An international squad of paleontologists together with other geoscientists has discovered the start North American co-occurrence of hadrosaur together with therizinosaur tracks inwards the lower Cantwell Formation inside Denali National Park, suggesting that an aspect of the continental ecosystem of cardinal Asia was too introduce inwards this business office of Alaska during the Late Cretaceous.
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| An international squad of paleontologists together with geoscientists has discovered the start North American co-occurrence of hadrosaur together with therizinosaur tracks inside Denali National Park inwards Alaska [Credit: Masato Hattori] |
Anthony R. Fiorillo, Ph.D., principal curator together with vice president of inquiry together with collections at the Perot Museum of Nature together with Science inwards Dallas, Texas, is the Pb author. Co-authors are Paul J. McCarthy, Ph.D., University of Alaska, Department of Geosciences; Yoshitsugu Kobayashi, Ph.D., Hokkaido University Museum, Sapporo, Hokkaido, Japan; Carla S. Tomsich, graduate student, University of Alaska, Department of Geosciences; Ronald S. Tykoski, Ph.D., manager of paleontology lab, Perot Museum of Nature together with Science; Yuong-Nam Lee, Ph.D., School of populace together with Environmental Sciences, Seoul National University, South Korea; Tomonori Tanaka, graduate student, Hokkaido University Museum, Sapporo, Hokkaido, Japan; together with Christopher R. Noto, Ph.D., Department of Biological Sciences, University of Wisconsin-Parkside, Kenosha, Wisconsin.
Fiorillo together with a colleague published on a distinct unmarried footprint inwards Denali National Park inwards 2012 that they determined to hold upwardly made past times a therizinosaur, an unusual predatory dinosaur persuasion to convey give-up the ghost an herbivore. Therizinosaurs are best known from Asia. Upon his render inwards 2013 together with 2014, they conducted a to a greater extent than detailed analysis of the area, together with he together with his colleagues unearthed dozens to a greater extent than tracks of therizinosaurs. What surprised Fiorillo together with his squad or then was the co-occurrence of dozens of hadrosaurs, too known equally duck-bill dinosaurs.
"Hadrosaurs are real mutual together with found all over Denali National Park. Previously, they had non been found amongst therizinosaurs inwards Denali. In Mongolia, where therizinosaurs are best known -- though no footprints convey been found inwards association -- skeletons of hadrosaurs together with therizinosaurs convey been found to co-occur from a unmarried stone unit of measurement then this was a highly unusual regain inwards Alaska, together with it prompted my interest," said Fiorillo. "From our research, we've determined that this rails association of therizinosaurs together with hadrosaurs is currently the entirely i of its sort inwards North America."
The plant-eating therizinosaurs are rare together with unusual creatures inwards the fossil record. The strange-looking dinosaurs had long skinny necks, piffling teeth, a small-scale pecker for cropping plants, together with large torsos accompanied past times large hind feet together with long arms with "hands similar Freddy Krueger."
Though therizinosaurs are known from Asia together with North America, the best together with or then various fossil tape is from Asia -- fifty-fifty upwardly to the fourth dimension of extinction -- together with therein is the connection. Fiorillo has long postulated that
Cretaceous Alaska could convey been the thoroughfare for fauna betwixt Western North America together with Asia -- 2 continents that shared each other's fauna together with flora inwards the latest stages of the Cretaceous.
"This study helps back upwardly the persuasion that Alaska was the gateway for dinosaurs equally they migrated betwixt Asia together with North America," said medico Kobayashi.
To back upwardly the theory, Fiorillo's international squad of scientists from across the U.S., Nippon together with Republic of Korea worked to found if the tracks were those of a therizinosaur together with to study whatever unique aspects of the ecosystem. The members -- including a sedimentologist, geologist, paleobotanist, paleoecologist together with additional paleontologists including an practiced on therizinosaurs -- determined that this special expanse of Denali was a wet, marsh-like surroundings together with that i fossil inwards special looked similar a H2O lily, which supported the theory that at that topographic point were ponds together with standing H2O nearby. They suspect that both therizinosaurs together with hadrosaurs liked these wetter locations.
Fiorillo believes that this Alaskan uncovering may connect these animals environmentally together with perhaps behaviorally to other therizinosaurs inwards cardinal Asia. An Asian written report of these animals beingness associated too came from an interval of rocks that was unusually 'wet' at the time, relative to rocks higher upwardly together with below it.
"This uncovering provides to a greater extent than testify that Alaska was mayhap the thruway for dinosaurs betwixt Asia together with western North America 65-70 i M m years ago," added Fiorillo.
Source: Perot Museum of Nature together with Science [August 06, 2018]
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