To see the other types of publications on this topic, follow the link: Dinosaurs.
Journal articles on the topic 'Dinosaurs'
Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles
Consult the top 50 journal articles for your research on the topic 'Dinosaurs.'
Next to every source in the list of references, there is an 'Add to bibliography' button. Press on it, and we will generate automatically the bibliographic reference to the chosen work in the citation style you need: APA, MLA, Harvard, Chicago, Vancouver, etc.
You can also download the full text of the academic publication as pdf and read online its abstract whenever available in the metadata.
Browse journal articles on a wide variety of disciplines and organise your bibliography correctly.
1
Nesbitt, Sterling J., Paul M. Barrett, Sarah Werning, Christian A. Sidor, and Alan J. Charig. "The oldest dinosaur? A Middle Triassic dinosauriform from Tanzania." Biology Letters 9, no. 1 (February 23, 2013): 20120949. http://dx.doi.org/10.1098/rsbl.2012.0949.
Full textAbstract:
The rise of dinosaurs was a major event in vertebrate history, but the timing of the origin and early diversification of the group remain poorly constrained. Here, we describe Nyasasaurus parringtoni gen. et sp. nov., which is identified as either the earliest known member of, or the sister–taxon to, Dinosauria. Nyasasaurus possesses a unique combination of dinosaur character states and an elevated growth rate similar to that of definitive early dinosaurs. It demonstrates that the initial dinosaur radiation occurred over a longer timescale than previously thought (possibly 15 Myr earlier), and that dinosaurs and their immediate relatives are better understood as part of a larger Middle Triassic archosauriform radiation. The African provenance of Nyasasaurus supports a southern Pangaean origin for Dinosauria.
2
Chure, Daniel J. "Quo Vadis Tyrannosaurus?: The Future of Dinosaur Studies." Short Courses in Paleontology 2 (1989): 175–83. http://dx.doi.org/10.1017/s2475263000000957.
Full textAbstract:
“Although I work a lot with fossils in my own research on fishes, I do not care to be called a paleontologist; and I am turned off by many aspects of the public-relations hoopla surrounding paleontology, especially dinosaurs…. One could easily argue that the schools' fascination with dinosaurs might also detract from the other aspects of earth science and biological science and, in the end, weaken paleontology's image as an activity for hard-nosed grown-ups.”K.S. Thomson, 1985: p. 73“Let dinosaurs be dinosaurs. Let the Dinosauria stand proudly alone, a Class by itself. They merit it. And let us squarely face the dinosaurness of birds and the birdness of the Dinosauria. When the Canada geese honk their way northward, we can say: “The dinosaurs are migrating, it must be spring!”R.T. Bakker, 1986: p. 462It is a now oft-repeated statement that we are in the Second Golden Age of dinosaur studies. This may at first seem to be yet another overstatement by dinosaur fanatics; in fact, it is substantiated on a number of fronts. Research activity is certainly at an all-time high, with resident dinosaur researchers on every continent (except Antarctica) and dinosaurs known from every continent (including Antarctica). This activity has resulted in a spate of discoveries, including not only new genera and species, but entirely new types of dinosaurs, such as the segnosaurs. Well-known groups are producing surprises, such as armored sauropods and sauropods bearing tail clubs. Good specimens of previously named genera are revealing unsuspected structural features that almost defy explanation, as in the skull of Oviraptor. However, dinosaur studies extend far beyond the traditional emphasis on dinosaur morphology, and encompass paleobiogeography, paleoecology, taphonomy, physiology, tracks, eggs, histology, and extinction, among others. In some cases, several of these studies can be applied to a single taxon or locality to give us a fairly detailed understanding of the paleobiology of some species.
3
Nesbitt, Sterling J., and Hans-Dieter Sues. "The osteology of the early-diverging dinosaur Daemonosaurus chauliodus (Archosauria: Dinosauria) from the Coelophysis Quarry (Triassic: Rhaetian) of New Mexico and its relationships to other early dinosaurs." Zoological Journal of the Linnean Society 191, no. 1 (August 3, 2020): 150–79. http://dx.doi.org/10.1093/zoolinnean/zlaa080.
Full textAbstract:
Abstract The early evolution of dinosaurs is documented by abundant postcranial material, but cranial material is much rarer and comparisons of cranial features among early dinosaurs are limited to only a few specimens. Here, we fully detail the osteology of the unusual early-diverging dinosaur Daemonosaurus chauliodus from the latest Triassic Coelophysis Quarry in northern New Mexico, USA. The taxon possesses a unique and curious suite of character states present in a variety of early dinosaurs, and the morphology of D. chauliodus appears to link the morphology of Herrerasaurus with that of later diverging eusaurichians. Our phylogenetic analyses places D. chauliodus at the base of dinosaurs and our interpretation of the unusual mix of character states of D. chauliodus does not lead to a firm conclusion about its nearest relationships or its implications for the evolution of character state transitions at the base of Dinosauria. The combination of character states of D. chauliodus should not be ignored in future considerations of character evolution in early dinosaurs. As one of the last members of the earliest radiation of saurischians in the Carnian–early Norian, D. chauliodus demonstrates that members of the original diversification of dinosaurs survived until nearly the end of the Triassic Period.
4
Leach, Connor T., Emma Hoffman, and Peter Dodson. "The promise of taphonomy as a nomothetic discipline: taphonomic bias in two dinosaur-bearing faunas in North America1." Canadian Journal of Earth Sciences 58, no. 9 (September 2021): 852–69. http://dx.doi.org/10.1139/cjes-2020-0176.
Full textAbstract:
The fossil record of dinosaurs is a rich, if biased, one with nearly complete skeletons, partial skeletons, and isolated parts found in diverse, well-studied faunal assemblages around the world. Among the recognized biases are the preferential preservation of large dinosaurs and the systematic underrepresentation of small dinosaurs. Such biases have been quantitatively described in the Upper Cretaceous (Campanian) Dinosaur Park Formation of Alberta, where large, nearly complete dinosaurs were found and described early in collecting history and small, very incomplete dinosaurs were found and described later. This pattern, apparently replicated in the Maastrichtian Hell Creek Formation of Montana, is so striking that it begs the question of whether this is a nomothetic principle for the preservation of dinosaur faunas elsewhere. We tested this hypothesis by analyzing the very well-studied dinosaur fauna of the Upper Jurassic (Kimmeridgian) Morrison Formation of the western United States. The Morrison Formation fails to show any correlation between body size and completeness, order of discovery, or order of description. Both large and small dinosaurs of the Morrison include highly complete as well as highly incomplete taxa, and both large and small dinosaurs were discovered and described early in collecting history as well as more recently. The differences in preservation between the Dinosaur Park Formation and the Morrison Formation are so striking that we posit a Dinosaur Park model of dinosaur fossil preservation and a Morrison model. Future study will show whether either or both represent durable nomothetic models for dinosaur fossil preservation.
5
Padian, Kevin. "The problem of dinosaur origins: integrating three approaches to the rise of Dinosauria." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 103, no. 3-4 (September 2012): 423–42. http://dx.doi.org/10.1017/s1755691013000431.
Full textAbstract:
ABSTRACTThe problem of the origin of dinosaurs has historically had three dimensions. The first is the question of whether Dinosauria is monophyletic, and of its relationships to other archosaurs. This question was plagued from the beginning by a lack of relevant fossils, an historical burden of confusing taxonomic terms and a rudimentary approach to devising phylogenies. The second dimension concerns the functional and ecological adaptations that differentiated dinosaurs from other archosaurs, a question also marred by lack of phylogenetic clarity and testable biomechanical hypotheses. The third dimension comprises the stratigraphic timing of the origin of dinosaurian groups with respect to each other and to related groups, the question of its synchronicity among various geographic regions, and some of the associated paleoenvironmental circumstances. None of these dimensions alone answers the question of dinosaur origins, and they sometimes provide conflicting implications. Since Dinosauria was named, one or another set of questions has historically dominated academic discussion and research. Paradigms have shifted substantially in recent decades, and current evidence suggests that we are due for more such shifts. I suggest two changes in thinking about the beginning of the “Age of Dinosaurs”: first, the event that we call the (phylogenetic) origin of dinosaurs was trivial compared to the origin of Ornithodira; and second, the “Age of Dinosaurs” proper did not begin until the Jurassic. Re-framing our thinking on these issues will improve our understanding of clade dynamics, timing of macroevolutionary events, and the effects of Triassic climate change on terrestrial vertebrates.
6
Jenkins, Xavier, John Foster, and Robert Gay. "First unambiguous dinosaur specimen from the Upper Triassic Chinle Formation in Utah." Geology of the Intermountain West 4 (December 15, 2017): 231–42. http://dx.doi.org/10.31711/giw.v4.pp231-242.
Full textAbstract:
Triassic dinosaurs represent relatively rare but important components of terrestrial faunas across Pangea. Whereas this record has been well studied at various locales across the American West, there has been no previous systematic review of Triassic material assigned to Dinosauria from Utah. Here, we critically examine the published body fossil and footprint record of Triassic dinosaurs from Utah and revise their record from the state. In addition, we describe a sacrum from a locality within the Upper Triassic Chinle Formation of southeastern Utah. _is specimen represents the only unambiguous Triassic dinosaur body fossil from Utah. MWC 5627 falls within the range of variation known for sacrum morphology from Coelophysis bauri. Based on a literature review and examination of specimens available to us, we restrict the Triassic Utah dinosaurian record to _eropoda from the Chinle Formation. Preliminary reports of Triassic dinosaurs from other clades and formations in Utah are unsubstantiated.
7
Jenkins, Xavier A., John R. Foster, and Robert J. Gay. "First unambiguous dinosaur specimen from the Upper Triassic Chinle Formation in Utah." Geology of the Intermountain West 4 (August 15, 2017): 231–42. http://dx.doi.org/10.31711/giw.v4i0.16.
Full textAbstract:
Triassic dinosaurs represent relatively rare but important components of terrestrial faunas across Pangea. Whereas this record has been well studied at various locales across the American West, there has been no previous systematic review of Triassic material assigned to Dinosauria from Utah. Here, we critically examine the published body fossil and footprint record of Triassic dinosaurs from Utah and revise their record from the state. In addition, we describe a sacrum from a locality within the Upper Triassic Chinle Formation of southeastern Utah. _is specimen represents the only unambiguous Triassic dinosaur body fossil from Utah. MWC 5627 falls within the range of variation known for sacrum morphology from Coelophysis bauri. Based on a literature review and examination of specimens available to us, we restrict the Triassic Utah dinosaurian record to _eropoda from the Chinle Formation. Preliminary reports of Triassic dinosaurs from other clades and formations in Utah are unsubstantiated.
8
Egorov, Pavel, Evgeny Nesterov, Stanislav Dubrova, Konstantin Shmoylov, and Maria Markova. "Variability in biological diversity of dinosaurs and types of their diet." E3S Web of Conferences 371 (2023): 01087. http://dx.doi.org/10.1051/e3sconf/202337101087.
Full textAbstract:
Biodiversity analysis underlies macroevolutionary studies and allows to identify mass extinctions. Numerous studies of mass extinctions show that geological factors play a central role in determining the diversity dynamics. The late Cretaceous extinction is of interest to science as the closest to us extinction of the five mass extinctions that occurred in the Phanerozoic. There is currently no scientific consensus on the scenario in which the extinction occurred on land. In order to assess the features of superorder Dinosauria development during the Cretaceous-Paleogene, the authors have analysed the diversity of terrestrial taxa of Mesozoic dinosaurs. Based on data from the paleobiodb paleontological database using the Python programming language and its libraries, the features of the species diversity of Dinosauria have been studied. An attempt was made to quantify the species diversity of this group based on the ratio of predators to herbivores using data on dinosaur food types. The simulated diversity data were compared with observed patterns and existing estimates. It is likely that less than one-third of the dinosaurs that existed are currently known, as indicated by the geography of the fossils, and the proportions of dinosaurs by type of diet.
9
Irmis, Randall B. "Evaluating hypotheses for the early diversification of dinosaurs." Earth and Environmental Science Transactions of the Royal Society of Edinburgh 101, no. 3-4 (September 2010): 397–426. http://dx.doi.org/10.1017/s1755691011020068.
Full textAbstract:
ABSTRACTMany hypotheses have been proposed for the rise of dinosaurs, but their early diversification remains poorly understood. This paper examines the occurrences, species diversity and abundance of early dinosaurs at both regional and global scales to determine patterns of their early evolutionary history. Four main patterns are clear: (1) sauropodomorph dinosaurs became abundant during the late Norian–Rhaetian of Gondwana and Europe; (2) Triassic dinosaurs of North America have low species diversity and abundance until the beginning of the Jurassic; (3) sauropodomorphs and ornithischians are absent in the Triassic of North America; and (4) ornithischian dinosaurs maintain low species diversity, relative abundance and small body size until the Early Jurassic. No one hypothesis fully explains these data. There is no evidence for a Carnian–Norian extinction event, but sauropodomorphs did become abundant during the Norian in some assemblages. No clear connection exists between palaeoenvironment and early dinosaur diversity, but environmental stress at the Triassic–Jurassic boundary is consistent with changes in North American dinosaur assemblages. Elevated growth rates in dinosaurs are consistent with the gradual phyletic increase in body size. This study demonstrates that early dinosaur diversification was a complex process that was geographically diachronous and probably had several causes.
10
Seebacher, Frank. "Dinosaur body temperatures: the occurrence of endothermy and ectothermy." Paleobiology 29, no. 1 (2003): 105–22. http://dx.doi.org/10.1666/0094-8373(2003)029<0105:dbttoo>2.0.co;2.
Full textAbstract:
Despite numerous studies, the thermal physiology of dinosaurs remains unresolved. Thus, perhaps the commonly asked question whether dinosaurs were ectotherms or endotherms is inappropriate, and it is more constructive to ask which dinosaurs were likely to have been endothermic and which ones ectothermic. Field data from crocodiles over a large size range show that body temperature fluctuations decrease with increasing body mass, and that average daily body temperatures increase with increasing mass. A biophysical model, the biological relevance of which was tested against field data, was used to predict body temperatures of dinosaurs. However, rather than predicting thermal relations of a hypothetical dinosaur, the model considered correct paleogeographical distribution and climate to predict the thermal relations of a large number of dinosaurs known from the fossil record (>700). Many dinosaurs could have had “high” (>30°) and stable (daily amplitude >2°) body temperatures without metabolic heat production even in winter, so it is unlikely that selection pressure would have favored the evolution of elevated resting metabolic rates in those species. Recent evidence of ontogenetic growth rates indicates that even the juveniles of large species (3000–4000 kg) could have had biologically functional body temperature ranges during early development. Smaller dinosaurs (<100 kg) at mid to high latitudes (>45°) could not have had high and stable body temperatures without metabolic heat production. However, elevated metabolic rates were unlikely to have provided selective advantage in the absence of some form of insulation, so probably insulation was present before endothermy evolved, or else it coevolved with elevated metabolic rates. Superimposing these findings onto a phylogeny of the Dinosauria suggests that endothermy most likely evolved among the Coelurosauria and, to a lesser extent, among the Hypsilophodontidae, but not among the Stegosauridae, Nodosauridae, Ankylosauridae, Hadrosauridae, Ceratopsidae, Prosauropoda, and Sauropoda.
11
Fukuoka, Yasuhiro, and Junki Akama. "Dynamic bipedal walking of a dinosaur-like robot with an extant vertebrate's nervous system." Robotica 32, no. 6 (December 5, 2013): 851–65. http://dx.doi.org/10.1017/s0263574713001045.
Full textAbstract:
SUMMARYIn this study, we attempt to develop a biped dinosaur-like walking robot by focusing on its nervous system as well as its mechanism. We developed a robot ‘Dinobot’ on the basis of palaeontological knowledge on dinosaurs and extant animals. In addition, we employed typical biologically inspired walking gait generation and control methods derived from an extant vertebrate's nervous system. In particular, we utilized a central pattern generator (CPG), which is a locomotion rhythm generator in a vertebrate's spinal cord, to generate the robot's walking rhythm. Moreover, a reflex centre was placed below CPG and it produced joint torque of the legs in the swing and stance phases. Thus, we successfully achieved adaptive 3D dynamic walking generated by the interaction between the original mechanism of dinosaurs and the nervous system of extant animals. Our future goal is to find out a dinosaur's robust locomotive nervous system suitable for its mechanism.
12
Sereno, Paul C. "Evolution of Bird-Hipped Dinosaurs (Ornithischia)." Short Courses in Paleontology 2 (1989): 48–57. http://dx.doi.org/10.1017/s2475263000000842.
Full textAbstract:
By the end of the last century, the assortment of dinosaur skeletons that had already accumulated were classified into two groups of approximately equal size based on the divergent plan of their hip bones: Saurischia, the “lizard-hipped” dinosaurs, and Ornithischia, the “bird-hipped” dinosaurs (Seeley, 1888). Today we continue to follow this early dinosaur classification, albeit for somewhat different reasons, and consider that it captures a fundamental, ancient bifurcation in dinosaur evolutionary history.
13
Curry Rogers, Kristina, Ricardo N. Martínez, Carina Colombi, Raymond R. Rogers, and Oscar Alcober. "Osteohistological insight into the growth dynamics of early dinosaurs and their contemporaries." PLOS ONE 19, no. 4 (April 3, 2024): e0298242. http://dx.doi.org/10.1371/journal.pone.0298242.
Full textAbstract:
Dinosauria debuted on Earth’s stage in the aftermath of the Permo-Triassic Mass Extinction Event, and survived two other Triassic extinction intervals to eventually dominate terrestrial ecosystems. More than 231 million years ago, in the Upper Triassic Ischigualasto Formation of west-central Argentina, dinosaurs were just getting warmed up. At this time, dinosaurs represented a minor fraction of ecosystem diversity. Members of other tetrapod clades, including synapsids and pseudosuchians, shared convergently evolved features related to locomotion, feeding, respiration, and metabolism and could have risen to later dominance. However, it was Dinosauria that radiated in the later Mesozoic most significantly in terms of body size, diversity, and global distribution. Elevated growth rates are one of the adaptations that set later Mesozoic dinosaurs apart, particularly from their contemporary crocodilian and mammalian compatriots. When did the elevated growth rates of dinosaurs first evolve? How did the growth strategies of the earliest known dinosaurs compare with those of other tetrapods in their ecosystems? We studied femoral bone histology of an array of early dinosaurs alongside that of non-dinosaurian contemporaries from the Ischigualasto Formation in order to test whether the oldest known dinosaurs exhibited novel growth strategies. Our results indicate that the Ischigualasto vertebrate fauna collectively exhibits relatively high growth rates. Dinosaurs are among the fastest growing taxa in the sample, but they occupied this niche alongside crocodylomorphs, archosauriformes, and large-bodied pseudosuchians. Interestingly, these dinosaurs grew at least as quickly, but more continuously than sauropodomorph and theropod dinosaurs of the later Mesozoic. These data suggest that, while elevated growth rates were ancestral for Dinosauria and likely played a significant role in dinosaurs’ ascent within Mesozoic ecosystems, they did not set them apart from their contemporaries.
14
Bailleul, Alida M., Jingmai O’Connor, and Mary H. Schweitzer. "Dinosaur paleohistology: review, trends and new avenues of investigation." PeerJ 7 (September 27, 2019): e7764. http://dx.doi.org/10.7717/peerj.7764.
Full textAbstract:
In the mid-19th century, the discovery that bone microstructure in fossils could be preserved with fidelity provided a new avenue for understanding the evolution, function, and physiology of long extinct organisms. This resulted in the establishment of paleohistology as a subdiscipline of vertebrate paleontology, which has contributed greatly to our current understanding of dinosaurs as living organisms. Dinosaurs are part of a larger group of reptiles, the Archosauria, of which there are only two surviving lineages, crocodilians and birds. The goal of this review is to document progress in the field of archosaur paleohistology, focusing in particular on the Dinosauria. We briefly review the “growth age” of dinosaur histology, which has encompassed new and varied directions since its emergence in the 1950s, resulting in a shift in the scientific perception of non-avian dinosaurs from “sluggish” reptiles to fast-growing animals with relatively high metabolic rates. However, fundamental changes in growth occurred within the sister clade Aves, and we discuss this major evolutionary transition as elucidated by histology. We then review recent innovations in the field, demonstrating how paleohistology has changed and expanded to address a diversity of non-growth related questions. For example, dinosaur skull histology has elucidated the formation of curious cranial tissues (e.g., “metaplastic” tissues), and helped to clarify the evolution and function of oral adaptations, such as the dental batteries of duck-billed dinosaurs. Lastly, we discuss the development of novel techniques with which to investigate not only the skeletal tissues of dinosaurs, but also less-studied soft-tissues, through molecular paleontology and paleohistochemistry—recently developed branches of paleohistology—and the future potential of these methods to further explore fossilized tissues. We suggest that the combination of histological and molecular methods holds great potential for examining the preserved tissues of dinosaurs, basal birds, and their extant relatives. This review demonstrates the importance of traditional bone paleohistology, but also highlights the need for innovation and new analytical directions to improve and broaden the utility of paleohistology, in the pursuit of more diverse, highly specific, and sensitive methods with which to further investigate important paleontological questions.
15
Doran Brownstein, Chase. "Dinosaurs from the Santonian–Campanian Atlantic coastline substantiate phylogenetic signatures of vicariance in Cretaceous North America." Royal Society Open Science 8, no. 8 (August 2021): 210127. http://dx.doi.org/10.1098/rsos.210127.
Full textAbstract:
During the Cretaceous, diversifications and turnovers affected terrestrial vertebrates experiencing the effects of global geographical change. However, the poor fossil record from the early Late Cretaceous has concealed how dinosaurs and other terrestrial vertebrates responded to these events. I describe two dinosaurs from the Santonian to Early Campanian of the obscure North American paleolandmass Appalachia. A revised look at a large, potentially novel theropod shows that it likely belongs to a new clade of tyrannosauroids solely from Appalachia. Another partial skeleton belongs to an early member of the Hadrosauridae, a highly successful clade of herbivorous dinosaurs. This skeleton is associated with the first small juvenile dinosaur specimens from the Atlantic Coastal Plain. The tyrannosauroid and hadrosaurid substantiate one of the only Late Santonian dinosaur faunas and help pinpoint the timing of important anatomical innovations in two widespread dinosaur lineages. The phylogenetic positions of the tyrannosauroid and hadrosaurid show Santonian Appalachian dinosaur faunas are comparable to coeval Eurasian ones, and the presence of clades formed only by Appalachian dinosaur taxa establishes a degree of endemism in Appalachian dinosaur assemblages attributable to episodes of vicariance.
16
Bittencourt, Jonathas S., and Max C. Langer. "Mesozoic dinosaurs from Brazil and their biogeographic implications." Anais da Academia Brasileira de Ciências 83, no. 1 (March 2011): 23–60. http://dx.doi.org/10.1590/s0001-37652011000100003.
Full textAbstract:
The record of dinosaur body-fossils in the Brazilian Mesozoic is restricted to the Triassic of Rio Grande do Sul and Cretaceous of various parts of the country. This includes 21 named species, two of which were regarded as nomina dubia, and 19 consensually assigned to Dinosauria. Additional eight supraspecific taxa have been identified based on fragmentary specimens and numerous dinosaur footprints known in Brazil. In fact, most Brazilian specimens related to dinosaurs are composed of isolated teeth and vertebrae. Despite the increase of fieldwork during the last decade, there are still no dinosaur body-fossils of Jurassic age and the evidence of ornithischians in Brazil is very limited. Dinosaur faunas from this country are generally correlated with those from other parts of Gondwana throughout the Mesozoic. During the Late Triassic, there is a close correspondence to Argentina and other south-Pangaea areas. Mid-Cretaceous faunas of northeastern Brazil resemble those of coeval deposits of North Africa and Argentina. Southern hemisphere spinosaurids are restricted to Africa and Brazil, whereas abelisaurids are still unknown in the Early Cretaceous of the latter. Late Cretaceous dinosaur assemblages of south-central Brazil are endemic only to genus or, more conspicuously, to species level, sharing closely related taxa with Argentina, Madagascar, Indo-Pakistan and, to a lesser degree, continental Africa.
17
Brusatte, Stephen L., Michael J. Benton, Marcello Ruta, and Graeme T. Lloyd. "The first 50 Myr of dinosaur evolution: macroevolutionary pattern and morphological disparity." Biology Letters 4, no. 6 (September 23, 2008): 733–36. http://dx.doi.org/10.1098/rsbl.2008.0441.
Full textAbstract:
The evolutionary radiation of dinosaurs in the Late Triassic and Early Jurassic was a pivotal event in the Earth's history but is poorly understood, as previous studies have focused on vague driving mechanisms and have not untangled different macroevolutionary components (origination, diversity, abundance and disparity). We calculate the morphological disparity (morphospace occupation) of dinosaurs throughout the Late Triassic and Early Jurassic and present new measures of taxonomic diversity. Crurotarsan archosaurs, the primary dinosaur ‘competitors’, were significantly more disparate than dinosaurs throughout the Triassic, but underwent a devastating extinction at the Triassic–Jurassic boundary. However, dinosaur disparity showed only a slight non-significant increase after this event, arguing against the hypothesis of ecological release-driven morphospace expansion in the Early Jurassic. Instead, the main jump in dinosaur disparity occurred between the Carnian and Norian stages of the Triassic. Conversely, dinosaur diversity shows a steady increase over this time, and measures of diversification and faunal abundance indicate that the Early Jurassic was a key episode in dinosaur evolution. Thus, different aspects of the dinosaur radiation (diversity, disparity and abundance) were decoupled, and the overall macroevolutionary pattern of the first 50 Myr of dinosaur evolution is more complex than often considered.
18
Allmon, Warren. "The Pre-Modern History of the Post-Modern Dinosaur: Phases and Causes in Post-Darwinian Dinosaur Art." Earth Sciences History 25, no. 1 (January 1, 2006): 5–35. http://dx.doi.org/10.17704/eshi.25.1.g2687j050u3w1546.
Full textAbstract:
Our images of dinosaurs have changed greatly and repeatedly since the group was first recognized in 1842. Although these changes have frequently been noted, their causes have not been adequately investigated. The history of dinosaur iconography since the publication of the Origin of Species can be usefully divided into at least four phases. During each of these phases, images of dinosaurs have been affected as much by what scientists thought dinosaurs should look like according to their particular views of the evolutionary process, as by empirical information derived from analysis of fossils. In the late nineteenth century, when paleontological views of evolution were diverse, views of dinosaurs were highly pluralistic, with some seen as slow and ponderous and others seen as agile and active. In the early twentieth century, as paleontological opinions about evolution narrowed around progressive orthogenesis, the spectrum of images narrowed to a view of almost all dinosaurs as primitive, slow, and stupid. The advent of the modern synthetic view of evolution in the 1940s had little effect on dinosaur science, and it was not until the late 1960s that dinosaurs would be viewed as advanced in many respects, harkening back to ideas first put forward just after Darwin.
19
Marsicano, Claudia A., Randall B. Irmis, Adriana C. Mancuso, Roland Mundil, and Farid Chemale. "The precise temporal calibration of dinosaur origins." Proceedings of the National Academy of Sciences 113, no. 3 (December 7, 2015): 509–13. http://dx.doi.org/10.1073/pnas.1512541112.
Full textAbstract:
Dinosaurs have been major components of ecosystems for over 200 million years. Although different macroevolutionary scenarios exist to explain the Triassic origin and subsequent rise to dominance of dinosaurs and their closest relatives (dinosauromorphs), all lack critical support from a precise biostratigraphically independent temporal framework. The absence of robust geochronologic age control for comparing alternative scenarios makes it impossible to determine if observed faunal differences vary across time, space, or a combination of both. To better constrain the origin of dinosaurs, we produced radioisotopic ages for the Argentinian Chañares Formation, which preserves a quintessential assemblage of dinosaurian precursors (early dinosauromorphs) just before the first dinosaurs. Our new high-precision chemical abrasion thermal ionization mass spectrometry (CA-TIMS) U–Pb zircon ages reveal that the assemblage is early Carnian (early Late Triassic), 5- to 10-Ma younger than previously thought. Combined with other geochronologic data from the same basin, we constrain the rate of dinosaur origins, demonstrating their relatively rapid origin in a less than 5-Ma interval, thus halving the temporal gap between assemblages containing only dinosaur precursors and those with early dinosaurs. After their origin, dinosaurs only gradually dominated mid- to high-latitude terrestrial ecosystems millions of years later, closer to the Triassic–Jurassic boundary.
20
Richards, Morgan. "Digitising Dinosaurs." Media International Australia 100, no. 1 (August 2001): 65–79. http://dx.doi.org/10.1177/1329878x0110000108.
Full textAbstract:
This article reflects on the intersection of science, art and technology in the construction of the televisual dinosaur. In particular, it is concerned with the class of digital dinosaurs hatched in Jurassic Park (1993) and The Lost World (1997), powered by the latest digital technologies for the reinscription of the filmic and televisual image, and recently grafted to that most domestic of media genres, the animal documentary. Focusing on the BBC television series Walking with Dinosaurs (1999), the digital dinosaur is proposed as an object of mimetic desire in which narratives of intimacy and otherness, resurrection and loss, anthropomorphism and monstrosity are played out. In analysing exactly how the mimetic is achieved, an alternative balance between science and art is proposed, one that foregrounds the complexities and paradoxes of a television program that offers realistic depictions of things we know don't exist in the familiar guise of an animal documentary.
21
Chebotareva, Elena. "Dinosaurs are the Characters of Cinema as a Reflection of the Transformation of Relations Between Science and Society." Logos et Praxis, no. 1 (April 2023): 44–51. http://dx.doi.org/10.15688/lp.jvolsu.2023.1.6.
Full textAbstract:
The author explores the social and cultural implications of dinosaurs as popular cinematic characters. The article shows how dinosaurs gradually become heroes of mass culture. They left paleontological research to enter the wide symbolic space, to visualize and develop themselves in the space of animation. The author provides a brief review of animated series and films with dinosaurs from the first short film in 1914 to the present day, considering the changing roles assigned to these ancient animals. The change in the semantic load of movie hero dinosaurs was analyzed in the context of ongoing events, value transformations and relations between science and society. To understand this connection, the author refers to the ideas of Svetlana Boym and Mario Ricca. Following Boym's ideas, the author considers dinosaurs as "ideal animals for nostalgia" and finds that due to their unique characteristics, the prehistoric era and its inhabitants, dinosaurs form a whole and peaceful human prehistory, filled with the values of friendship, cooperation and love, fueled by appropriate cinematic stories. Thus biology, with its key idea of evolution and the struggle of species for survival, turns into a story with its victories, struggles and dramatic chance in the context of dinosaur filmography. Based on Ricca's ideas, the author considers dinosaurs in the context of the cultural history of animals, which a person turns into metaphorical icons of moral feelings and behavioral habits; the author draws a parallel between medieval bestiaries and modern presentations of ancient lizards. In addition, dinosaur characters are structured as semantic figures, paradoxically uniting the past, present and future of humankind, the prehistoric era and technological progress. In conclusion, the author uses optics of global evolutionism and posthumanism.
22
Rathore, Akshaya. "Use of Artificial Reality and Virtual Reality in Creation of Virtual Fossils Museum: Dinosaur Fossils National Park Bagh Dhar." International Journal for Research in Applied Science and Engineering Technology 10, no. 3 (March 31, 2022): 805–11. http://dx.doi.org/10.22214/ijraset.2022.40740.
Full textAbstract:
Abstract: Dinosaur Fossils National Park Bagh has huge fossils reserves of late cretaceous period that includes Dinosaurs bones, whole dinosaurs’ nests, dinosaurs’ eggs, tree fossils, shark teeth, ammonites, bivalves, inoceramids, and other marine organisms. With the help of local researchers and forest staff over the period oftime we had collected fossils of many species. Firstly, we inventoried the fossils physically then we created 3dmodels of at least one specimen of each fossils’ species. These 3D models can be displayed on website using Artificial Reality and also using virtual reality with the help of VR headsets.
23
Fastovsky, David E. "Dinosaurs in Space and Time: The Geological Setting." Short Courses in Paleontology 2 (1989): 22–33. http://dx.doi.org/10.1017/s2475263000000829.
Full textAbstract:
The title of this chapter makes a promise that cannot be kept: that somehow there could be summarized in its few pages all the paleoenvironments of dinosaur-bearing strata through time. Dinosaurs were –as far as can be determined – ubiquitious in the terrestrial realm. It would be impossible to summarize the Recent terrestrial settings of birds (avian dinosaurs), let alone 135 million years of terrestrial settings. For this reason, this paper will be restricted to generalizations about ancient environments, highlighting particularly interesting or productive dinosaur-bearing localities in North America.
24
Archibald, J. David. "The Demise of the Dinosaurs and the Rise of the Mammals." Short Courses in Paleontology 2 (1989): 162–74. http://dx.doi.org/10.1017/s2475263000000945.
Full textAbstract:
The demise of the dinosaurs some 66.4 million years ago (MYA) has come to embody for scientist and layman alike the concept of extinction, especially that of mass extinction. So pervasive has this idea become that no book, whether specializing on dinosaurs or representing a general overview of biology or geology, concludes without dealing with dinosaur extinction. In the context of the Phanerozoic history of life, this preoccupation with dinosaur extinction is probably not warranted because it may tell us little about extinction or evolutionary processes in general.
25
Teppo, Anne R., and Ted Hodgson. "Dinosaurs, Dinosaur Eggs, and Probability." Mathematics Teacher 94, no. 2 (February 2001): 86–92. http://dx.doi.org/10.5951/mt.94.2.0086.
Full textAbstract:
In their article “What Every High School Graduate Should Know about Statistics,” Scheaffer, Watkins, and Landwehr (1998) contend that one cannot understand statistics without understanding probability. As a consequence, the authors outline several recommendations regarding teaching probability in the secondary school.
26
Averianov, A. O., H. D. Sues, and P. A. Tleuberdina. "The forgotten dinosaurs of Zhetysu (Eastern Kazakhstan; Late Cretaceous)." Proceedings of the Zoological Institute RAS 316, no. 2 (June 25, 2012): 139–47. http://dx.doi.org/10.31610/trudyzin/2012.316.2.139.
Full textAbstract:
The Late Cretaceous dinosaur-bearing localities discovered in the Ili River Basin in the foothills of Dzhungar Alatau, in the center of the historical region Zhetysu (Semirechie), in 1925–1927 are among the first occurrences for dinosaurs discovered in Asia. Preliminary identifications of dinosaurian remains from the Zhetysu localities, reviewed by Nesov (1995a), included Sauropoda, Tyrannosauridae, Hadrosauridae, Ankylosauridae, and possible Ceratopsidae. The only previously described specimen from this assemblage is a tibia attributed to cf. Ceratopsia by Riabinin (1939) from the Kara-Cheku locality. This bone is considered currently as Dinosauria indet. We describe here the most important find from this fauna to date, a partial tyrannosaurid dentary collected by a team from the Institute of Zoology of the Kazakh Academy of Sciences at the Kara-Cheku locality in 1950. This specimen can be confidently identified as a derived tyrannosaurine based on the incrassate teeth and the small first alveolus. This is the first record of a tyrannosaurine from the Late Cretaceous of Kazakhstan and Middle Asia. The age of Zhetysu dinosaur fauna is possibly Campanian or Maastrichtian.
27
Monnin, Victor. "The Dinosaur Renaissance 1960s-80s: A Foundational Episode for the Historiography of Paleoart." HoST - Journal of History of Science and Technology 17, no. 1 (June 1, 2023): 4–16. http://dx.doi.org/10.2478/host-2023-0002.
Full textAbstract:
Abstract The “Dinosaur Renaissance” is known as a crucial event in the study of dinosaurs. From sluggish and lizard-like, they came to be conceived and represented as more dynamic animals. This paper argues that the “Dinosaur Renaissance” did not only constitute a significant scientific and artistic shift. Indeed, it can also be interpreted as a foundational episode for the historiography of paleoart. During the “Dinosaur Renaissance,” a growing community of artists and paleontologists promoted the integration of artistic processes in paleontology. They began to actively discuss the historical legacy and future of such integration. The itinerant paleoart exhibition Dinosaurs Past and Present, hosted in eight major cities across North America at the end of the 1980s, can be identified as having played a significant role in setting the foundation for the historiography of paleoart. The “Dinosaur Renaissance” did not only result in revised visual representations of dinosaurs, but also spurred some of the first investigations on the historical relationship between visual arts and paleontology. This article concludes by offering some remarks on how the present historiography of paleoart can continue to build on the efforts made during the “Dinosaur Renaissance” while remaining cognizant of their context. To effectively answer the needs of historians, as well as of paleontologists and paleoartists alike, the growing historiography of paleoart has much to gain in clarifying its own history.
28
Horner, John R. "Dinosaur behavior and growth." Paleontological Society Special Publications 6 (1992): 135. http://dx.doi.org/10.1017/s247526220000695x.
Full textAbstract:
Geological and paleontological data derived from the Upper Cretaceous Two Medicine Formation of Montana indicates that at least some dinosaur species exhibited complex social behaviors comparable to many living birds. Two species of duck-billed dinosaurs, a hypsilophodontid and a troodontid, nested in colonies and attended their respective young. Duckbilled dinosaurs had altricial young, whereas the hypsilophodontid and troodontid had precocial young. Morphological evidence indicates that several of the cranial elements of the nestling duckbills experienced retarded development, and a retention of juvenile features. Following their respective nesting periods duck-billed and horned dinosaurs aggregated into large herds, and apparently migrated seasonally. Cranial ornamentations possessed by duck-billed and horned dinosaurs were most likely used for sexual display and mate recognition.Osteohistological data indicates that the duck-billed dinosaurs hatched from their eggs at .50 to .75 meters in length, and exited their nests at 1.5 to 2 meters in length, at an age of about one month. These dinosaurs reached 3 to 4 meters in length their first year, and 7 to 8 meters in length after about 5 years. Growth and metabolic rates decreased substantially upon reaching adult size.
29
Sankey, Julia T. "Late Campanian southern dinosaurs, Aguja Formation, Big Bend, Texas." Journal of Paleontology 75, no. 1 (January 2001): 208–15. http://dx.doi.org/10.1017/s0022336000031991.
Full textAbstract:
One of the southernmost North American late Campanian microvertebrate assemblages was collected from the upper Aguja Formation, Big Bend National Park, Texas. The dinosaurs provide additional evidence that distinct southern and northern terrestrial vertebrate provinces occurred contemporaneously during this time due to latitudinal differences in temperature and rainfall. Southern areas, such as west Texas, were warm dry, with non-seasonal climates, and with open-canopy woodlands; they appear to be less fossil-rich and less diverse than northern areas. Nine dinosaurs are present, based on isolated teeth: pachycephalosaurid; hadrosaurid; ceratopsian; tyrannosaurid; Saurornitholestes cf. langstoni (Sues, 1978); Richardoestesia cf. gilmorei (Currie et al., 1990); a new species of Richardoestesia, which is named here; and a undetermined theropod unlike any previously described. Previous reports of Troodon sp. from the Talley Mt. and Terlingua microsites are mistaken; they are a pachycephalosaurid. Many of the dinosaur teeth are small, and are probably from juveniles or younger individuals, evidence that dinosaurs nested in the area. Paleoecologically, the upper Aguja was probably more similar to the lower and more inland faunas of the Scollard Formation (~66 Ma) of Alberta than to contemporaneous northern faunas: both had drier, open environments and lower dinosaur abundance. This connection between climate and dinosaur abundance suggests that climatic factors were important in the Late Cretaceous dinosaur extinctions.
30
Harries, Judith. "Dinosaur stomp." Early Years Educator 22, no. 6 (January 2, 2021): S4—S5. http://dx.doi.org/10.12968/eyed.2021.22.6.s4.
Full text
31
Berman, David S., and John S. McIntosh. "The Recapitation of Apatosaurus." Paleontological Society Special Publications 7 (1994): 83–98. http://dx.doi.org/10.1017/s2475262200009436.
Full textAbstract:
In 1915 the Carnegie Museum of Natural History's magnificent skeleton of the sauropod dinosaur Apatosaurus louisae, discovered in 1909 at what is now Dinosaur National Monument in northeastern Utah, took its place alongside the equally impressive skeleton of Diplodocus carnegii in the Hall of Dinosaurs. At that time and for the next 17 years, however, it stood conspicuously headless. It was not until December of 1932 that the skeleton was completed, and then with the wrong head—a Camarasaurus skull. How this came about and how the error was corrected requires the untangling of a long series of events that began with the first discoveries and descriptions of the giant sauropod dinosaurs of North America over a century ago.
32
Armitage, Mark H. "Ultraviolet Autofluorescence Microscopy of Nanotyrannus lancensis Sections Reveals Blood Clots in Vessel Canals." Microscopy Today 30, no. 6 (November 2022): 34–39. http://dx.doi.org/10.1017/s1551929522001262.
Full textAbstract:
Abstract:Theropod dinosaurs have captured the imagination of the public and paleontologists alike. Histology of the bones of theropods has revealed much about dinosaur physiology, behavior, and growth. Histology and ultraviolet fluorescence (UVFL) microscopy of one controversial dinosaur, Nanotyrannus lancensis, reveals the presence of blood clots in post-fixed vessel canals of claw, vertebra, and other isolated post-cranial elements collected at Hell Creek, MT. These clots are thicker, more closely adherent to canal walls, and more reactive to 347 nm UVFL incident light than unfixed specimens. Theropod histology images in the literature display similar clots, and those should be subjected to UVFL for confirmation. In addition, nematodes are evidently preserved in vessel canals of dinosaurs.
33
Lloyd, G. T., D. W. Bapst, M. Friedman, and K. E. Davis. "Probabilistic divergence time estimation without branch lengths: dating the origins of dinosaurs, avian flight and crown birds." Biology Letters 12, no. 11 (November 2016): 20160609. http://dx.doi.org/10.1098/rsbl.2016.0609.
Full textAbstract:
Branch lengths—measured in character changes—are an essential requirement of clock-based divergence estimation, regardless of whether the fossil calibrations used represent nodes or tips. However, a separate set of divergence time approaches are typically used to date palaeontological trees, which may lack such branch lengths. Among these methods, sophisticated probabilistic approaches have recently emerged, in contrast with simpler algorithms relying on minimum node ages. Here, using a novel phylogenetic hypothesis for Mesozoic dinosaurs, we apply two such approaches to estimate divergence times for: (i) Dinosauria, (ii) Avialae (the earliest birds) and (iii) Neornithes (crown birds). We find: (i) the plausibility of a Permian origin for dinosaurs to be dependent on whether Nyasasaurus is the oldest dinosaur, (ii) a Middle to Late Jurassic origin of avian flight regardless of whether Archaeopteryx or Aurornis is considered the first bird and (iii) a Late Cretaceous origin for Neornithes that is broadly congruent with other node- and tip-dating estimates. Demonstrating the feasibility of probabilistic time-scaling further opens up divergence estimation to the rich histories of extinct biodiversity in the fossil record, even in the absence of detailed character data.
34
Florides, Georgios A., and Paul Christodoulides. "On Dinosaur Reconstruction: Posture of Dinosaurs." Open Journal of Geology 11, no. 12 (2021): 756–93. http://dx.doi.org/10.4236/ojg.2021.1112037.
Full text
35
Rathore, Akshaya. "Digital Inventory of Fossils: Dinosaur Fossils National Park Bagh Dhar." International Journal for Research in Applied Science and Engineering Technology 9, no. 12 (December 31, 2021): 1311–17. http://dx.doi.org/10.22214/ijraset.2021.39528.
Full textAbstract:
Abstract: Dinosaur Fossils National Park Bagh has huge fossils reserves of late cretaceous period that includes Dinosaurs bones, whole dinosaurs’ nests, dinosaurs’ eggs, tree fossils, shark teeth, ammonites, bivalves, inoceramids, and other marine organisms. With the help of local researchers and forest staff over the period oftime we had collected fossils of many species. Firstly, we inventoried the fossils physically and documented each by maintaining Stock Registers. Digitizing the Stock Registers – to convert each register in excel file which includes all the details regarding that fossil. To make it more attractive and useful in future, we have created 3dmodels of at least one specimen of each fossils’ species. To have worldwide reach, we have created and hosted the website www.dinosaurfossilsnationalparkbagh.in . I
36
Barrick, Reese E. "Thermal Physiology of the Dinosauria: Evidence from Oxygen Isotopes in Bone Phosphate." Paleontological Society Special Publications 7 (1994): 243–54. http://dx.doi.org/10.1017/s2475262200009552.
Full textAbstract:
Dinosaurs were an abundant group of reptiles that originated in the mid-Triassic. They rapidly diversified, filling all of the ecological niches for large-bodied terrestrial vertebrates by the Late Triassic and dominated this landscape for 163 m.y. Yet due to the lack of direct evidence little is known about their metabolism. The question as to whether dinosaurs were “warm-blooded” or “cold-blooded” has been debated for over 25 years. Knowledge of dinosaur thermal physiology is critical if we are to understand how they lived and functioned. This knowledge can then be used to help answer questions regarding to their origin, diversification, and their eventual extinction. The question that is being resolved here is, “How do you stick a thermometer into dinosaur bone?”.
37
Novas, Fernando E. "The tibia and tarsus in Herrerasauridae (Dinosauria, incertae sedis) and the origin and evolution of the dinosaurian tarsus." Journal of Paleontology 63, no. 5 (September 1989): 677–90. http://dx.doi.org/10.1017/s0022336000041317.
Full textAbstract:
The tarsus and distal end of the tibia are described in Herrerasauridae, a family that includes the oldest known dinosaurs. This tarsal configuration is compared to those of more advanced dinosaurs and to other archosaurs. Through phylogenetic analysis of the morphological characters, a picture emerges of the evolutionary changes in the ankles of early dinosaurs.The tibia of the herrerasaurids has a quadrangular distal articular surface, with a shallow ventrolateral notch. This morphology is strikingly similar to that of the lagosuchid thecodontsPseudolagosuchusandLagosuchusand represents the most primitive tibial condition known for Dinosauria.Aside from the derived states possessed by Theropoda, Sauropodomorpha, and Ornithischia, respectively, it was impossible to recognize synapomorphies in tibiotarsal anatomy shared by these groups exclusive of Herrerasauridae. The transverse broadening of the distal end of the tibia seems to have been attained independently by ornithischians, theropods, and sauropodomorphs.The tarsus of herrerasaurids is characterized by an astragalus with a small but conspicuous lateroventral depression, by a pyramidal calcaneum with a ventromedial projection that articulates into the cavity of the astragalus just mentioned, and by a posterolaterally directed calcaneal tuber. These characters are also seen inLagosuchus(a close relative of dinosaurs), in the prosauropodRiojasaurusand, insofar as the astragalus is concerned, in the primitive dinosaurWalkeria, which suggests that dinosaurs of different lineages shared the same tarsal condition.By definition, this type of articulation between the astragalus and calcaneum follows the “crocodile-reversed” tarsal condition, suggesting that the tarsus in lagosuchids and dinosaurs could be derived from the “crocodile-reversed” pattern present in Ornithosuchidae andEuparkeria. In contrast, the mesotarsal ankle of lagosuchids and dinosaurs lacks the synapomorphies of the “crocodile-normal” ankle present in Crocodylia, Rauisuchidae, Aetosauria, and other archosaurs.It is concluded that Herrerasauridae retained the primitive tibiotarsal condition for Dinosauria, from which those of the Ornithischia, Sauropodomorpha, and Theropoda were derived. Furthermore, tibiotarsal anatomy supports monophyly of Dinosauria.
38
Hone, David W. E., Andrew A. Farke, and Mathew J. Wedel. "Ontogeny and the fossil record: what, if anything, is an adult dinosaur?" Biology Letters 12, no. 2 (February 2016): 20150947. http://dx.doi.org/10.1098/rsbl.2015.0947.
Full textAbstract:
Identification of the ontogenetic status of an extinct organism is complex, and yet this underpins major areas of research, from taxonomy and systematics to ecology and evolution. In the case of the non-avialan dinosaurs, at least some were reproductively mature before they were skeletally mature, and a lack of consensus on how to define an ‘adult’ animal causes problems for even basic scientific investigations. Here we review the current methods available to determine the age of non-avialan dinosaurs, discuss the definitions of different ontogenetic stages, and summarize the implications of these disparate definitions for dinosaur palaeontology. Most critically, a growing body of evidence suggests that many dinosaurs that would be considered ‘adults’ in a modern-day field study are considered ‘juveniles’ or ‘subadults’ in palaeontological contexts.
39
Brinkman, Paul. "Red Deer River shakedown: a history of the Captain Marshall field paleontological expedition to Alberta, 1922, and its aftermath." Earth Sciences History 32, no. 2 (January 1, 2013): 204–34. http://dx.doi.org/10.17704/eshi.32.2.n450m52t2964730k.
Full textAbstract:
A Field Museum expedition to collect Late Cretaceous dinosaurs operated for three and a half months in the summer of 1922 in the Red Deer River badlands (Oldman and Dinosaur Park formations, Belly River Group) in an area now known as Dinosaur Provincial Park in southern Alberta, Canada. Associate Curator of Vertebrate Paleontology Elmer S. Riggs led the expedition. He was ably assisted by veteran collectors George F. Sternberg and John B. Abbott. A trio of novice collectors, Anthony Dombrosky, George Bedford and C. Harold Riggs, Elmer's youngest son, rounded out the party. The expedition was a success, netting several quality specimens of duckbilled dinosaurs; one small, partial theropod skeleton; an unidentified duckbilled dinosaur skull; four turtles; other miscellaneous fossil vertebrate remains; numerous fossil plants and invertebrates; and a large fossil log. In 1956, one of these specimens—a nearly complete lambeosaurine hadrosaur reconstructed as Lambeosaurus—debuted as the less fortunate partner of Gorgosaurus in the museum's iconic ‘Dinosaurs, Predator and Prey’ exhibit in Stanley Field Hall. Both of these specimens are still on display in a permanent exhibit called ‘Evolving Planet’. Another notable specimen prepared in 1999-2000 after nearly eighty years in an unopened field jacket has been identified as a juvenile Gorgosaurus. This specimen—nicknamed ‘Elmer’—was recently touring the globe as part of the ‘Dinosaurs: Ancient Fossils, New Discoveries’ exhibit. More importantly, the expedition was an invaluable shakedown experience for the fossil hunting crew and their new equipment in the months before they left on an ambitious, multi-year fossil mammal collecting expedition to Argentina and Bolivia. An oft-repeated myth holds that Riggs viewed the Alberta expedition as a failure and departed the field the moment he obtained permission to go to South America. This paper shows that myth to be unfounded.
40
Araújo, Bruno de Lima, Alexia Satie Augusto, André Prates, Francisca Raiany Soares de Moura, Gabriel Figueiredo Cardoso, Greyck Willyan Marques Santos, Letícia Lopes Dutra, et al. "“PATAGOTITAN – O MAIOR DO MUNDO”: CIÊNCIA, EDUCAÇÃO E DECOLONIALIDADE EM UMA EXPOSIÇÃO DE DINOSSAUROS." PALEONTOLOGIA EM DESTAQUE - Boletim Informativo da Sociedade Brasileira de Paleontologia 38, no. 79 (May 24, 2024): 32–44. http://dx.doi.org/10.4072/paleodest.2023.38.79.03.
Full textAbstract:
“Patagotitan - World’s Largest Dinosaur”: Science, Education and Decoloniality in a Dinosaur Exhibition. During three months, a dinosaur exhibition was held in the Central-South Zone of the city of São Paulo, Brazil. There were 21 educators serving tens of thousands of visitors from the general public, including 157 schools and 6528 students. The exhibition featured replicas of 14 species of dinosaurs found in Argentina and one dinosaur that inhabited southern Brazil, as well as six original fossils, originally from the Egidio Feruglio Paleontological Museum, located in Chubut, Argentina. Among these, the replica of the sauropod Patagotitan mayorum stands out, one of the largest dinosaurs described so far, estimated at around 37 meters in length. In this paper, we seek to report the potentiality of this type of exhibition with regard to dissemination, teaching and scientific literacy; the training of teachers in the different areas involved; and the importance of this event for education with a decolonial aspect, promoting awareness about Latin American scientific production. Keywords: Biology, scientific dissemination, decolonial education, scientific event, Geology, Museology.
41
Mallon, Jordan C. "Recognizing sexual dimorphism in the fossil record: lessons from nonavian dinosaurs." Paleobiology 43, no. 3 (March 27, 2017): 495–507. http://dx.doi.org/10.1017/pab.2016.51.
Full textAbstract:
AbstractThe demonstration of sexual dimorphism in the fossil record can provide vital information about the role that sexual selection has played in the evolution of life. However, statistically robust inferences of sexual dimorphism in fossil organisms are exceedingly difficult to establish, owing to issues of sample size, experimental control, and methodology. This is particularly so in the case of dinosaurs, for which sexual dimorphism has been posited in many species, yet quantifiable data are often lacking. This study presents the first statistical investigation of sexual dimorphism across Dinosauria. It revisits prior analyses that purport to find quantitative evidence for sexual dimorphism in nine dinosaur species. After the available morphological data were subjected to a suite of statistical tests (normality and unimodality tests and mixture modeling), no evidence for sexual dimorphism was found in any of the examined taxa, contrary to conventional wisdom. This is not to say that dinosaurs were not sexually dimorphic (phylogenetic inference suggests they may well have been), only that the available evidence precludes its detection. A priori knowledge of the sexes would greatly facilitate the assessment of sexual dimorphism in the fossil record, and it is suggested that unambiguous indicators of sex (e.g., presence of eggs, embryos, medullary bone) be used to this end.
42
Mikulic, Donald G. "Giant Lizards: A Brief History of Early Dinosaur Reconstruction." Paleontological Society Special Publications 7 (1994): 7–20. http://dx.doi.org/10.1017/s2475262200009394.
Full textAbstract:
Although they have been extinct for more than 60 million years, dinosaurs are a familiar part of our culture. Featured regularly in entertainment, advertising and the news, they are recognized more readily in today's society than many living animals. Dinosaurs also function as a powerful educational tool, stimulating the interest of children and adults in the natural world. Moreover, they serve as a primary symbol of evolution, extinction and the long history of life on Earth. Yet, few people realize how radically our understanding of dinosaurs has changed since their discovery 170 years ago.The initial recognition of dinosaurs as a distinct group of extinct animals was one of the major accomplishments of nineteenth century science. When first discovered, dinosaurs were an unexpected and almost alien life form whose interpretation was inhibited by a scarcity of good fossils and absence of close living relatives. For this reason, early nineteenth century dinosaur reconstructions, which were later ridiculed for their inaccuracies, may seem simplistic and conservative. In reality, they were quite innovative. Examination of this early work reveals just how profound these ideas actually were in light of the limited evidence available and demonstrates how interpretations changed as new fossil discoveries were made.
43
Carpenter, Kenneth, and Peter Galton. "A photo documentation of bipedal ornithischian dinosaurs from the Upper Jurassic Morrison Formation, USA." Geology of the Intermountain West 5 (August 17, 2018): 167–207. http://dx.doi.org/10.31711/giw.v5.pp167-207.
Full textAbstract:
Bipedal ornithischian dinosaurs from the Upper Jurassic Morrison Formation are rare, forming only about 15% of the dinosaur specimens. Nevertheless, one of them was among the first dinosaurs named from what was then the ‘’Atlantosaurus Beds’’ of Colorado. Collecting and restudy for 140 years has increased the diversity from the initial 1877 discovery to the currently valid four genera and six species, viz., Fruitadens haagaroum, Nanosaurus agilis, Camptosaurus dispar, C. aphanoecetes, Dryosaurus altus, and D. elderae, which we briefly review. We demonstrate that the enigmatic Nanosaurus agilis is the senior name for Drinker nisti, Othnielosaurus consors, and Othnielia rex. In addition, a new species, Dryosaurus elderae is proposed for the Dryosaurus specimens from Dinosaur National Monument that are characterized by elongate cervical verebrae and a long, low ilium among other features.
44
Breeden, Benjamin T., Thomas J. Raven, Richard J. Butler, Timothy B. Rowe, and Susannah C. R. Maidment. "The anatomy and palaeobiology of the early armoured dinosaur Scutellosaurus lawleri (Ornithischia: Thyreophora) from the Kayenta Formation (Lower Jurassic) of Arizona." Royal Society Open Science 8, no. 7 (July 2021): 201676. http://dx.doi.org/10.1098/rsos.201676.
Full textAbstract:
The armoured dinosaurs, Thyreophora, were a diverse clade of ornithischians known from the Early Jurassic to the end of the Cretaceous. During the Middle and Late Jurassic, the thyreophorans radiated to evolve large body size, quadrupedality, and complex chewing mechanisms, and members of the group include some of the most iconic dinosaurs, including the plated Stegosaurus and the club-tailed Ankylosaurus ; however, the early stages of thyreophoran evolution are poorly understood due to a paucity of relatively complete remains from early diverging thyreophoran taxa. Scutellosaurus lawleri is generally reconstructed as the earliest-diverging thyreophoran and is known from over 70 specimens from the Lower Jurassic Kayenta Formation of Arizona, USA. Whereas Scutellosaurus lawleri is pivotal to our understanding of character-state changes at the base of Thyreophora that can shed light on the early evolution of the armoured dinosaurs, the taxon has received limited study. Herein, we provide a detailed account of the osteology of Scutellosaurus lawleri , figuring many elements for the first time. Scutellosaurus lawleri was the only definitive bipedal thyreophoran. Histological studies indicate that it grew slowly throughout its life, possessing lamellar-zonal tissue that was a consequence neither of its small size nor phylogenetic position, but may instead be autapomorphic, and supporting other studies that suggest thyreophorans had lower basal metabolic rates than other ornithischian dinosaurs. Faunal diversity of the Kayenta Formation in comparison with other well-known Early Jurassic-aged dinosaur-bearing formations indicates that there was considerable spatial and/or environmental variation in Early Jurassic dinosaur faunas.
45
Horner, John R., Kevin Padian, and Armand de Ricqlès. "Comparative osteohistology of some embryonic and perinatal archosaurs: developmental and behavioral implications for dinosaurs." Paleobiology 27, no. 1 (2001): 39–58. http://dx.doi.org/10.1666/0094-8373(2001)027<0039:coosea>2.0.co;2.
Full textAbstract:
Histologic studies of embryonic and perinatal longbones of living birds, non-avian dinosaurs, and other reptiles show a strong phylogenetic signal in the distribution of tissues and patterns of vascularization in both the shafts and the bone ends. The embryonic bones of basal archosaurs and other reptiles have thin-walled cortices and large marrow cavities that are sometimes subdivided by erosion rooms in early stages of growth. The cortices of basal reptiles are poorly vascularized, and osteocyte lacunae are common but randomly organized. Additionally, there is no evidence of fibrolamellar tissue organization around the vascular spaces. Compared with turtles, basal archosaurs show an increase in vascularization, better organized osteocytes, and some fibrolamellar tissue organization. In dinosaurs, including birds, vascularization is greater than in basal archosaurs, as is cortical thickness, and the osteocyte lacunae are more abundant and less randomly organized. Fibrolamellar tissues are evident around vascular canals and form organized primary osteons in older perinates and juveniles.Metaphyseal (“epiphyseal”) morphology varies with the acquisition of new features in derived groups. The cartilage cone, persistent through the Reptilia (crown-group reptiles, including birds), is completely calcified in ornithischian dinosaurs before it is eroded by marrow processes; cartilage canals, absent in basal archosaurs, are present in Dinosauria; a thickened calcified hypertrophy zone in Dinosauria indicates an acceleration of longitudinal bone growth.Variations in this set of histological synapomorphies overlap between birds and non-avian dinosaurs. In birds, these variations are strongly correlated with life-history strategies. This overlap, plus independent evidence from nesting sites, reinforces the hypothesis that variations in bone growth strategies in Mesozoic dinosaurs reflect different life-history strategies, including nesting behavior of neonates and parental care.
46
Benson, Roger B. J. "Dinosaur Macroevolution and Macroecology." Annual Review of Ecology, Evolution, and Systematics 49, no. 1 (November 2, 2018): 379–408. http://dx.doi.org/10.1146/annurev-ecolsys-110617-062231.
Full textAbstract:
Dinosaurs were large-bodied land animals of the Mesozoic that gave rise to birds. They played a fundamental role in structuring Jurassic–Cretaceous ecosystems and had physiology, growth, and reproductive biology unlike those of extant animals. These features have made them targets of theoretical macroecology. Dinosaurs achieved substantial structural diversity, and their fossil record documents the evolutionary assembly of the avian body plan. Phylogeny-based research has allowed new insights into dinosaur macroevolution, including the adaptive landscape of their body size evolution, patterns of species diversification, and the origins of birds and bird-like traits. Nevertheless, much remains unknown due to incompleteness of the fossil record at both local and global scales. This presents major challenges at the frontier of paleobiological research regarding tests of macroecological hypotheses and the effects of dinosaur biology, ecology, and life history on their macroevolution.
47
PRIETO-MÁRQUEZ, ALBERT. "Revised diagnoses of Hadrosaurus foulkii Leidy, 1858 (the type genus and species of Hadrosauridae Cope, 1869) and Claosaurus agilis Marsh, 1872 (Dinosauria: Ornithopoda) from the Late Cretaceous of North America." Zootaxa 2765, no. 1 (February 15, 2011): 61. http://dx.doi.org/10.11646/zootaxa.2765.1.6.
Full textAbstract:
Hadrosauridae constitutes a very diverse clade of herbivorous dinosaurs that were extremely abundant during the Campanian–Maastrichtian (Late Cretaceous) of Europe, Asia, both Americas, and probably also Antarctica (Horner et al. 2004). The fact that hadrosaurids are one of the best-known clades of dinosaurs, represented by arguably the richest dinosaurian fossil record, contrasts with the scarcity of material and apparently undiagnostic nature of their type genus and species, Hadrosaurus foulkii. The holotype and only known specimen of H. foulkii is also historically significant for being the first skeletal remains of a dinosaur described outside Europe (Leidy 1858).
48
Lyson, Tyler R., Antoine Bercovici, Stephen G. B. Chester, Eric J. Sargis, Dean Pearson, and Walter G. Joyce. "Dinosaur extinction: closing the ‘3 m gap’." Biology Letters 7, no. 6 (July 13, 2011): 925–28. http://dx.doi.org/10.1098/rsbl.2011.0470.
Full textAbstract:
Modern debate regarding the extinction of non-avian dinosaurs was ignited by the publication of the Cretaceous–Tertiary (K–T) asteroid impact theory and has seen 30 years of dispute over the position of the stratigraphically youngest in situ dinosaur. A zone devoid of dinosaur fossils reported from the last 3 m of the Upper Cretaceous, coined the ‘3 m gap’, has helped drive controversy. Here, we report the discovery of the stratigraphically youngest in situ dinosaur specimen: a ceratopsian brow horn found in a poorly rooted, silty, mudstone floodplain deposit located no more than 13 cm below the palynologically defined boundary. The K–T boundary is identified using three criteria: (i) decrease in Cretaceous palynomorphs without subsequent recovery, (ii) the existence of a ‘fern spike’, and (iii) correlation to a nearby stratigraphic section where primary extraterrestrial impact markers are present (e.g. iridium anomaly, spherules, shocked quartz). The in situ specimen demonstrates that a gap devoid of non-avian dinosaur fossils does not exist and is inconsistent with the hypothesis that non-avian dinosaurs were extinct prior to the K–T boundary impact event.
49
Brusatte, Stephen L., Grzegorz Niedźwiedzki, and Richard J. Butler. "Footprints pull origin and diversification of dinosaur stem lineage deep into Early Triassic." Proceedings of the Royal Society B: Biological Sciences 278, no. 1708 (October 6, 2010): 1107–13. http://dx.doi.org/10.1098/rspb.2010.1746.
Full textAbstract:
The ascent of dinosaurs in the Triassic is an exemplary evolutionary radiation, but the earliest phase of dinosaur history remains poorly understood. Body fossils of close dinosaur relatives are rare, but indicate that the dinosaur stem lineage (Dinosauromorpha) originated by the latest Anisian ( ca 242–244 Ma). Here, we report footprints from the Early–Middle Triassic of Poland, stratigraphically well constrained and identified using a conservative synapomorphy-based approach, which shifts the origin of the dinosaur stem lineage back to the Early Olenekian ( ca 249–251 Ma), approximately 5–9 Myr earlier than indicated by body fossils, earlier than demonstrated by previous footprint records, and just a few million years after the Permian/Triassic mass extinction (252.3 Ma). Dinosauromorph tracks are rare in all Polish assemblages, suggesting that these animals were minor faunal components. The oldest tracks are quadrupedal, a morphology uncommon among the earliest dinosauromorph body fossils, but bipedality and moderately large body size had arisen by the Early Anisian ( ca 246 Ma). Integrating trace fossils and body fossils demonstrates that the rise of dinosaurs was a drawn-out affair, perhaps initiated during recovery from the Permo-Triassic extinction.
50
Dodson, Peter. "What the Fossil Record of Dinosaurs Tells Us." Paleontological Society Special Publications 7 (1994): 21–38. http://dx.doi.org/10.1017/s2475262200009400.
Full textAbstract:
Dinosaurs were enormously successful animals. They inhabited all seven continents, including polar regions during the Mesozoic. Their temporal range, as currently understood, extends from the Carnian stage of the Late Triassic beginning 228 Ma, to the Maastrichtian stage of the Late Cretaceous, ending 65 Ma. With a temporal span of 163 million years, dinosaurs cannot be judged as failures by puny naked bipeds who have been here for two million years or less and who threaten not only their own existence but that of much of the biosphere. The fossil record of dinosaurs is a complex document that cannot merely be read at face value but which must be carefully evaluated with respect to its inherent biases. There is much we wish to ask about dinosaurs that can only be answered with a mature reliable record. The object of this essay is to discuss some of the factors that impact both on dinosaur diversity itself, and on our understanding of that diversity. While fossils have an objective existence in the rocks, our understanding of their record is the result of a very human process of scientific discovery, subject to the contingencies and biases of history (Dodson, and Dawson, 1991).