Newly discovered dinosaur Lokiceratops boasts big, blade-like horns - Warner College of Natural Resources
Reconstruction of Lokiceratops in the 78-million-year-old swamps of northern Montana, as two Probrachylophosaurus move past in the background.
Artwork by Fabrizio Lavezzi © Evolutionsmuseet, Knuthenborg
Like almost everything that ever lived, this dinosaur, Lokiceratops, lived in the 99.99975% of history that happened before creationists like to imagine the universe was created. It lived a mere 78 million years before the mythical creation week, to be precise.
An interesting feature of this species - one of a number that appear to have evolved rapidly in the region - is the large 'ornamental' horns that may have been used in courtship, implying female sex-selection played a part. Female sex-selection is a known driver of rapid speciation because it produces genetic isolation and forms an important pre-zygotic barrier to hybridization, just as display and sex-selection does in many birds today.
This could account for the apparent proliferation of these types of dinosaurs.
Tell me about the geology of the 'badlands' of northern Montana, USA and how they were dated, please. The "badlands" of northern Montana, particularly in the region of the Missouri River Breaks, present a fascinating geological landscape characterized by eroded sedimentary rock formations. These badlands extend over a vast area, showcasing dramatic landforms such as deep gullies, steep slopes, and isolated buttes. Here’s an overview of their geology and dating methods:The fossil fragments from which was reconstructed were recovered from the lower portion of the McClelland Ferry Member of the Judith River Formation in the Kennedy Coulee region along the Canada-USA border. The scientists' findings are published in the open access journal, PeerJ and are described in Colorado State University (CSU) news release by Jayme DeLoss:
Geology
- Sedimentary Layers: The badlands consist predominantly of sedimentary rock layers, including shales, sandstones, and mudstones. These rocks were deposited during different geological periods, primarily the Cretaceous Period (about 145 to 66 million years ago) and the Paleogene Period (about 66 to 23 million years ago).
- Depositional Environment: During the Cretaceous, this area was part of the Western Interior Seaway, a vast inland sea that split North America. The sediments were deposited in various environments such as marine, deltaic, and fluvial settings.
- Erosion Processes: The distinctive landforms of the badlands are a result of intense erosion processes. Water, wind, and freeze-thaw cycles have sculpted the landscape over millions of years, exposing the stratified layers and creating the rugged terrain seen today.
- Fossil Content: The sedimentary layers in the badlands are rich in fossils, particularly from the Cretaceous Period. Fossils of dinosaurs, marine reptiles, and early mammals have been found, providing valuable insights into the ancient ecosystems.
Dating Methods
- Radiometric Dating: To date the rocks and fossils within the badlands, geologists often use radiometric dating methods. This technique measures the decay of radioactive isotopes within minerals to determine the age of the rocks. Common isotopes used include Uranium-238 (which decays to Lead-206) and Potassium-40 (which decays to Argon-40).
- Relative Dating: In addition to radiometric dating, geologists employ relative dating techniques. This involves examining the stratigraphic succession of rock layers. The principle of superposition suggests that in an undisturbed sequence, the older layers lie beneath the younger ones. Fossil correlation, where fossils of known ages are used to date rock layers, is also widely applied.
- Paleomagnetic Dating: Another method used is paleomagnetic dating. This technique involves studying the magnetic minerals within rock layers. As these minerals form, they align with the Earth's magnetic field, which has reversed many times throughout history. By comparing the magnetic alignment in the rocks with the known history of geomagnetic reversals, geologists can estimate the age of the rocks.
- Tephrochronology: In areas with volcanic activity, layers of volcanic ash (tephra) can be found interbedded with sedimentary layers. These ash layers can be dated precisely using radiometric methods, providing a timeline that helps date the surrounding sedimentary rocks.
Summary
The badlands of northern Montana are a striking geological feature shaped by millions of years of sediment deposition and erosion. They provide a window into the Earth's past, revealing a history that spans from the time of the dinosaurs to the development of early mammals. Through a combination of radiometric dating, relative dating, paleomagnetic dating, and tephrochronology, geologists have been able to construct a detailed chronology of this unique landscape.
Newly discovered dinosaur Lokiceratops boasts big, blade-like horns
Ancient marvel’s ornate horns point to evolutionary insights
What do you get when you cross Norse mythology with a 78-million-year-old ancestor to the Triceratops? Answer: Lokiceratops rangiformis, a plant-eating dinosaur with a very fancy set of horns.
The new dinosaur was identified and named by Colorado State University affiliate faculty member Joseph Sertich and University of Utah Professor Mark Loewen. The dinosaur’s name, announced today in the scientific journal PeerJ, translates roughly to “Loki’s horned face that looks like a caribou.”
Loewen and Sertich, co-lead authors of the PeerJ study, dubbed the new species Lokiceratops (lo-Kee-sare-a-tops) rangiformis (ran-ɡi-FOHR-mees) because of the unusual, curving blade-like horns on the back of its frill – the shield of bone at the back of the skull – and the asymmetrical horns at the peak of the frill, reminiscent of uneven caribou antlers.
Loewen, a paleontologist at the Natural History Museum of Utah, and Sertich, a paleontologist with the Smithsonian Tropical Research Institute, are both scientific consultants for the Museum of Evolution in Denmark, Lokiceratops’ new home.The dinosaur now has a permanent home in Denmark, so we went with a Norse god, and in the end, doesn’t it just really look like Loki with the curving blades?
Professor Mark A. Loewen, co-lead author
University of Utah, USA.
New dinosaur discoveryIt’s one of those stories with a happy ending, where it didn’t go to somebody’s mansion. It ended up in a museum, where it will be preserved forever so people can study it and enjoy visiting it.
Joseph J. W. Sertich, co-lead author
Evolutionsmuseet, Knuthenborg, Maribo, Denmark,
Smithsonian Tropical Research Institute
Panama City, Panamá, And Department of Geosciences
Colorado State University
Fort Collins, Colorado, USA.
Lokiceratops was discovered in 2019 in the badlands of northern Montana, two miles (3.2 kilometers) south of the U.S.-Canada border. Sertich and Loewen helped reconstruct the dinosaur from fragments the size of dinner plates and smaller. Once they had pieced the skull together, they realized the specimen was a new type of dinosaur.
Study authors Brock Sisson (left), Joseph Sertich (top) and technician Ben Meredith (right) use casts of the real bones to reconstruct the skull of Lokiceratops.Credit: Mark Loewen
Estimated to be 22 feet (6.7 meters) long and weigh 11,000 pounds (5 metric tonnes), Lokiceratops is the largest dinosaur from the group of horned dinosaurs called centrosaurines ever found in North America. It has the largest frill horns ever seen on a horned dinosaur and lacks the nose horn that is characteristic among its kin.
Sertich likened dinosaur horns to feathers on birds. Birds use feather colors and patterns to differentiate their own species among other, similar species of birds.This new dinosaur pushes the envelope on bizarre ceratopsian headgear, sporting the largest frill horns ever seen in a ceratopsian. These skull ornaments are one of the keys to unlocking horned dinosaur diversity and demonstrate that evolutionary selection for showy displays contributed to the dizzying richness of Cretaceous ecosystems. We think that the horns on these dinosaurs were analogous to what birds are doing with displays,” Sertich said. “They’re using them either for mate selection or species recognition.
Joseph J. W. Sertich
What Loki’s horns tell us about dinosaurs
Reconstructed fossil skull bones of Lokiceratops are displayed at the Museum of Evolution in Denmark.Credit: Museum of Evolution
Lokiceratops was excavated from the same rock layer as four other dinosaur species, indicating that five different dinosaurs lived side by side 78 million years ago in the swamps and coastal plains along the eastern shore of Laramidia, the western landmass of North America created when a seaway divided the continent. Three of these species were closely related but not found outside the region.
It’s unheard-of diversity to find five living together, similar to what you would see on the plains of East Africa today with different horned ungulates.
Joseph J. W. Sertich
Unlike the broad range of large wild mammals that roam the U.S. West today, such as elk, these ancient animals were geographically limited, he added. Loki’s discovery provides evidence that these species evolved rapidly within a small area, a process sometimes seen in birds.
By the time Triceratops came onto the scene 12 million years later, regional differences had been homogenized into just two species of horned dinosaurs from Canada to Mexico – possibly in response to a more homogenous climate, Sertich said.
The study shows that dinosaur diversity has been underestimated and presents the most complete family tree of horned dinosaurs to date.
Lokiceratops helps us understand that we only are scratching the surface when it comes to the diversity and relationships within the family tree of horned dinosaurs.
Professor Mark A. Loewen.
AbstractJust to allay creationist hopes that the scientists used a flawed dating method that just happened to make 10,000 years or less look like 78 million years, the team were at pains to pointout that the dating was based on the method that creationists dread most - Uranium/Lead dating of volcanic zircon crystals, but they noted how close this estimate was to that calculated by several other geologists using different methods. And of course we can rule out creationists claims that radioactive decay rates have changed massively in the last 10,000 years because the changes to the weak and strong nuclear forces need for that to be true would have meant atoms could not have existed, so suns, planets and living organisms could not have existed either when creationist mythology claims they were all created out of nothing in a matter of days, by magic.
The Late Cretaceous of western North America supported diverse dinosaur assemblages, though understanding patterns of dinosaur diversity, evolution, and extinction has been historically limited by unequal geographic and temporal sampling. In particular, the existence and extent of faunal endemism along the eastern coastal plain of Laramidia continues to generate debate, and finer scale regional patterns remain elusive. Here, we report a new centrosaurine ceratopsid, Lokiceratops rangiformis, from the lower portion of the McClelland Ferry Member of the Judith River Formation in the Kennedy Coulee region along the Canada-USA border. Dinosaurs from the same small geographic region, and from nearby, stratigraphically equivalent horizons of the lower Oldman Formation in Canada, reveal unprecedented ceratopsid richness, with four sympatric centrosaurine taxa and one chasmosaurine taxon. Phylogenetic results show that Lokiceratops, together with Albertaceratops and Medusaceratops, was part of a clade restricted to a small portion of northern Laramidia approximately 78 million years ago. This group, Albertaceratopsini, was one of multiple centrosaurine clades to undergo geographically restricted radiations, with Nasutuceratopsini restricted to the south and Centrosaurini and Pachyrostra restricted to the north. High regional endemism in centrosaurs is associated with, and may have been driven by, high speciation rates and diversity, with competition between dinosaurs limiting their geographic range. High speciation rates may in turn have been driven in part by sexual selection or latitudinally uneven climatic and floral gradients. The high endemism seen in centrosaurines and other dinosaurs implies that dinosaur diversity is underestimated and contrasts with the large geographic ranges seen in most extant mammalian megafauna.
Introduction
Late Cretaceous dinosaur-dominated ecosystems from the Western Interior of North America present an unparalleled opportunity to examine evolution along a latitudinal gradient and within a relatively constrained time interval (~83 to ~70 Ma). Lying along the alluvial and coastal plains of Laramidia, the differences between dinosaur assemblages of the Western Interior were noted several decades ago (e.g., Russel, 1967, 1969), and they were later divided broadly into northern and southern regions (e.g., Lehman, 1997, 2001).
Recent discoveries from underexplored regions of Laramidia, with increased attention to stratigraphic position, geochronology, and regional ecologies, have refined hypotheses regarding dinosaur distribution and evolution in Laramidia (e.g., Gates et al., 2010b; Sampson & Loewen, 2010.1; Sampson et al., 2010.2; Loewen et al., 2013), though some doubts persist regarding the degree and nature of these differences (e.g., Lucas et al., 2016; Fowler, 2017). Regardless, increased sampling and stratigraphic resolution reveal local and regional patterns in dinosaur evolution, including rapid turnover of megaherbivores (Mallon et al., 2012; Mallon, 2019), potential anagenetic evolution (Horner, Varricchio & Goodwin, 1992; Freedman-Fowler & Horner, 2015; Carr et al., 2017.1; Fowler & Freedman-Fowler, 2020; Wilson, Ryan & Evans, 2020.1), and unexpected new forms (e.g., Brown & Henderson, 2015.1; Wiersma & Irmis, 2018).
Within the dinosaur ecosystems of Laramidia, the Ceratopsidae were geographically widespread and morphologically diverse, possessing highly variable cranial ornaments including horns and morphologically diverse parietosquamosal frills (Marsh, 1891a; Hatcher, Marsh & Lull, 1907; Lull, 1933; Dodson, Forster & Sampson, 2004; Sampson & Loewen, 2010.1). Two distinct clades within Ceratopsidae diverged by at least ~83 Ma. These are the long-nosed, long-frilled Chasmosaurinae, characterized by Chasmosaurus belli (Lambe, 1902), Pentaceratops sternbergii (Osborn, 1923), and Torosaurus latus (Marsh, 1891.1b), and the round-nosed, relatively short-frilled Centrosaurinae, characterized by Diablocerataops eatoni (Kirkland & DeBlieux, 2010.3), Centrosaurus apertus (Lambe, 1904), Styracosaurus albertensis (Lambe, 1913), and Pachyrhinosaurus lakustai (Currie, Langston & Tanke, 2008).
Centrosaurinae represent an ecologically important and diverse radiation of ceratopsids, reaching peak diversity in the Campanian (~83–70 Ma). Historically known from abundant remains in Alberta, Canada and Montana, USA, discoveries over the past two decades have rapidly expanded our understanding of the clade, particularly its geographic (Xu et al., 2010.4; Loewen et al., 2010.5; Fiorillo & Tykoski, 2012.1) and morphologic breadth, with additional insights into centrosaurine ontogeny (Sampson, Ryan & Tanke, 1997.1; Ryan et al., 2001.1; Tumarkin-Deratzian, 2009; Frederickson & Tumarkin-Deratzian, 2014; Brown, Russell & Ryan, 2009.1; Brown et al., 2020.2). Though locally abundant in some localities in southern Alberta and northern Montana (e.g., Centrosaurus apertus (Lambe, 1904), Styracosaurus albertensis (Lambe, 1913), and Pachyrhinosaurus canadensis (Sternberg, 1950)), centrosaurines were previously rare or poorly known from other regions of Laramidia. Our expanding knowledge about centrosaurines includes new taxa from the southwestern United States and Mexico (e.g., Diabloceratops eatoni (Kirkland & DeBlieux, 2010.3), Nasutoceratops titusi (Sampson et al., 2013.1; Lund, Sampson & Loewen, 2016.1), Machairoceratops cornusi (Lund et al., 2016.2), Yehuecauhceratops mudei (Rivera-Sylva, Hendrick & Dodson, 2016.3; Rivera-Sylva et al., 2017.2), Crittendenceratops krzyzanowskii (Dalman et al., 2018.1), Menefeeceratops sealeyi (Dalman et al., 2021)) and new and reinterpreted taxa from Montana and Canada (e.g., Coronosaurus brinkmani (Ryan & Russell, 2005; Ryan, Evans & Shepherd, 2012.2), Albertaceratops nesmoi (Ryan, 2007), Pachyrhinosaurus lakustai (Currie, Langston & Tanke, 2008), Styracosaurus ovatus (McDonald & Horner, 2010.6; Wilson, Ryan & Evans, 2020.1), Spinops sternbergorum Farke et al., 2011, Medusaceratops lokii (Ryan, Russell & Hartman, 2010.7; Chiba et al., 2017.3), Pachyrhinosaurus perotorum (Fiorillo & Tykoski, 2012.1), Xenoceratops foremostensis (Ryan, Evans & Shepherd, 2012.2), Wendiceratops pinhornensis (Evans & Ryan, 2015.2), and Stellasaurus ancellae (Wilson, Ryan & Evans, 2020.1)). Many of these new taxa have changed our understanding of morphological disparity within the clade. This proliferation of new taxa and occurrences has enhanced our understanding of the evolution of Centrosaurinae and provides clues regarding the mechanisms driving diversification of large vertebrates in Laramidia (Sampson & Loewen, 2010.1; Gates et al., 2010.8a).
The Campanian deposits of the Judith River Formation of Montana and the Belly River Group of Alberta and Saskatchewan (Foremost, Oldman, and Dinosaur Park formations) preserve a suite of parasynchronous non-marine biotas. Among the most abundant large vertebrates from these deposits are ceratopsid dinosaurs, including both chasmosaurines and centrosaurines. These assemblages represent some of the richest known from the Western Interior (Weishampel et al., 2004.1; Ryan & Evans, 2005.1; Currie & Russell, 2005.2), spanning sediments dated between ~79.4 and ~75.2 million years ago (Roberts et al., 2013.2; Rogers et al., 2016.4; Ramezani et al., 2022; Rogers, Eberth & Ramezani, 2023).
A new, relatively complete centrosaurine from the lower part of the McClelland Ferry Member of the Judith River Formation, in Kennedy Coulee in northern Montana, USA, is described here as a distinct genus and species, Lokiceratops rangiformis. The new taxon is in the same narrow stratigraphic interval and geographic area (Fig. 1) as three other centrosaurines (Wendiceratops pinhornensis, Albertaceratops nesmoi, and Medusaceratops lokii) and one chasmosaurine (Judiceratops tigris). Morphologically, Lokiceratops resembles both Albertaceratops and Medusaceratops, implying rapid, sympatric diversification within a clade, a pattern not previously seen in dinosaurs. Furthermore, the possible sympatric occurrence of five distinct ceratopsids (four centrosaurines, one chasmosaurine) is unparalleled in any other known interval in Laramidia, even in more heavily sampled and documented horizons (e.g., Mallon et al., 2012). This discovery supports a novel hypothesis that some dinosaur clades saw rapid regional radiations rather than anagenesis in geographically limited regions along the coastal and alluvial plains of Laramidia.
Geological context
Figure 1: Geographic and stratigraphic relationships of the holotype EMK 0012 and the Loki Quarry in northern Montana.
(A) Regional relationships between the cross-border paleontological sites in the Oldman and Judith River formations along the Milk River and in Kennedy Coulee in Alberta and Montana. (B) Generalized stratigraphic section in the Kennedy Coulee area modified after Goodwin & Deino (1989) and Rogers, Eberth & Ramezani (2023) with the relationships between the Foremost and Oldman formations in Canada and the Judith River Formation in Montana. Relative placements of important taxa in this area are indicated. Position of 40Ar/39Ar dates originally obtained by Goodwin & Deino (1989) are shown in relation to the new U–Pb CA-ID-TIMS date for KC061517-1 by Ramezani et al. (2022). Bentonite ash beds are only 5 to 7 cm thick so they are exaggerated for clarity. Scale bars delineated in map view are indicated kilometers and in meters stratigraphically.
The Loki Quarry producing the new specimen lies on private land in the badlands of Kennedy Coulee, north of the town of Rudyard in Hill County, Montana, USA (Fig. 1). The upstream end of Kennedy Coulee is also known as Canadian Creek where it originates north of the US/Canada border, west of its confluence with the Milk River. In these badlands, Campanian alluvial deposits of the lower part of the Judith River Formation (Goodwin & Deino, 1989; Rogers, 1998) crop out extensively along the drainage systems flowing toward the Milk River Valley in the north (Fig. 1).
Following recent stratigraphic revision of the Judith River Formation by Rogers et al. (2016.4), Rogers, Eberth & Ramezani (2023), the exposed Kennedy Coulee beds correlate in the subsurface to the McClelland Ferry Member to the south, as well as to the upper parts of the Foremost and overlying Oldman formations of southern Alberta to the north, including the Taber Coal Zone and the Herronton Sandstone Zone (Ogunyomi & Hills, 1977; Eberth & Hamblin, 1993; Cullen et al., 2016.5; Eberth, 2024). The Taber Coal Zone, representing the top of the Foremost Formation in Alberta and its correlative coal deposits capped by the Marker A Coal exposed to the south in Montana, represents a datum for calibrating stratigraphic sections and associated fossil taxa (Eberth & Hamblin, 1993; Brinkman et al., 2004.2; Eberth, 2005.3; Ryan, 2007; Evans & Ryan, 2015.2; Freedman-Fowler & Horner, 2015; Cullen et al., 2016.5; Ryan et al., 2017.4; Rogers, Eberth & Ramezani, 2023). It should be noted that the Taber Coal Zone is a sequence of coal seams that is much thicker north and west of the Loki Quarry in Canada, near the South Side Ceratopsian Quarry. Physical tracing of this interval along the Milk River into Kennedy Coulee in the area of the Loki Quarry demonstrates that it is laterally continuous with the Marker A Coal seam.
The Loki Quarry lies near two other significant ceratopsian localities in the same Canadian Creek area within Kennedy Coulee (Fig. 1). The Loki Quarry is 4.9 km northwest of the site where the holotype of the putative chasmosaurine ceratopsid Judiceratops tigris (YPM VPPU 022404) was collected, and 2.6 km west of the Mansfield Bonebed (Medusaceratops lokii). The Mansfield Bonebed that produced Medusaceratops occurs ~8 km southwest of the Probrachylophosaurus bergei quarry. The Loki Quarry lies 2.8 km west of the Brachylophosaurus goodwini (Horner, 1988) holotype locality (UCMP Locality No. V83125). Two other important ceratopsian quarries lie just north of the Montana/Alberta border. The South Side Ceratopsian Wendiceratops quarry (Evans & Ryan, 2015.2) is 10 km north of the Montana-Alberta border and the Albertaceratops quarry (Ryan, 2007) is 3.5 km north of the South Side Ceratopsian Wendiceratops quarry. The Loki Quarry is 22 km southwest of the South Side Ceratopsian quarry (Fig. 1).
The Loki Quarry sits 922 m above sea level and 11.4 m above the top of the Marker A Coal (MAC) seam. The MAC seam is equivalent to the top of the Taber Coal Zone (sensu Goodwin & Deino, 1989) based on multiple sections measured in the Kennedy Coulee and at the Probrachylophosaurus (Freedman-Fowler & Horner, 2015) locality (MOR locality JR-518). The Mansfield Bonebed producing Medusaceratops occurs ~10 m above the MAC. All of these quarries occur near the top of a 10–15 m thick interval of interbedded organic-rich mudstones with discontinuous carbonaceous seams, siltstone, and sandstones (Fig. 1).
The stratigraphic occurrence of the Loki Quarry places it above Medusaceratops (~10 m above the MAC) and places both taxa within equivalents of the Herronton Sandstone Zone, in the same stratigraphic interval where Albertaceratops and Wendiceratops were recovered in southern Alberta. Correlation to the top of the Taber Coal Zone (TCZ) places Albertaceratops slightly lower in section (~8 m above the TCZ) with respect to Medusaceratops (~10 m above the MAC) and places the Loki Quarry at roughly the same level as Wendiceratops (~8 and 12 m above the TCZ), making them virtually indistinguishable stratigraphically. The multiple mudstone and sandstone beds and channel deposits recognized as the Herronton Sandstone Zone and its correlative equivalents in the McClelland Ferry Member to the south are laterally discontinuous and variable in nature across the region from north to south and east to west, but do represent a package of similar deposition (Rogers et al., 2016.4; Eberth, 2024). These relationships suggest that these centrosaurine quarries are stratigraphically equivalent within the precision that is possible, even though the relative occurrences of these taxa may be slightly uncertain with respect to one another.
Two bentonite ash beds that bracket the Loki Quarry (21 m below and 16 m above) were first radiometrically dated by Goodwin & Deino (1989). The single-crystal, laser-fusion 40Ar/39Ar ages on biotite crystals yielded a weighted mean of 78.5 ± 0.2 Ma for bentonite 85MG7-16-1, approximately 21 m below the quarry, and a weighted mean of 78.2 ± 0.2 Ma for bentonite 84MG8-3-4, approximately 16 m above the quarry (Fig. 1). The ages were recalibrated to the Fish Canyon Tuff (Kuiper et al., 2008.1; Renne et al., 2011.1) by Roberts et al. (2013.2) to 79.02 and 78.71 Ma respectively (using the original legacy decay constant and known fluence monitors) and by Fowler (2017.5) to 79.76 ± 0.2 and 79.46 ± 0.2 Ma using the original mean. For the purposes of this study, and until additional geochronologic work is undertaken in the northern Judith River Fm near the study area, we instead prefer to use recently published high-precision U-Pb dates of Ramezani et al. (2022), summarized below.
High-precision U–Pb analyses of zircons by the CA-ID-TIMS method from a bentonitic ash bed within Marker A Coal (KC061517-1) 11.4 m below the Loki Quarry date to 78.594 ± 0.024 Ma (Ramezani et al., 2022). Bayesian model uncertainty constrained by U-Pb dates (Ramezani et al., 2022) places the Loki Quarry between 78.4 and 77.2 Ma, with a model median age estimate of roughly 78.1 Ma. The use of Bayesian models to bound ages allows for better accommodation of changes in sedimentation and more honest (i.e., asymmetric) evaluation of uncertainties.
The lithology of the Loki Quarry is characterized by carbonaceous fine-grained sandstones, siltstones, and mudstones, with depositional features indicating a poorly-drained fluvial system (Figs. 1 and 2). Gar scales and mollusks occur in the quarry. Some of the quarry matrix is in the collections of Evolutionsmuseet, Knuthenborg, Maribo, Denmark. Carbonized plant fragments are common, many attributable to Araucariales, along with beads of amber and indeterminate fragments of carbonized wood.
Many bones recovered from the quarry are broken, but there is no evidence of subaerial or subaqueous weathering of any elements. Some breakage may reflect collection techniques, because most elements were plucked from the quarry sediments and only two plaster jackets (scapulocoracoid and sacrum) were made. Many of the bones were plasticly deformed after deposition by compression of the clay-rich, fine-grained sediments. This deformation skews the bones so that the mount does not accurately represent the skull shape. Taphonomic indicators, including a high degree of association of the cranial bones (Fig. 2), indicate little to no fluvial transport after death and disarticulation.
Figure 2: The Loki Quarry where EMK 0012 was excavated in Hill County, northcentral Montana USA.
(A) View of the Loki Quarry facing north. (B) Quarry map with 1-m grids marked by corner ticks. (C) Osetograph of the skeletal completeness of EMK 0012, cranial elements represent presence on either right or left side. (D) Jacketed pelvic block awaiting removal from the Loki Quarry. Osteological abbreviations: ca, caudal vertebrae; co, coracoid; ej, epijugal, il, ilium; is, ischium; j, jugal; l, lacrimal; m, maxilla; oc, occipital condyle; pa, parietal; pb, palpebral; pm, premaxilla; po, postorbital; q, quadrate; qj, quadratojugal; r, rostral; sc, scapula sq, squamosal. Skeletal reconstruction by Mark Loewen. Photo A by David Evans and Photo D provided courtesy of Evolutionsmuseet, Knuthenborg, Maribo, Denmark. Scale bar in C equals 2 m.
Discovery and excavational history
EMK 0012 is an associated skeleton of a mature ceratopsid. The specimen was discovered by Mark Eatman on private land of the Wolery Ranch in Kennedy Coulee in late spring of 2019 and excavated under lease later that fall. The skull was associated, but partially disarticulated. The right jugal and squamosal were found together, dorsal side up. Portions of the parietosquamosal frill were found in close association. Both orbits and postorbital horns were found on either side of the braincase, with both maxillae directly in front of them followed by the nasal, premaxillae, and rostral. The synsacrum and ilia were found ventral side facing up, with the right ischium in articulation; the left ischium lay one meter away (Fig. 2). The left parietal with fused epiparietals ep1–ep7 was found dorsal side up along with the left ischium. The right scapulocoracoid was found medial side up just posterior to the pelvis. The free anterior caudal vertebra and chevron were found next to the pelvis. Legal ownership of EMK 0012 was permanently transferred to Evolutionsmuseet, Knuthenborg in 2021 where the specimen is available to researchers.Mounting and restoration was performed by Ben Meredith, Ethan Storrer, Jose Muñoz, and Seth Bourgeous during the spring of 2022. Upon completion of the mount, two large solid wooden crates were constructed. One held the steel and replica material, and the other was for packing of all of the original material. The packing was done using a custom spray-in-place foam system that allowed for a perfectly form fitting, reusable padding that protects the specimen during transport. Upon completion, the specimen was transported to Evolutionsmuseet, Knuthenborg, Maribo, Denmark via airfreight, where it was received by museum staff.Figure 3: Mounted skull of EMK 0012.
(A) Mounted skull in posterior view. (B) Mounted skull in right lateral view. (C) Mounted skull in dorsal view. (D) Mounted skull in left lateral view. Areas in gray are reconstructed. Minor changes from side to side and in the orbits are the result of post depositional deformation. Photos by Marcus Donivan and contain parallax. Scale bar equals 1 m.
Loewen MA, Sertich JJW, Sampson S, O’Connor JK, Carpenter S, Sisson B, Øhlenschlæger A, Farke AA, Makovicky PJ, Longrich N, Evans DC. 2024.
Lokiceratops rangiformis gen. et sp. nov. (Ceratopsidae: Centrosaurinae) from the Campanian Judith River Formation of Montana reveals rapid regional radiations and extreme endemism within centrosaurine dinosaurs.
PeerJ 12:e17224 https://doi.org/10.7717/peerj.17224
Copyright: © 2024 The authors.
Published by PeerJ, Inc. Open access.
Reprinted under a Creative Commons Attribution 4.0 International license (CC BY 4.0)
But then, if the evidence of dinosaurs living and rapidly speciating around 78 million years ago doesn't convince creationists that evolution happens and Earth is billions of years old, then nothing will, because their superstition isn't based on evidence but on the unshakable conviction that their mummy and daddy couldn't possibly have been wrong, so what they believed in must be true.
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Obscene, threatening or obnoxious messages, preaching, abuse and spam will be removed, as will anything by known Internet trolls and stalkers, by known sock-puppet accounts and anything not connected with the post,
A claim made without evidence can be dismissed without evidence. Remember: your opinion is not an established fact unless corroborated.