Earth Science Club of Northern Illinois - ESCONI

480-million-year-old fossils reveal sea lilies' ancient roots #fossils #crinoids

The newly-discovered Athenacrinus broweri, a sea lily that lived 480 million years ago. The arrows drawn on the fossil point out some of its long, skinny arms. Credit: (c) Field Museum, Kate Golembiewski

Phys.org has a story about the origin of crinoids.  Tom Guensburg, research associate at the Field Museum in Chicago, is the lead author of a paper in the Journal of Paleontology, that describes Athenacrinus browneri.  This new fossil shows evidence that is key to how sea lilies evolved from the earliest known echinoderms, which lived up to 515 million years ago.

You might remember Tom spoke to ESCONI about crinoid origins back in September 2018.

Sea lilies, despite their name, aren't plants. They're animals related to starfish and sea urchins, with long feathery arms resting atop a stalk that keeps them anchored to the ocean floor. Sea lilies have been around for at least 480 million years—they first evolved hundreds of millions of years before the dinosaurs. For nearly two centuries, scientists have thought about how modern sea lilies evolved from their ancient ancestors. In a new study in the Journal of Paleontology, researchers are rewriting the sea lily family tree, aided by newly-discovered fossils that help show how these animals' arms evolved.

"These early fossils provide new key evidence showing that what we had thought about the origin of sea lilies since 1846 is wrong," says Tom Guensburg, the paper's lead author and a research associate at the Field Museum in Chicago. "It's not very often that we're challenging ideas that are almost two hundred years old."

Sea lilies are more formally known as crinoids, but they've earned their nickname—they really do look like flowers growing at the bottom of the ocean. They spend their adult lives stuck in one place, with stem-like stalks that attach them to the sea floor. At the top of these stalks are a cluster of arms, maybe the size of the palm of your hand. These arms trap tiny plankton floating through the water, which the sea lily then eats.

"Some people actually consider sea lilies and their relatives, the feather stars, the most beautiful animals. They come in any color—purple, bright red, green," says Guensburg. "They look plant-like, but when you actually look at their bodies, you find all the usual anatomy of complex animals like a digestive tract and nervous system—they're closer to vertebrates, and us, than almost any other invertebrate animals."

 

 

Alfred Wegener, Beyond the Drift Dispute #geology #platetectonics

Alfred Wegener (left) and Rasmus Villumsen at station Eismitte in the last photo taken of them before their deaths. ARCHIVE OF ALFRED WEGENER INSTITUTE/PUBLIC DOMAIN

The podcast "The Stuff You Missed In History Class" has a great episode about Alfred Wegener.  Wegener, who came up with a theory similar to plate tectonics back in the years before World War I, had a very interesting career.  Here are just a few highlights.  Check it out!

Alfred Wegener had a HUGE career outside of his ideas around what we now understand as plate tectonics, which had both detractors and supporters. He did important and respected work that touched on multiple disciplines.

Tracy's Research:

• "Alfred Wegener Introduces the Concept of Continental Drift." Science and Its Times, edited by Neil Schlager and Josh Lauer, vol. 6, Gale, 2001. Gale In Context: Science, https://link.gale.com/apps/doc/CV2643450602/GPS?u=mlin_n_melpub&sid=GPS&xid=0ab41523. Accessed 11 Nov. 2019.
• "Alfred Wegener." Scientists: Their Lives and Works, UXL, 2006. Gale In Context: Science, https://link.gale.com/apps/doc/K2641500212/GPS?u=mlin_n_melpub&sid=GPS&xid=c55b650e. Accessed 11 Nov. 2019.
• "Wegener, Alfred Lothar (1880-1930)." Encyclopedia of World Biography, Gale, 1998. Gale General OneFile, https://link.gale.com/apps/doc/A148417477/GPS?u=mlin_n_melpub&sid=GPS&xid=3dcfbe55. Accessed 11 Nov. 2019.
• Antonescu, Bogdan, et al. "100 YEARS LATER: Reflecting on Alfred Wegener's Contributions to Tornado Research in Europe: Alfred Wegener not only proposed the theory of continental drift but was also a pioneer of modern tornado research in Europe." Bulletin of the American Meteorological Society, Apr. 2019, p. 567+. Gale In Context: Science, https://link.gale.com/apps/doc/A588990531/GPS?u=mlin_n_melpub&sid=GPS&xid=c0122c74. Accessed 11 Nov. 2019.
• Aronsohn, Marie DeNoia. “Walter Pitman and the Smoking Gun of Plate Tectonics.” Lamont Geological Observatory. 4/19/2016. https://www.ldeo.columbia.edu/news-events/walter-pitman-smoking-gun-plate-tectonics
• Earle, Steven. “Physical Geology – 2nd Edition.” https://opentextbc.ca/physicalgeology2ed/
• Feffer, Loren Butler, et al. "Historic Dispute : Are Earth's continents stationary throughout geologic time." Science in Dispute, vol. 1, Gale, 2002, pp. 57-65. Gale In Context: Global Issues, https://link.gale.com/apps/doc/CX3411400016/GPS?u=mlin_n_melpub&sid=GPS&xid=8a3d947b. Accessed 11 Nov. 2019.
• Greene, Mott T. "Wegener, Alfred Lothar." Complete Dictionary of Scientific Biography, vol. 25, Charles Scribner's Sons, 2008, pp. 245-248. Gale In Context: U.S. History, https://link.gale.com/apps/doc/CX2830906196/GPS?u=mlin_n_melpub&sid=GPS&xid=1279735e. Accessed 11 Nov. 2019.
• Greene, Mott T. “Alfred Wegener and the Origin of Lunar Craters.” Earth Sciences History, Vol. 17, No. 2. 1998. Via JSTOR. https://www.jstor.org/stable/24138636
• Greene, Mott T. “Alfred Wegener.” Social Research, Vol. 51, No. 3, Modern Masters of Science. Autumn 1984. https://www.jstor.org/stable/40970960
• Hoffman, Paul. “The Tooth of Time: Alfred Wegener.” Geoscience Canada. Vol. 39. 2012.
• Hughes, Patrick. “Alfred Wegener, The meteorologist who started a revolution.” Weatherwise, 00431672, Apr/May94 . Via NASA Earth Observatory. 2/8/2001. https://earthobservatory.nasa.gov/features/Wegener/wegener.php
• Isacks, Bryan et al. “Seismology and the New Global Tectonics.” Journal of Geophysical Research. Vol. 73, No. 18. 1968. http://www.mantleplumes.org/WebDocuments/Isacks1968.pdf
• Kehrt, Christian. “The Wegener Diaries: Scientific Expeditions into the Eternal Ice.” Environment & Society Portal. Virtual Exhibitions 2013, no. 2. http://www.environmentandsociety.org/exhibitions/wegener-diaries/overview
• Lamplugh, G. W., et al. “Wegener's Hypothesis of Continental Drift: Discussion.” The Geographical Journal, vol. 61, no. 3, 1923, pp. 188–194. JSTOR, www.jstor.org/stable/1781671.
• Stäblein, G. “Alfred Wegener, from Research in Greenland to Plate Tectonics.” GeoJournal, Vol. 7, No. 4, Polar Research (1983). Via JSTOR. https://www.jstor.org/stable/41143144
• The Geological Society. “Plate Tectonics.” https://www.geolsoc.org.uk/Plate-Tectonics/Chap1-Pioneers-of-Plate-Tectonics/Alfred-Wegener
• USGS. “Historical Perspective.” https://pubs.usgs.gov/gip/dynamic/historical.html

Early meat-eating dinosaur revealed via spectacular fossil #dinosaurs

Gnathovorax cabreirai, seen here in an illustration, was the oldest meat-eating dinosaur of its kind in Brazil and one of the oldest in the world.

National Geographic has a story about a new dinosaur discovery.  This new dinosaur, named Gnathovorax cabreirai, dates to about 230 million years ago during the Triassic Period.  It represents one of the earliest dinosaurs ever found.   This discovery was made near the town of Sao Joao do Polesine in southern Brazil.  Details can be found in a new paper in the journal PeerJ.

SÃO PAULO, BRAZILPaleontologist Rodrigo Muller was working in a nearby town in 2014 when his team members started sending him photos of the remarkable fossils.

...

The animal died in a flood plain, allowing sediment from a nearby river to cover its skeleton and create a stunningly intact fossil, which Muller and colleagues from the Federal University of Santa Maria and the University of São Paulo have now described in the journal Peer J.

The nearly perfect preservation of the dinosaur’s bones includes an undamaged brain case, an extremely rare find that allowed the team to reconstruct the dinosaur’s brain with CT scans. The structure reveals that this species was an active predator with good vision, focus, and balance, traits that helped it use its sharp, serrated teeth and long claws to capture its prey. (Also see a piece of fossilized brain tissue from a Cretaceous dinosaur.)

The fossil also bears visible scars at muscle insertion points, which will allow the team to eventually reconstruct its musculature to understand how it moved and got around.

 

 

New Cretaceous-Period Mammal Unveiled

Life reconstruction of Origolestes lii. Image credit: Chuang Zhao.

Sci-News has a story about a new mammal that lived along side the dinosaurs during the Mesozoic Era.  The animal, named Origolestes lii, is part of the famous Jehol Biota, which dates to the Cretaceous Period 133 to 120 million years ago.  This biota was a terrestrial and freshwater ecosystem found across the Chinese provinces of Liaoning, Hebei, and Inner Mongolia. Origolestes is important as it shed lights on the final step in the evolution of the mammalian middle ear.  Detail can be found in a paper published in the journal Science.

“While modern mammals owe their keen sense of hearing to the three tiny bones that form the complex architecture of the middle ear, these tiny ossicles were once instead part of the jaw, which served a dual function for both chewing and hearing in our earliest ancestors,” said Dr. Fangyuan Mao, a researcher in the Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, the CAS Center for Excellence in Life and Paleoenvironment, and the American Museum of Natural History, and her colleagues.

“The evolutionary event in which jaw bones were co-opted to form the tri-ossicular hearing apparatus of mammals is widely recognized. However, fossilized examples demonstrating the intermittent steps are elusive.”

“The detached auditory bones of the newly-discovered Cretaceous mammal represent an important final step in the evolution of the definitive mammalian middle ear.”

The ancient mammal belongs to Symmetrodonta, a group of Mesozoic mammals and mammal-like synapsids.

Did a million years of rain jump-start dinosaur evolution? #dinosaurs

Triassic rocks in the Italian Dolomites bear evidence of a surprisingly wet episode in Earth’s history.Credit: Arterra/Universal Images Group via Getty

Nature has an interesting post about a spell of wet weather in the middle Triassic that may have spurred the evolution of the dinosaurs.  This wet spell occurred for about a million years about 232 million years ago.  The evidence for the very wet period (pluvial episode) is contained in Triassic rocks from the Carnian age.  These rocks have been found in Germany, the United States, the Himalayas, and other places.  The origins of the dinosaurs coincided with this wet period and may have helped them to rise to the dominance they enjoyed in the Jurassic and Cretaceous periods.

Alastair Ruffell could see there was something odd about the rocks near his childhood home in Somerset, UK. The deposits hail from the Triassic period, more than 200 million years ago, and most are a dull orange-red, signifying that they formed when the region was a parched landscape, baked by the sun. Nothing strange there. But outcrops on Somerset’s Lipe Hill have a thin stripe of grey running through the heart of the red stone. That band signals a time when arid desert disappeared and the region transformed into a swampy wetland. For some reason, an incredibly dry climate had turned wet, and stayed that way for more than a million years.

The change intrigued Ruffell when he first found the outcrops in the mid-1980s, but the young geologist had a PhD project to finish. So he put the Triassic puzzle to one side, until a chance encounter in 1987 with another young scientist, palaeontologist Michael Simms. During his postdoctoral studies, Simms had discovered evidence of extinctions in the Late Triassic, during Ruffell’s mysterious wet period. In the late 1980s, the pair pushed the idea that the two findings were connected, but for years, their results were dismissed.

Three decades later, there is a growing consensus that they were right, after all. Something strange happened in the Late Triassic — and not just in Somerset. About 232 million years ago, during a span known as the Carnian age, it rained almost everywhere. After millions of years of dry climates, Earth entered a wet period lasting one million to two million years. Nearly any place where geologists find rocks of that age, there are signs of wet weather. This so-called Carnian pluvial episode coincides with some massive evolutionary shifts.

ESCONI Flashback Friday #30: Jim and Sylvia Konecny #MazonCreek #fossils

As part of the celebration of ESCONI's 70th Anniversary, here is Flashback Friday post #30.  If you have pictures or stories to contribute, please send them over to [email protected].  Thanks!

-----------------------------

Jim and Sylvia Konecny were very active in the early days of ESCONI.  Jim held a few posts on the ESCONI board, including president from 1966 to 1968.  Eventually, they moved to Arizona.  A few years ago, they donated a large portion of their collection of Mazon Creek, Ordovician, and Silurian fossils to the Field Museum.

ESCONI Events December 2019

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

Fri, Dec 6th	ESCONI Holiday Party, 5:30 PM Cozymels in Wheaton
Fri, Dec 6th	ESCONI General Meeting, 8:00 PM College of Dupage - Tech Ed (TEC) Building, Room 1038A (Map) - Topic: "Microsites to Macro-inferences a Multiscale Approach to Analyzing Dinosaur Paleoecology" by Dr. Thomas Cullen a Postdoctoral Research Scientist at the Field Museum

Paleontologists Find Fossils of Six New Dragonfly Species

Ypshna brownleei, an image reversed left/right so that wing apices are to the right for ease of comparison. Scale bar is 5 mm. Image credit: S. Archibald & R. Cannings, doi: 10.4039/tce.2019.61.

Sci-News has a post about the discovery of 6 new species of fossil dragonflies.  These animals lived about 50 million years ago during the Eocene epoch.  The fossils were found in the Okanagan Highlands, whih is an elevated hilly plateau area in British Columbia, Canada and the state of Washington.  All the details are in a paper which was published in the journal The Canadian Entomologist.

Dr. Bruce Archibald, a paleontologist at Simon Fraser University, and Royal BC Museum dragonfly expert Robert Cannings examined nine rare dragonfly fossils from the site of McAbee in British Columbia and from the town of Republic in northern Washington.

They found the fossils represent eight previously unknown species, six of which were well-enough preserved to be given scientific names: Antiquiala snyderae, Idemlinea versatilis, Ypshna brownleei, Ypshna latipennata, Eoshna thompsonensis, and Auroradraco eos.

“While some of the fossil insect groups from these beds lived alongside the dinosaurs before eventually becoming extinct, and would be strange to see today, these dragonflies belong to modern families, mostly to a diverse group called the darners,” the researchers explained.

“They would not look out of place today flying beside a modern pond. Other dragonfly groups that are familiar today appear to have begun their diversification to modern dominance shortly after,” Dr. Archibald said.

A Kansas Find Reveals A 17-foot, Previously Unknown, Long-Extinct Shark Species #sharks #kansas

Cretodus teeth uncovered at Ringneck Ranch in Mitchell County, Kansas.

COURTESY OF MIKE EVERHART

NPR has a story about the discovery of a new species of shark from Kansas.  This animal, Cretodus, lived about 91 million years ago in the Western Interior Seaway.  It measured about 17 feet long.  Read all the details in a paper published in the Journal of Vertebrate Paleontology.

GARDEN CITY, Kansas — Paleontologist Mike Everhart had found a rib from a plesiosaur — an ancient ocean reptile — on the Ringneck Ranch in north-central Kansas in 2009. He returned in early spring 2010 searching for more bones. 

Everhart brought a friend, Gail Pearson, and Pearson’s friend Fred Smith. Both men had experience hunting fossils.

But Smith, Everhart said, was bored and decided to search elsewhere. Five minutes later, Smith came back and told Everhart he found a piece of petrified wood.

“There was this round fossil on one end and another round fossil on the other end and, to him, it looked like a tree branch,” Everhart said. “I took one look at it and said, ‘No, Fred, that’s a shark.’”

The ground was muddy that day, which made searching for more fossils impractical. Then a snowstorm hit the ranch. Everhart and the group came back a month later and began finding vertebrae and shark teeth.

Reminder: ESCONI Holiday Party December 6th, 2019, 5:30 PM at Cozymel's in Wheaton

An artist’s depiction of the extinct giant, frond-shaped organisms known as rangeomorphs. Credit: Reid Psaltis

The 2019 ESCONI Holiday Dinner is December 6, 2019, starting at 5:30 PM at Cozymel's in Wheaton. We will be ordering off the menu. As in the past few years, there will be door prizes given away.

Please RSVP to Dave at [email protected]

Flesh-Ripping Dinosaurs Replaced Their Teeth Multiple Times a Year #dinosaurs

Two Majungasaurus hunting down a Rapetosaurus. (ABelov2014 via Wikicommons under CC BY-SA 3.0)

The Smithsonian has a story about tooth replacement in theropod dinosaurs.  A new study published in the journal PLOS ONE has found that Majungasaurus probably replaced its teeth every 56 days.  This is faster than the previous highest tooth replacement rate which was about 100 days in Jurassic carnivores Allosaurus and Ceratosaurus.  This new rate is about 14 times faster than Tyrannosaurus rex, which is thought to replace it's teeth about once every 2 years.  These rate were based on the number of shed teeth found for each species.

Like all toothy dinosaurs, prehistoric carnivores replaced their teeth throughout their lives. New cutlery constantly grew in their jaws to push old or broken teeth out of the way. And a new study published today in PLOS ONE reveals how often three Mesozoic meat eaters replaced their chompers. The evidence that these carnivores grew new teeth several times a year also can tell us new things about how these animals hunted and fed.

The research, published by Adelphi University paleontologist Michael D’Emic and colleagues, continues previous work that examined the teeth of herbivorous dinosaurs. In 2013 D’Emic and coauthors calculated that the long-necked Jurassic herbivores Camarasaurus and Diplodocus replaced one tooth every 62 days and 35 days, respectively. Plant food can be abrasive, wearing down teeth quickly, and so herbivorous dinosaurs required a constantly renewed supply. But what about the carnivores?

While at Stony Brook University, D’Emic saw a wealth of Majungasaurus teeth that had been shed while the dinosaurs were alive. This dinosaur was the apex predator of its time, reaching about 20 feet in length and weighing roughly a ton. “There are lots of other species known from the same formation and area in Madagascar, but their shed teeth are not incredibly abundant, so I thought there must be something unique about Majungasaurus itself,” D’Emic says.

Flesh-Ripping Dinosaurs Replaced Their Teeth Multiple Times a Year #dinosaurs

Two Majungasaurus hunting down a Rapetosaurus. (ABelov2014 via Wikicommons under CC BY-SA 3.0)

The Smithsonian has a story about tooth replacement in theropod dinosaurs.  A new study published in the journal PLOS ONE has found that Majungasaurus probably replaced its teeth every 56 days.  This is faster than the previous highest tooth replacement rate which was about 100 days in Jurassic carnivores Allosaurus and Ceratosaurus.  This new rate is about 14 times faster than Tyrannosaurus rex, which is thought to replace it's teeth about once every 2 years.  These rate were based on the number of shed teeth found for each species.

Like all toothy dinosaurs, prehistoric carnivores replaced their teeth throughout their lives. New cutlery constantly grew in their jaws to push old or broken teeth out of the way. And a new study published today in PLOS ONE reveals how often three Mesozoic meat eaters replaced their chompers. The evidence that these carnivores grew new teeth several times a year also can tell us new things about how these animals hunted and fed.

The research, published by Adelphi University paleontologist Michael D’Emic and colleagues, continues previous work that examined the teeth of herbivorous dinosaurs. In 2013 D’Emic and coauthors calculated that the long-necked Jurassic herbivores Camarasaurus and Diplodocus replaced one tooth every 62 days and 35 days, respectively. Plant food can be abrasive, wearing down teeth quickly, and so herbivorous dinosaurs required a constantly renewed supply. But what about the carnivores?

While at Stony Brook University, D’Emic saw a wealth of Majungasaurus teeth that had been shed while the dinosaurs were alive. This dinosaur was the apex predator of its time, reaching about 20 feet in length and weighing roughly a ton. “There are lots of other species known from the same formation and area in Madagascar, but their shed teeth are not incredibly abundant, so I thought there must be something unique about Majungasaurus itself,” D’Emic says.

‘Remarkable’ fossil features an insect trapped in amber, stuck to a dinosaur jaw

Science has a post about a special fossil insect.  The 'remarkable' fossil consists of sap-sucking aphids trapped in amber and stuck to the jawbone of a duck-billed dinosaur.  It was discovered in 2010 in Dinosaur Provincial Park in Alberta, Canada.  All the detail are in a paper publish in the journal Science.

The “remarkable” two-for-one fossil would have been preserved in an incredibly unlikely chain of events, the researchers write today in Scientific Reports. The paleontologists believe that after the Prosaurolophus hadrosaur died—and the flesh had decayed off its jawbone—it washed into a river. There, a blob of sticky resin from either a redwood or an araucarian conifer tree also fell. The blob, containing an unlucky aphid, washed up against the bone and was pressed against it by the flow of water, the scientists argue. It was then covered in sediment for tens of millions of years, during which time the resin hardened into amber.

The find—the first of its kind in North America—carries a cargo of secrets about the dinosaur’s environment. For example, the plant and insect traces inside confirm what many paleontologists already hypothesized: that some hadrosaurs, including the 9-meter-long Prosaurolophus, fed on conifers near coastal floodplains.

‘Remarkable’ fossil features an insect trapped in amber, stuck to a dinosaur jaw

Science has a post about a special fossil insect.  The 'remarkable' fossil consists of sap-sucking aphids trapped in amber and stuck to the jawbone of a duck-billed dinosaur.  It was discovered in 2010 in Dinosaur Provincial Park in Alberta, Canada.  All the detail are in a paper publish in the journal Science.

The “remarkable” two-for-one fossil would have been preserved in an incredibly unlikely chain of events, the researchers write today in Scientific Reports. The paleontologists believe that after the Prosaurolophus hadrosaur died—and the flesh had decayed off its jawbone—it washed into a river. There, a blob of sticky resin from either a redwood or an araucarian conifer tree also fell. The blob, containing an unlucky aphid, washed up against the bone and was pressed against it by the flow of water, the scientists argue. It was then covered in sediment for tens of millions of years, during which time the resin hardened into amber.

The find—the first of its kind in North America—carries a cargo of secrets about the dinosaur’s environment. For example, the plant and insect traces inside confirm what many paleontologists already hypothesized: that some hadrosaurs, including the 9-meter-long Prosaurolophus, fed on conifers near coastal floodplains.