Fossils of a novel genus too species of an ankylosaurid dinosaur -- Akainacephalus johnsoni -- bring been unearthed inwards the Kaiparowits Formation of Grand Staircase-Escalante National Monument (GSENM), inwards Kane County, southern Utah, U.S.A., too are revealing novel details nigh the multifariousness too development of this grouping of armoured dinosaurs. Expected to expect similar other North American Late Cretaceous ankylosaurid dinosaurs amongst smoothen bony armour on the skull, the novel inquiry suggests merely the contrary too indicates that the defining features of Akainacephalus, specifically the spiky bony armour roofing the skull too snout, align to a greater extent than closely amongst Asian ankylosaurids, who also bring to a greater extent than pronounced spikes roofing their skulls.
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| Life reconstruction of the novel armoured dinosaur Akainacephalus johnsoni [Credit: Andrey Atuchin too the Denver Museum of Nature & Science] |
"I'm a retired chemist, but I've ever been interested inwards most of the scientific discipline disciplines. I never idea that I would bring the chance to genuinely function on fossils that could hold out of import for paleontologists," said Randy Johnson. "Now that I'm a museum volunteer, I'm getting the chance to function on a large variety of fossils too consult amongst top paleontologists -- it's similar a dream minute career. I couldn't believe it when they told me they are naming the ankylosaur later on me, a 1 time inwards a lifetime honor," said Johnson.
Ankylosaurids are a grouping of four-legged herbivorous armoured dinosaurs amongst imposing bony tail clubs. Though ankylosaurids originated inwards Asia betwixt 125 -- 100 1 one m thousand years ago, they create non appear inwards the western North American fossil tape until 77 1 one m thousand years ago. The novel species Akainacephalus lived 76 1 one m thousand years agone during the Late Cretaceous Period too offers the most consummate skeleton of an ankylosaurid dinosaur flora inwards the southwestern US. It includes a consummate skull, much of the vertebral column, including a consummate tail club, several fore too hind limbs elements, too bony torso armour that includes 2 cervix rings too spiked armour plates.
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| A Natural History Museum of Utah acre crew excavate bones from the skeleton of Akainacephalus johnsoni inwards 2009 [Credit: Randall Irmis/Natural History Museum of Utah] |
"A reasonable hypothesis would hold out that ankylosaurids from Utah are related to those flora elsewhere inwards western North America, hence nosotros were genuinely surprised to discovery that Akainacephalus was hence closely related to species from Asia," remarked Randall Irmis, co-author of the study.
Though ankylosaurids originated inwards Asia betwixt 125 -- 100 1 one m thousand years ago, they create non appear inwards the North American fossil tape until about 77 1 one m thousand years ago. Akainacephalus 1 time roamed the southern business office of Laramidia, a landmass on the western coast of a shallow ocean that flooded the cardinal region, splitting the continent of North America inwards two. This caused isolation along western too eastern portions of the North American continent during the Late Cretaceous Period, betwixt 95-70 1 one m thousand years ago.
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| Expert preparator Randy Johnson, spent hundreds of hours removing the Akainacephalus johnsoni skeleton from the surrounding stone too debris. The species part of the dinosaur cite was selected inwards his honour [Credit: Mark Johnston/Natural History Museum of Utah] |
"It is ever exciting to cite a novel fossil taxon, but it is every bit exciting if that taxon also provides additional insights into the bigger pic of its life, such as its diet or aspects of its behavior, too the environs it lived in," said Wiersma. "Such is just the illustration amongst Akainacephalus johnsoni; non alone is this the offset described too named Late Cretaceous ankylosaurid dinosaur from Utah, but this unique creature also strengthens the bear witness that distinct northern too southern provincialism existed during the slowly Campanian phase inwards Laramidia, because to date, nosotros don't run into this type of ankylosaurid dinosaurs inwards the fossil tape of northern Laramidia," he said.
Wiersma explained that additionally, together amongst its unopen relative Nodocephalosaurus from New Mexico, Akainacephalus looks real dissimilar compared to other North American ankylosaurids such as Ankylosaurus, but instead, expect much to a greater extent than similar Asian ankylosaurids including Saichania too Tarchia. From these observations nosotros tin conclude that at to the lowest degree 2 immigration events took house during Late Cretaceous times when lowered ocean levels exposed the Beringian dry soil bridge, connecting Asia amongst western North America.
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| Skeleton of the novel armoured dinosaur Akainacephalus johnsoni as represented yesteryear preserved bones (top) too total reconstructed skeleton inwards top-down (middle) too side (bottom) views [Credit: © Jelle Wiersma/PeerJ] |
"It is extremely fascinating too of import for the scientific discipline of paleontology that nosotros tin read hence much information from the fossil record, allowing us to ameliorate empathize extinct organisms too the ecosystems they were a business office of," concluded Wiersma.
These novel findings are business office of a written report funded inwards large business office yesteryear the Bureau of Land Management, as good as the Geological Society of America, too a University of Utah Department of Geology & Geophysics Graduate Student Grant. The projection was led yesteryear University of Utah M.Sc. educatee Jelle Wiersma, straightaway a Ph.D. educatee inwards the Dept. of Geosciences at James Cook University, Queensland, Australia. Wiersma was advised yesteryear co-author Dr. Randall Irmis, principal curator too curator of paleontology at the Natural History Museum of Utah, too associate professor inwards the Dept. of Geology too Geophysics, University of Utah.
Anklysaurid Dinosaurs on the Lost Continent of Southern Laramidia
Akainacephalus johnsoni was discovered inwards Grand Staircase-Escalante National Monument (GSENM) which encompasses a large surface area of high desert terrain inwards south-central Utah. This vast too rugged region, business office of the National Landscape Conservation System administered yesteryear the Bureau of Land Management (BLM), was the terminal major surface area inwards the lower 48 states to hold out formally mapped yesteryear cartographers.
During the Late Cretaceous, GSENM was inwards the southern part of Laramidia, which stretched from the Arctic Circle to the Gulf of Mexico. Akainacephalus is business office of a growing set out of novel dinosaur discoveries over the yesteryear xv years demonstrating the incredible multifariousness of animals too plants living on Laramidia betwixt 80-75 1 one m thousand years ago. One of the most exciting conclusions from this function is that nearly every species of dinosaur discovered inwards GSENM is novel to science, too Akainacephalus is no exception. Other of late discovered species include large too small-scale meat-eating dinosaurs (e.g., tyrannosaurs), horned dinosaurs, too duck-billed dinosaurs. "A major long-term goal of our function inwards southern Utah is to endeavor too empathize why the species inwards GSENM differ from relatives of the same geologic historic menstruum flora inwards other parts of Laramidia," said Wiersma. Hypotheses for the differences include changes inwards ocean level, climate differences across latitude, too physical barriers to creature movement such as mountains too large rivers.
Fact Sheet: Major Points of the Paper
(1) Akainacephalus is a remarkable novel species of ankylosaurid dinosaur from the upper Campanian Kaiparowits Formation inwards Grand Staircase-Escalante National Monument inwards Kane County, southern Utah.
(2) Akainacephalus is the most consummate Late Cretaceous ankylosaurid dinosaur discovered from Utah too the southwestern U.S., too is distinguished yesteryear a set out of unique features, including spikes too cones of the bony outside roofing the caput too snout.
(3) The spikes too cones of bony armour on the skull of Akainacephalus are similar to those flora on the New Mexican ankylosaurid Nodocephelausaurus kirtlandensis but distinct from all other known Late Cretaceous Laramidian ankylosaurids such as Ankylosaurus, Euoplocephalus, too Ziapelta, indicating these 2 species are to a greater extent than closely related to some Asian ankylosaurids.
(4) The novel ankylosaurid Akainacephalus suggests multiple ankylosaurid emigration events from Asia to Laramidia during the Late Cretaceous.
(5) Together amongst some anklylosaurid dinosaurs from northern Laramidia, including Dyoplosaurus acutossquameus too Scolosaurus cutleri (both 77 Ma), Akainacephalus represents 1 of the oldest known ankylosaurid dinosaurs from the Late Cretaceous of western North America ( 76 Ma).
New Dinosaur Name: Akainacephalus johnsoni
- The offset business office of the name, Akaina, is a Greek give-and-take that tin hold out translated to spike or thorn. The minute business office of the cite cephalus agency head, too the epithet johnsoni honors Randy Johnson, a dedicated paleontology volunteer at the Natural History Museum of Utah who prepared the specimen's skull.
Size
- Akainacephalus, is a medium-sized dinosaur, too was 13-16 feet long (4-5 meters) too was iii ½ feet tall (1 -- 1.5 meters) at the hips.
Relationships
- Akainacephalus belongs to a grouping of herbivorous armoured dinosaurs called anklosaurids that lived inwards Asia too western North America during the Late Cretaceous Period (100-66 1 one m thousand years ago). One of the unique features of ankylosaurid dinosaurs is the presence of a characteristic bony tail club.
Anatomy
- Akainacephalus walked on 4 legs, which were positioned straight underneath his body.
- Akainacephalus was covered inwards bony armour from caput to tail, amongst diverse sized too shaped bony plates, called osteoderms, which are idea to render protection.
- Akainacephalus is characterized yesteryear its elaborate roofing of spikes too horns on the skull, as good a large bony companionship at the goal of its tail.
- Akainacephalus presumably had small, leaf-shaped teeth for eating plants. These savage out of the jaw later on death, but earlier the skeleton was buried yesteryear sediment.
Age too Geography
- Akainacephalus lived during the upper Campanian phase of the Late Cretaceous Period, which spanned from some 84 1 one m thousand to 72 1 one m thousand years ago. This creature lived nigh 76 1 one m thousand years ago.
- Akainacephalus was discovered inwards 76 Ma former rocks of the Kaiparowits Formation, a geological/stratigraphic unit of measurement exposed inwards southern Utah consisting of sedimentary rocks deposited yesteryear rivers too streams.
Discovery & Excavation
- Akainacephalus was offset discovered inwards 2008 during a museum-led paleontological expedition inwards a remote surface area of BLM-administered Grand Staircase-Escalante National Monument (GSENM) inwards Kane County, southern Utah, USA. The site was discovered yesteryear BLM employee Scott Richardson.
- The bones of Akainacephalus that were discovered include a consummate skull, bony armour that includes cervix rings too spiked plates, many vertebrae, forelimb too hindlimb bones, too a nigh consummate tail amongst tail club.
- Akainacephalus was flora together amongst skeletons of several other animals at the same site, including a duck-bill dinosaur (Gryposaurus), a recently-described species of turtle (Arvinachelys), too a nonetheless unnamed relative of alligators too caimans).
- Akainacephalus is permanently housed inwards the collections of the Natural History Museum of Utah at the Rio Tinto Center inwards Salt Lake City too on populace display at the museum's Past Worlds exhibit.
- These discoveries are the effect of an ongoing collaboration betwixt the Natural History Museum of Utah too the Bureau of Land Management.
Preparation
- It required almost 4 years to fully ready all of the bones of Akainacephalus.
- Preparation of the skull was done yesteryear museum volunteer Randy Johnson, who is honored inwards the novel name, Akainacephalus johnsoni
Source: University of Utah [July 19, 2018]
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