D.E. Fastovsky

University of Rhode Island | URI · Department of Geosciences

Fossil eggshells were recovered from the El Gallo formation, Baja California, northwest Mexico, is one of the few North American Campanian continental outcrops outside the Western Interior Basin. Based on microstructure, the eggshells are referred to ornithopod (ootaxon Spheroolithus), theropods (ootaxa Prismatoolithus, two Tubercuoolithidae eggshe...

The Late Campanian (Late Cretaceous), upper part of the El Disecado Member, El Gallo Formation, Baja California, México, preserves a rich fossil assemblage of microvertebrates and macrovertebrates, silicified logs, macroscopic plant remains, and pollen that was likely deposited as the distal part of a subaerial fan. The unit was episodic and high e...

Cambridge Core - Palaeontology and Life History - Dinosaurs - by David E. Fastovsky

The early history of dinosaurs in North America is obscured by an incomplete fossil record, taxonomic uncertainties and speculative correlations of tetrapod-bearing rocks, as well as poor calibration of the Late Triassic time scale. High-precision U-Pb geochronology provides a reliable means of correlating terrestrial rock formations independent of...

Paleontology has undergone a renaissance in the past 50 years, expanding from an empirical field focused on stratigraphic context to the theoretically grounded discipline of paleobiology. This transformation has been propelled by conceptual advances in two broadly construed areas, evolution and paleoecology. Phylogenetic systematic has revised our...

Multiple > 1‰ δ13C isotopic excursions measured across the Cretaceous–Paleogene (K–Pg) boundary in an iridium-bearing stratigraphic section from Mud Buttes, North Dakota, USA, fail to demonstrate an unambiguous chemostratigraphic signal for the extinction. Results of two-sample Kolmogorov–Smirnov tests using δ13C records for the Mud Buttes section...

Recovery of marine biodiversity following the Permo-Triassic extinction is thought to have been delayed relative to other mass extinctions. Terrestrial vertebrate biodiversity is said to have taken as much as 15 Myr longer to recover than the marine. The present study tests, at the scale of an individual fossil community, whether a disparity in bio...

Paleosols and sedimentological studies are useful tools in the reconstruction of past environments; they are also used as stratigraphic markers for correlation in small areas or for determining the rate of deposition. The oldest known paleosols are from the Precambrian, however the most studied are those from the Quaternary. The purpose of this wor...

Paleosols and sedimentological studies are useful tools in the reconstruction of past environments; they are also used as stratigraphic markers for correlation in small areas or for determining the rate of deposition. The oldest known paleosols are from the Precambrian, however the most studied are those from the Quaternary. The purpose of this wor...

Exposures of the Chinle Formation in Petrified Forest National Park (PEFO), Arizona, preserve one of the most important Upper Triassic terrestrial faunal assemblages in the world: in it are found key elements in the global and regional correlation of continental deposits of Upper Triassic age. Rare components of the Chinle Formation faunal assembla...

A remarkable specimen of the small neoceratopsian dinosaur Protoceratops andrewsi (Late Cretaceous, Mongolia) reveals the first nest of this genus, complete with fifteen juveniles. The relatively large size of the individuals and their advanced state of development suggests the possibility that Protoceratops juveniles remained and grew in their nes...

The Triassic successions of the Colorado Plateau preserve an important record of vertebrate evolution and climate change, but correlations to a global Triassic framework are hampered by a lack of geochronological control. Tuffaceous sandstones and siltstones were collected from the Upper Triassic Chinle Formation exposed in the Petrified Forest Nat...

Understanding patterns of biotic evolution and climate change in deep time requires a reliable temporal framework. The Colorado Plateau contains a rich record of both, but is lacking in reliable age data. High-precision U-Pb geochronology has the power to resolve subtle differences among mixed populations of volcanic zircon contained in tuffaceous...

From the authors of The Evolution and Extinction of the Dinosaurs comes an introduction to the study of dinosaurs for non-specialists designed to excite readers about science by using dinosaurs to illustrate and discuss geology, natural history and evolution. While focusing on dinosaurs it also uses them to convey other aspects of the natural scien...

Eggs containing well-preserved skeletons were collected from Bugin-tsav, an Upper Cretaceous locality in the Nemegt Formation, Ömnögov' Aimag, Mongolia. These embryos, found in a weathered nest of eggs, are oviraptorid theropods. Eggshell morphotype is Elongatoolithidae, typical of theropods, including basal birds. Bone histology indicates that all...

Upper Cretaceous marine deposits from the Mid-Atlantic region of North America (Delaware, Maryland, and New Jersey) and the Maastricht area (southern Netherlands, and nearby Belgium and Germany) are correlated across the Atlantic using a variety of macroinvertebrates, nannofossils, and sequence stratigraphy. Four late Cretaceous Mid-Atlantic sequen...

Rightly or wrongly, dinosaurs are poster children for the Cretaceous-Tertiary (K-T) extinction. The rate and cause of their extinction, however, has been contentious, at least in part because of their rarity. Nonetheless, significant data have accumulated to indicate that the dinosaur extinction, in North America at least, was geologically instanta...

We thank J.D. Archibald for his comment on our study ([Fastovsky et al., 2004][1]) because his misunderstanding of our work provides the opportunity to clarify ideas that may have similarly confused other readers. The raw data show high abundance in the late Campanian, decreased abundance in the

Written for non-specialists, this detailed survey of dinosaur origins, diversity, and extinction is designed as a series of successive essays covering important and timely topics in dinosaur paleobiology, such as "warm-bloodedness," birds as living dinosaurs, the new, non-flying feathered dinosaurs, dinosaur functional morphology, and cladistic met...

Huizachal Canyon, one of a series of generally east-west trending canyons in Tamauli- pas, northeastern Mexico, exposes a pre-Late Jurassic sequence of fossiliferous pyroclastic and epiclastic rocks, the Huizachal Group. Heretofore considered a sedimentary package associated with either metamorphic or intrusive rocks, structural relationships and p...

The richness of Mesozoic Dinosauria is examined through the use of a new global database. Mesozoic dinosaurs show a steadily increasing rate of diversification, in part attributable to the development of new innovations driving an increasing variety of behavioral strategies. The data do not suggest that dinosaurs were decreasing in richness leading...

This chapter discusses the paleoecology of dinosaurs. It first examines the variety of adaptations of dinosaurs to sustain their herbivorous habits. It then describes Mesozoic paleobotany and outlines the coevolution between dinosaurs and plants. During the Late Triassic, there was the coincident rise of conifers and the appearance of prosauropods,...

The disappearance of nonavian dinosaurs is only a small part of a greater class of extinctions known as “mass extinctions.” Mass extinctions are global events characterized by unusually high rates of extinction. The five episodes of mass extinctions in Earth history are the Permo-Triassic extinction, the Late Ordovician extinction, the Late Devonia...

This study of Tepexi de Rodríguez (Puebla, Mexico), a mid-Cretaceous (Aptian?) locality with exceptional fossil preservation, combines statistically based microfacies-transition analysis with spectral analysis of depth-series measurements, in an attempt to constrain the paleoenvironmental setting. Tepexi de Rodríguez (Tepexi) is largely composed of...

This study of Tepexi de Rodrı´guez (Puebla, Mexico), a mid-Cretaceous (Aptian?) locality with exceptional fossil preservation, combines statistically based microfacies-transition analysis with spectral analysis of depth-series measurements, in an attempt to constrain the paleoenvironmental setting. Tepexi de Rodrıguez (Tepexi) is largely composed o...

Science progresses whenever new ways of explaining natural phenomena are revealed. New ideas can only be put to use after the results and significance of research have been brought to the attention of both the scientific and lay communities. The Milwaukee Public Museum Dig-A-Dinosaur Program is a model for scientists who want to conduct research as...

Evolution of Herbivory in Terrestrial Vertebrates: Perspectives from the Fossil Record, H.-D. Sues (Editor), 2000, Cambridge University Press, New York, 256 p. ($80) ISBN: 0521-59449-9. Terrestrial habits are immanent to Amniota. The history of amniotes utilizing terrestrial primary production (e.g., plants) is ultimately the central story of amni...

An ˜3 m stratigraphic interval that entirely lacks dinosaur fossils or has very few fossils has been reported at the top of the Hell Creek Formation in the upper Great Plains of North America. The presence of the “3 m gap” in fossil distribution has been cited as evidence that dinosaurs had either become extinct or were on the verge of extinction p...

Three localities in the Chinle Formation (Late Triassic), Petrified Forest National Park (PEFO), Arizona, provide in- sights into the paleoenvironments frequented by primitive North American theropods. At the Dinosaur Wash locality, an undetermined theropod is preserved in paleosols that in- dicate a transition from wet to dry conditions on the flo...

An ˜3 m stratigraphic interval that entirely lacks dinosaur fossils or has very few fossils has been reported at the top of the Hell Creek Formation in the upper Great Plains of North America. The presence of the ``3 m gap'' in fossil distribution has been cited as evidence that dinosaurs had either become extinct or were on the verge of extinction...

The measured sections show that the oldest strata in Petrified Forest National Park are present in the vicinity of the Haystacks. Controversial units are exposed in this vicinity; these include sandstones, siltstones, mudstones and a purple mottled horizon, whose characteristics are reminiscent of strata of the Moenkopi Formation (Early to Middle T...

The nature of the hindlimb posture and gait of pterosaurs has been controversial, partly because most of the pterosaur skeletons that have been found were flattened in thin-bedded rocks, therefore obscuring three-dimensional anatomy. A major controversy concerns the extent to which pterosaurs move on the ground; they have been variously interpreted...

This study quantifies the taphonomic context of fossil dinosaur elements in the Late Cretaceous Hell Creek Formation of Montana and North Dakota, USA. A previously published data base consisting of 649 individuals (counted at the family level) was used to establish statistically fundamental associations between the vertebrate faunal elements and th...

Tugrikin-shireh, south-central Gobi Desert, Mongolia, consists of about 1.5 km of west- and northwest-facing exposures that produce a rich vertebrate fauna dominated by the ornithischian dinosaur Protoceratops. The sandstones of Tugrik are thick-bedded (2-9 m) and are distinguished by large-scale (10's to 100's of meters in cross-section), high-ang...

A large assemblage of vertebrate fossils from the La Boca Formation in Huizachal Canyon, near Ciudad Victoria, Tamaulipas, Mexico, is preserved in a unique setting: debris-flow sediments deposited over a landscape with at least modest topographic relief. Angular feldspar lathes in the rock suggest that deposition was associated with penecontemporan...

A one-year study of two ponds and a river in Rhode Island was implemented to determine whether Elliptio complanata secretes aragonite in oxygen isotopic equilibrium with the water in which they grow. In fact, disequilibrium is manifested as an offset of approximately -2‰ in the summer and -2.5‰ in the winter. Incorporation of metabolic CO 2 may con...

A large database recording species of terrestrial vertebrates present in formations above and below the Cretaceous-Tertiary (K-T) boundary in eastern Montana was assembled by J.D. Archibald and L.J. Bryant. Division of the species in this database into freshwater and land-dwelling vertebrate assemblages reveals that the K-T vertebrate extinction wa...

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In the terrestrial latest Cretaceous Hell Creek (HC) Formation, both non-biotic events and patterns of extinction and survivorship are consistent with an asteroid impact causing the extinctions. Environments through the last 2--3 million-year interval represented by the HC remained relatively constant: an aggrading coastal lowland dissected by mean...

A large database recording species of terrestrial vertebrates present in formations above and below the Cretaceous-Tertiary (K-T) boundary in eastern Montana was assembled by J. D. Archibald and L. J. Bryant. Division of the species in this database into freshwater and land-dwelling vertebrate assemblages reveals that the K-T vertebrate extinction...

Vertically stacked paleosol profiles in the Round Knob (RK) shale are exposed in road cuts near Steubenville, OH. This unit overlies an interdistributary bay-fill type coarsening-upward sequence and is overlain by the Harlem coal. The RK characteristically possesses hackly soil-like structure and red coloration. The clay mineral assemblage consists...

The fossil record is commonly (but not universally) invoked as an historical record with which to test evolutionary scenarios. The process by which this takes place involves the recognition of patterns of taxa in a temporal framework. The patterns are in turn interpreted as the result of some evolutionary mechanism. We submit that if the fossil rec...

Results of a three-year field study of family-level patterns of ecological diversity of dinosaurs in the Hell Creek Formation of Montana and North Dakota show no evidence (probability P < 0.05) of a gradual decline of dinosaurs at the end of the Cretaceous. Stratigraphic reliability was maintained through a tripartite division of the Hell Creek, an...

The Petrified Forest Plateau of Theodore Roosevelt National Park (TRNP) in western North Dakota provides an excellent setting for exploring the influence of ancient, exhumed land surfaces upon modern ones. Here, a sequence of Paleocene rocks preserves a succession of ancient terrestrial land surfaces characterized by fine-grained, laminated sedimen...

Cemented paleosols of the Cretaceous Hell Creek Formation were examined in an attempt to discern origin of cementing agents. Six 3-m columnar sections were selected for detailed study. The soils were formed in interbedded sand and mud fluvial sediments and typically exhibit only weak signatures of pedogenesis. Furthermore, the sediments have been s...

The spatial and temporal distributions of vertebrate fossil assemblages at the terrestrial Cretaceous/Paleogene (K/P) boundary in eastern Montana and western North Dakota are constrained by the meandering fluvial depositional system in which they are preserved. Vertebrate fossils are clasts within that system, and thus their positions within the se...

The fabric, mineralogy, and geochemistry of a 0.5-1.5 cm-thick claystone parting indicate that certain of its features are the result of contemporaneous pedogenesis, a diastem (i.e., micro-disconformity) between the 2:1 and 1:1 claystone layers. The temporal separation between these two layers, indicated by the contrast in the nature and arrangemen...

Microscopy is used to distinguish pedogenic features from those associated with primary sedimentary fabric and non-pedogenic diagenesis in a suite of 65 million year old sediments. Sand-to-clay-sized material was deposited in meandering river systems over a broad coastal alluvial plain, and pedogenesis occurred in all lithologies. A variety of petr...

Paleosols occur in exposures of the latest Cretaceous Hell Creek and Paleocene Tullock (=Ludlow) Formations in Montana and western North Dakota. The paleosols indicate that changes in ancient soil development occurred concomitantly with the better-known faunal transition. Features suggest that throughout the Cretaceous-Paleogene transition pedogeni...

The nonmarine Glen Canyon Group in northern Arizona has the best known and most diverse assemblage of vertebrate fossils from the latest Triassic or Early Jurassic in North America. The purpose of this paper is to review the stratigraphic distributions of the vertebrate fossils within the group, especially those of the Moenave and Kayenta Formation...

Exposures of the Hell Creek and Tullock formations in eastern Montana and the Ludlow Formation in western North Dakota allow detailed reconstruction of the paleoenvironments associated with the Cretaceous-Paleogene (K-P) faunal transition in the Western Interior of North America. Facies associations demonstrate an ancient meandering fluvial environ...

Bug Creek Valley, the source of an unusual and controversial Cretaceous-Paleogene coincidence of mammals, dinosaurs, pollen, and indium, exemplifies the importance of depositional process in the reconstruction of evolutionary events. Five sedimentary facies are recognized at Bug Creek: a cross-stratified sandstone, a green and purple siltstone, a l...