October 2021

Jurassic Graveyard Reveals Oldest Evidence That Dinosaurs Traveled in Herds

dinosaur, Earth History, extinction 6:42 PM

<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-7-5GxmIwA_A/YXwVjPYh8OI/AAAAAAAATYk/PASk5dW6XTY34WtJqfYLKdI5rdG9iD25gCLcBGAsYHQ/s1240/Jurassic%2BGraveyard%2BReveals%2BOldest%2BEvidence%2BThat%2BDinosaurs%2BTraveled%2Bin%2BHerds%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="680" data-original-width="1240" height="350" src="https://1.bp.blogspot.com/-7-5GxmIwA_A/YXwVjPYh8OI/AAAAAAAATYk/PASk5dW6XTY34WtJqfYLKdI5rdG9iD25gCLcBGAsYHQ/w640-h350/Jurassic%2BGraveyard%2BReveals%2BOldest%2BEvidence%2BThat%2BDinosaurs%2BTraveled%2Bin%2BHerds%2B%25281%2529.jpg" title="A nest of 192 million-year-old fossilized eggs found in Argentina. (Diego Po)" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">A nest of 192 million-year-old fossilized eggs found in Argentina. (Diego Po) </td></tr></tbody></table>The discovery included more than 100 dinosaur eggs and the partial skeletons of 80 juvenile and adult dinosaurs. To borrow a line from the movie "Jurassic Park:" Dinosaurs do move in herds. And a new study shows that the prehistoric creatures lived in herds much earlier than previously thought. In a paper appearing in Scientific Reports, researchers from MIT, Argentina, and South Africa detail their discovery of an exceptionally preserved group of early dinosaurs that shows signs of complex herd behavior as early as 193 million years ago -- 40 million years earlier than other records of dinosaur herding. Since 2013, members of the team have excavated more than 100 dinosaur eggs (about the size of chicken eggs) and the partial skeletons of 80 juvenile and adult dinosaurs from a rich fossil bed in southern Patagonia. Using X-ray imaging, they were able to examine the eggs' contents without breaking them apart, and discovered preserved embryos within, which they used to confirm that the fossils were all members of Mussaurus patagonicus -- a plant-eating dinosaur that lived in the early Jurassic period and is classified as a sauropodomorph, a predecessor of the massive, long-necked sauropods that later roamed the Earth. Surprisingly, the researchers observed that the fossils were grouped by age: Dinosaur eggs and hatchlings were found in one area, while skeletons of juveniles were grouped in a nearby location. Meanwhile, remains of adult dinosaurs were found alone or in pairs throughout the field site. <div style="width:100%;margin: 0px auto">
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</div> This "age segregation," the researchers believe, is a strong sign of a complex, herd-like social structure. The dinosaurs likely worked as a community, laying their eggs in a common nesting ground. Juveniles congregated in "schools," while adults roamed and foraged for the herd. "This may mean that the young were not following their parents in a small family structure," says team member Jahandar Ramezani, a research scientist in MIT's Department of Earth, Atmospheric and Planetary Sciences. "There's a larger community structure, where adults shared and took part in raising the whole community." Ramezani dated ancient sediments among the fossils and determined that the dinosaur herd dates back to around 193 million years ago, during the early Jurassic period. The team's results represent the earliest evidence of social herding among dinosaurs. Living in herds may have given Mussaurus and other social sauropodomorphs an evolutionary advantage. These early dinosaurs originated in the late Triassic, shortly before an extinction event wiped out many other animals. For whatever reason, sauropodomorphs held on and eventually dominated the terrestrial ecosystem in the early Jurassic. "We've now observed and documented this earliest social behavior in dinosaurs," Ramezani says. "This raises the question now of whether living in a herd may have had a major role in dinosaurs' early evolutionary success. This gives us some clues to how dinosaurs evolved." <h4 style="text-align: left;">A fossil flood</h4>Since 2013, paleontologists on the team have worked in the Laguna Colorada Formation, a site in southern Patagonia that is known for bearing fossils of early sauropodomorphs. When scientists first discovered fossils within this formation in the 1970s, they named them Mussaurus for "mouse lizard," as they assumed the skeletons were of miniature dinosaurs. Only much later did scientists, including members of the Argentinian team, discover bigger skeletons, indicating Mussaurus adults were much larger than their rodent namesakes. The name stuck, however, and the team has continued to unearth a rich collection of Mussaurus fossils from a small, square kilometer of the formation. The fossils they have identified so far were found in three sedimentary layers spaced close together, indicating that the region may have been a common breeding ground where the dinosaurs returned regularly, perhaps to take advantage of favorable seasonal conditions. Among the fossils they uncovered, the team discovered a group of 11 articulated juvenile skeletons, intertwined and overlapping each other, as if they had been suddenly thrown together. In fact, judging from the remarkably preserved nature of the entire collection, the team believes this particular herd of Mussaurus died "synchronously," perhaps quickly buried by sediments. Based on evidence of ancient flora in the nearby outcrops, the Laguna Colorada Formation has long been assumed to be relatively old on the dinosaur timescale. The team wondered: Could these dinosaurs have been herding from early on? "People already knew that in the late Jurassic and Cretaceous, the large herbivore dinosaurs exhibited social behavior -- they lived in herds and had nesting spots," Ramezani says. "But the question has always been, when was the earliest time for such herding behavior?" <h4 style="text-align: left;">A gregarious line</h4>To find out, Diego Pol, a paleontologist at the Egidio Feruglio Paleontological Museum in Argentina who led the study, looked for samples of volcanic ash among the fossils to send to Ramezani's lab at MIT. Volcanic ash can contain zircon -- mineral grains contaning uranium and lead, the isotopic ratios of which Ramezani can precisely measure. Based on uranium's half-life, or the time it takes for half of the element to decay into lead, he can calculate the age of the zircon and the ash in which it was found. Ramezani successfully identified zircons in two ash samples, all of which he dated to around 193 million years old. Since the volcanic ash was found in the same sediment layers as the fossils, Ramezani's analyses strongly suggest that the dinosaurs were buried at the same time the ash was deposited. A likely scenario may have involved a flash flood or windblown dust that buried the herd, while ash from a distant eruption happened to drift over and, luckily for science, deposit zircons in the sediments. Taken together, the team's results show that Mussaurus and possibly other dinosaurs evolved to live in complex social herds as early as 193 million years ago, around the dawn of the Jurassic period. Scientists suspect that two other types of early dinosaurs -- Massospondylus from South Africa and Lufengosaurus from China -- also lived in herds around the same time, although the dating for these dinosaurs has been less precise. If multiple separate lines of dinosaurs lived in herds, the researchers believe the social behavior may have evolved earlier, perhaps as far back as their common ancestor, in the late Triassic. "Now we know herding was going on 193 million years ago," Ramezani says. "This is the earliest confirmed evidence of gregarious behavior in dinosaurs. But paleontological understanding says, if you find social behavior in this type of dinosaur at this time, it must have originated earlier." This research was supported, in part, by National Science Foundation in the U.S. and the National Scientific and Technical Research Council of Argentina.  The above story is based on <a href="https://news.mit.edu/2021/dinosaurs-may-have-lived-social-herds-early-1021" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"> provided by <a href="https://www.mit.edu/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Massachusetts Institute of Technology</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">. Original written by Jennifer Chu.

Jurassic Graveyard Reveals Oldest Evidence That Dinosaurs Traveled in Herds

A nest of 192 million-year-old fossilized eggs found in Argentina. (Diego Po) The discovery included more than 100 dinosaur eggs and the p...

Giant Ammonites Once Thrived on Both Sides of Atlantic

evolution, extinction, Fossils 7:31 PM

Giant Ammonites Once Thrived on Both Sides of Atlantic

This was a replica that we used to show how big ammonites could grow. Made of polystyrene it squeaked as we rolled it down the beach at Lyme...

Tiny Crab Preserved in 100-million-year-old Amber Lived Among Dinosaurs

amber, Fossils 7:32 PM

<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-LXfZnXKYrl8/YXQ4g2yOZHI/AAAAAAAATYA/XGBmjO2R3uwosrN2Fxeqd2ua0dUp7fZDACLcBGAsYHQ/s1047/Cretapsara-athanata-Crab-in-Burmese-Amber%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="735" data-original-width="1047" height="450" src="https://1.bp.blogspot.com/-LXfZnXKYrl8/YXQ4g2yOZHI/AAAAAAAATYA/XGBmjO2R3uwosrN2Fxeqd2ua0dUp7fZDACLcBGAsYHQ/w640-h450/Cretapsara-athanata-Crab-in-Burmese-Amber%2B%25281%2529.jpg" title="Cretapsara athanata, a modern-looking eubrachyuran crab in Burmese amber. Image credit: Luque et al.," width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Cretapsara athanata, a modern-looking eubrachyuran crab in Burmese amber. Image credit: Luque </td></tr></tbody></table>Scientists have found the oldest aquatic animal preserved in amber -- and it's the most complete crab fossil ever discovered. Fossils trapped in amber provide a unique snapshot of the anatomy, biology, and ecology of extinct organisms. The most common fossils found in amber, which is formed from resin exuded from tree bark, are land-dwelling animals, mainly insects. But on very rare occasions scientists discover amber housing an aquatic organism. In a study published in Science Advances an international team of researchers describe the first crab from the Cretaceous dinosaur era preserved in amber. The study used micro CT to examine and describe Cretapsara athanata, the oldest modern-looking crab (approximately 100 million years old) and the most complete fossil crab ever discovered. It is rivalled in completeness by the mysterious Callichimaera perplexa, a very distant relative nicknamed the platypus of the crab world. Callichimaera's stunning preservation included soft tissues and delicate parts that rarely fossilize. Both Cretapsara and Callichimaera are new branches in the crab tree of life that lived during the Cretaceous Crab Revolution, a period when crabs diversified worldwide and the first modern groups originated while many others disappeared. True crabs, or Brachyura, are an iconic group of crustaceans whose remarkable diversity of forms, species richness, and economic importance have inspired celebrations and festivals worldwide. They've even earned a special role in the pantheon of social media. True crabs are found all around the world, from the depths of the oceans, to coral reefs, beaches, rivers, caves, and even in trees as true crabs are among the few animal groups that have conquered land and freshwater multiple times. <div style="margin: 0px auto; width: 100%;">
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</div> The crab fossil record extends back into the early Jurassic, more than 200 million years ago. Unfortunately, fossils of nonmarine crabs are sparse and largely restricted to bits and pieces of the animals carapace -- claws and legs found in sedimentary rocks. That is until now with the discovery of Cretapsara athanata. "The specimen is spectacular, it is one of a kind. It's absolutely complete and is not missing a single hair on the body, which is remarkable," said lead author Javier Luque, postdoctoral researcher in the Department of Organismic and Evolutionary Biology, Harvard University. A group of scientists led by co-lead author Lida Xing, China University of Geosciences, Beijing, made micro CT scans of the fossil, which is housed in the Longyin Amber Museum in Yunnan, China. The scans created a full three-dimensional reconstruction of the exquisite preservation of the animal allowing Luque, Xing, and their team to see the complete body of the animal including delicate tissues, like the antennae and mouthparts lined with fine hairs. Shockingly they discovered the animal also had gills. "The more we studied the fossil, the more we realized that this animal was very special in many ways," said Luque. Cretapsara is remarkably modern-looking -- superficially resembling some shore crabs found today -- unlike most crabs during the mid-Cretaceous era which looked quite different from modern crabs. Yet, the animal was entombed in Cretaceous amber and the presence of well-developed gills indicated an aquatic to semi-aquatic animal. Aquatic animals are rarely preserved in tree resins that become amber. Crabs previously found in amber are by the handful and belong to a living group of tropical land and tree-dwelling crabs known as Sesarmidae from the Miocene (15 million years ago). How then, the researchers asked, did a 100 million year old aquatic animal become preserved in tree amber, which normally houses land-dwelling specimens? Gills allow aquatic animals to breathe in water. But crabs have successfully and independently conquered land, brackish water, and fresh water at least twelve times since the dinosaur era. In doing so their gills evolved to include lung-like tissue allowing them to breathe both in and out of the water. Cretapsara however, had no lung tissue, only well-developed gills indicating the animal was not completely land dwelling. "Now we were dealing with an animal that is likely not marine, but also not fully terrestrial," Luque said. "In the fossil record, nonmarine crabs evolved 50 million years ago, but this animal is twice that age." The team's phylogenetic studies show that carcinization (the evolution of true crab-looking forms) had actually already occurred in the most recent common ancestor shared by all modern crabs more than 100 million years ago. Cretapsara bridges the gap in the fossil record and confirms that crabs actually invaded land and fresh water during the dinosaur era, not during the mammal era, pushing the evolution of nonmarine crabs much further back in time. The researchers hypothesize that Cretapsara, measuring at five millimeters in leg span, was a juvenile crab of a freshwater to amphibious species. Or, that the animal is perhaps a semi-terrestrial juvenile crab migrating onto land from water as occurs to the iconic Christmas Island red crabs where land dwelling mother crabs release their babies into the ocean, which later swarm out of the water back onto land. They further hypothesize that like the crabs found in amber from the Miocene, Cretapsara could have been a tree climber. "These Miocene crabs are truly modern looking crabs and, as their extant relatives, they live in trees in little ponds of water," said Luque, "these arboreal crabs can get trapped in tree resin today, but would it explain why Cretapsara is preserved in amber?" Luque's research is centered on understanding why things evolve into crabs, and their evolution and diversification over time leading to the modern forms seen today. "This study is pushing the timing of origin of many of these groups back in time. Every fossil we discover challenges our preconceptions about the time and place of origin of several organisms, often making us look further back in time," Luque said. The study is part of a National Science Foundation funded project with Luque, Professor Javier Ortega-Hernández and postdoctoral researcher Joanna Wolfe, both in the Department of Organismic and Evolutionary Biology, Harvard University, and Professor Heather Bracken-Grissom, Florida International University. The researchers chose the name Cretapsara athanata, which means the immortal Cretaceous spirit of the clouds and waters, to honor the Cretaceous, during which this crab lived, and Apsara, a spirit of the clouds and waters in South and Southeast Asian mythology. The species name is based on "athanatos," immortal, referring to its lifelike preservation as if 'frozen in time' in the time capsule that is amber. Author's Statement: The studied fossil, deposited in the Longyin Amber Museum (LYAM), Yunnan Province, China, comes from a batch of commercial "raw" (dull, unpolished) amber pieces collected by local miners and sold to a vendor at an amber jewelry market in Myitkyina on May 12, 2015. The polished piece containing the fossil studied was acquired by LYAM from the vendor's mineral store in Tengchong, China, on 10 August 2015. We acknowledge the existence of a sociopolitical conflict in northern Myanmar and have limited our research to material predating the 2017 resumption of hostilities in the region. We hope that conducting research on specimens collected before the conflict and acknowledging the situation in the Kachin State will serve to raise awareness of the current conflict in Myanmar and the human cost behind it. The above story is based on <a href="https://oeb.harvard.edu/news/international-team-researchers-discover-first-dinosaur-era-crab-fully-preserved-amber" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"> provided by <a href="https://oeb.harvard.edu/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Harvard University, Department of Organismic and Evolutionary Biology</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">.

Tiny Crab Preserved in 100-million-year-old Amber Lived Among Dinosaurs

Cretapsara athanata, a modern-looking eubrachyuran crab in Burmese amber. Image credit: Luque Scientists have found the oldest aquatic anima...

Evidence of Ancient Life Was Discovered Inside a Ruby

Earth History, Geochemistry, Tectonic 7:05 PM

Evidence of Ancient Life Was Discovered Inside a Ruby

The ruby found to contain carbon-12 graphite. (University of Waterloo) A ruby that formed in Earth's crust 2.5 billion years ago encas...

Rare Eocene Grass Spikelet Found Preserved in Baltic Amber

amber, Fossils 5:07 PM

<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-gSV_Rz97zJA/YW7Qz9xGFwI/AAAAAAAATXk/mTxV50tTGn4zYMXjSQReNF-jTJCXe8dIACLcBGAsYHQ/s1200/Rare%2BEocene%2BGrass%2BSpikelet%2BFound%2BPreserved%2Bin%2BBaltic%2BAmber%2B%25281%2529.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="564" data-original-width="1200" height="300" src="https://1.bp.blogspot.com/-gSV_Rz97zJA/YW7Qz9xGFwI/AAAAAAAATXk/mTxV50tTGn4zYMXjSQReNF-jTJCXe8dIACLcBGAsYHQ/w640-h300/Rare%2BEocene%2BGrass%2BSpikelet%2BFound%2BPreserved%2Bin%2BBaltic%2BAmber%2B%25281%2529.jpg" title="Rare Eocene Grass Spikelet Found Preserved in Baltic Amber" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Side view of Eograminis balticus. Image credit: Poinar & Soreng </td></tr></tbody></table>  Amber research by the Oregon State University College of Science has produced the first definite identification of grass in fossilized tree resin from the Baltic region, home to the world’s most well-known amber deposits. The specimen studied by George Poinar Jr., named Eograminis balticus, also represents the first fossil member of Arundinoideae, a subfamily of the widespread Poaceae family that includes cereal grasses, bamboos and many species found in lawns and natural grasslands. Findings, now in preprint, will be published in the International Journal of Plant Sciences. Blown or shoved against a resin-producing tree, the fossil grass lost one of its spikelets some 40 or 50 million years ago, along with an accompanying insect that had been feeding on it. <div style="width:100%;margin: 0px auto">
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</div> A spikelet is one unit of inflorescence, or flower arrangement, and consists of two glumes and one or more florets. A glume is a leaflike structure below the flower cluster, and a floret is one of the small flowers in the cluster. The fossil spikelet is the first definite evidence that grasses were among the various plants in the Baltic amber forest. “The discovery not only adds a new plant group to the extensive flora that have been described from Baltic amber but provides new insights into the forest habitat the amber came from, a controversial topic in this field of study,” said Poinar, an international expert in using plant and animal life forms preserved in amber to learn more about the biology and ecology of the distant past. Poinar says some scientists have proposed that fossiliferous amber from the Baltic region was formed in tropical and subtropical woods, and others say it came from a humid, marshy, warm-temperate forest. “Our new grass suggests that for at least a time the habitat was warm-temperate, like you see today in mixed deciduous and conifer forests,” said Poinar, who collaborated on the study with Roberg Soreng of the Smithsonian Institution. “Present on the spikelet is an immature grasshopper-like insect and a leaf-spot fungal spore that provide information on the microhabitat of the fossil grass. The spikelet has structural and developmental features that existed in early Cenozoic grasses and establishes an important calibration point for future studies on the origin and splitting of genera in its subtribe.” Because of the excellent preservation of the spikelet, observations could be made under direct light with both stereoscopic and compound microscopes, Poinar said. “The spikelet has some features of members of the extant wetland genus Molinia in the tribe Molinieae, subtribe Moliniinae,” Poinar said. “Molinia species are concentrated around the Baltic Sea, but some of those species’ characteristics are different from what we see in this fossil.” Informally known as moor grass, Molinia is a wetland genus. In addition to the Baltic region, Molinia is found in sand in habitats ranging from coastal to subalpine, and in fens and sphagnum bogs in forests. A fen is a peat-accumulating wetland that is fed by surface or ground water rich in minerals. The Eograminis balticus spikelet specimen originated from the Samland Peninsula in the Kalinin District of the Russian Federation, Poinar said. The name of the genus derives from the Latin words for age (aeon) and grass (graminis). The above story is based on <a href="https://today.oregonstate.edu/news/oregon-state-fossil-research-leads-first-description-grass-baltic-amber" rel="nofollow" target="_blank">materials </a>provided by <a href="https://oregonstate.edu/" rel="nofollow" target="_blank">Oregon State University. </a>

Rare Eocene Grass Spikelet Found Preserved in Baltic Amber

Side view of Eograminis balticus. Image credit: Poinar & Soreng Amber research by the Oregon State University College of Science has p...

Earth's Solid Inner Core May Be a Little Bit Mushy

earth, Tectonic 6:07 PM

<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-9V34ZLW2viU/YWw7mfRbg_I/AAAAAAAATXY/SrA6vj7Yasge8mXX-DVJlcj029Zm2GlmwCLcBGAsYHQ/s1100/Earth%2527s%2BSolid%2BInner%2BCore%2BMay%2BBe%2Ba%2BLittle%2BBit%2BMushy.jpg" imageanchor="1" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="723" data-original-width="1100" height="420" src="https://1.bp.blogspot.com/-9V34ZLW2viU/YWw7mfRbg_I/AAAAAAAATXY/SrA6vj7Yasge8mXX-DVJlcj029Zm2GlmwCLcBGAsYHQ/w640-h420/Earth%2527s%2BSolid%2BInner%2BCore%2BMay%2BBe%2Ba%2BLittle%2BBit%2BMushy.jpg" title="Earth's Solid Inner Core May Be a Little Bit Mushy" width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">The Earth’s major layers consist of the thin rocky crust, the mantle (very hot but solid rock), the outer core (liquid iron), and the inner core (solid iron). Credit: Getty Images / Anuwat Meereewee </td></tr></tbody></table>  3,200 miles beneath Earth's surface lies the inner core, a ball-shaped mass of mostly iron that is responsible for Earth's magnetic field. In the 1950's, researchers suggested the inner core was solid, in contrast to the liquid metal region surrounding it. New research led by Rhett Butler, a geophysicist at the University of Hawai'i at Manoa School of Ocean and Earth Science and Technology (SOEST), suggests that Earth's "solid" inner core is, in fact, endowed with a range of liquid, soft, and hard structures which vary across the top 150 miles of the inner core. No human, nor machine has been to this region. The depth, pressure and temperature make inner Earth inaccessible. So Butler, a researcher at SOEST's Hawai'i Institute of Geophysics and Planetology, and co-author Seiji Tsuboi, research scientist at the Japan Agency for Marine-Earth Science and Technology, relied on the only means available to probe the innermost Earth -- earthquake waves. <div style="width:100%;margin: 0px auto">
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</div> "Illuminated by earthquakes in the crust and upper mantle, and observed by seismic observatories at Earth's surface, seismology offers the only direct way to investigate the inner core and its processes," said Butler. As seismic waves move through various layers of Earth, their speed changes and they may reflect or refract depending on the minerals, temperature and density of that layer. In order to infer features of the inner core, Butler and Tsuboi utilized data from seismometers directly opposite of the location where an earthquake was generated. Using Japan's Earth Simulator supercomputer, they assessed five pairings to broadly cover the inner core region: Tonga-Algeria, Indonesia-Brazil, and three between Chile-China. "In stark contrast to the homogeneous, soft iron alloys considered in all Earth models of the inner core since the 1970's, our models suggest there are adjacent regions of hard, soft, and liquid or mushy iron alloys in the top 150 miles of the inner core," said Butler. "This puts new constraints upon the composition, thermal history, and evolution of Earth. The study of the inner core and discovery of its heterogeneous structure provide important new information about dynamics at the boundary between the inner and outer core, which impact the generation Earth's magnetic field. "Knowledge of this boundary condition from seismology may enable better, predictive models of the geomagnetic field which shields and protects life on our planet," said Butler. The researchers plan to model the inner core structure in finer detail using the Earth Simulator and compare how that structure compares with various characteristics of Earth's geomagnetic field.    The above story is based on <a href="https://www.soest.hawaii.edu/soestwp/announce/news/earths-solid-inner-core-may-contain-both-mushy-and-hard-iron-uh-research-finds/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">Materials</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;"> provided by <a href="https://www.hawaii.edu/" rel="nofollow" style="-webkit-text-stroke-width: 0px; background-color: white; border-radius: 0px !important; box-sizing: border-box; color: #004276; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;" target="_blank">University of Hawaii at Manoa</a><span style="-webkit-text-stroke-width: 0px; background-color: white; color: #333333; display: inline !important; float: none; font-size: 14px; font-variant-caps: normal; font-variant-ligatures: normal; font-weight: 400; letter-spacing: normal; text-align: start; text-decoration-color: initial; text-decoration-style: initial; text-decoration-thickness: initial; text-indent: 0px; text-transform: none; white-space: normal; word-spacing: 0px;">. Original written by Marcie Grabowski.

Earth's Solid Inner Core May Be a Little Bit Mushy

The Earth’s major layers consist of the thin rocky crust, the mantle (very hot but solid rock), the outer core (liquid iron), and the inner ...

This 390-Million-Year-Old Trilobite Fossil Had a Bunch of Tiny Eyes Inside Its Eyes

evolution, Fossils 6:18 PM

<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-pAB2XvJ-Q84/YWGyULwZHiI/AAAAAAAATW4/GgTLuBO4SB0qAXQmttnLKn7CHEVOB5QswCLcBGAsYHQ/s1202/Phacops%2Bgeesops%252C%2Ba%2Btrilobite%2Bfrom%2Bthe%2BDevonian%2Bage.%2BThe%2Banimal%2527s%2Beyes%2Bconsist%2Bof%2B200%2Bsingle%2Blenses%2Beach%252C%2Bspanning%2Bsix%2Bsmall%2Bfacets%252C%2Bwhich%2Bagain%2Bform%2Bone%2Beye%2Beach..jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="600" data-original-width="1202" height="320" src="https://1.bp.blogspot.com/-pAB2XvJ-Q84/YWGyULwZHiI/AAAAAAAATW4/GgTLuBO4SB0qAXQmttnLKn7CHEVOB5QswCLcBGAsYHQ/w640-h320/Phacops%2Bgeesops%252C%2Ba%2Btrilobite%2Bfrom%2Bthe%2BDevonian%2Bage.%2BThe%2Banimal%2527s%2Beyes%2Bconsist%2Bof%2B200%2Bsingle%2Blenses%2Beach%252C%2Bspanning%2Bsix%2Bsmall%2Bfacets%252C%2Bwhich%2Bagain%2Bform%2Bone%2Beye%2Beach..jpg" title="Phacops geesops, a trilobite from the Devonian age. The animal's eyes consist of 200 single lenses each, spanning six small facets, which again form one eye each." width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Phacops geesops, a trilobite from the Devonian age. The animal's eyes consist of 200 single lenses each, spanning six small facets, which again form one eye each. </td></tr></tbody></table> The humble trilobite, a helmet-headed creature that swam the seas hundreds of millions of years ago, was hiding an extraordinary secret — a "hyper-eye" never seen before in the animal kingdom. An international research team has found an eye system in trilobites of the suborder Phacopina from the Devonian (390 million years B.P.) that is unique in the animal kingdom: each of the about 200 lenses of a hyper-facet eye spans a group of six normal compound-eye-facets, forming a compound eye itself. In addition to the hyper-facetted eyes, the researchers, led by zoologist Dr. Brigitte Schoenemann at the University of Cologne’s Institute for Didactics of Biology, identified a structure that they believe to be a local neural network which directly processed the information from this special eye, and an optic nerve that carried information from the eye to the brain. The article, ‘A 390 million-year-old hyper-compound eye in Devonian phacopid trilobites,’ has been published in Scientific Reports. Trilobites are arthropods that once inhabited the world’s oceans and became extinct about 251 million years ago. The discovery was made when Schoenemann and her colleagues examined X-ray images taken by radiologist and amateur paleontologist Wilhelm Stürmer in the 1970s. <div style="margin: 0px auto; width: 100%;">
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</div> Stürmer had already believed the filaments under the trilobite eyes to be nerves, or a light guiding system. Schoenemann also found markings by Stürmer on the images designating the six subfacets. However, scientists at the time did not believe his interpretations. Now, however, the re-examination of the images and verification with modern computed tomography succeeded in confirming his conjectures. Most trilobites had compound eyes similar to those that are still found in insects today: a large number of hexagonal facets form the eye. There are usually eight photoreceptors under each facet. Comparable to the image of a computer screen, which is built up from individual pixels, an image is built up from the individual facets. In dragonflies, there are up to ten thousand individual facets. In order to produce a coherent image, the facets must be very close together and connected by neurons. However, in the trilobite suborder Phacopinae, the externally visible lenses of the compound eyes are much larger, up to 1 mm in diameter and more. In addition, they are set farther apart. Until now, scientists had not been able to explain this because space is wasted where light could be captured. Since a small cup sits under the lens, they assumed that at the bottom of the capsule was a small retina comparable to that of humans. Dr Schoenemann’s analysis of Wilhelm Stürmer's 40-year-old X-ray archive now suggests a different interpretation: a hyper-compound eye. Each phacopid had two eyes, one on the left and one on the right. ‘Each of these eyes consisted of about 200 lenses up to 1 mm in size,’ said Schoenemann. ‘Under each of these lenses, in turn, at least 6 facets are set up, each of which together again makes up a small compound eye. So we have about 200 compound eyes (one under each lens) in one eye.’ These sub-facets are arranged in either one ring or two rings. ‘Underneath sat a foam-like nest that was probably a small neural network to process the signals,’ the zoologist added. The filaments Stürmer found in fact did turn out to be nerves leading from the eyes to the trilobite’s brain. Further examination with modern computer tomography confirmed these structures. Wilhelm Stürmer was the head of the X-ray department at Siemens and an avid paleontologist. With a VW bus equipped as an X-ray station, he drove from quarry to quarry to X-ray fossils. Among other things, he discovered structures called filaments under the animals’ eyes, which he thought were fossils of soft tissues, especially optic nerves. ‘At that time, the consensus was that only bones and teeth, the hard parts of living things, could be seen in the fossils, but not the soft parts, such as intestines or nerves,’ Schoenemann explained. Stürmer’s heir gave the zoologist his archive. But the hobby-paleontologist had not only correctly identified the optic nerve, she notes: ‘On an X-ray negative, there was an arrow in red pen pointing to the structure of the six lower facets under a main lens. This probably indicated that Stürmer had already recognized the hyper-compound eye.’ At the time, however, scientists assumed that nerves did not fossilize, nor that light guides existed in natural optical system. Optical fibres were not discovered until the 1980s in the compound eyes of a deep-sea crab. The trilobite’s ‘hyper-eye’ may have been an evolutionary adaptation to life in low light conditions, Schoenemann believes. With its highly complex visual apparatus, it may have have been much more sensitive to light than a normal trilobite eye. ‘It is also possible that the individual components of the eye performed different functions, enabling, for example, contrast enhancement or the perception of different colours,’ the biologist said. So far, such an eye has only been found in the trilobite suborder Phacopinae: ‘This is unique in the animal kingdom,’ she concluded. In the course of evolution, this eye system was not continued, since the trilobites of the suborder Phacopinae died out at the end of the Devonian period 360 million years ago.  The above story is based on <a href="https://portal.uni-koeln.de/en/universitaet/aktuell/press-releases/single-news/primordial-hyper-eye-discovered" rel="nofollow" target="_blank">materials </a>provided by <a href="https://portal.uni-koeln.de/en/uoc-home" rel="nofollow" target="_blank">University of Cologne.</a>

This 390-Million-Year-Old Trilobite Fossil Had a Bunch of Tiny Eyes Inside Its Eyes

Phacops geesops, a trilobite from the Devonian age. The animal's eyes consist of 200 single lenses each, spanning six small facets, whic...

Fossil Footprints Reveal Humans Inhabited North America Over 21,000 Years Ago

Earth History, Fossils 6:05 PM

<table align="center" cellpadding="0" cellspacing="0" class="tr-caption-container" style="margin-left: auto; margin-right: auto;"><tbody><tr><td style="text-align: center;"><a href="https://1.bp.blogspot.com/-Nr3pMMAevZI/YVciVrqND0I/AAAAAAAATWc/uwk75BCpW4QrmZymhISy_XSaSOR4MFsYwCLcBGAsYHQ/s1200/Footprints-White-Sands-National-Park%2B%25281%2529.jpg" style="margin-left: auto; margin-right: auto;"><img border="0" data-original-height="900" data-original-width="1200" height="480" src="https://1.bp.blogspot.com/-Nr3pMMAevZI/YVciVrqND0I/AAAAAAAATWc/uwk75BCpW4QrmZymhISy_XSaSOR4MFsYwCLcBGAsYHQ/w640-h480/Footprints-White-Sands-National-Park%2B%25281%2529.jpg" title="Newly discovered fossil human footprints embedded in an ancient lakebed show that humans inhabited North America during the Last Glacial Maximum (LGM), occupying the region of what is now White Sands National Park in New Mexico, United States, between 23 and 21 thousand years ago." width="640" /></a></td></tr><tr><td class="tr-caption" style="text-align: center;">Footprints Found at White Sands National Park in New Mexico, Providing the Earliest Evidence of Human Activity in the Americas. Credit: Cornell University </td></tr></tbody></table>   Footprints found at White Sands National Park in New Mexico provide the earliest unequivocal evidence of human activity in the Americas and shed light on life over 23,000 years ago. Footprints found at White Sands National Park in New Mexico provide the earliest unequivocal evidence of human activity in the Americas and provide insight into life over 23,000 years ago. "For decades, archaeologists have debated when people first arrived in the Americas," said Holliday, a professor in the UArizona School of Anthropology and Department of Geosciences. "Few archaeologists see reliable evidence for sites older than about 16,000 years. Some think the arrival was later, no more than 13,000 years ago by makers of artifacts called Clovis points. The White Sands tracks provide a much earlier date. There are multiple layers of well-dated human tracks in streambeds where water flowed into an ancient lake. This was 10,000 years before Clovis people." Researchers Jeff Pigati and Kathleen Springer, with the U.S. Geological Survey, used radiocarbon dating of seed layers above and below the footprints to determine their age. The dates range in age and confirm human presence over at least two millennia, with the oldest tracks dating back 23,000 years. <div style="margin: 0px auto; width: 100%;">
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</div> This corresponds to the height of the last glacial cycle, during something known as the Last Glacial Maximum, and makes them the oldest known human footprints in the Americas. It was previously thought that humans entered America much later, after the melting of the North American ice sheets, which opened up migration routes. "Our dates on the seeds are tightly clustered and maintain stratigraphic order above and below multiple footprint horizons – this was a remarkable outcome," Springer said. The footprints tell an interesting tale of what life was like at this time. Judging by their size, the tracks were left mainly by teenagers and younger children, with the occasional adult. "The footprints left at White Sands give a picture of what was taking place, teenagers interacting with younger children and adults," said lead study author Matthew Bennett from Bournemouth University in England. "We can think of our ancestors as quite functional, hunting and surviving, but what we see here is also activity of play, and of different ages coming together. A true insight into these early people." Holliday and study co-author Brendan Fenerty, a UArizona doctoral student in the Department of Geosciences, documented basic geologic layering and dating in trenches on the White Sands Missile Range near the discovery site several years before the tracks were found. "We were interested in reconstructing the evolution of the landscape in the context of environmental changes and some younger archaeological sites in the area," Holliday said. "We had no idea what was buried nearby." Tracks of mammoth, giant ground sloth, dire wolves and birds are also all present at the White Sands site. "It is an important site because all of the trackways we've found there show an interaction of humans in the landscape alongside extinct animals, like mammoths and giant sloths," said study co-author Sally Reynolds of Bournemouth University. "We can see the co-existence between humans and animals on the site as a whole, and by being able to accurately date these footprints, we're building a greater picture of the landscape." The human tracks at White Sands were first discovered by David Bustos, resources manager at the park. "It is incredible to have the confirmation on the age of the human prints, and exciting but also sad to know that this is only a small portion of the 80,000 acres where the prints have been revealed bare and are also being rapidly lost to ongoing soil erosion," Bustos said.   The team also pioneered non-invasive geophysical techniques to help locate the site. Tommy Urban, from Cornell University, led this part of the work. "Detection and imaging with nondestructive technology has greatly expanded our capacity to study these remarkable footprints in their broader context," he said. Traditional archaeology relies on the discovery of bones and tools but can often be difficult to interpret. Human footprints provide unequivocal evidence of presence and also of behavior. "White Sands provides the first unequivocal evidence for human presence in the Americas during the Last Glacial Maximum," said study co-author Dan Odess of the National Park Service. "Not all archaeological sites contain such unequivocal evidence. One reason why this discovery is important is that it makes the idea that other purportedly ancient sites really are evidence for human presence that much more plausible, even if the evidence they contain is less unequivocal. This doesn't mean all of those sites are legitimate, but it means they cannot be dismissed out of hand."   The above story is based on <a href="https://news.arizona.edu/story/earliest-evidence-human-activity-found-americas" rel="nofollow" target="_blank">materials </a>provided by <a href="https://marcomm.arizona.edu/?_ga=2.197702892.211321583.1633099880-1920504190.1633099880" rel="nofollow" target="_blank">The University of Arizona.</a>

Fossil Footprints Reveal Humans Inhabited North America Over 21,000 Years Ago

Footprints Found at White Sands National Park in New Mexico, Providing the Earliest Evidence of Human Activity in the Americas. Credit: Corn...

Geology In