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Discoveries
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" In 1986, an expedition descended on Mount Owen in New Zealand with the intention of exploring the vast network of caves that dwell deep beneath the mountain.
Ominous setting, isolated expedition, vast network of unexplored caves. Yep, sounds like somebody's filming a sequel to The Descent, all right. And true to horror cliche form, the team was excavating a path between two caves when they found something ... disturbing: a pile of strange bones. Still connected to shredded fragments of skin, as though fresh. Imagine peering through the darkness, with only the tiny, wavering beam of your flashlight picking out the world in front of you, when you're confronted by that: a very large, very claw-happy foot from some sort of hell-beast that looks like it probably died recently. And you're down there, trapped in an underground cave system, not knowing whether its bloodthirsty relatives are nearby. We mean, best case scenario, it's going to grant you four ironically cursed wishes that will ultimately kill you, right? It turns out that the team had stumbled onto the 3,000-year-old remains of an upland moa, a flightless bird that somehow went extinct despite possessing claws that would make a Velociraptor jealous. " 
When the Earth, the dry, rather wet, land belonged to the insects, arthropods, annelids and other invertebrates. The Carboniferous period essentially. Among the vertebrates, only a few amphibians were competing them for the place. But it's an other subject...
" Even-More-Enormous Centipede: Arthropleura. Arthropleura was an ancestor to centipedes and millipedes. It could reach more than eight feet (2.4 m) in length, and the fatter creatures could be several feet wide—think, for a moment, of something like that brushing up against your leg. It was so massive that despite being an invertebrate it probably had very few predators, and it is by far the largest invertebrate species ever unearthed. Arthropleura lived from the Carboniferous to the early Permian period—throughout what is now North America and Scotland—around 300 million years ago. Strangely, even though its monstrous form would have allowed it to prey on most anything, Arthropleura was entirely herbivorous (as shown by the fossilized remnants of its stomach). It wouldn’t have taken any magic to resize this bug for James’ giant peach. "
Indian Fossils Support New Hypothesis for Origin of Hoofed Mammals
November 9, 2020  *This image is copyright of its original author *This image is copyright of its original author Image Credit : Elaine KasmerNew research published today in the Journal of Vertebrate Paleontology describes a fossil family that illuminates the origin of perissodactyls – the group of mammals that includes horses, rhinos, and tapirs. It provides insights on the controversial question of where these hoofed animals evolved, concluding that they arose in or near present day India. With more than 350 new fossils, the 15-year study pieces together a nearly complete picture of the skeletal anatomy of the Cambaytherium – an extinct cousin of perissodactyls that lived on the Indian subcontinent almost 55 million years ago. Among the findings includes a sheep-sized animal with moderate running ability and features that were intermediate between specialized perissodactyls and their more generalized mammal forerunners. Comparing its bones with many other living and extinct mammals, revealed that Cambaytherium represents an evolutionary stage more primitive than any known perissodactyl, supporting origin for the group in or near India – before they dispersed to other continents when the land connection with Asia formed. This new landmark article was selected for publication as a part of the prestigious Society of Vertebrate Paleontology Memoir Series, a special yearly publication that provides a more in-depth analysis of the most significant vertebrate fossils. Cambaytherium, first described in 2005, is the most primitive member of an extinct group that branched off just before the evolution of perissodactyls, providing scientists with unique clues to the ancient origins and evolution of the group. “The modern orders Artiodactyla (even-toed ungulates), Perissodactyla, and Primates appeared abruptly at the beginning of the Eocene around 56 million years ago across the Northern Hemisphere, but their geographic source has remained a mystery,” explained Ken Rose, emeritus professor at Johns Hopkins University and lead author of the study. Prof. Rose became intrigued by a new hypothesis suggesting that perissodactyls may have evolved in isolation in India. Then India was an island continent drifting northwards, but it later collided with the continent of Asia to form a continuous landmass. “In 1990, Krause & Maas proposed that these orders might have evolved in India, during its northward drift from Madagascar, dispersing across the northern continents when India collided with Asia.” Armed with this new hypothesis, Rose and colleagues obtained funding from The National Geographic Society to explore India for rare fossil-bearing rocks of the correct age that might provide critical evidence for the origin of perissodactyls and other groups of mammals. The first trip to Rajasthan in 2001 had little success, “Although we found only a few fish bones on that trip, the following year our Indian colleague, Rajendra Rana, continued exploring lignite mines to the south and came upon Vastan Mine in Gujarat.” This new mine proved much more promising. Rose added: “In 2004 our team was able to return to the mine, where our Belgian collaborator Thierry Smith found the first mammal fossils, including Cambaytherium.” Encouraged, the team returned to the mines and collected fossilized bones of Cambaytherium and many other vertebrates, despite challenging conditions. “The heat, the constant noise and coal dust in the lignite mines were tough–basically trying to work hundreds of feet down near the bottom of open-pit lignite mines that are being actively mined 24/7,” he said. Through the cumulation of many years of challenging fieldwork, the team can finally shed light on a mammal mystery. Despite the abundance of perissodactyls in the Northern Hemisphere, Cambaytherium suggests that the group likely evolved in isolation in or near India during the Paleocene (66-56 million years ago), before dispersing to other continents when the land connection with Asia formed.
Optimizing extraction and targeted capture of ancient environmental DNA for reconstructing past environments using the PalaeoChip Arctic-1.0 bait-set
Abstract Sedimentary ancient DNA (sedaDNA) has been established as a viable biomolecular proxy for tracking taxon presence through time in a local environment, even in the total absence of surviving tissues. SedaDNA is thought to survive through mineral binding, facilitating long-term biomolecular preservation, but also challenging DNA isolation. Two common limitations in sedaDNA extraction are the carryover of other substances that inhibit enzymatic reactions, and the loss of authentic sedaDNA when attempting to reduce inhibitor co-elution. Here, we present a sedaDNA extraction procedure paired with targeted enrichment intended to maximize DNA recovery. Our procedure exhibits a 7.7–19.3x increase in on-target plant and animal sedaDNA compared to a commercial soil extraction kit, and a 1.2–59.9x increase compared to a metabarcoding approach. To illustrate the effectiveness of our cold spin extraction and PalaeoChip capture enrichment approach, we present results for the diachronic presence of plants and animals from Yukon permafrost samples dating to the Pleistocene-Holocene transition, and discuss new potential evidence for the late survival (~9700 years ago) of mammoth (Mammuthus sp.) and horse (Equus sp.) in the Klondike region of Yukon, Canada. This enrichment approach translates to a more taxonomically diverse dataset and improved on-target sequencing. |
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