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January 2019 Page 2 Atlanta Geological Society Newsletter ODDS AND ENDS Dear AGS members, January Meeting Like that, it’s on into a new year. While that Join us Tuesday, January 29, 2019 at makes a difference to human endeavors, it is so the Fernbank Museum of Natural inconsequential geologically. My recent trip to History, 760 Clifton Road NE, Atlanta the Scotland only emphasized that more. After I GA. The social/dinner starts at 6:30 pm worked on my talk for last November, I ran and the meeting starts at approximately across a TV series from the BBC called Men of Rock. No, its not about Jimmy Page but rather 7 p.m. the mostly Scottish men who laid the historical foundation for geology. This is right up my This month out presentation is alley. There are three episodes presented by Dr. “Investigating Rare Biomineralization Ian Stewart and available free on YouTube. Structures in Trilobites” While viewing, you might get the impression presented by Ms. Raya Greenberger that only the Scots were doing any geology at Please find more information about the that time. That aside, I do believe it would be presentation and Ms. Greenbergerger’s worth your time as there’s great scenes and bio on the next page. scenery. Just about a month ago, there was an earthquake in East Tennessee. While a magnitude of 4.3 is Please come out, enjoy a bite to not big on a worldwide scale, it was big for the eat, the camaraderie, an interesting East. As the result of a Google search on Atlanta presentation and perhaps some and geology, I was contacted by a local TV discussion on the importance of station to give some technical background. My accurate mineral characterization and 20 seconds of fame evaporated quickly but I biomineralization of fossils. have added a ‘Volcanoes and Earthquake’ app to my phone. It is both fun and amazing to be able to know that there was an earthquake in New www.atlantageologicalsociety.org Zealand 37 minutes ago. BTW, our dues renew on a calendar basis. I just facebook.com/Atlanta-Geological- went to our website, followed the links and it Society took less than 2 minutes to be paid in full. Hope to see you on the 29th. Ben Bentkowski, President 2019 AGS Dues Renew This Month AGS January 2019 Page 2 AGS January 2019 Page 3 Middle East Fossils Push Back Origin of Key Plant Groups Millions of Years Paleobotanists exploring a site near the Dead Sea have unearthed a startling connection between today's conifer forests in the Southern Hemisphere and an unimaginably distant time torn apart by a global cataclysm. Exquisitely preserved plant fossils show the podocarps, a group of ancient evergreens that includes the massive yellowwood of South Africa and the red pine of New Zealand, thrived in the Permian period, more than 250 million years ago. That's tens of millions of years earlier than thought, and it shows that early podocarps survived the "great dying" at the end of the Permian, the worst mass extinction the planet has ever known. Reported in this week's issue of Science, the fossils push back the origins not just of podocarps, but also of groups of seed ferns and cycadlike plants. Beyond altering notions of plant evolution, the discoveries lend support to a 45-year-old idea that the tropics serve as a "cradle" of evolution. "This is an exciting paper," says Douglas Soltis, a plant evolutionary biologist at the University of Florida (UF) in Gainesville. By revealing the richness of the Permian tropics, he adds, "The findings may also help researchers decide where to look for crucial fossil discoveries." During the Permian, from 299 million to 251 million years ago, Earth's landmasses had merged to form a supercontinent, bringing a cooler, drier climate. Synapsids, thought to be ancient predecessors of mammals, and sauropsids, ancestors to reptiles and birds, roamed the landscape. Simple seed-bearing plants had already appeared on the scene. Family trees reconstructed from the genomes of living plants suggest more sophisticated plant groups might also have evolved during the Permian, but finding well-preserved plant fossils from that time has been difficult. About 50 years ago, a German geologist described the Umm Irna formation, a series of sedimentary layers exposed along the Jordanian coast of the Dead Sea. Working at the site in the early 2000s, paleontologist Abdalla Abu Hamad, now with the University of Jordan in Amman, discovered some exquisitely preserved plants from Permian swamps and drier lowlands. After moving to the University of Münster in Germany for a Ph.D., he teamed up with paleobotanists there to analyze hundreds of newly collected plant fossils, including leaves, stems, and reproductive organs. Many of the fossils preserve the ancient plants' cuticle, a waxy surface layer that captures fine features, such as the leaf pores called stomata. That made it possible for the team to positively identify many of the plants. "At first, we couldn't really believe our eyes," Benjamin Bomfleur, a study co-author at the University of Münster, recalls. Many were plants thought have gotten their start later in the Mesozoic, the period when dinosaurs ruled. Along with the podocarps, they identified corystosperms, seed ferns common in the dinosaur age but extinct now, and cycadlike Bennettitales, another extinct group that had flowerlike reproductive structures. Such finds could help resolve an ongoing debate about why the tropics have more species than colder latitudes do. Some have suggested that species originate at many latitudes but are more likely to diversify in the tropics, with its longer growing seasons, higher rainfall and temperatures, and other features. But another theory proposes that most plant—and animal—species actually got their start near the equator, making the low latitudes an evolutionary "cradle" from which some species migrate north and south. The new work "supports the idea of the evolution cradle," Bomfleur says. Philip Mannion, a paleontologist at Imperial College London agrees, but says the case is not fully settled. "Our sampling of the fossil record is extremely Page 4 AGS January 2019 Middle East Fossils Push Back Origin of Key Plant Groups Millions of Years (Continued) Freed from rock by a strong acid, this fossilized frond preserves enough detail to identify it as a seed fern. It's not clear how the newfound Permian plants made it through the great dying, a 100,000-year period when, for reasons that are still unclear, 90% of marine life and 70% of life on land disappeared. But their presence in the Permian raises the possibility that other plant groups thought to have later origins actually emerged then in the tropics, says UF plant evolutionary biologist Pamela Soltis. If these select plants survived the mass extinction, she says, "Perhaps the communities they supported may have been more stable as well." Read more about this article at: http://www.sciencemag.org/news/2018/12/middle-east-fossils-push-back-origin-key-plant-groups-millions-years Ancient Steroids Establish the Ediacaran Fossil Dickinsonia as One of The Earliest Animals Abstract The enigmatic Ediacara biota (571 million to 541 million years ago) represents the first macroscopic complex organisms in the geological record and may hold the key to our understanding of the origin of animals. Ediacaran macrofossils are as “strange as life on another planet” and have evaded taxonomic classification, with interpretations ranging from marine animals or giant single-celled protists to terrestrial lichens. Here, we show that lipid biomarkers extracted from organically preserved Ediacaran macrofossils unambiguously clarify their phylogeny. Dickinsonia and its relatives solely produced cholesteroids, a hallmark of animals. Our results make these iconic members of the Ediacara biota the oldest confirmed macroscopic animals in the rock record, indicating that the appearance of the Ediacara biota was indeed a prelude to the Cambrian explosion of animal life. The Ediacara biota remains one of the greatest mysteries in paleontology. Members of this assemblage were initially described as animals; however, as collections grew, it became apparent that Ediacaran fossils and their body plans are difficult to compare with modern phyla. A major complication for the study of Ediacaran organisms is their soft-bodied nature and particular mode of preservation, rarely found in younger fossils. Thus, the interpretation of various members of the Ediacara biota has crossed several Kingdoms and Domains, ranging from bacterial colonies, marine fungi, lichens, and giant protists to stem-group animals and crown-group Eumetazoa. The recent general consensus is that these fossils are polyphyletic: At least Page 5 AGS January 2019 Ancient Steroids Establish the Ediacaran Fossil Dickinsonia as One of The Earliest Animals (Continued) some members of the Ediacara biota are almost unanimously interpreted as bilaterian animals (Kimberella), whereas others are confidently ascribed to giant protozoa (Palaeopascichnus). Beltanelliformis—although previously interpreted as bacteria, benthic and planktonic algae, as well as different animals—is now recognized as a spherical colony of cyanobacteria on the basis of their biomarker content. The affinity of most other Ediacarans, however, remains controversial, even at the Kingdom level. Most recently, arguments surrounding these fossils have centered on lichens, giant protists, and stem- or crown-group Metazoa. Whereas the lichen hypothesis requires an implausible reinterpretation of the habitat of the Ediacara biota from a marine to a continental depositional environment, for many Ediacaran fossils, including dickinsoniids, it currently seems impossible to distinguish between giant protist and metazoan origins. Some Ediacaran fossils, such as Palaeopascichnus, were likely giant unicellular eukaryotes (protists), which means that in contrast to modern ecosystems, these organisms were present and sometimes extremely abundant in shallow- water Ediacaran habitats. Features of dickinsoniids such as “quilting” patterns, the inferred absence of dorso- ventral differentiation, and putative external digestion mode were found to be compatible with modern giant protists and hard to reconcile with metazoans.
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