To see the other types of publications on this topic, follow the link: Cretaceous ecosystem.
Journal articles on the topic 'Cretaceous ecosystem'
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 'Cretaceous ecosystem.'
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
Wilson, Lauren N., Daniel T. Ksepka, John P. Wilson, et al. "Arctic bird nesting traces back to the Cretaceous." Science 388, no. 6750 (2025): 974–78. https://doi.org/10.1126/science.adt5189.
Full textAbstract:
Polar ecosystems are structured and enriched by birds, which nest there seasonally and serve as keystone ecosystem members. Despite the ecological importance of polar birds, the origins of high-latitude nesting strategies remain obscured by a sparse fossil record. We report an extreme-latitude Arctic avialan assemblage from the Prince Creek Formation of Alaska—the northernmost Late Cretaceous terrestrial ecosystem. Numerous three-dimensionally preserved fossils constitute one of the most taxonomically rich Late Cretaceous avialan assemblages, including members of Hesperornithes, Ichthyornithes, and near-crown or crown birds (Neornithes), recording a previously undocumented interval in avialan evolution. Abundant perinatal fossils represent the oldest evidence of birds nesting at polar latitudes, which demonstrates that birds began using seasonal polar environments for breeding during the Cretaceous, long before their modern descendants.
2
Zhou, Zhonghe, Paul M. Barrett, and Jason Hilton. "An exceptionally preserved Lower Cretaceous ecosystem." Nature 421, no. 6925 (2003): 807–14. http://dx.doi.org/10.1038/nature01420.
Full text
3
Vellekoop, Johan, Lineke Woelders, Appy Sluijs, Kenneth G. Miller, and Robert P. Speijer. "Phytoplankton community disruption caused by latest Cretaceous global warming." Biogeosciences 16, no. 21 (2019): 4201–10. http://dx.doi.org/10.5194/bg-16-4201-2019.
Full textAbstract:
Abstract. Phytoplankton responses to a ∼350 kyr (kiloyear) long phase of gradual late Maastrichtian (latest Cretaceous) global warming starting at ∼66.4 Ma can provide valuable insights into the long-term influences of global change on marine ecosystems. Here we perform micropaleontological analyses on three cores from the New Jersey paleoshelf to assess the response of phytoplankton using cyst-forming dinoflagellates and benthic ecosystems using benthic foraminifera. Our records show that this latest Maastrichtian warming event (LMWE), characterized by a 4.0±1.3 ∘C warming of sea surface waters on the New Jersey paleoshelf, resulted in a succession of nearly monospecific dinoflagellate-cyst assemblages, dominated by the species Palynodinium grallator. This response, likely triggered by the combination of warmer and seasonally thermally stratified seas, appears to have been more intense at offshore sites than at nearshore sites. The LMWE, and related dinoflagellate response, is associated with an impoverished benthic ecosystem. A wider geographic survey of literature data reveals that the dominance of P. grallator is a marker for the LMWE throughout the northern midlatitudes. While the dinocyst assemblage returned to a stable, normal marine community in the last tens of thousands of years of the Maastrichtian, benthic foraminiferal diversity appears to have remained slightly suppressed. Increased ecosystem stress during the latest Maastrichtian potentially primed global ecosystems for the subsequent mass extinction following the Cretaceous Paleogene (K–Pg) boundary Chicxulub impact.
4
Suarez, Celina A., Joseph Frederickson, Richard L. Cifelli, et al. "A new vertebrate fauna from the Lower Cretaceous Holly Creek Formation of the Trinity Group, southwest Arkansas, USA." PeerJ 9 (October 21, 2021): e12242. http://dx.doi.org/10.7717/peerj.12242.
Full textAbstract:
We present a previously discovered but undescribed late Early Cretaceous vertebrate fauna from the Holly Creek Formation of the Trinity Group in Arkansas. The site from the ancient Gulf Coast is dominated by semi-aquatic forms and preserves a diverse aquatic, semi-aquatic, and terrestrial fauna. Fishes include fresh- to brackish-water chondrichthyans and a variety of actinopterygians, including semionotids, an amiid, and a new pycnodontiform, Anomoeodus caddoi sp. nov. Semi-aquatic taxa include lissamphibians, the solemydid turtle Naomichelys, a trionychid turtle, and coelognathosuchian crocodyliforms. Among terrestrial forms are several members of Dinosauria and one or more squamates, one of which, Sciroseps pawhuskai gen. et sp. nov., is described herein. Among Dinosauria, both large and small theropods (Acrocanthosaurus, Deinonychus, and Richardoestesia) and titanosauriform sauropods are represented; herein we also report the first occurrence of a nodosaurid ankylosaur from the Trinity Group. The fauna of the Holly Creek Formation is similar to other, widely scattered late Early Cretaceous assemblages across North America and suggests the presence of a low-diversity, broadly distributed continental ecosystem of the Early Cretaceous following the Late Jurassic faunal turnover. This low-diversity ecosystem contrasts sharply with the highly diverse ecosystem which emerged by the Cenomanian. The contrast underpins the importance of vicariance as an evolutionary driver brought on by Sevier tectonics and climatic changes, such as rising sea level and formation of the Western Interior Seaway, impacting the early Late Cretaceous ecosystem.
5
Henehan, Michael J., Pincelli M. Hull, Donald E. Penman, James W. B. Rae, and Daniela N. Schmidt. "Biogeochemical significance of pelagic ecosystem function: an end-Cretaceous case study." Philosophical Transactions of the Royal Society B: Biological Sciences 371, no. 1694 (2016): 20150510. http://dx.doi.org/10.1098/rstb.2015.0510.
Full textAbstract:
Pelagic ecosystem function is integral to global biogeochemical cycling, and plays a major role in modulating atmospheric CO 2 concentrations ( p CO 2 ). Uncertainty as to the effects of human activities on marine ecosystem function hinders projection of future atmospheric p CO 2 . To this end, events in the geological past can provide informative case studies in the response of ecosystem function to environmental and ecological changes. Around the Cretaceous–Palaeogene (K–Pg) boundary, two such events occurred: Deccan large igneous province (LIP) eruptions and massive bolide impact at the Yucatan Peninsula. Both perturbed the environment, but only the impact coincided with marine mass extinction. As such, we use these events to directly contrast the response of marine biogeochemical cycling to environmental perturbation with and without changes in global species richness. We measure this biogeochemical response using records of deep-sea carbonate preservation. We find that Late Cretaceous Deccan volcanism prompted transient deep-sea carbonate dissolution of a larger magnitude and timescale than predicted by geochemical models. Even so, the effect of volcanism on carbonate preservation was slight compared with bolide impact. Empirical records and geochemical models support a pronounced increase in carbonate saturation state for more than 500 000 years following the mass extinction of pelagic carbonate producers at the K–Pg boundary. These examples highlight the importance of pelagic ecosystems in moderating climate and ocean chemistry.
6
Baranov, Viktor A., Yinan Wang, Rok Gašparič, Sonja Wedmann, and Joachim T. Haug. "Eco-morphological diversity of larvae of soldier flies and their closest relatives in deep time." PeerJ 8 (November 27, 2020): e10356. http://dx.doi.org/10.7717/peerj.10356.
Full textAbstract:
Stratiomyomorpha (soldier flies and allies) is an ingroup of Diptera, with a fossil record stretching back to the Early Cretaceous (the Barremian, about 125 MYA). Stratiomyomorpha includes at least 3,000 species in the modern fauna, with many species being crucial for ecosystem functions, especially as saprophages. Larvae of many stratiomyomorphans are especially important as scavengers and saproxyls in modern ecosystems. Yet, fossil larvae of the group are extremely scarce. Here we present 23 new records of fossil stratiomyomorphan larvae, representing six discrete morphotypes. Specimens originate from Cretaceous amber from Myanmar, Eocene Baltic amber, Miocene Dominican amber, and compression fossils from the Eocene of Messel (Germany) and the Miocene of Slovenia. We discuss the implications of these new records for our understanding of stratiomyomorphan ecomorphology in deep time as well as their palaeoecology.
7
Carvalho, Mónica R., Carlos Jaramillo, Felipe de la Parra, et al. "Extinction at the end-Cretaceous and the origin of modern Neotropical rainforests." Science 372, no. 6537 (2021): 63–68. http://dx.doi.org/10.1126/science.abf1969.
Full textAbstract:
The end-Cretaceous event was catastrophic for terrestrial communities worldwide, yet its long-lasting effect on tropical forests remains largely unknown. We quantified plant extinction and ecological change in tropical forests resulting from the end-Cretaceous event using fossil pollen (>50,000 occurrences) and leaves (>6000 specimens) from localities in Colombia. Late Cretaceous (Maastrichtian) rainforests were characterized by an open canopy and diverse plant–insect interactions. Plant diversity declined by 45% at the Cretaceous–Paleogene boundary and did not recover for ~6 million years. Paleocene forests resembled modern Neotropical rainforests, with a closed canopy and multistratal structure dominated by angiosperms. The end-Cretaceous event triggered a long interval of low plant diversity in the Neotropics and the evolutionary assembly of today’s most diverse terrestrial ecosystem.
8
Jacobs, Louis, Michael Polcyn, Octávio Mateus, and Anne Schulp. "Deep Time Conservation Paleobiology of the Atlantic Jigsaw Puzzle and the Future of the Southwestern Angolan Coast." Bulletin of the Florida Museum of Natural History 60, no. 2 (2023): 90. http://dx.doi.org/10.58782/flmnh.fior9961.
Full textAbstract:
The puzzle-like fit of Africa and South America reflects the tectonically driven opening of the South Atlantic Ocean beginning over 130 mya. By 90 Ma, the North and South Atlantics were conjoined. The introduction of Cretaceous marine reptiles into the central South Atlantic from the north coincides with through-flow in the Equatorial Atlantic Gateway and with increased productivity and upwelling of the Benguela Current. The K-Pg extinction saw the demise of most marine reptiles, but upwelling apparently persisted, evidenced by a growing Cenozoic fossil record of sea turtles and marine mammals from the Angolan coast. Convergent similarities between the Cretaceous marine reptile vertebrate community and the modern vertebrate community of the Benguela Large Marine Ecosystem suggest essentially continuous productivity related to upwelling along the southwest African coast since Cretaceous time. Paleolatitude reconstructions show that predicted positions of coastal upwelling of the Benguela Current have moved south along the coast as Africa drifted northward through the descending limb of the southern Hadley Cell. The Cretaceous and modern faunas were both adapted to a productive upwelling zone. The Cretaceous relict Welwitschia mirabilis is consistent with coastal aridity alongside upwelling. Thus, the sediments of coastal Angola and the fossils they entomb are relevant to conservation paleobiology because they provide a baseline through deep time. Comparisons underscore the resilience of the Benguela Current on the one hand and emphasize human-driven threats to the Benguela Large Marine Ecosystem on the other. Solutions are being sought; for instance, through the evaluation of Ecologically or Biologically Significant Marine Areas (EBSA) in the Benguela Current Large Marine Ecosystem. In Angola, the geologic record of the opening of the South Atlantic, the fossils, public interest, and the value for sustainable development are positive indications for the future.
9
WANG, QIANG, XIAOLIN WANG, ZIKUI ZHAO, JIALIANG ZHANG, and SHUNXING JIANG. "New turtle egg fossil from the Upper Cretaceous of the Laiyang Basin, Shandong Province, China." Anais da Academia Brasileira de Ciências 85, no. 1 (2013): 103–11. http://dx.doi.org/10.1590/s0001-37652013000100008.
Full textAbstract:
A new type of turtle egg fossil was established: Emydoolithus laiyangensis oogen. et oosp. nov.. Based on its elliptical morphological shape, rigid eggshells, and eggshell characteristics, it is different from other types of round chelonian egg fossils. It is the second chelonian egg fossil found in Cretaceous in China. This discovery shows the Laiyang ecosystem in Late Cretaceous is more diversified than previously thought.
10
Brownstein, Chase D. "Trace fossils on dinosaur bones reveal ecosystem dynamics along the coast of eastern North America during the latest Cretaceous." PeerJ 6 (June 11, 2018): e4973. http://dx.doi.org/10.7717/peerj.4973.
Full textAbstract:
Direct evidence of paleoecological processes is often rare when the fossil record is poor, as in the case of the Cretaceous of eastern North America. Here, I describe a femur and partial tibia shaft assignable to theropods from two Late Cretaceous sites in New Jersey. The former, identifiable as the femur of a large ornithomimosaur, bears several scores interpreted as shark feeding traces. The tibia shaft has punctures and flaked bone from the bites of mid-sized crocodyliforms, the first documented occurrence of crocodyliform traces on dinosaur bone from the Maastrichtian of the Atlantic Coastal Plain. The surface of the partial tibia is also littered with indentations interpreted as the traces of invertebrates, revealing a microcosm of biological interaction on the coastal seafloor of the Cretaceous Atlantic Ocean. Massive crocodyliforms, such as Deinosuchus rugosus and the slightly smaller Deltasuchus motherali, maintained the role of terrestrial vertebrate taphonomic process drivers in eastern North America during the Cretaceous. The report of crocodyliform bite marks on the ornithomimosaur tibia shaft in this manuscript reinforces the importance of the role of crocodyliforms in the modification of terrestrial vertebrate remains during the Cretaceous in North America. The preserved invertebrate traces add to the sparse record of the presence of barnacles and other marine invertebrates on dinosaur bone, and the evidence of shark feeding on the ornithomimosaur femur support the “bloat-and-float” model of terrestrial vertebrate fossil deposition in marine deposits from the Cretaceous of eastern North America.
11
Mitchell, Jonathan S., and Peter J. Makovicky. "Low ecological disparity in Early Cretaceous birds." Proceedings of the Royal Society B: Biological Sciences 281, no. 1787 (2014): 20140608. http://dx.doi.org/10.1098/rspb.2014.0608.
Full textAbstract:
Ecological divergence is thought to be coupled with evolutionary radiations, yet the strength of this coupling is unclear. When birds diversified ecologically has received much less attention than their hotly debated crown divergence time. Here, we quantify how accurately skeletal morphology can predict ecology in living and extinct birds, and show that the earliest known assemblage of birds (= pygostylians) from the Jehol Biota (≈ 125 Ma) was substantially impoverished ecologically. The Jehol avifauna has few representatives of highly preservable ecomorphs (e.g. aquatic forms) and a notable lack of ecomorphological overlap with the pterosaur assemblage (e.g. no large or aerially foraging pygostylians). Comparisons of the Jehol functional diversity with modern and subfossil avian assemblages show that taphonomic bias alone cannot explain the ecomorphological impoverishment. However, evolutionary simulations suggest that the constrained ecological diversity of the Early Cretaceous pygostylians is consistent with what is expected from a relatively young radiation. Regardless of the proximate biological explanation, the anomalously low functional diversity of the Jehol birds is evidence both for ecological vacancies in Cretaceous ecosystems, which were subsequently filled by the radiation of crown Aves, and for discordance between taxonomic richness and ecological diversity in the best-known Mesozoic ecosystem.
12
Sprain, Courtney J., Paul R. Renne, Loÿc Vanderkluysen, Kanchan Pande, Stephen Self, and Tushar Mittal. "The eruptive tempo of Deccan volcanism in relation to the Cretaceous-Paleogene boundary." Science 363, no. 6429 (2019): 866–70. http://dx.doi.org/10.1126/science.aav1446.
Full textAbstract:
Late Cretaceous records of environmental change suggest that Deccan Traps (DT) volcanism contributed to the Cretaceous-Paleogene boundary (KPB) ecosystem crisis. However, testing this hypothesis requires identification of the KPB in the DT. We constrain the location of the KPB with high-precision argon-40/argon-39 data to be coincident with changes in the magmatic plumbing system. We also found that the DT did not erupt in three discrete large pulses and that >90% of DT volume erupted in <1 million years, with ~75% emplaced post-KPB. Late Cretaceous records of climate change coincide temporally with the eruption of the smallest DT phases, suggesting that either the release of climate-modifying gases is not directly related to eruptive volume or DT volcanism was not the source of Late Cretaceous climate change.
13
Cilliers, Charl D., Ryan T. Tucker, James L. Crowley, and Lindsay E. Zanno. "Age constraint for the Moreno Hill Formation (Zuni Basin) by CA-TIMS and LA-ICP-MS detrital zircon geochronology." PeerJ 9 (March 9, 2021): e10948. http://dx.doi.org/10.7717/peerj.10948.
Full textAbstract:
The “mid-Cretaceous” (~125–80 Ma) was punctuated by major plate-tectonic upheavals resulting in widespread volcanism, mountain-building, eustatic sea-level changes, and climatic shifts that together had a profound impact on terrestrial biotic assemblages. Paleontological evidence suggests terrestrial ecosystems underwent a major restructuring during this interval, yet the pace and pattern are poorly constrained. Current impediments to piecing together the geologic and biological history of the “mid-Cretaceous” include a relative paucity of terrestrial outcrop stemming from this time interval, coupled with a historical understudy of fragmentary strata. In the Western Interior of North America, sedimentary strata of the Turonian–Santonian stages are emerging as key sources of data for refining the timing of ecosystem transformation during the transition from the late-Early to early-Late Cretaceous. In particular, the Moreno Hill Formation (Zuni Basin, New Mexico) is especially important for detailing the timing of the rise of iconic Late Cretaceous vertebrate faunas. This study presents the first systematic geochronological framework for key strata within the Moreno Hill Formation. Based on the double-dating of (U-Pb) detrital zircons, via CA-TIMS and LA-ICP-MS, we interpret two distinct depositional phases of the Moreno Hill Formation (initial deposition after 90.9 Ma (middle Turonian) and subsequent deposition after 88.6 Ma (early Coniacian)), younger than previously postulated based on correlations with marine biostratigraphy. Sediment and the co-occurring youthful subset of zircons are sourced from the southwestern Cordilleran Arc and Mogollon Highlands, which fed into the landward portion of the Gallup Delta (the Moreno Hill Formation) via northeasterly flowing channel complexes. This work greatly strengthens linkages to other early Late Cretaceous strata across the Western Interior.
14
JI, GAO-ZHE, CHEN-YANG CAI, XUE-FEI YU, et al. "Distribution and mineralogical characteristics of amber in the Upper cretaceous Gaogou Formation in Xixia, Henan Province, china." Mesozoic 2, no. 1 (2025): 60–69. https://doi.org/10.11646/mesozoic.2.1.8.
Full textAbstract:
The Xixia amber is the largest known Mesozoic amber deposit in China to date. Here we analyse amber collected over the years from 12 localities in the Upper Cretaceous Gaogou Formation in Xixia, Henan, including physical property tests and Fourier transform infrared spectroscopy (FT-IR) analysis. The main preservation forms of the Xixia amber include nest-like, vein-like, and layered irregular shapes, as well as gravel-like forms resulting from secondary transportation. Recent discoveries include numerous small-grained amber specimens preserved in grey-black silty shale rich in plant debris, suggesting a near-in-situ depositional environment. The Xixia Basin’s Late Cretaceous strata are renowned for their abundance in dinosaur eggs. In-depth research on the Xixia amber will help to understand the geological history and ecosystem evolution of the Xixia Basin during the Late Cretaceous, as well as the global distribution characteristics of Cretaceous amber.
15
YU, Kaifeng, Wenhao WU, Wei SUN, Jun CHEN, and Xuri WANG. "New Dinosaur Teeth from the Upper Cretaceous Nenjiang Formation in Songliao Basin, Northeast China." Acta Geologica Sinica - English Edition 99, no. 2 (2025): 320–31. https://doi.org/10.1111/1755-6724.15288.
Full textAbstract:
AbstractTwelve new dinosaur teeth have recently been recovered from three localities in the Upper Cretaceous Nenjiang Formation of the Songliao Basin. Although fragmentary, the material offers enough evidence to identify the following taxa: tyrannosaurids, dromaeosaurines, velociraptorines, hadrosauroids, and titanosaurs. In addition to the previously known dinosaurs from the basin, several new ones have been identified, extending the paleogeographic range of related taxa. The discovery of these new fossil remains provides valuable insights into dinosaur diversity and sheds light on the terrestrial ecosystem during the Late Cretaceous in the Songliao Basin.
16
Gimmel, Matthew L., Karol Szawaryn, Chenyang Cai, and Richard A. B. Leschen. "Mesozoic sooty mould beetles as living relicts in New Zealand." Proceedings of the Royal Society B: Biological Sciences 286, no. 1917 (2019): 20192176. http://dx.doi.org/10.1098/rspb.2019.2176.
Full textAbstract:
New Zealand is an island continent that completed its split from the Gondwanan continent at 52 Ma, harbouring an iconic biota of tuatara, kiwi and weta. The sooty mould community is a distinctive trophic element of New Zealand forest ecosystems that is driven by plant-feeding sternorrhynchan Hemiptera. These produce honeydew, which supports fungal growth, which in turn supports numerous endemic invertebrates, including endemic New Zealand beetle families. Ancient New Zealand insect fossils are rare but a single fossil of a sooty mould cyclaxyrid was recently described from Cretaceous Burmese amber, a family that was previously known from two extant New Zealand species. Well-preserved fossils like this one are recasting Earth history, and, based on a wealth of additional specimens, we re-evaluate the taxonomy of Cretaceous cyclaxyrids and one Eocene species here transferred to Cyclaxyridae. Cyclaxyridae are highly tied to the sooty mould community and have now been discovered to occur in disparate biogeographic realms in deep time. Our discovery indicates that the family, and perhaps the sooty mould community in general, was widespread in Pangaea from at least the Cretaceous and survived as a relict in New Zealand. Persistence of a sooty mould ecosystem in New Zealand and fungal specialization may not necessarily be an evolutionary ‘dead-end’ for cyclaxyrids and other insects.
17
Maidment, Susannah C. R., Christopher D. Dean, Robert I. Mansergh, and Richard J. Butler. "Deep-time biodiversity patterns and the dinosaurian fossil record of the Late Cretaceous Western Interior, North America." Proceedings of the Royal Society B: Biological Sciences 288, no. 1953 (2021): 20210692. http://dx.doi.org/10.1098/rspb.2021.0692.
Full textAbstract:
In order for palaeontological data to be informative to ecologists seeking to understand the causes of today's diversity patterns, palaeontologists must demonstrate that actual biodiversity patterns are preserved in our reconstructions of past ecosystems. During the Late Cretaceous, North America was divided into two landmasses, Laramidia and Appalachia. Previous work has suggested strong faunal provinciality on Laramidia at this time, but these arguments are almost entirely qualitative. We quantitatively investigated faunal provinciality in ceratopsid and hadrosaurid dinosaurs using a biogeographic network approach and investigated sampling biases by examining correlations between dinosaur occurrences and collections. We carried out a model-fitting approach using generalized least-squares regression to investigate the sources of sampling bias we identified. We find that while the raw data strongly support faunal provinciality, this result is driven by sampling bias. The data quality of ceratopsids and hadrosaurids is currently too poor to enable fair tests of provincialism, even in this intensively sampled region, which probably represents the best-known Late Cretaceous terrestrial ecosystem on Earth. To accurately reconstruct biodiversity patterns in deep time, future work should focus on smaller scale, higher resolution case studies in which the effects of sampling bias can be better controlled.
18
Pike, E. M. "Upper Cretaceous amber arthropods and their implications on changes in insect community structure." Paleontological Society Special Publications 6 (1992): 234. http://dx.doi.org/10.1017/s2475262200007942.
Full textAbstract:
Assessment of changes in terrestrial ecosystems since Cretaceous time, until recently, has had to rely on paleobotany (including paleopalynology) and vertebrate paleontology to provide data for analysis. Insects contribute a major portion of the terrestrial diversity in any ecosystem, but their fossil record and state of preservation had discouraged paleoecological study beyond the Pleistocene. With the discovery of prolific Upper Cretaceous amber deposits in Russia and Canada, and the investigation of Tertiary amber deposits from the Baltic, the Dominican Republic, Mexico and the USA, the prospect of clarifying changes in insect diversity and ecology over time becomes real. Methods are reported which allow the description of species richness and relative abundance of arthropod taxa from an Upper Cretaceous (Campanian: 75 MYA) amber deposit in Alberta, Canada. Diversity and abundance are described at the Order level for hexapods, and for the Acarina and Araneae. Taxa present, in order of abundance, are Homoptera (66 specimens/kg of amber), Diptera (28/kg), Acarina (21/kg), Hymenoptera (13/kg), Araneae (12/kg), Psocoptera (4/kg), Coleoptera (2/kg), Blattodea (1/kg), Thysanoptera (1/kg), Trichoptera (0.6/kg). Other orders present are Lepidoptera, Collembola, Dermaptera, Mantodea, and Ephemeroptera. In total, of 35 identified families, 8 are extinct. There are about 20 genera identified, of which only 1 is extant. All identified species are extinct. Estimated species richness is about 100 species of arthropods. In comparison, virtually all Families reported from Baltic amber (Oligocene) are still extant, as are the majority of genera. Morphology and feeding structures are well within the variation seen in modern insects. This suggests that throughout the Tertiary, Entomologists would feel quite at home with the insect fauna, and during the Upper Cretaceous, they would have little difficulty identifying insects at least to the family level. It is hypothesized that the taxonomic structure of modern insect communities was well established before the end of the Cretaceous, and that the structure and interrelationships of insect guilds were also very similar to those of today.
19
Cullen, T. M., F. J. Longstaffe, U. G. Wortmann, et al. "Large-scale stable isotope characterization of a Late Cretaceous dinosaur-dominated ecosystem." Geology 48, no. 6 (2020): 546–51. http://dx.doi.org/10.1130/g47399.1.
Full textAbstract:
Abstract In the Cretaceous of North America, environmental sensitivity and habitat specialization have been hypothesized to explain the surprisingly restricted geographic ranges of many large-bodied dinosaurs. Understanding the drivers behind this are key to determining broader trends of dinosaur species and community response to climate change under greenhouse conditions. However, previous studies of this question have commonly examined only small components of the paleo-ecosystem or operated without comparison to similar modern systems from which to constrain interpretations. Here we perform a high-resolution multi-taxic δ13C and δ18O study of a Cretaceous coastal floodplain ecosystem, focusing on species interactions and paleotemperature estimation, and compare with similar data from extant systems. Bioapatite δ13C preserves predator-prey offsets between tyrannosaurs and ornithischians (large herbivorous dinosaurs), and between aquatic reptiles and fish. Large ornithischians had broadly overlapping stable isotope ranges, contrary to hypothesized niche partitioning driven by specialization on coastal or inland subhabitat use. Comparisons to a modern analogue coastal floodplain show similar patterns of ecological guild structure and aquatic-terrestrial resource interchange. Multi-taxic oxygen isotope temperature estimations yield results for the Campanian of Alberta (Canada) consistent with the few other paleotemperature proxies available, and are validated when applied for extant species from a modern coastal floodplain, suggesting that this approach is a simple and effective avenue for paleoenvironmental reconstruction. Together, these new data suggest that dinosaur niche partitioning was more complex than previously hypothesized, and provide a framework for future research on dinosaur-dominated Mesozoic floodplain communities.
20
Lomax, B. H., D. J. Beerling, G. R. Upchurch, and B. L. Otto-Bliesner. "Terrestrial ecosystem responses to global environmental change across the Cretaceous-Tertiary boundary." Geophysical Research Letters 27, no. 14 (2000): 2149–52. http://dx.doi.org/10.1029/1999gl011097.
Full text
21
Calvo, Jorge O., Juan D. Porfiri, Bernardo J. González-Riga, and Alexander W. A. Kellner. "A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur." Anais da Academia Brasileira de Ciências 79, no. 3 (2007): 529–41. http://dx.doi.org/10.1590/s0001-37652007000300013.
Full textAbstract:
A unique site at the northern area of Patagonia (Neuquén, Argentina) reveals a terrestrial ecosystem preserved in a detail never reported before in a Late Cretaceous deposit. An extraordinary diversity and abundance of fossils was found concentrated in a 0.5 m horizon in the same quarry, including a new titanosaur sauropod, Futalognkosaurus dukei n.gen., n.sp, which is the most complete giant dinosaur known so far. Several plant leaves, showing a predominance of angiosperms over gymnosperms that likely constituted the diet of F. dukei were found too. Other dinosaurs (sauropods, theropods, ornithopods), crocodylomorphs, pterosaurs, and fishes were also discovered, allowing a partial reconstruction of this Gondwanan continental ecosystem.
22
Hassler, A., J. E. Martin, R. Amiot, et al. "Calcium isotopes offer clues on resource partitioning among Cretaceous predatory dinosaurs." Proceedings of the Royal Society B: Biological Sciences 285, no. 1876 (2018): 20180197. http://dx.doi.org/10.1098/rspb.2018.0197.
Full textAbstract:
Large predators are overabundant in mid-Cretaceous continental dinosaur assemblages of North Africa. Such unbalanced ecosystem structure involves, among predatory dinosaurs, typical abelisaurid or carcharodontosaurid theropods co-occurring with long-snouted spinosaurids of debated ecology. Here, we report calcium (Ca) isotope values from tooth enamel (expressed as δ 44/42 Ca) to investigate resource partitioning in mid-Cretaceous assemblages from Niger (Gadoufaoua) and Morocco (Kem Kem Beds). In both assemblages, spinosaurids display a distinct isotopic signature, the most negative in our dataset. This distinct taxonomic clustering in Ca isotope values observed between spinosaurids and other predators provides unambiguous evidence for niche partitioning at the top of the trophic chains: spinosaurids foraged on aquatic environments while abelisaurid and carcharodontosaurid theropods relied almost exclusively on terrestrial resources.
23
Currano, Ellen D. "Ancient Bug Bites on Ancient Plants Record Forest Ecosystem Response to Environmental Perturbations." Paleontological Society Papers 19 (October 2013): 157–74. http://dx.doi.org/10.1017/s1089332600002722.
Full textAbstract:
Leaf-compression fossils with insect feeding traces are unique in providing rich, direct evidence of two levels in a fossil food web. Plant-insect associations dominate terrestrial trophic interactions, emphasizing the need to understand their ecological and evolutionary history. This paper first discusses methods of recognizing insect herbivore damage on fossil leaves and quantifying fossil insect herbivory. By conducting an unbiased insect damage census, damage frequency (percent of leaves with insect feeding damage), percent of leaf surface area removed by insects, and damage diversity (the number of discrete damage morphotypes, or DTs, found on a fossil flora or individual host plant) can all be measured. Three examples of responses of past plant-insect trophic interactions to environmental stresses are examined. In the first case study, late Oligocene fossil floras from Ethiopia document forest response to local perturbation and key characteristics to recognize disturbance in the plant fossil record. The second case study considers the terrestrial ecosystem response to the catastrophic global perturbation at the Cretaceous–Paleogene boundary. In the third case study, the impact of past global warming events—including the Paleocene–Eocene Thermal Maximum—on insect herbivory is discussed. Productive avenues for further research include: insect damage studies conducted outside the North American Cretaceous and Paleogene, actualistic and taphonomic studies of insect herbivory, and tighter collaboration across paleobotany, paleoentomology, botany, and entomology.
24
Rajanikanth, A., and Ch Chinnappa. "Early Cretaceous flora of India- A review." Journal of Palaeosciences 65, no. (1-2) (2016): 209–45. http://dx.doi.org/10.54991/jop.2016.312.
Full textAbstract:
Earth’s terrestrial ecosystem during the early Cretaceous was marked by the dominance of naked seeded plants and appearance of flowering plants. Tectonic changes and evolutionary processes affected southern floras of the globe during this time. Review of Indian early Cretaceous flora distributed in peri and intra–cratonic basins signify homogenity of composition with regional variations. The flora composed of pteridophytes, pteridospermaleans, pentoxylaleans, bennettitaleans, ginkgoaleans, coniferaleans, taxaleans and taxa of uncertain affinity along with sporadic occurrence of flowering plants represent a unique Indian Early Cretaceous flora. Similitude of basinal floras with marginal differences can be attributed to taphonomic limitations and taxonomic angularity. A perusal of available data brings out an opportunity for novelty in floral composition and variable associations dictated by prevailed environmental conditions. The eastern, western and central regions of India hold distinct litho units encompassing plant mega fossils represented by leaf, wood / axis, seed, fructification and associated marker forms. Remarkable tenacity of certain plant groups, which even found in modern flora and vulnerability of many taxa constitute a blend of extinct and extant. The appearance and extinction of certain taxa can be explained as a cumulative affect of evolutionary and climatic factors. Perpetuation of gondwanic floral elements during the early Cretaceous along with newly evolved floral components testifies evolutionary innovations and changing ecological constraints.
25
Tanaka, Kohei, Otabek Ulugbek Ogli Anvarov, Darla K. Zelenitsky, Akhmadjon Shayakubovich Ahmedshaev, and Yoshitsugu Kobayashi. "A new carcharodontosaurian theropod dinosaur occupies apex predator niche in the early Late Cretaceous of Uzbekistan." Royal Society Open Science 8, no. 9 (2021): 210923. http://dx.doi.org/10.1098/rsos.210923.
Full textAbstract:
Carcharodontosauria is a group of medium to large-sized predatory theropods, distributed worldwide during the Cretaceous. These theropods were probably the apex predators of Asiamerica in the early Late Cretaceous prior to the ascent of tyrannosaurids, although few Laurasian species are known from this time due to a poor rock record. Here, we describe Ulughbegsaurus uzbekistanensis gen. et sp. nov. from the early Late Cretaceous (Turonian) of Central Asia, which represents the first record of a Late Cretaceous carcharodontosaurian from the region. This new taxon is represented by a large, isolated maxilla from the Bissekty Formation of the Kyzylkum Desert, the Republic of Uzbekistan, a formation yielding a rich and diverse assemblage of dinosaurs and other vertebrates from fragmentary remains. Comparison of the maxilla with that of other allosauroids indicates Ulughbegsaurus was 7.5–8 m in body length and greater than 1000 kg in body mass, suggesting it was the previously unrecognized apex predator of the Bissekty ecosystem while smaller known tryannosauroids and dromaeosaurids were probable mesopredators. The discovery of Ulughbegsaurus records the geologically latest stratigraphic co-occurrence of carcharodontosaurid and tyrannosauroid dinosaurs from Laurasia, and evidence indicates carcharodontosaurians remained the dominant predators relative to tyrannosauroids, at least in Asia, as late as the Turonian.
26
Brownstein, Chase Doran. "Osteology and phylogeny of small-bodied hadrosauromorphs from an end-Cretaceous marine assemblage." Zoological Journal of the Linnean Society 191, no. 1 (2020): 180–200. http://dx.doi.org/10.1093/zoolinnean/zlaa085.
Full textAbstract:
Abstract The timing of non-avian dinosaur decline is one of the most debated subjects in dinosaur palaeontology. Dinosaur faunas from the last few million years of the Mesozoic appear far less diverse than those from earlier in the Cretaceous, a trend that could suggest non-avian dinosaur extinction occurred gradually. However, the limited nature of the latest Cretaceous dinosaur record outside western North America has obscured patterns in dinosaur diversity just before the extinction. Here, I describe two associated skeletons and several isolated fossils recovered from the New Egypt Formation of New Jersey, a latest Maastrichtian unit that underlies the K–Pg boundary. The larger skeleton appears to be a small-bodied adult from a lineage outside Hadrosauridae, the dominant group of these animals during the Maastrichtian, that persisted along the eastern coast of North America. Smaller specimens are identifiable as juvenile hadrosauromorphs. These results substantiate an important assemblage of herbivorous dinosaurs from the poorly-known Cretaceous of eastern North America. The marine depositional setting for these skeletons demonstrates that proposed ecosystem preferences among hadrosauromorphs may be biased by post-mortem transportation, and the adult skeleton has implications for assessing the proposed relictual nature of Late Cretaceous eastern North American vertebrates.
27
Janssen, R., R. R. van Baal, and A. S. Schulp. "Bone damage in Allopleuron hofmanni (Cheloniidae, Late Cretaceous)." Netherlands Journal of Geosciences - Geologie en Mijnbouw 92, no. 2-3 (2013): 153–57. http://dx.doi.org/10.1017/s0016774600000081.
Full textAbstract:
AbstractWe describe pathologies and post-mortem damage observed in specimens of the late Maastrichtian marine cheloniid turtle Allopleuron hofmanni. Shallow circular lesions on carapace bones are common and possibly illustrate barnacle attachment/embedment. Deep, pit-like marks are confined to the neural rim and the inner surface of peripheral elements; these may have been caused either by barnacle attachment or disease. A number of linear marks found on outer carapace surfaces are identified as tooth marks of scavengers, others as possible domichnia of boring bivalves. A fragmentary scapula and prescapular process displays radular traces of molluscs (gastropods and/or polyplacophorans; ichnogenus Radulichnus). These diverse types of bone damage suggest both live and dead marine turtles to have been commonly utilised by predators, scavengers and encrusters in the type Maastrichtian marine ecosystem.
28
Sibert, Elizabeth, Richard Norris, Jose Cuevas, and Lana Graves. "Eighty-five million years of Pacific Ocean gyre ecosystem structure: long-term stability marked by punctuated change." Proceedings of the Royal Society B: Biological Sciences 283, no. 1831 (2016): 20160189. http://dx.doi.org/10.1098/rspb.2016.0189.
Full textAbstract:
While the history of taxonomic diversification in open ocean lineages of ray-finned fish and elasmobranchs is increasingly known, the evolution of their roles within the open ocean ecosystem remains poorly understood. To assess the relative importance of these groups through time, we measured the accumulation rate of microfossil fish teeth and elasmobranch dermal denticles (ichthyoliths) in deep-sea sediment cores from the North and South Pacific gyres over the past 85 million years (Myr). We find three distinct and stable open ocean ecosystem structures, each defined by the relative and absolute abundance of elasmobranch and ray-finned fish remains. The Cretaceous Ocean (pre-66 Ma) was characterized by abundant elasmobranch denticles, but low abundances of fish teeth. The Palaeogene Ocean (66–20 Ma), initiated by the Cretaceous/Palaeogene mass extinction, had nearly four times the abundance of fish teeth compared with elasmobranch denticles. This Palaeogene Ocean structure remained stable during the Eocene greenhouse (50 Ma) and the Eocene–Oligocene glaciation (34 Ma), despite large changes in the overall accumulation of both groups during those intervals, suggesting that climate change is not a primary driver of ecosystem structure. Dermal denticles virtually disappeared from open ocean ichthyolith assemblages approximately 20 Ma, while fish tooth accumulation increased dramatically in variability, marking the beginning of the Modern Ocean. Together, these results suggest that open ocean fish community structure is stable on long timescales, independent of total production and climate change. The timing of the abrupt transitions between these states suggests that the transitions may be due to interactions with other, non-preserved pelagic consumer groups.
29
Kauffman, Erle G., Villamil Tomás, Peter J. Harries, Christian A. Meyer, and Bradley B. Sageman. "The flat clam controversy: Where did they come from? Where did they go?" Paleontological Society Special Publications 6 (1992): 159. http://dx.doi.org/10.1017/s247526220000719x.
Full textAbstract:
Thin-shelled, weakly articulated, epifaunal byssate to free-living flat clams characterize Devonian-Cretaceous dark, organic-rich shale facies. Convergent evolution on the flat-clam morph occurs among several families of Bivalvia. Flat clams regularly occurred in dense populations, dominating low diversity, inequitable communities for which they were commonly the pioneer species and formed shell islands for the colonization of smaller, firm-substrate dependent invertebrates. The unique flat-clam dominated ecosystem, as well as the widespread environments to which they were adapted, disappeared at the end of the Cretaceous. Although locally, low-oxygen benthic muds exist through the Cenozoic to Recent, they do not support large populations of flat clams, whose ecological niche was never filled after the Cretaceous. Flat clams underwent an exponential increase in size and apparent growth rates through the mid- and Late Cretaceous, reaching over 3 m in diameter (Inoceramidae). Most of this increase in shell size also involved expansion of mantle tissue and probably gills, relative to the size of the visceral mass. This suggests specific adaptations to colonization of oxygen-poor benthic habitats with hydrogensulfide enriched substrates, which broadly characterized Paleozoic and Mesozoic epicontinental seas, during greenhouse intervals. Such conditions were particularly well-developed during Cretaceous Oceanic Anoxic Events, at which time flat clams thrived.Functional morphology, geochemistry, and facies associations suggest that many flat clams were chemosymbiotic and/or had greatly expanded oxygen-absorption surfaces. These adaptations allowed them to be opportunistic in chemically stressed benthic environments; growth rates also seem to be enhanced in these environments, a characteristic of living chemosymbiotic species. Many lines of evidence prove that flat clams lived in these environments and do not represent pseudoplanktic rain. A combination of factors seems to have been responsible for their disappearance near the end of the Cretaceous; i.e., mass extinction, loss of primary habitats, and major radiation among bottom-feeding bivalve predators.
30
Smith, Selena Y., Steven R. Manchester, Bandana Samant, et al. "Integrating Paleobotanical, Paleosol, and Stratigraphic Data to Study Critical Transitions: A Case Study From The Late Cretaceous–Paleocene Of India." Paleontological Society Papers 21 (October 2015): 137–66. http://dx.doi.org/10.1017/s1089332600002990.
Full textAbstract:
During the Cretaceous and Paleogene, the Indian subcontinent was isolated as it migrated north from the east coast of Africa to collide with Asia. As it passed over the Reunion hotspot in the late Maastrichtian–early Danian, a series of lava flows extruded, known as the Deccan Traps. Also during this interval, there was a major mass-extinction event at the Cretaceous–Paleogene boundary, punctuated by a meteorite impact at Chicxulub, Mexico. What were the biological implications of these changes in paleogeography and the extensive volcanism in terms of biodiversity, evolution, and biogeography? By combining chronostratigraphic, paleosol, and paleobotanical data, an understanding of how the ecosystems and climates changed and the relative contributions of the Chicxulub impact, Deccan Traps volcanism, and paleogeographic isolation can be gained. Understanding relative ages of paleobotanical localities is crucial to determining floristic changes, and is challenging because different methods (e.g., magnetostratigraphy, radiometric dating, vertebrate and microfossil biostratigraphy) sometimes give conflicting answers, or have not been done for paleobotanical localities. Climatic data can be obtained quantitatively by studying paleosol geochemistry, as well as qualitatively by examining functional traits and nearest living relatives of fossil plants. An additional challenge is revising macrofossil data, which includes some confidently identified taxa and others with uncertain affinities. This is important for understanding ecosystem composition both spatially and temporally, as well as the biogeographic implications of an isolated India.
31
Lu, Xiumei, Bo Wang, Weiwei Zhang, Michael Ohl, Michael S. Engel, and Xingyue Liu. "Cretaceous diversity and disparity in a lacewing lineage of predators (Neuroptera: Mantispidae)." Proceedings of the Royal Society B: Biological Sciences 287, no. 1928 (2020): 20200629. http://dx.doi.org/10.1098/rspb.2020.0629.
Full textAbstract:
Mantidflies (Mantispidae) are an unusual and charismatic group of predatory lacewings (Neuroptera), whereby the adults represent a remarkable case of morphological and functional convergence with praying mantises (Mantodea). The evolutionary history of mantidflies remains largely unknown due to a scarcity of fossils. Here, we report the discovery of a highly diverse palaeofauna of mantidflies from the mid-Cretaceous (lowermost Cenomanian) of Myanmar. The raptorial forelegs of these mantidflies possess highly divergent morphological modifications, some of which are unknown among modern mantidflies, e.g. the presence of forked basal profemoral spines or even the complete loss of foreleg spine-like structures. A phylogenetic analysis of Mantispidae reveals a pattern of raptorial foreleg evolution across the family. The high species diversity and disparate foreleg characters might have been driven by diverse niches of predator–prey interplay in the complex tropical forest ecosystem of the mid-Cretaceous.
32
Barrick, Reese. "Dietary Evidence for Competing in the New World Order." Paleontological Society Papers 6 (November 2000): 271–72. http://dx.doi.org/10.1017/s1089332600000796.
Full textAbstract:
Many changes were taking place in the terrestrial landscape near the end of the Mesozoic. Angiosperms are first unequivocally recorded in Cretaceous strata; a rapid diversification and increase in abundance occurred during the Campanian-Maastrichtian. This shift from ferns-gymnosperm to angiosperm dominance was of major importance to terrestrial herbivores. Increasing complexity in the dental batteries of hadrosaurs and ceratopsians also occurred simultaneously. Stable carbon isotopes from teeth have provided detailed information on ecosystem and dietary shifts during the Miocene-Pliocene, with the advent and spread of C4 grasses. However, during the Late Cretaceous all plants probably used only the C3 pathway and carbon isotopes are less useful in distinguishing browsing and grazing habits. However, a large range of carbon isotope values is produced by C3 plants, and indicates that environmental parameters (aridity/humidity) are more important than those produced by taxonomic effects.
33
Chin, Karen, John Bloch, Arthur Sweet, et al. "Life in a temperate Polar sea: a unique taphonomic window on the structure of a Late Cretaceous Arctic marine ecosystem." Proceedings of the Royal Society B: Biological Sciences 275, no. 1652 (2008): 2675–85. http://dx.doi.org/10.1098/rspb.2008.0801.
Full textAbstract:
As the earth faces a warming climate, the rock record reminds us that comparable climatic scenarios have occurred before. In the Late Cretaceous, Arctic marine organisms were not subject to frigid temperatures but still contended with seasonal extremes in photoperiod. Here, we describe an unusual fossil assemblage from Devon Island, Arctic Canada, that offers a snapshot of a ca 75 Myr ago marine palaeoecosystem adapted to such conditions. Thick siliceous biogenic sediments and glaucony sands reveal remarkably persistent high primary productivity along a high-latitude Late Cretaceous coastline. Abundant fossil faeces demonstrate that this planktonic bounty supported benthic invertebrates and large, possibly seasonal, vertebrates in short food chains. These ancient organisms filled trophic roles comparable to those of extant Arctic species, but there were fundamental differences in resource dynamics. Whereas most of the modern Arctic is oligotrophic and structured by resources from melting sea ice, we suggest that forested terrestrial landscapes helped support the ancient marine community through high levels of terrigenous organic input.
34
Paulina-Carabajal, Ariana, Francisco T. Barrios, Ariel H. Méndez, Ignacio A. Cerda, and Yuong-Nam Lee. "A Late Cretaceous dinosaur and crocodyliform faunal association–based on isolate teeth and osteoderms–at Cerro Fortaleza Formation (Campanian-Maastrichtian) type locality, Santa Cruz, Argentina." PLOS ONE 16, no. 9 (2021): e0256233. http://dx.doi.org/10.1371/journal.pone.0256233.
Full textAbstract:
The Late Cretaceous dinosaur record in southern South America has been improved recently; particularly with findings from Chorrillo and Cerro Fortaleza formations, both bearing ankylosaur remains, a clade that was not previously recorded in the Austral Basin. The dinosaur fauna of the type locality of Cerro Fortaleza Formation is known from -and biased to- large-sized sauropod remains and a single described taxon, the titanosaur Dreadnoughtus schrani. Here, we report the taxonomic composition of a site preserving thirteen isolated teeth and several osteoderms belonging to three dinosaur clades (Abelisauridae, Titanosauria, and Nodosauridae), and at least one clade of notosuchian crocodyliforms (Peirosauridae). They come from sediments positioned at the mid-section of the Cerro Fortaleza Formation, which is Campanian-Maastrichtian in age, adding valuable information to the abundance and biodiversity of this Cretaceous ecosystem. Since non-titanosaur dinosaur bones are almost absent in the locality, the teeth presented here provide a window onto the archosaur biodiversity of the Late Cretaceous in southern Patagonia. The nodosaurid tooth and small armor ossicles represent the first record of ankylosaurs for this stratigraphic unit. The peirosaurid material also represents the most austral record of the clade in South America.
35
Feild, Taylor S., Garland R. Upchurch, David S. Chatelet, et al. "Fossil evidence for low gas exchange capacities for Early Cretaceous angiosperm leaves." Paleobiology 37, no. 2 (2011): 195–213. http://dx.doi.org/10.1666/10015.1.
Full textAbstract:
The photosynthetic gas exchange capacities of early angiosperms remain enigmatic. Nevertheless, many hypotheses about the causes of early angiosperm success and how angiosperms influenced Mesozoic ecosystem function hinge on understanding the maximum capacity for early angiosperm metabolism. We applied structure-functional analyses of leaf veins and stomatal pore geometry to determine the hydraulic and diffusive gas exchange capacities of Early Cretaceous fossil leaves. All of the late Aptian—early Albian angiosperms measured possessed low vein density and low maximal stomatal pore area, indicating low leaf gas exchange capacities in comparison to modern ecologically dominant angiosperms. Gas exchange capacities for Early Cretaceous angiosperms were equivalent or lower than ferns and gymnosperms. Fossil leaf taxa from Aptian to Paleocene sediments previously identified as putative stem-lineages to Austrobaileyales and Chloranthales had the same gas exchange capacities and possibly leaf water relations of their living relatives. Our results provide fossil evidence for the hypothesis that high leaf gas exchange capacity is a derived feature of later angiosperm evolution. In addition, the leaf gas exchange functions of austrobaileyoid and chloranthoid fossils support the hypothesis that comparative research on the biology of living basal angiosperm lineages reveals genuine signals of Early Cretaceous angiosperm ecophysiology.
36
Gallagher, W. B. "Oligotrophic oceans and minimalist organisms: collapse of the Maastrichtian marine ecosystem and Paleocene recovery in the Cretaceous-Tertiary sequence of New Jersey." Netherlands Journal of Geosciences - Geologie en Mijnbouw 82, no. 3 (2003): 225–31. http://dx.doi.org/10.1017/s0016774600020813.
Full textAbstract:
AbstractThe inner Atlantic Coastal Plain of New Jersey reveals exposures of fossiliferous Maastrichtian and Danian deposits. Recent fossil discoveries in this interval are here reported, and placed in the context of Cretaceous/Tertiary (K/T) faunal changes. The exposure at the Inversand Pit at Sewell (New Jersey) is the last active marl mine in the region, and stands as an important reference section for the many significant discoveries of vertebrate fossils produced by the marl mining industry at its zenith. Changes in planktonic populations across the K/T boundary are related to Maastrichtian/Danian marine ecosystem community reorganisation, by demonstrating changes in abundance of dominant marine invertebrates in successive fossil assemblages. Marine invertebrates with non-planktotrophic larval stages were briefly the commonest fossils preserved in the Danian sediments of this region. Late surviving examples of Cretaceous fauna now restricted to the Indo-Pacific region may imply biogeographic changes linked to the K/T mass extinction event.
37
Martin, Elissa, Susan Butts, Leanne Elder, et al. "Cretaceous World TCN: Digitizing the Western Interior Seaway at the Yale Peabody Museum." Biodiversity Information Science and Standards 2 (June 15, 2018): e26115. https://doi.org/10.3897/biss.2.26115.
Full textAbstract:
Yale Peabody Museum (YPM) is a partner in the Western Interior Seaway Thematic Collections Network (TCN), along with the University of Kansas (lead) and seven other institutions (National Science Foundation Award # DBI-1601884). This project seeks to digitize the fossil organisms of the Western Interior Seaway, a shallow sea that covered inland North America from 100 to 65 million years ago. The resultant data will be a resource for K-16 education and will enable scientists to answer fundamental questions about the changing environment of a marine ecosystem during a key time in the history of life. The data generated will be ideal for use with an assortment of modern quantitative tools like paleoecological niche modeling (PaleoENM) and will help improve paleoclimate and paleoceanographic models. Less than two years into this three-year project, the YPM has digitized nearly 70,000 Cretaceous fossils from the seaway. Specimens are georeferenced and most have multiple images. To achieve project goals, we have overcome obstacles of digitizing multi-specimen concretions and foraminifera microslides by developing high-throughput digitization workflows that incorporate the open-source Inselect program and scripts to streamline image naming, image formatting, and uploading to our Axiell EMu collection management system. To facilitate use of the data in K-16 environments, an easy to use collections interface has been built using the iDigPaleo platform (idigpaleo.org). <i>Cretaceous World</i> (cretaceousworld.org) pulls data from iDigBio for all Cretaceous World TCN providers. Students can browse specimens using filters, rather than entering specific search terms. Navigation is simplified using common names harvested from the Encyclopedia of Life. Specimens are displayed as images accompanied by collection and locality data and plotted on a map. Registration provides access to tools supporting annotation, measurement, specimen record commenting, and social media sharing. Images can be curated as galleries and used for education. This includes sharing of galleries between students and teachers and PDF or PowerPoint exports. Fifty-eight 3D models of vertebrates and invertebrates have been placed on morphosource.org and will be made available via a 3D embedded viewer on cretaceousworld.org for use in K-16 education. Undergraduate students from Dartmouth, Oberlin, Southern Connecticut State University, and Yale, have participated in the project and served as mentors for high school interns. These interns, recruited from the Peabody EVOLUTIONS afterschool program, gained first-hand experience in collections-based research, digitization, and imaging techniques, while learning about the science of paleontology and the process of curating museum collections, and researching and reconstructing food webs in this fascinating ancient ecosystem.
38
Holtz, Thomas R. "Endemicity analysis of global Cretaceous dinosaurian faunas." Paleontological Society Special Publications 6 (1992): 132. http://dx.doi.org/10.1017/s2475262200006924.
Full textAbstract:
It has often been assumed that the intensively studied dinosaur faunal assemblages of western North America and the Gobi Desert of Mongolia and China represent “typical” Late Cretaceous terrestrial vertebrate communities. This assumption has led to a paleoecological scenario in which a global ecological shift occurs from the dominance of high-browsing saurischian (i.e., sauropod) to low-browsing ornithischian (i.e., iguanodontian, marginocephalian, ankylosaurian) herbivore communities. Furthermore, the assumption that the Asiamerican dinosaur faunas are communities “typical” of the Late Cretaceous has forced the conclusion that the sauropod-dominated Argentine population must have been an isolated relict ecosystem of primitive taxa (i.e., titanosaurid sauropods, abelisaurid ceratosaurs). Recent discoveries and reinterpretations of other Late Cretaceous assemblages, however, seriously challenge these assumptions.Paleogeography and paleobiogeography have demonstrated that terrestrial landmasses became progressively fractionated from the Late Jurassic (Kimmeridgian-Tithonian) to the Late Cretaceous (Campanian), owing to continental drift and the development of large epicontinental seas (the Western Interior Seaway, the Turgai Sea, etc.). The Maastrichtian regressions resulted in the reestablishment of land connection between long isolated regions (for example, western and eastern North America). These geographic changes are reflected in changes in the dinosaurian faunas. These assemblages were rather cosmopolitan in the Late Jurassic (Morrison, Tendaguru, and Upper Shaximiao Formations) but became more provincialized throughout the Cretaceous.Cluster analysis of presence/absence data for the theropod, sauropod, and ornithischian clades indicates that previous assumptions for Late Cretaceous dinosaurian paleoecology are largely in error. These analyses instead suggest that sauropod lineages remained a major faunal component in both Laurasia (Europe, Asia) and Gondwana (South America, Africa, India, and Australia). Only the pre-Maastrichtian Senonian deposits of North America were lacking sauropodomorphs. Furthermore, the abelisaurid/titanosaurid fauna of Argentina is, in fact, probably more typical of Late Cretaceous dinosaurian communities. Rather, it is the coelurosaurian/ornithischian communities of Asiamerica (and particularly North America) that are composed primarily of dinosaurs of small geographic distribution. Thus, the Judithian, Edmontonian, and Lancian faunas, rather than being typical of the Late Cretaceous, most likely represent an isolated island-continent terrestrial vertebrate population, perhaps analogous to the extremely isolated vertebrate communities of Tertiary South America. Furthermore, the shift from high-browsing to low-browsing herbivore “dynasties” more likely represents a local event in Senonian North America and does not represent a global paleoecological transformation of Late Cretaceous dinosaur community structure.
39
Retallack, Gregory J., Guy D. Leahy, and Michael D. Spoon. "Evidence from paleosols for ecosystem changes across the Cretaceous/Tertiary boundary in eastern Montana." Geology 15, no. 12 (1987): 1090. http://dx.doi.org/10.1130/0091-7613(1987)15<1090:efpfec>2.0.co;2.
Full text
40
Vellekoop, Johan, Kris H. Van Tilborgh, Paul Van Knippenberg, et al. "Type‐Maastrichtian gastropod faunas show rapid ecosystem recovery following the Cretaceous–Palaeogene boundary catastrophe." Palaeontology 63, no. 2 (2020): 349–67. http://dx.doi.org/10.1111/pala.12462.
Full text
41
Rohling, E. J., W. J. Zachariasse, and H. Brinkhuis. "A terrestrial scenario for the Cretaceous-Tertiary boundary collapse of the marine pelagic ecosystem." Terra Nova 3, no. 1 (1991): 41–48. http://dx.doi.org/10.1111/j.1365-3121.1991.tb00842.x.
Full text
42
Navarro-Ramirez, J. P., S. Bodin, L. Consorti, and A. Immenhauser. "Response of western South American epeiric-neritic ecosystem to middle Cretaceous Oceanic Anoxic Events." Cretaceous Research 75 (July 2017): 61–80. http://dx.doi.org/10.1016/j.cretres.2017.03.009.
Full text
43
Fiorillo, Anthony R., Paul J. McCarthy, Grant Shimer, et al. "New Dinosaur Ichnological, Sedimentological, and Geochemical Data from a Cretaceous High-Latitude Terrestrial Greenhouse Ecosystem, Nanushuk Formation, North Slope, Alaska." Geosciences 14, no. 2 (2024): 36. http://dx.doi.org/10.3390/geosciences14020036.
Full textAbstract:
The Nanushuk Formation (Albian–Cenomanian) crops out over much of the central and western North Slope of Alaska, varying from ≈1500 to ≈250 m thick from west to northeast. The Nanushuk Formation records an inter-tonguing succession of marine and nonmarine conglomerate, sandstone, mudstone, and coal. These rock units comprise the Kukpowruk and Corwin formations of the former Nanushuk Group, respectively. Work presented here is centered in the foothills of the DeLong Mountains along the Kukpowruk River, from an area west of Igloo Mountain in the Coke Basin to the Barabara Syncline, approximately 80 km to the north. A radiometric date recovered from a tuff in our study area suggests a Cenomanian age for at least some of these rocks. Outcrops along the Kukpowruk River contain a well-preserved fossil flora previously recovered from marine, marginal marine, and terrestrial sediments. Our own work focuses on detailed measured sections of terrestrial rocks, interpretation of sedimentary facies and facies associations, and documentation of fossil vertebrates. Eight facies associations are identified in the study area that together are interpreted to represent meandering fluvial and upper delta plain environments. Plant fossils are common and include standing tree trunks up to 58 cm in diameter at some locations. Approximately 75 newly discovered tracksites, and a heretofore unknown, rich fossil vertebrate ichnofauna, are present. The ichnofaunal assemblage includes evidence of small and large theropod dinosaurs (including birds) and bipedal and quadrupedal ornithischian dinosaurs. Approximately 15% of the dinosaur ichnofauna record is represented by fossil bird tracks. Wood fragments from the Nanushuk Formation were analyzed for their carbon isotopic composition to relate δ13C to mean annual precipitation. Samples averaged −26.4‰ VPDB, suggesting an average MAP of 1412 mm/year. This record of increased precipitation in the Nanushuk Fm. during the mid-Cretaceous provides new data that supports global precipitation patterns associated with the Cretaceous Thermal Maximum. This work provides an important framework for much-needed further paleoecological and paleoclimatic analyses into greenhouse conditions in the terrestrial Cretaceous Arctic during this important window in time.
44
Birch, Heather, Daniela N. Schmidt, Helen K. Coxall, Dick Kroon, and Andy Ridgwell. "Ecosystem function after the K/Pg extinction: decoupling of marine carbon pump and diversity." Proceedings of the Royal Society B: Biological Sciences 288, no. 1953 (2021): 20210863. http://dx.doi.org/10.1098/rspb.2021.0863.
Full textAbstract:
The ocean biological pump is the mechanism by which carbon and nutrients are transported to depth. As such, the biological pump is critical in the partitioning of carbon dioxide between the ocean and atmosphere, and the rate at which that carbon can be sequestered through burial in marine sediments. How the structure and function of planktic ecosystems in the ocean govern the strength and efficiency of the biological pump and its resilience to disruption are poorly understood. The aftermath of the impact at the Cretaceous/Palaeogene (K/Pg) boundary provides an ideal opportunity to address these questions as both the biological pump and marine plankton size and diversity were fundamentally disrupted. The excellent fossil record of planktic foraminifera as indicators of pelagic-biotic recovery combined with carbon isotope records tracing biological pump behaviour, show that the recovery of ecological traits (diversity, size and photosymbiosis) occurred much later (approx. 4.3 Ma) than biological pump recovery (approx. 1.8 Ma). We interpret this decoupling of diversity and the biological pump as an indication that ecosystem function had sufficiently recovered to drive an effective biological pump, at least regionally in the South Atlantic.
45
Tian, Jiahui, Yongjia Zhan, Chengmin Shi, Hirotsugu Ono, and Lihong Tu. "Solenysa, a Cretaceous Relict Spider Group in East Asia." Diversity 14, no. 2 (2022): 120. http://dx.doi.org/10.3390/d14020120.
Full textAbstract:
A time scale of phylogenetic relationships contributes to a better understanding of the evolutionary history of organisms. Herein, we investigate the temporal divergence pattern that gave rise to the poor species diversity of the spider genus Solenysa in contrast with the other six major clades within linyphiids. We reconstructed a dated phylogeny of linyphiids based on multi-locus sequence data. We found that Solenysa diverged from other linyphiids early in the Cretaceous (79.29 mya), while its further diversification has been delayed until the middle Oligocene (28.62 mya). Its diversification trend is different from all of the other major lineages of linyphiids but is closely related with the Cenozoic ecosystem transition caused by global climate changes. Our results suggest that Solenysa is a Cretaceous relict group, which survived the mass extinction around the K-T boundary. Its low species diversity, extremely asymmetric with its sister group, is largely an evolutionary legacy of such a relict history, a long-time lag in its early evolutionary history that delayed its diversification. The limited distribution of Solenysa species might be related to their extreme dependence on highly humid environments.
46
Fletcher, Tamara L., Patrick T. Moss, and Steven W. Salisbury. "The palaeoenvironment of the Upper Cretaceous (Cenomanian–Turonian) portion of the Winton Formation, Queensland, Australia." PeerJ 6 (September 7, 2018): e5513. http://dx.doi.org/10.7717/peerj.5513.
Full textAbstract:
The Winton Formation is increasingly recognised as an important source of information about the Cretaceous of Australia, and, more broadly, the palaeobiogeographic history of eastern Gondwana. With more precise dating and stratigraphic controls starting to provide temporal context to the geological and palaeontological understanding of this formation, it is timely to reassess the palaeoenvironment in which it was deposited. This new understanding helps to further differentiate the upper, most-studied portion of the formation (Cenomanian–Turonian) from the lower portions (Albian–Cenomanian), allowing a coherent picture of the ecosystem to emerge. Temperatures during the deposition of the Upper Cretaceous portion of the Winton Formation were warm, with high, seasonal rainfall, but not as extreme as the modern monsoon. The landscape was heterogeneous, a freshwater alluvial plain bestrode by low energy, meandering rivers, minor lakes and mires. Infrequent, scouring flood events were part of a multi-year cycle of drier and wetter years. The heavily vegetated flood plains supported abundant large herbivores. This was the final infilling of the great Eromanga Basin.
47
Diaz, J. F., L. Schwark, P. K. Pedersen, J. M. Galloway, M. Bringué, and S. E. Grasby. "Late Cretaceous ecosystem dynamics in the southern incipient Arctic Ocean: A micropaleontological and geochemical perspective." Global and Planetary Change 244 (January 2025): 104643. http://dx.doi.org/10.1016/j.gloplacha.2024.104643.
Full text
48
Boudinot, F. Garrett, Nadia Dildar, R. Mark Leckie, et al. "Neritic ecosystem response to Oceanic Anoxic Event 2 in the Cretaceous Western Interior Seaway, USA." Palaeogeography, Palaeoclimatology, Palaeoecology 546 (May 2020): 109673. http://dx.doi.org/10.1016/j.palaeo.2020.109673.
Full text
49
Barral, Abel, Bernard Gomez, Juan M. Zorrilla, et al. "Local-scale analysis of plant community from the Early Cretaceous riparian ecosystem of Hautrage, Belgium." Palaeogeography, Palaeoclimatology, Palaeoecology 443 (February 2016): 107–22. http://dx.doi.org/10.1016/j.palaeo.2015.11.026.
Full text
50
McIver, E. E. "Paleobotanical evidence for ecosystem disruption at the Cretaceous-Tertiary boundary from Wood Mountain, Saskatchewan, Canada." Canadian Journal of Earth Sciences 36, no. 5 (1999): 775–89. http://dx.doi.org/10.1139/e97-112.
Full textAbstract:
A continuous, subsurface Cretaceous-Tertiary boundary section, including the boundary clay within an 87 cm thick lignite, has been recovered from a core hole near Wood Mountain, Saskatchewan, Canada. The lignite-encompassed clay layer with geochemical anomaly indicates that peat deposition was continuous across the boundary. Core data indicate that, locally, a pre-boundary, conifer-dominated swamp was abruptly replaced by an angiosperm-dominated, herbaceous wetland. Sudden extermination of the dominant forest elements indicates mass kill at the level of the boundary and supports the theory of extraterrestrial impact accompanied by catastrophic destruction. Devastation of the standing vegetation may have been caused by one or more of the killing agents predicted to have accompanied impact, including freezing temperatures caused by atmospheric dust, acid rain, thermal pulse, and shock waves. There is no evidence supporting wildfires as a killing agent. Vegetational change apparent within the boundary interval is consistent with observations elsewhere in the Western Interior of North America of abrupt replacement of an ecosystem. Early Paleocene reestablishment of the cypress swamp vegetation is calculated to have taken from 1 to 5 millennia.