dr. Rainer Zangerl provided the genial matrix within which this study was made and Dr. Eugene S. Richardson, Jr., established valuable liaisons with collectors and gave advice and help generously.
The following is from Creature Corner, by Andrew A. Hay and Don Auler. This column first appeared in the November 1987 issue of the ESCONI Bulletin "The Earth Science News".
Discoveries at Pit 11 of hitherto rare and/or unknown marine, near-shore invertebrates alerted investigators to the probability of finding annelid type worms among the Essex Fauna. They were not disappointed. Over 20 worm-like species have been described, 2/3 of which have been classified as polychaetes.
The polychaete structures preserved with the best detail are the jaws (mandibles), setae, and cirri (bristles and hairs/tentacles). One of the most common Essex polychaetes, Esconites zelus, also possessed the most visible and largest mandibles.
E. zelus has a long (5 and ½ inches in some specimens) narrow body outline. The number of body segments, 20 to 80, increase with length. Commonly the body outline is seen as a difference in color on the concretion surface. In other specimens, the fine detail visible is remarkable. Jaw apparatus is the most obvious feature. These large, prominent, wing-like mandibles are dark brown to black carbon films.
Body segments bear parapodia (fleshy protrusions/stump feet) on each side. Parapodia are equipped with bristles and hairs, used to propel these predaceous, free-swimming annelids. Occasionally, the branchia (gills) can be seen among the setae and cirri that adorn the parapodia. The "head" is equipped with long tentacles and a "tail" with several long hairs. Well preserved jaws and long body configuration are the best field marks.
LiveScience has a post about a strange mammal from Madagascar. This mammal, called Adalatherium hui, lived about 66 million years ago in what is now northwestern Madagascar. This was the very last of the Cretaceous Period and just before the K-Pg mass extinction. The new fossil is the oldest and only nearly complete specimen of an extinct group known as Gondwanatherians. Its has been described in a paper in the journal Nature.
The fossil is from northwestern Madagascar and dates back 66 million years, to the end of the Cretaceous period. Madagascar was already an island at the time, having drifted away from Africa by 88 million years ago, and the animals that lived there were completely bizarre, said David Krause, the senior curator of vertebrate paleontology at the Denver Museum of Nature & Science, who led the new research.
Among the animals found on Madagascar at this time were: the predatory, buck-toothed dinosaur Masiakasaurus knopfleri; a frog wider than a No. 2 pencil is long that may have eaten baby dinosaurs and was named Beelzebufo ampinga, or "devil frog"; and a crocodile with a short snout and bumpy teeth that probably ate plants.
"We actually think we had an herbivorous crocodile, and it doesn't get much weirder than that," Krause said during a press briefing.
This is the "Fossil Friday" post #4. 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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This week we visit the Green River Formation and its enormously diverse faunal and floral fossil. The Green River Formation dates to the Eocene, about 53.5 to 48.5 million years ago. The formation is composed of very fine layers, a dark layer during the growing season and a light-hue inorganic layer in the dry season. Each pair of layers is called a varve and represents one year.
The sedimentary layers were formed in a large area named for the Green River, a tributary of the Colorado River. The three separate basins lie around the Uinta Mountains (north, east, and south) of northeastern Utah:
Fossil Butte National Monument in Lincoln County, Wyoming is in a part of the formation known as Fossil Lake because of its abundance of exceptionally well preserved fish fossils.
The following fossils were contributed by ESCONI member Keith Robitschek. All of these specimens were self collected and prepared. They all have remarkable preservation and detail. Thank you, Keith!
Green River Fossil Lake Aquarium
The fish aquarium below contains mostly Knightia, both Knightia eocaena and Knightia alta. Hidden within this school is a lone Amphiplaga brachyptera.
Knightia alta
Knightia is a representative of the herring family of fishes. They are the most common of the Green River fish forming immense schools. They can be as large as 10 inches but in most cases are found to range from 2 ½ inches to 4 inches.
Amphiplaga brachyptera
Amphiplaga is in the trout-perch family. They only have a superficial resemblance to trout and perch but are not related to either group. They have never been found in mass mortally, indicating that they were solitary fish and didn’t gather in schools. They are a small fish with a maximum length of about 5 ½ inches. Most common size is around three inches but are relatively rare to find.
The fish aquarium below contains mostly Diplomystus dentus but also contains Mioplosus labracoides, Priscacara liops and Phareodus encaustus.
Diplomystus dentus
Diplomystus (Diplo) belonged to a primitive form of herring-like fish and is one of the most common fish. It is also one of the most common of the large fish. They can be as large as 24 inches. A schooling fish that commonly range from three to seven inches in length.
Mioplosus labracoides
Mioplosus (Mio) belong with the perches and basses. Classifying this species is difficult since there are over 10,000 living species of Perciformes, the largest order of vertebrate animals. They can be as large are 20 inches long. Well known for being preserved with another fish in its mouth. This example contains the remains of a fish in its stomach.
Priscacara liops
Priscacara liops (Priscy) belong with the perches and basses. It contains tooth pads within its throat indicating that they ate arthropods and small mollusks. They are a schooling fish much like today’s Bluegill. They are frequently found to be a little less than 6 inches long.
