Machairoceratops cronusi: a new Ornate Centrosaurine Ceratopsid From Campanian Cretaceous Utah

A New Centrosaurine Ceratopsid, Machairoceratops cronusi gen et sp. nov., from the Upper Sand Member of the Wahweap Formation (Middle Campanian), Southern Utah

Authors:

Lund et al

Abstract:

The Upper Cretaceous (middle-late Campanian) Wahweap Formation of southern Utah contains the oldest diagnostic evidence of ceratopsids (to date, all centrosaurines) in North America, with a number of specimens recovered from throughout a unit that spans between 81 and 77 Ma. Only a single specimen has been formally named, Diabloceratops eatoni, from the lower middle member of the formation. Machairoceratops cronusi gen. et sp. nov., a new centrosaurine ceratopsid from the upper member of the Wahweap Formation, is here described based on cranial material representing a single individual recovered from a calcareous mudstone. The specimen consists of two curved and elongate orbital horncores, a left jugal, a nearly complete, slightly deformed braincase, the left squamosal, and a mostly complete parietal ornamented by posteriorly projected, anterodorsally curved, elongate spikes on either side of a midline embayment. The fan-shaped, stepped-squamosal is diagnostic of Centrosaurinae, however, this element differs from the rectangular squamosal in Diabloceratops. Machairoceratops also differs in the possession of two anterodorsally (rather than laterally) curved epiparietal ornamentations on either side of a midline embayment that are distinguished by a posteromedially-oriented sulcus along the entire length of the epiparietal. Additionally, the parietosquamosal frill is lacking any other epiossifications along its periphery. Machairoceratops shares a triangular (rather than round) frill and spike-like epiparietal loci (p1) ornamentation with the stratigraphically lower Diabloceratops. Both parsimony and Bayesian phylogenetic analyses place Machairoceratops as an early-branching centrosaurine. However, the parsimony-based analysis provides little resolution for the position of the new taxon, placing it in an unresolved polytomy with Diabloceratops. The resultant Bayesian topology yielded better resolution, aligning Machairoceratops as the definitive sister taxon to a clade formed by Diabloceratops and Albertaceratops. Considered together, both phylogenetic methods unequivocally place Machairoceratops as an early-branching centrosaurine, and given the biostratigraphic position of Machairoceratops, these details increase the known ceratopsid diversity from both the Wahweap Formation and the southern portion of Laramidia. Finally, the unique morphology of the parietal ornamentation highlights the evolutionary disparity of frill ornamentation near the base of Centrosaurinae.

A Juvenile Barosaurs (sauropod) From Jurassic Utah also had an Avian-like Airsac Respiratory System

A juvenile sauropod dinosaur from the Late Jurassic of Utah, U.S.A., presents further evidence of an avian style air-sac system

Authors:

Melstrom et al

Abstract:

Well-preserved, articulated juvenile sauropod dinosaur material is very rare, hindering attempts to understand ontogenetic changes within the clade. Here, we describe an exceptionally preserved partial skeleton of a Barosaurus from the Morrison Formation of Dinosaur National Monument, Utah, U.S.A., that is only about one-third adult size. This small size and the lack of fusion of neurocentral and costovertebral sutures indicate that the individual is a juvenile. Apomorphy-based taxonomic identification of the specimen combined with the excellent preservation of its vertebral column allows documentation of both serial and ontogenetic morphological changes in Barosaurus. Each vertebra underwent substantial morphological change in the relative height of the neural spine and location of the zygapophyseal and diapophyseal articular facets during ontogeny but not in the degree of bifurcation of the neural spines. Pneumaticity in the dorsal vertebrae varies serially: large pneumatic fossae punctuate the centra of dorsal vertebrae 1–4 and 8–9, whereas these spaces are occupied by shallow depressions in dorsal vertebrae 5–7. This represents the first known caudal dorsal pneumatic hiatus in a sauropod dinosaur, which suggests that separate air sacs pneumatized the anterior and posterior regions of the dorsal vertebral column, congruent with the pattern observed in non-avian and avian theropod dinosaurs and the presence of an avian-style lung in sauropods.

A Possible Ceratopsian Found in Cenomanian Cretaceous Utah

A possible juvenile ceratopsoid ilium from the Cenomanian of central Utah, U.S.A.

Authors:

Carpenter et al

Abstract:

We describe a small ilium, with fibrous texture characteristic of juvenile bone, from the lower Cenomanian of central Utah, U.S.A. The ilium was recovered from the upper part of the Mussentuchit Member of the Cedar Mountain Formation. The ilium most closely resembles that of immature ceratopsid ilia referred to Agujaceratops mariscalensis from the Campanian Aguja Formation of southern Texas, U.S.A. Both have everted dorsal margins over the iliac body, subhorizontal postacetabular processes, and laterally compressed, anteroventrally curved preacetabular processes. If correctly identified, the small ilium from the Cedar Mountain Formation is the oldest ceratopsid or ceratopsoid known, and shows that the diversity of early ceratopsians was greater than previously realized.

"Giant" Pterosaur Found at Rhaetian (?) Triassic Oasis "Sandpit"

Scientists have found an unprecedented cache of fossils of weird animals that thrived at a desert oasis some 200 million years ago, providing a snapshot of a place and time that have long been a mystery.

The fossils include the bones of a fanged flying predator and creatures that looked, one scientist says, like tiny crocodiles with a Chihuahua's legs. Small reptiles whose "hands" resemble a mole's lived alongside dinosaurs that scampered on their hind legs.

Researchers suspect that many of the fossils represent entirely new species.

"Probably almost everything we're finding (at the site) is previously unknown to science," says Dan Chure of Dinosaur National Monument, one of the site's co-discoverers. "It's just an amazing paleontological candy shop."

The fossils are "a spectacular find," agrees University of Utah paleontologist Randall Irmis, who isn't involved in the project. "We so rarely get sites that preserve such a variety of different animals from the beginning of the age of dinosaurs."

The animals at the site should help illuminate the period just before the mass extinction that allowed the dinosaurs to take over the Earth, Irmis says. The fossils also illuminate exactly what was living in the vast sand box that filled what is now the western United States, where fossils from the Late Triassic fossils are scarce.

link.

Burgess Shale-type Organisms Found in Middle Cambrian UTah

New records of Burgess Shale-type taxa from the middle Cambrian of Utah

Authors:

Conway Morris et al

Abstract:

Cambrian strata of the Laurentian craton contain numerous examples of Burgess Shale–type faunas. Although displaying a more or less concentric distribution around the cratonal margin, most faunal occurrences are in present-day western North America, extending from the Northwest Territories to California. Nevertheless, the soft-bodied and lightly skeletalized fossils in most of these Lagerstätten are highly sporadic. Here, we extend knowledge of such Middle Cambrian occurrences in Utah with reports of four taxa. An arthropod from the Marjum Formation, Dytikosicula desmatae gen. et sp. nov., is a putative megacheiran. It is most similar to Dicranocaris guntherorum, best known from the younger Wheeler Formation, but differs primarily in the arrangement of pleurae and overall size. Along with a specimen of ?Yohoia sp, a new species of Yohoia, Y. utahana sp. nov., is described. It differs from the type and only known species, Y. tenuis, principally in its larger size and shorter exopods; it is the first description of this genus from outside the Burgess Shale. A new species of a stem-group lophotrochozoan from the Spence Shale, Wiwaxia herka sp. nov., possesses a palisade of dorso-lateral spines that are more robust and numerous than the type species of Wiwaxia, W. corrugata. Another notable taxon is Eldonia ludwigi from the Marjum Formation, which is interpreted as a primitive ambulacrarian (assigned to the cambroernids) and a new specimen of the ?cnidarian Cambrorhytium from the Wheeler Shale is illustrated.

Rapid vegetation shifts in the Uinta Mountains During the Late Pleistocene and Holocene Quaternary

Rapid vegetation shifts in the Uinta Mountains (Utah and Wyoming, USA) during the Late Pleistocene and Holocene

Authors:

Louderback et al

Abstract:

The Uinta Mountains lie along an important transition between major climate regimes and thus are sensitive to major climatic changes and consequent vegetation shifts. Two pollen cores from montane Uinta sites on the Utah–Wyoming border (Marsh Lake Bog and Camp Bog, respectively) were used to analyze vegetation shifts from the latest Pleistocene through the Holocene. The records correspond with those from adjacent portions of the Rocky Mountains, all demonstrating a major shift from alpine steppe to open spruce parkland at ~ 11,700–11,200 cal yr BP. A second major shift to lodgepole pine forest began at ~ 8400 cal yr BP at Marsh Lake Bog and could have been a direct response of the dominant species to warmer conditions and/or the result of subtle changes in the competitive hierarchy of tree species near a sensitive ecotone. The difference in the rate and full expression of lodgepole forest development (taking nearly 2000 years longer at Camp Bog) was probably due to a set of complex and local factors, such as cold air drainage and landscape position. Lodgepole pine forest persisted throughout the late Holocene and appears to be the long-term regional “climax” forest, rather than a seral habitat. Fire does not appear to have triggered the middle Holocene shift from spruce-dominated to lodgepole pine-dominated forests in this area but may have contributed to its long-term persistence to the present day.

Alternate History Crazy Thought: "Next Year in Nauvoo!"

James wrote a review of a book which in turn got me thinking because he mentioned the Utah War. This was the clash between Mormons in Utah under Brigham Young vs the Buchanan administration in DC, which little actual fighting took place and there were few deaths for something of an armed conflict of the time, save for the Mountain Meadows Massacre.

One of the contingencies Young planned was to move the Mormon community north on yet another exodus.  In this case, the plan was actually for the island of Vancouver.  For the moment, let's assume the US government has decided to rid themselves of these troublesome missionaries and Young triggers the exodus.  

Young showing up in British Columbia with more people than would have been in Vancouver until the 1900 would have really alarmed the Brits.  There would be three different possibilities here.  

The first is the least likely, IMO, and the border gets scarier in the late 1850s.  However, that's tempered in a big way by the fact the American Civil War was about to go boom.  On the other hand, it might not be after the Civil War since the President Grant tried to exploit the Red River Rebellion and Louis Riel to try to take Manitoba for the US.  On the gripping hand, if the Mormons had been harried out of Utah to Vancouver,  they are not likely to be big fans of America.

The next most likely event is the Mormons becoming fervent Canadians.  The Mormons get the spin of the Loyalist being persecuted by the damned Yanks and get used to anchor the western seaboard from American encroachment.  Vancouver becomes a Canadian Utah and Mormon Zion.  

Honestly though, with the reputation the Mormons had and their particular doctrines of the time, its more than likely the Brits are going to see them off.  I'm sorry, chaps, time to move along.  But where to?  After all, the Go West, Young Mormon!  Go West! kinda runs into the end of the continent.  They could go north, but...

Historically, Mormons when proselytizing in Polynesia and the Pacific Ocean islands.  Hawaii is probably the most noted of those missions.  So, harried from Missouri, harried from Utah, harried from Vancouver, the Mormons go West again...to Polynesia, but especially to Micronesia during the American Civil War while the Brits feel they can uproot the weird Americans with less chance of something going wrong.

Missonary work still goes on in Europe and elsewhere, but Zion is now the atolls and islands of Micronesia.  Guam would get a coral block temple and there they would stay for 30 years.  The world would not be done with our ATL Mormons.

The Spanish American War and the Imperial expansion of the Japanese would bring more misery to the ATL Mormons.  The Mormons would attempt to help the Spanish hold off the Americans, and it would have consequences.  The Americans would chase the Mormons from Guam and the Mormons would set up in the surrounding islands.  While already present in many places, they ended up concentrating in the Northern Mariana Islands. 

When the Japanese took them in 1914, things did not go well.  Increasingly wondering whether or not the Mormons were a 5th Column for the Americans, the Japanese packed up the lot of them and deported the Mormons to Taiwan at first, emptying the South Pacific Mandate of the potential guerilla army threat.  This is declared a success in 1925.  Once in Taiwan, the Japanese kept them apart in separate, dedicated colonies.  When the Kominka Movement kicked off, it was decided the Mormons were unredeemable and could not be remade into Japanese citizens.  The 60,000 of them were deported to Manchuria to work camps.

They would suffer through the deprivations of WW2 and come out the other side.  Unfortunately, the Chinese Communists, Mao especially, were not overly fond of them.  They were then moved to the Chinese West, Xinjiang, in the early 1950s.  Their numbers were now 50,000.  There they would stay and slow grow over the next 15 years.  Unfortunately, the Cultural Revolution would strike and being the most western (albeit very mixed at this point) group, the Mormons would suffer again.

However, this time the Mormons would make their own move.  The Prophet, Hyriam Hattig, would organize the exodus of the majority of members across the Chinese border into Afghanistan.  In 1968, the Mormons left China.  They would take up farming for a time in the mountains of Afghanistan.  The Afghanis were suspicious but also sympathetic.  At least until 1978.

The Soviet invasion of Afghanistan was a disaster.  For the Afghanis, the Soviets and now for the Mormons.  It would kill a number of Mormons.  It would also cause the Great Schism.  The Mormons had finally broken through 100,000 people at the start of the war in their settlements in their valleys.  However, Mormons had become very apolitical and only out for their own survival rather than to change or convert the world.  Most followed the 'render unto Caesar...'  When the communists took over, they rendered until caesar, or at least 75% of them did.  The rest, sick of their being the narrator of the world's dog, moved south, across the Hindu Kush and became the partisans everyone feared they would.  They would even spawn rival Prophets.  Those who moved south became the Abandoned (the Fallen as called by the Wanderers), in the Mormon terminology, and those who remained, the Wanderers (the Lost as called by the Abandoned).  

When the Soviet Union began withdrawing from Afghanistan, the Wanderer Mormons pleaded with the Soviets.  Gorbachev took them in and placed them in Crimea.  It did not make them popular with their new neighbors.  However, when the coup came in August 1991, Mormons took it on themselves to free and hide Gorbachev.  It would not stop the fall of the Soviet Union, but it would make the Ukrainians even less fond of them.  

They would cross into Europe and Wanderers would become a traveling people in the 1990s making their name a reality.  They would wander in their RVs there for another 24 years.  They would reunite once every three years for 'General Conference.'  Each band of Wanderer's is called a Ward.  Given how few Wanderers there are, each country has a Stake.  All of them report to the Prophet and Quorums.  The biggest change to the church and people would be they took up missionary work again.  Unfortunately, this didn't help their image.  A wandering group seeking converts.  Great.

Back in Pakistan, the Abandoned would slowly evolve their own way.  Their own revelations would state that Christ visited the Kashmir like he had the Americas.  They migrated to Kashmir and integrated, albeit roughly into society.  However, they were far, far more rough than their Wanderer cousins.  If someone knocked heads with them, they knocked them right back.  They built their own temple up in the glaciers.  It's been blown up twice.  But each time rebuilt.

In 2016, Jackson Tanner, an aspiring politician, would begin, successfully, to lobby for bringing the Mormons back to the US.  He succeeded in 2024 having argued the Mormons were US citizens by birth.  The genealogical records the Mormons kept were key.  

The Wanderers had always had the saying, "Next Year in Nauvoo" and in 2024, it came true.

Falcatamacaris: a Non-trilobite Artiopodan Arthropod From Cambrian Utah

A rare non-trilobite artiopodan from the Guzhangian (Cambrian Series 3) Weeks Formation Konservat-Lagerstätte in Utah, USA

Authors:

Ortega-Hernández et al

Abstract:

We describe a weakly biomineralized non-trilobite artiopodan arthropod from the Guzhangian Weeks Formation of Utah. Falcatamacaris bellua gen. et sp. nov. is typified by a thin calcitic cuticle, broad cephalon without eyes or dorsal ecdysial sutures, an elongate trunk with distinctively sickle-shaped pleural spines and a long tailspine with a bifurcate termination. The precise affinities of Falcatamacaris gen. nov. are problematic due to the presence of unique features within Artiopoda, such as the peculiar morphology of the pleural and posterior regions of the trunk. Possible affinities with aglaspidid-like arthropods and concilitergans are discussed based on the possession of 11 trunk tergites, edge-to-edge articulations and overall body spinosity. The new taxon highlights the importance of the Weeks Formation Konservat-Lagerstätte for further understanding the diversity of extinct arthropod groups in the upper Cambrian.

Earth Observing Satellites Note Large Methane Leaks From American SouthWest/Four Corners Regions

An unexpectedly high amount of the climate-changing gas methane, the main component of natural gas, is escaping from the Four Corners region in the U.S. Southwest, according to a new study by the University of Michigan and NASA.

The researchers mapped satellite data to uncover the nation's largest methane signal seen from space. They measured levels of the gas emitted from all sources, and found more than half a teragram per year coming from the area where Arizona, New Mexico, Colorado and Utah meet. That's about as much methane as the entire coal, oil, and gas industries of the United Kingdom give off each year.

Four Corners sits on North America's most productive coalbed methane basin. Coalbed methane is a variety of the gas that's stuck to the surface of coal. It is dangerous to miners (not to mention canaries), but in recent decades, it's been tapped as a resource.

"There's so much coalbed methane in the Four Corners area, it doesn't need to be that crazy of a leak rate to produce the emissions that we see. A lot of the infrastructure is likely contributing," said Eric Kort, assistant professor of atmospheric, oceanic and space sciences at the U-M College of Engineering.

link.

Fire Scars Found on Petrified Wood From Late Triassic Chinle Formation

First known fire scar on a fossil tree trunk provides evidence of Late Triassic wildfire

Authors:

Byers et al

Abstract:

Fire scars are well known to fire ecologists and dendrochronologists worldwide, and are used in dating fires and reconstructing the fire histories of modern forests. Evidence of fires in ancient forests, such as fossil charcoal (fusain), is well known to paleontologists and has been reported in geologic formations dating back to the Late Devonian. We describe what we conclude is a fire scar on a fossil tree trunk from the Late Triassic Chinle Formation of southeastern Utah (~ 200–225 Ma). The external features of the prehistoric scar match those of modern fire scars better than those of scars created by other kinds of wounding events. The fossil specimen also exhibits a number of changes in wood anatomy similar to those reported in modern fire-scarred trees, including a band of very small tracheids that indicate growth suppression immediately associated with the scarring event; an area with a tangential row of probable traumatic resin ducts; and a significant increase in tracheid size following the scarring event that indicates a growth release. No fire scar resembling those in modern trees has previously been described in petrified wood as far as we can determine. The presence of a fire scar not only provides further evidence of ancient fires, but also shows that at least some individual trees survived them, indicating that fire could have been an ecological and evolutionary force in forests at least as early as the Late Triassic.

Siats meekorum: The New Giant Allosauroid Rivaling T. rex From Cenomanian Cretaceous Utah

The large carnivorous dinosaurs of the Mesozoic are inevitably among the most exciting of these extinct animals, but they are also among the hardest to study as they were rare. Anyone who has been on safari will recognise the issue – you can see hundreds of wildebeest or zebra for you set eyes on a lion, and similarly there may have been only one Tyrannosaurus knocking around for every few dozen Triceratops or other big herbivores. As a result, fossil of these are few and far between and reconstructing evolutionary or ecological patterns.

Enter the new dinosaur Siats meekerorum, named today in a paper in Nature Communications. The genus name Siats is from a legendary monster from the Ute tribe of Utah (where the dinosaur was found), with the species name meekerorum a tribute to the Meeker family who support palaeontological research. The fossil is rather incomplete and there’s little more than a partial pelvis and some vertebrae and part of the lower leg, but this is enough to confidently assign this to a new animal, and to work out to which evolutionary group it belongs. Siats is part of a group called the allosauroids, one of the major lineages of large carnivorous dinosaurs with some members becoming true giants that rivaled anything the tyrannosaurs (Tyrannosaurus and its relatives) could produce.

link.  2nd link.

The genus name sounds a lot like the Russian word for rabbit.   :)

The Time Calibrated Phylogeny of Nasutoceratops titusi

Nasutoceratops titusi: A New Ceratopsian From Campanian Cretaceous Utah

Pop sci write ups abound.  However, the tPotRSb has not yet released the open access paper to the public as of my writing.

  It's available now here and open access.

Changes to Trade and Social Connectivity in the Pre Hispanic American Southwest

Transformation of social networks in the late pre-Hispanic US Southwest

Authors:

1. Barbara J. Mills (a)
2. Jeffery J. Clark (b)
3. Matthew A. Peeples (b)
4. W. R. Haas, Jr. (a)
5. John M. Roberts, Jr. (c)
6. J. Brett Hill (b,d)
7. Deborah L. Huntley (b)
8. Lewis Borck (a)
9. Ronald L. Breiger (e)
10. Aaron Clauset (f,g)
11. M. Steven Shackley (h)

Affiliations:

a. School of Anthropology, University of Arizona, Tucson, AZ 85721

b. Archaeology Southwest, Tucson, AZ 85701

c. Department of Sociology, University of Wisconsin, Milwaukee, WI 53201

d. Department of Sociology and Anthropology, Hendrix College, Conway, AR 72032

e. Department of Sociology, University of Arizona, Tucson, AZ 85721

f. Department of Computer Science and BioFrontiers Institute, University of Colorado, Boulder, CO 80309

g. Santa Fe Institute, Santa Fe, NM 87501

h. Archaeological XRF Laboratory, Albuquerque, NM 87113

Abstract:

The late pre-Hispanic period in the US Southwest (A.D. 1200–1450) was characterized by large-scale demographic changes, including long-distance migration and population aggregation. To reconstruct how these processes reshaped social networks, we compiled a comprehensive artifact database from major sites dating to this interval in the western Southwest. We combine social network analysis with geographic information systems approaches to reconstruct network dynamics over 250 y. We show how social networks were transformed across the region at previously undocumented spatial, temporal, and social scales. Using well-dated decorated ceramics, we track changes in network topology at 50-y intervals to show a dramatic shift in network density and settlement centrality from the northern to the southern Southwest after A.D. 1300. Both obsidian sourcing and ceramic data demonstrate that long-distance network relationships also shifted from north to south after migration. Surprisingly, social distance does not always correlate with spatial distance because of the presence of network relationships spanning long geographic distances. Our research shows how a large network in the southern Southwest grew and then collapsed, whereas networks became more fragmented in the northern Southwest but persisted. The study also illustrates how formal social network analysis may be applied to large-scale databases of material culture to illustrate multigenerational changes in network structure.

Southwestern Monsoon Projected to be Delayed Under Global Warming

A delay in the summer monsoon rains that fall over the southwestern United States and northwestern Mexico is expected in the coming decades according to a new study in the Journal of Geophysical Research. The North American monsoon delivers as much as 70 percent of the region's annual rainfall, watering crops and rangelands for an estimated 20 million people.

"We hope this information can be used with other studies to build realistic expectations for water resource availability in the future," said study lead author, Benjamin Cook, a climate scientist with joint appointments at Columbia University's Lamont-Doherty Earth Observatory and the NASA Goddard Institute for Space Studies.

Much of the arid U.S. Southwest is expected to get even drier as winter precipitation declines under climate change, but the present modeling study predicts that summer rain levels will stay constant over southern Arizona and New Mexico, and northwestern Mexico. What will shift is the arrival of the heaviest rains, from July and August or so, to September and October, the study says. "There still will be a healthy monsoon which is good news for agriculture in the southern U.S. and northwestern Mexico—the timing is the problem here," said study co-author Richard Seager, a climate scientist at Lamont-Doherty.

A delayed monsoon could potentially lower crop yields as rains come later in the growing season, when the days are getting shorter. By prolonging hot and dry conditions during spring, a late monsoon could also trigger more wildfires and force cities to stretch diminished water supplies. The study makes use of the latest climate change models (those used by the Intergovernmental Panel on Climate Change in its Fifth Assessment Report due out next fall), to estimate monthly changes in precipitation by the end of the century, 2080-2099. The researchers hypothesize that future warming will make it more difficult to form clouds and rainfall early in the monsoon when soils are dry, followed reduced winter rain and snowfall, thus delaying the onset of the monsoon rains until enough moisture can be moved in from the oceans.

Diabloceratops eatoni

There is a guest post by one of the describers, Dr James Kirkland, at Archosaur Musings. Go read. This has been quite a week for ceratopsians!

New Brachiosaur Found

A team of paleontologists has discovered a new dinosaur species they're calling Abydosaurus, which belongs to the group of gigantic, long-necked, long-tailed, four-legged, plant-eating dinosaurs such as Brachiosaurus.

In a rare twist, they recovered four heads – two still fully intact – from a quarry in Dinosaur National Monument in eastern Utah. Complete skulls have been recovered for only eight of more than 120 known varieties of sauropod.

"Their heads are built lighter than mammal skulls because they sit way out at the end of very long necks," said Brooks Britt, a paleontologist at Brigham Young University. "Instead of thick bones fused together, sauropod skulls are made of thin bones bound together by soft tissue. Usually it falls apart quickly after death and disintegrates."

Britt is a co-author on the discovery paper scheduled to appear in the journal Naturwissenshaften.

The lead author is Daniel Chure, a paleontologist at Dinosaur National Monument, who has no trouble boiling down the significance of the discovery.

"We've got skulls!" he shouted with sweeping hand gestures during a recent visit to the site.

BYU geology students and faculty resorted to jackhammers and concrete saws to cut through the hardened 105-million-year-old sandstone containing the bones. At one point the National Park Service called in a crew to blast away the overlying rock with explosives.

The skulls are temporarily on display at BYU's Museum of Paleontology, where visitors can also watch BYU students prepare other bones from Abydosaurus.

"The hardest bone I personally have worked on is a vertebra that was half-eroded before discovery and is so fragile that it crumbles if you look at it wrong," said Kimmy Hales, a geology major studying vertebrate paleontology at BYU. "The funnest project I have worked on was a set of five toe bones. Each toe bone was larger than my hand."

Analysis of the bones indicates that the closest relative of Abydosaurus is Brachiosaurus, which lived 45 million years earlier. The four Abydosaurus specimens were all juveniles.

Most of what scientists know about sauropods is from the neck down, but the skulls from Abydosaurus give a few clues about how the largest land animals to roam the earth ate their food.

"They didn't chew their food; they just grabbed it and swallowed it," Britt said. "The skulls are only one two-hundredth of total body volume and don't have an elaborate chewing system."

All sauropods ate plants and continually replaced their teeth throughout their lives. In the Jurassic Period, sauropods exhibited a wide range of tooth shapes. But by the end of the dinosaur age, all sauropods had narrow, pencil-like teeth.

Abydosaurus teeth are somewhere in between, reflecting a trend toward smaller teeth and more rapid tooth replacement.

No time to discuss...however, does anyone have the age of the fossils?

A New North American Therizinosaur

A new North American therizinosaurid and the role of herbivory in ‘predatory’ dinosaur evolution



1. Lindsay E. Zanno (1,*)
2. David D. Gillette (2)
3. L. Barry Albright (3)
4. Alan L. Titus (4)

-Author Affiliations

1. Department of Geology, The Field Museum

2. Museum of Northern Arizona,

3. Department of Chemistry and Physics, University of North Florida

4. Grand Staircase-Escalante National Monument

* Author for correspondence (lzanno@fieldmuseum.org).


Abstract

Historically, ecomorphological inferences regarding theropod (i.e. ‘predatory’) dinosaurs were guided by an assumption that they were singularly hypercarnivorous. A recent plethora of maniraptoran discoveries has produced evidence challenging this notion. Here, we report on a new species of maniraptoran theropod, Nothronychus graffami sp. nov. Relative completeness of this specimen permits a phylogenetic reassessment of Therizinosauria—the theropod clade exhibiting the most substantial anatomical evidence of herbivory. In the most comprehensive phylogenetic study of the clade conducted to date, we recover Therizinosauria as the basalmost maniraptoran lineage. Using concentrated changes tests, we present evidence for correlated character evolution among herbivorous and hypercarnivorous taxa and propose ecomorphological indicators for future interpretations of diet among maniraptoran clades. Maximum parsimony optimizations of character evolution within our study indicate an ancestral origin for dietary plasticity and facultative herbivory (omnivory) within the clade. These findings suggest that hypercarnivory in paravian dinosaurs is a secondarily derived dietary specialization and provide a potential mechanism for the invasion of novel morpho- and ecospace early in coelurosaurian evolution—the loss of obligate carnivory and origin of dietary opportunism.

Hat tip to Bill Parker of Chinleana.

New Utah Jurassic Excavation

An excavation revealed at least four sauropods, which are long-necked, long-tailed plant-eating dinosaurs, and two carnivorous ones, according to the bureau. It may have also uncovered an herbivorous stegosaurus.

Animal burrows and petrified tree trunks 6 feet in diameter were found nearby. The site doesn't contain any new species but offers scientists the chance to learn more about the ecology of that time, said Scott Foss, a BLM paleontologist.

The fossilized dinosaurs are from the same late Jurassic period as those at Dinosaur National Monument, which straddles the Utah-Colorado state line, and the Cleveland-Lloyd quarry near Price.

[...]

The site, roughly 50 yards wide by 200 yards long, was excavated by a team from the Burpee Museum of Natural History in Rockford, Ill. Museum officials visited the site for about a week last summer and returned this year for a three-week excavation.

[...]

The mix of dinosaurs, trees and other species in the area may help scientists piece together what life was like 145 million years to 150 million years ago, including details about the ancient climate, Foss said.

Four sauropods, two theropods, a stegosaur, burrows (!!!) and petrified trees. That's some haul.