Soil organisms, as recorded by trace fossils in paleosols of the Willwood Formation, Wyoming, show significant body-size reductions and increased abundances during the Paleocene-Eocene Thermal Maximum (PETM). Paleobotanical, paleopedologic, and oxygen isotope studies indicate high temperatures during the PETM and sharp declines in precipitation compared with late Paleocene estimates. Insect and oligochaete burrows increase in abundance during the PETM, suggesting longer periods of soil development and improved drainage conditions. Crayfish burrows and molluscan body fossils, abundant below and above the PETM interval, are significantly less abundant during the PETM, likely because of drier floodplain conditions and lower water tables. Burrow diameters of the most abundant ichnofossils are 30-46% smaller within the PETM interval. As burrow size is a proxy for body size, significant reductions in burrow diameter suggest that their tracemakers were smaller bodied. Smaller body sizes may have resulted from
... for sale here exhibiting the various specimens from this important epoch which was the period just before the present. It included many famous fauna such as sabre toothed cats, woolly mammoths, woolly rhinos, sloths, whales and even early humans. In this section, fossils such as teeth, bones and more can be viewed.
The occurrence of intact sterols has been restricted to immature Cretaceous (~125 Ma) sediments with one report from the Late Jurassic (~165 Ma). Here we report the oldest occurrence of intact sterols in a Crustacean fossil preserved for ca. 380 Ma within a Devonian concretion. The exceptional preservation of the biomass is attributed to microbially induced carbonate encapsulation, preventing full decomposition and transformation thus extending sterol occurrences in the geosphere by 250 Ma. A suite of diagenetic transformation products of sterols was also identified in the concretion, demonstrating the remarkable coexistence of biomolecules and geomolecules in the same sample. Most importantly the original biolipids were found to be the most abundant steroids in the sample. We attribute the coexistence of steroids in a diagenetic continuum-ranging from stenols to triaromatic steroids-to microbially mediated eogenetic processes.. ...
We have analysed the distribution of post mortem DNA damage derived miscoding lesions from the datasets of seven published Neandertal specimens that have extensive cloned sequence coverage over the mitochondrial DNA (mtDNA) hypervariable region 1 (HVS1). The analysis was restricted to C→T and G→A miscoding lesions (the predominant manifestation of post mortem damage) that are seen at a frequency of more than one clone among sequences from a single PCR, but do not represent the true endogenous sequence. The data indicates an extreme bias towards C→T over G→A miscoding lesions (observed ratio of 67:2 compared to an expected ratio of 7:2), implying that the mtDNA Light strand molecule suffers proportionally more damage-derived miscoding lesions than the Heavy strand. The clustering of Cs in the Light strand as opposed to the singleton pattern of Cs in the Heavy strand could explain the observed bias, a phenomenon that could be further tested with non-PCR based approaches. The characterization of
Numerous studies have proposed different lists of morphological features to define the species of Homo erectus; among these, some are considered to be autapomorphic. The intention of this study is to discuss two of these possible autapomorphic traits: thickened cranial bones and equal participation of the three structural bone layers (inner and outer tables, diploe) in this thickening. This study brings new information concerning cranial vault thickness and structural composition in the mid-sagittal plane of some Asian Homo erectus. The Ngandong and Sambungmacan fossils, as well as the Zhoukoudian and Sangiran individuals, have cranial vault thickness values within the range of variation observed in our Homo sapiens comparative sample. Moreover, even if the frontal and sagittal keels in Homo erectus constitute a relief on the external cranial vault surface, they do not necessary correspond to a real thickening of the underlying bone. The diploic layer principally contributes to their internal
Although the taxonomic affinities of the tubular body fossils, erniettomorphs and other problematic body fossils are not well understood, the data presented herein and in other recent fossil reports [21,32,65,71-73] from late Ediacaran strata in a range of taphonomic modes (e.g. pyritization, carbonaceous compressions, casts and moulds) have made it increasingly apparent that a morphologically diverse assemblage of macroscopic organisms comprising at least two disparate phyla existed at the end of the Ediacaran Period. Specifically, the co-occurrences of Ernietta, Conotubus, Corumbella, and Gaojiashania in terminal Ediacaran strata in Nevada biostratigraphically link a number of late Ediacaran fossil localities globally to validate the existence of a distinctive cosmopolitan biotic assemblage at the close of the Proterozoic, providing support that the Nama assemblage represents true biological turnover within the Ediacaran Period rather than reflecting provincial, palaeoecological or taphonomic ...
Presented is the first absolute age for the basal Albian from the Schwicheldt Ton Member, Gault Formation, Vöhrum, Germany. A 206Pb/238U age of 113.1 ± 0.3 Ma is determined for chemically abraded zircon from a tuff horizon 65 cm above the Aptian/Albian boundary. The new U-Pb age, although within uncertainty of the GTS 2008 determination (112 ± 1 Ma), is nominally older. The younger GTS 2008 basal Albian age is obtained from cyclostratigraphy using an 40Ar-39Ar age from the base Cenomanian. The nominal difference between the GTS 2008 age and new basal Albian age is consistent with the documented ca. 0.65% bias between U-Pb and 40Ar/39Ar geochronology. The new 206Pb/238U age calls into question a recently published age for the basal Albian (106.9 ± 0.4 Ma) determined from K-Ar glauconite analysis, as well as the K-Ar age for the GL-O international standard. Rhenium-osmium isotope analysis of the basal Albian grey clay of the Schwicheldt Ton Member, Gault Formation and basal Turonian grey shale ...
Diagenetic overprint to a negative carbon isotope anomaly associated with the Gaskiers glaciation of the Ediacaran Doushantuo Formation in South ChinaDiagenetic overprint to a negative carbon isotope anomaly associated with the Gaskiers glaciation of the Ediacaran Doushantuo Formation in South China ...
The Cretaceous/Tertiary boundary interval, Raton Basin, Colorado and New Mexico, and its content of shock-metamorphosed minerals; Evidence relevant to the K/T boundary impact-extinction ...
We wouldnt be scientists if we didnt ask ourselves why this is. I dont think its simply a sampling issue. The pterosaur record is not great, but we are talking about several thousand specimens now - enough that we might start looking at what we dont have as well as what we do. So why does Rhamphorhynchus show 10 palaeoecologically-relevant fossils, but other Solnhofen species only preserve one confirmed piece of gut content? Why do azhdarchids, which are never found in sites of exception preservation and are generally only known from bits and pieces, have a better record than those lineages which are abundant, represented by dozens of complete skeletons, and often found in sites of exceptional preservation? Interestingly, theres no obvious correlation between factors like abundance, preservation quality and palaeoecological data. Several lineages - the ctenochasmatoids (wading pterodactyloids), the rhamphorhynchids (excluding Rhamphorhynchus) and ornithocheiroids (excluding Pteranodon) - ...
From: Ben Creisler [email protected] New in PLoS ONE: Neil Brocklehurst, Paul Upchurch, Philip D. Mannion & Jingmai OConnor (2012) The Completeness of the Fossil Record of Mesozoic Birds: Implications for Early Avian Evolution. PLoS ONE 7(6): e39056. doi:10.1371/journal.pone.0039056 http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0039056 Many palaeobiological analyses have concluded that modern birds (Neornithes) radiated no earlier than the Maastrichtian, whereas molecular clock studies have argued for a much earlier origination. Here, we assess the quality of the fossil record of Mesozoic avian species, using a recently proposed character completeness metric which calculates the percentage of phylogenetic characters that can be scored for each taxon. Estimates of fossil record quality are plotted against geological time and compared to estimates of species level diversity, sea level, and depositional environment. Geographical controls on the avian fossil record are ...
Modern imaging methods make it possible to perform detailed, non-invasive studies on the internal structures of irreplaceable fossil specimens. Researchers led by Dr. Yu Liu of LMUs Department of Biology II now demonstrate the power of this approach by using computed microtomography (micro-CT) to investigate a specimen recovered from the famous fossil beds of Chengjiang in southwestern China. The results of the study, which appear in the online Open Access journal "Scientific Reports", demonstrate the ability of micro-CT to reveal anatomical details preserved inside fossil slabs.. The fossil Lagerstätte Chengjiang in China is a UNESCO World Heritage Site, which harbors a rich fossil assemblage dating from 520 million years ago. The rocks preserved here are among the oldest that document the so-called Cambrian explosion - the relatively abrupt appearance of a highly diverse, species-rich multicellular fauna in the fossil record. And many of the specimens discovered in these beds are extremely ...
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Distribution Characteristics of Geologic Age and Rock Type of Bedrocks at the National Wood Culture Heritage Site by GIS - Wood culture heritage;Geologic age;Geologic province;Rock type(Jgr, Qa, Kp, Krt+Kav+Kav1+Kav2, Kbgr and GC2);
In 16. I asked: Are the authors suggesting that the enhancement in global temperature by about 5 Deg C near the time of the Paleocene Eocene Thermal Maximum (PETM) 55 million years ago (mya) may have been largely due to a global transformation in vegetation from one associated mainly with a temperate climate to one associated mainly with a tropical and subtropical global climate? In his Response to my question gavin replied: Not possible. The amounts of carbon released at the PETM are roughly 3 times the total amount of terrestrial biomass - it therefore needed a completely different source of carbon. - gavin]. However, my question in 16. pertained to an "enhancement" in global temperature (by about 5 Deg C), not the full extent of the rise in global temperature to the PETM.. From Zanchos(2005), … "During the Paleocene-Eocene thermal maximum (PETM), sea surface temperatures (SST) rose by 5° C in the tropics and as much as 9° C at high latitudes (1-3), whereas bottom-waters temperatures ...
3. The Cambrian "Explosion" - Nearly all animal phyla made their first appearance in the fossil record at essentially the same time, an interval of some 5 million years (about 525 to 530 million years ago) called the "Cambrian Explosion." Scientists have found that these early fossils exhibit more anatomical body designs than exist today, and that early animals, the trilobites, had eyes as fully developed as their counterparts today. Many of the Cambrian fauna, still survive today, all looking much like they did over 500 million years ago. The prominent British evolutionist, Richard Dawkins, comments, "… [W]e find many of them already in an advanced state of evolution, the very first time they appear. It is as though they were just planted there, without any evolutionary history." Two places in the world that have an abundance of early (Cambrian) fossils; the Burgess Shale in the Canadian Rockies and the Chengjiang site in China. In Stephen J. Goulds popular book, Wonderful Life, he points ...
The Paleogene is a significant climatic transition from a warm, "greenhouse" Earth to one in which sizeable glaciers advanced on Antarctica. My research program in this area has focused on the long-term climatic change, but more recently on transient warming events that occurred within this transition. The Paleocene-Eocene Thermal Maximum (PETM) event is among the most rapid and transient (~170 thousand year long) warming events known from the geologic record. Thus this is one of the best intervals for geologists to contribute to the understanding of the impacts of present global warming on life. My students and I have been involved in the study of the impact of warming and changing ocean circulation during the PETM on life in the oceans. This work is based on the recovery of unique records from Integrated Ocean Drilling Program sites and more recently in shelf sections from the Atlantic coastal plain.. ...
Are There Disagreements Between the Fossil Record and Molecular Data?. Molecular biologists have a tradition of reworking a lot of the evolutionary relationships and timescales that morphologists and paleontologists worked so hard to figure out. This can really piss off the non-molecular folks, but I prefer to think of it as a cooperative relationship. The molecular clock, for example, would not be possible without calibration from the fossil record. It is important to note that molecular and morphological data tell two different stories, which I outline below the fold . . .. When I wrote that the Cambrian Explosion never happened, I did not mean that the Cambrian Explosion never happened - I meant, the Cambrian Explosion never happened. Confused? Well, it all depends on how we define the Cambrian Explosion. My preferred definition of the Cambrian Explosion is "The sudden appearance of many animal body plans in the fossil record." (Of, course, by sudden we mean over the span of millions of ...
Development of a predictive model for the distribution of diagenetic alterations and related evolution of reservoir quality of sandstones was achieved by integrating the knowledge of diagenesis to sequence stratigraphy. This approach allows a better elucidation of the distribution of eogenetic alterations within sequence stratigraphy, because changes in the relative sea level induce changes to: (i) pore water chemistry, (ii) residence time of sediments under certain near-surface geochemical conditions, (iii) variations in the detrital composition, and (iv) amounts and type of organic matter.. This thesis revealed that eogenetic alterations, which are linked to sequence stratigraphy and have an impact on reservoir quality evolution, include formation of: (i) pseudomatrix and mechanically infiltrated clays in fluvial sandstones of the lowstand and highstand systems tracts (LST and HST, respectively), (ii) kaolinite in tide-dominated deltaic and foreshore-shoreface sandstones of HST, Gilbert-type ...
The eminent historian Patrick J. Geary has written a provocative book, based on lectures delivered at the Historical Society of Israel about the role of language and ideology in the study and history of the early Middle Ages. He includes a fascinating discussion of the rush by nationalist philologists to rediscover the medieval roots of their respective vernaculars, the rivalry between vernacular languages and Latin to act as transmitters of Christian sacred texts and administrative documents, and the rather sloppy and ad hoc emergence in different places of the vernacular as the local administrative idiom. This is a fascinating look at the weakness of language as a force for unity: ideology, church authority, and emerging secular power always trumped language ...
Fossils are the preserved remains of the bodies of dead organisms or the remains of the organisms actions - things such as footprints or burrows. The total of all fossils is called the fossil record. The fossil record informs scientists about evolution in several important ways:. i In the past, creatures that we dont find today lived on the planet.. i Not all creatures alive today are represented in the past.. i Through time, the physical complexity of organisms has increased. The earliest organisms that scientists can identify were single celled; now complex creatures exist.. i The earliest forms of life were aquatic; terrestrial forms appeared later.. The fossil record, incomplete though it may be, is a record of change through time. This record gives us clues to the progression of the development of life on Earth: Small single-celled organisms evolved into more complex ones; life started in the oceans and only later moved onto dry land. The fossil record provides a rough draft of the tree ...
Interpretation of fossil finds and what they imply about human evolution often means different things to different scientists. To many, evidence shows that the sequence of species in the Homo genus followed a linear route, fromHomo habilis to Homo erectus and eventually to Homo sapiens. To other scientists, the fossil record points to a bushy, branching tree rather than a single stem. Two new fossil finds from the rich deposits around the Koobi Fora ridge in Kenyas Lake Turkana basin add more conclusive evidence that our ancestral tree branches and that species often occupied the same time periods and the same regions. Some species evolved on their own paths and died out, leaving no ancestors, while others eventually developed into new species.. The discovery team, which was led by University College London anthropologist Fred Spoor and Meave Leakey of the National Museums of Kenya, has identified the fossils as belonging to Homo habilis and Homo erectus. The fossils dated to similar time ...
The value of the empirical results in Figs. 2 and 3 lies not in any individual data points but rather in their collective trends. The following picture emerges. Carbon isotopic events rarely exceed a maximum isotopic shift that grows roughly like the logarithm of their time scale. This upper bound appears related to the minimum rate-zero-at which organic carbon can be immobilized as rock. Events outside this limit result from a fundamental disturbance of the carbon cycle, possibly related to unstable dynamics, mass extinction, or both.. These conclusions follow from analyzing all isotopic events the same way. Exceptions are, however, expected. For example, four events (Ediacaran-Cambrian, Nemakit-Daldynian-Tommotian, Paleocene-Eocene Thermal Maximum, and Miocene Climatic Optimum 2) unaccompanied by mass extinction exceed the upper error bar of the critical rate. If, say, these events were driven by dissociation of methane hydrates [for example, (36)] rather than respired organic carbon, the ...
Despite the ever-increasing use of fossil calibrations (figure 1), many divergence dating studies have spawned controversy. Palaeontologists frequently voice concern over problematic calibrations (e.g. [2]), and molecular evolutionists have repeatedly articulated the dangers of inappropriate application of fossil data [3,4]. Unfortunately, such concerns are often expressed after divergence results for a clade of interest have already been published and rarely result in reanalysis. Daniel Ksepka presented data from 171 fossil calibrations, quantifying the prevalence of inaccurate calibrations within Aves. For 67 per cent of these calibrations, the phylogenetic position of the fossil remains untested, meaning that the fossil may not even pertain to the node of interest. Only 24 per cent of calibrations were based on fossils that had been included in phylogenetic analyses. Of these, 33 per cent were improperly applied, potentially introducing large errors into divergence results. The most common ...
The early Paleogene, nominally 62 - 58 million years ago, was characterized by major changes in Earth surface temperature. The time included the Early Eocene Climate Optimum (EECO), a multi-million year interval of peak Cenozoic warmth, as well as a series of hyperthermal events, or geological brief episodes of rapid temperature warmth, the Paleocene-Eocene Thermal Maximum (PETM) being the outstanding example. The changes in temperature are associated with large changes in global carbon cycling, likely involving organic carbon. This talk highlights the above, as well as suggesting that much can be explained through a dynamic seafloor methane cycle. ...
Yutyrannus huali was named and scientifically described in 2012 by Xu Xing et al. The name is derived from Mandarin Chinese yǔ (羽, "feather") and Latinised Greek tyrannos (τύραννος, "tyrant"), a reference to the classification as a feathered member of the Tyrannosauroidea. The specific name consists of the Mandarin huáli (华丽(simplified, 華麗 traditional, "beautiful"), in reference to the beauty of the plumage.[1]. Yutyrannus is known from three nearly complete fossil specimens (an adult, a subadult and a juvenile) acquired from a fossil dealer who claimed all three had their provenance in a single quarry at Batuyingzi in Liaoning Province, China. They thus probably were found in a layer of the Yixian Formation, dating from the Aptian, approximately 125 million years old.[1] The specimens had been cut into pieces about the size of bath mats, which could be carried by two people.[3]. The holotype, ZCDM V5000, is the largest specimen, consisting of a nearly complete skeleton with ...
Washington (UPI) Jul 6, 2017 - Thanks to a new molecular analysis technique, researchers have established relationships among 200-million-year-old plants for the first time.
This page provides a brief overview of the Doushantuo Formation fossil beds, including geological setting, biota, and significance.
I spent the last three weeks in China partly for a conference, partly for a vacation, and partly for a rest. In catching up over the last couple of days, I notice that the break has given me a slightly different perspective on a couple of issues that are relevant here.. First off, the conference I attended was on paleoceanography and there were was a lot of great new science presented, particularly concerning the Paleocene-Eocene Thermal Maximum (around 55 million years ago), and on past changes to tropical rainfall patterns (see this weeks Nature) - two issues where there is a lot of relevance for climate change and its impacts today. Ill discuss the new data in separate posts over the next few weeks, but for now Ill just mention a topic that came up repeatedly in conversations over the week - that was how to improve the flow of information from the paleo community to the wider climate community, as represented by the IPCC for instance. There was a palpable sense that insights from ...
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Very similar high-resolution δ13Ccarb and δ13Corg curves are reported for the early Aptian "Livello Selli" (LS, oceanic anoxic subevent 1a) at two pelagic successions of the Alpine Tethys: "Roter Sattel" (Swiss Préalpes), deposited along the northwest margin, and "Cismon" (southern Alps of northern Italy), deposited along the southeast margin. The δ13Ccarb and δ13Corg curves are both divided into eight segments, six of which occur within the early Aptian Globigerinelloides blowi foraminiferal zone, indicating significant subzonal resolution. Most of the LS coincides with a chemostratigraphically defined "Selli event": a period of constant isotopic values (mean values of δ13Ccarb and δ13Corg ≈ +2.6‰ and −25‰ respectively) lasting 500 kyr to 1 Myr, rather than of positive excursion as previously supposed. This uniformity may reflect an equilibrium between Corg burial and increased recycling rates of 12C and nutrient-rich intermediate water resulting from the intensification of ...
Principal Investigator:NISHIDA Harufumi, Project Period (FY):1998 - 1999, Research Category:Grant-in-Aid for Scientific Research (C), Section:一般, Research Field:自然史科学
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Palaeolagus (ancient hare) is an extinct genus of lagomorph. Palaeolagus lived in the Oligocene period which was about 33-23 million years ago. The earliest leporids described from the fossil record of North America and Asia date to the upper Eocene some 40 million years ago. The fossil remains of rabbits are scanty and those specimens that have been found are often too fragmentary to determine satisfactory the relationship with living forms. The bones of rabbits and hares are lightweight and fragile in structure, and so they are not easily preserved as fossils. Most of the species are inhabitants of uplands where conditions are not ideal for preservation. In a few deposits, rabbit remains seem numerous but many fossil species are known only from a few teeth and bones. The 25 centimetres (9.8 in) long creature closely resembled modern rabbits. They were common herbivorous inhabitants of the savanna, plains and woodlands of North America 30 million years ago. Palmer, D., ed. (1999). The ...
We hypothesize that the rapid onset of the carbon isotope excursion (CIE) at the Paleocene/Eocene boundary (V55 Ma) may have resulted from the accretion of a significant amount of 12C-enriched carbon from the impact of a V10 km comet, an event that would also trigger greenhouse warming leading to the Paleocene/Eocene thermal maximum and, possibly, thermal dissociation of seafloor methane hydrate. Indirect evidence of an impact is the unusual abundance of magnetic nanoparticles in kaolinite-rich shelf sediments that closely coincide with the onset and nadir of the CIE at three drill sites on the Atlantic Coastal Plain. After considering various alternative mechanisms that could have produced the magnetic nanoparticle assemblage and by analogy with the reported detection of iron-rich nanophase material at the Cretaceous/Tertiary boundary, we suggest that the CIE occurrence was derived from an impact plume condensate. The sudden increase in kaolinite is thus thought to represent the redeposition on the
Thus several groups within the Ediacaran fauna exist today, and so the whole fauna did not become extinct. This is not to say that there are not some unique forms, there are, but the idea that they are all unique is overstepping things. My own opinion is that several groups of extant organisma can be traced back to the Ediacaran fauna. However, the origin of the metazoans is another matter. The Ediacaran fauna appears as a fully intergrated ecosystem with some quite advanced forms (eg. the colonial octocoral sea-pens), so the question of origins has to be pushed back even farther, maybe as a consequence the late Proterozoic glaciation that ended approx 650 million years. Body fossil evidence will probably never be found, since they occur in meiofauna - too small to leave anything but chemical traces ...
Most fossils preserve the physical remains of organisms and their structure; however, geologists and paleobiologists at the University of Missouri recently collaborated to study fossils that reveal the behaviors of predators preserved as traces in ancient sediments. Thus, fossils from southeast Missouri are helping scientists unlock clues about the behaviors of these predators and their interactions with their prey. Evidence shows that these ancient organisms were behaviorally sophisticated, tailoring their attacks for effectiveness.
Read more. The Cambrian explosion (530-520 mya). While scientists now know that animal life existed prior to the Cambrian explosion, the diversity of life that evolves during its 10 million years remains significant. While the soft-bodied Ediacaran animals had no protective coverings, many Cambrian animals evolved skeletons, such as shells or other brittle coatings. Among the more familiar groups to appear include sponges, brachiopods (lamp shells), spiny-skinned echinoderms, early gastropods (snails), cone-shelled cephalopods, and primitive arthropods called trilobites. Several other creatures that are unrelated to any currently living form also appear, but they die off after a short time.. A combination of environmental factors probably contributes to this evolutionary burst. Oxygen, which is plentiful in both the atmosphere and in the oceans, allows physically larger animals to evolve. Warm, free-flowing ocean currents probably carry these animals to new marine niches, where they adapt to new ...
Stromatolites are layered accretionary structures formed in shallow water by the trapping, binding and cementation of sedimentary grains by biofilms of microorganisms, especially cyanobacteria.[30] Stromatolites provide some of the most ancient fossil records of life on Earth, dating back more than 3.5 billion years ago.[31]. Stromatolites were much more abundant in Precambrian times. While older, Archean fossil remains are presumed to be colonies of cyanobacteria, younger (that is, Proterozoic) fossils may be primordial forms of the eukaryote chlorophytes (that is, green algae). One genus of stromatolite very common in the geologic record is Collenia. The earliest stromatolite of confirmed microbial origin dates to 2.724 billion years ago.[32]. A 2009 discovery provides strong evidence of microbial stromatolites extending as far back as 3.45 billion years ago.[33]. Stromatolites are a major constituent of the fossil record for lifes first 3.5 billion years, peaking about 1.25 billion years ...
The fossil record of conodonts may be among the best of any group of organisms, but it is biased nonetheless. Pre- and syndepositional biases, including predation and scavenging of carcasses, current activity, reworking and bioturbation, cause loss, redistribution and breakage of elements. These biases may be exacerbated by the way in which rocks are collected and treated in the laboratory to extract elements. As is the case for all fossils, intervals for which there is no rock record cause inevitable gaps in the stratigraphic distribution of conodonts, and unpreserved environments lead to further impoverishment of the recorded spatial and temporal distributions of taxa. On the other hand, because they are resistant to abrasion and can withstand considerable metamorphism conodonts can preserve evidence of otherwise lost sequences or environments through reworking.. We have conducted a preliminary investigation into how the various forms of gross collecting bias arising from period to period ...
A 160-million-year old pterosaur that fed exactly like a flamingo is the earliest filter-feeding pterosaur on record, a new study finds.
Many of the fossils left by the strange "Ediacara biota" that thrived during the Ediacaran Period (about 635 to 540 million years ago) look like ribbed pancakes, armored worms, and fat fern fronds. Despite finding these fossil deposits worldwide, paleontologists have struggled to place the unfamiliar creatures on the tree of life or even to agree on where and when they lived. Now, researchers are turning to data science tools to make sense of Ediacaran fossil data accumulated from decades of paleontological research. For the first time, researchers used a technique called network analysis, which reveals connections in complex systems, to analyze Ediacaran fossil collections and to match them to specific environments and times. The analysis provides evidence that two extinction events potentially linked to disturbances in the global carbon cycle occurred during this period. The extinctions created an opening for the subsequent Cambrian explosion, when most major groups of animals appeared for the ...
Principles of Sedimentology and Stratigraphy by Sam, Jr. Boggs and Jr, Sam Boggs available in Hardcover on Powells.com, also read synopsis and reviews. A concise treatment of the fundamental principles of sedimentology and stratigraphy, featuring the...
The Mesopsychidae is an extinct family of Mecoptera, comprising eleven described genera from Upper Permian to Lower Cretaceous deposits. In 2009, several well-preserved mesopsychids with long proboscides were reported from the mid Mesozoic of Northeastern China, suggesting the presence of pollination mutualisms with gymnosperm plants and highlighting their elevated genus-level diversity. Since that time, additional mesopsychid taxa have been described. However, the phylogeny of genera within Mesopsychidae has not been studied formally, attributable to the limited number of well-preserved fossils. Here, we describe two new species, Lichnomesopsyche prochorista sp. nov. and Vitimopsyche pristina sp. nov. and revise the diagnosis of Lichnomesopsyche daohugouensis Ren, Labandeira and Shih, 2010, based on ten specimens from the latest Middle Jurassic Jiulongshan Formation of Inner Mongolia, China. After compiling data from these new fossil species and previously reported representative taxa, we conducted
The developmental mode revealed by the minute larva of L. illecebrosa is similar to that in many extant eucrustaceans. Eucrustaceans (e.g., prawns, lobsters, brine shrimps, and barnacles) are so diverse morphologically that they share just a few specific and unique characters-one of which is the nauplius larva (14). Right after hatching, the nauplius (15) bears three pairs of functional appendages (14, 15). In subsequent stages, further segments and their appendages emerge from a growth zone in the posterior portion of the body (15, 16). The minute larva of L. illecebrosa resembles the late-stage metanauplius of certain eucrustaceans, especially anostracans (17), other branchiopods, and cephalocarids (14), in several aspects. First, the anterior (post-SGA segments 1-4) and posterior (post-SGA segments 5-14) portions of the body differ in outline (rounded vs. narrow and elongated; Fig. 3 and Fig. S2). This is not a result of flattening: The outline of soft-bodied fossils is not subject to ...
Our symposium will focus on the main aspect of mammalian faunas evolutionary patterns and modifications during the last 3 Ma. For the last decades, many scientists compiled database on fossil terrestrial vertebrates, especially mammals, at regional or sub-continent scale. These studies bring important insights about evolutonary processes, biochronology, or paleoecological and paleoenvironmental informations; which are sometimes connected with early hominid evolution and peopling. One of the main topics concerns the relation with Plio-Pleistocene global climate change as an important influence on evolution and faunal community change. The role played by environmental factors in large mammal changes has been interpreted in various ways: for instance following the "Stationary" model, diversity is primarily regulated by density-dependent factors in the physical environment (Rosenzweig 1975); according to the "Habitat Theory" (Vrba 1992), "Turnover Pulse Hypothesis" (Vrba 1992, 1995a), "Traffic ...
To Tom and George, and to the rest of the list (of course): The problems with stratigraphy, geography, and biodiversity are something at odds with the present analyis Ive done on oviraptorid phylogeny. This being that stratigraphy directly and oppositely contradicts the phylogeny. Odd. I got into wondering about ghost lineages, but its heading towards what I feel is a dead end. Im going to pursue the thread, just to see what I can crunch from the result, but when one opposes the other, who does it figure? It goes like this: The most oldest _known_ oviraptorid is crested. The youngest is crested. The ones in between have nothing but a little ridge above their pretty little noses, and generally rounded and short heads. The sequences go like this: (Ovi (Ingen (Concho (Rinchen)))) (stratigraphically), and (((Ingen + Concho) Ovi) Rinchen) or ((Ingen + Concho) + (Ovi + Rinchen)). I havent finished the work, but this is a prime example of the discrepancy George was talking about. == Jaime A. ...
View Notes - Fish_lecture_for_angel_3-1 from ANS 282 at Michigan State University. Fish Fossil evidence indicates that fish developed in the Ordovician period about 425 to 500 million years ago.
PANGAEA - Publishing Network for Geoscientific and Environmental Data. (Figure 2) Distribution of dinoflagellate cysts in the mid-Cretaceous of ODP Hole 101-627B. Occurrence Dataset https://doi.org/10.1594/pangaea.742967 accessed via GBIF.org on 2018-02-24 ...
Data of PANGAEA ONCOLOGY: Founded in Barcelona in 2006, Pangaea Oncology is a medical services company focused on precision oncology, personalized medicine based on genetic
Fossil Evidence is a Saison / Farmhouse Ale style beer brewed by Tired Hands Brewing Company in Ardmore, PA. 3.99 average with 26 ratings, reviews and opinions.
John, Well, that is a tantalizing introduction to the paper, but probably not a paper to which many people will have ready access any time soon. But just off hand, I am frankly most concerned with the implication (or is it a definite conclusion?) that the lower jaw (a paratype) is not the same species as the cranium/upper jaw (the holotype). Would this detract substantially from the view that the holotype is a hominid (and I mean hominid sensu stricto, not including chimps and gorillas)? ------- Ken Kinman P.S. Isnt the thick supra-orbital torus thought to be a sexual dimorphic characteristic, and thus of relatively marginal importance in this debate? ********************************************************* John Grehan wrote: Those interested the problematic situation regarding the quality of hominid systematics (as I have raised in earlier postings, much of the systematic work on fossil hominids is pretty bad if not awful) might be interested in the following publication: Schwartz, J.H. ...
Without action, we are facing extinction at unprecedented scale. In many respects, we are already in the sixth mass extinction of Earths history. Up to 96% of all marine species and 70% of terrestrial vertebrate species became extinct when temperatures rose by 8 °C (14 °F) during the Permian-Triassic extinction, or the Great Dying, 252 million years ago. During the Palaeocene-Eocene Thermal Maximum (PETM), which occurred 55 million years ago, global temperatures rose as rapidly as by 5°C in ~13 years, according to a study by Wright et al. A recent study by researchers led by Zebee concludes that the present anthropogenic carbon release rate is unprecedented during the past 66 million years. Back in history, the highest carbon release rates of the past 66 million years occurred during the PETM. Yet, the maximum sustained PETM carbon release rate was less than 1.1 Pg C per year, the study by Zebee et al. found. By contrast, a recent annual carbon release rate from anthropogenic sources was ~10 ...
Well known examples of such preservation of complete soft-bodied fish and other creatures include the Burgess Shale (dating to the Middle Cambrian Period of about 508 million years ago and found near Field, British Columbia) and the Solnhofen Plattenkalk (dating to the Late Jurassic Period of about 150 million years ago and found in Bavaria, Germany). Such exceptional assemblages were thought to have been preserved in environments that were unusually low in oxygen, highly saline, very cold, or extremely dry. What was not suspected until the new compilation was the global distribution of other exceptional fossil deposits of the same ages. Independent estimates of atmospheric pollution crises come from studies of carbon anomalies, microscopic pores of fossil leaves and climatic indicators from fossil soils. Methane outbursts from volcanically intruded coals and submarine gas hydrates are prime suspects for these lethal atmospheric pollution events ...
The 36,000-year-old skull provides evidence that modern humans left Africa 70,000 to 50,000 years ago to colonize Eurasia, a study says.
A review of the available information on ichnofaunas from tide-dominated successions allows us to understand the Waverly ichnofauna in a broader context and provides implications for trace-fossil facies models. For this review, we have selected a number of papers that integrate trace fossils and sedimentary facies. A substantial amount of information is known about lower Paleozoic quartzites that commonly contain abundant ichnofaunas in subtidal-sandwave and intertidal-flat facies. For example, Baldwin (1977) documented several ichnotaxa from the Skolithos and Cruziana ichnofacies in tidal successions of the Cambrian-Ordovician of Spain. He showed that trilobite traces characterized beach and tidal-flat deposits, whereas vertical burrows of suspension feeders were abundant in barrier and subtidal sandstones. He concluded that the dominance of trilobite traces in onshore areas results from both actual abundance of tracemakers and enhanced preservational potential of the structures. Mángano et ...
This is part five of a video series on collapse of evolution. Todays discussion is on fossil records. More information can be obtained from harunyahya.com.
The consensus view that the amount of rock available for sampling does not significantly and systematically bias Phanerozoic marine diversity patterns has broken down. How changes in rock availability and sampling intensity affect our estimates of past biodiversity has been investigated with a variety of new approaches. A number of proxies for the amount of rock available for sampling have been used, but most of these proxies do not rely directly on evidence from large-scale geological maps (maps that cover small areas) and accompanying memoirs. Most previous map-based studies focused on single regions or relied on small-scale synoptic maps. We collected data from published geological maps and memoirs from western Europe, Australia, and Chile, which we combined with COSUNA data from the United States to generate the first multiregional data set for investigating whether the global Phanerozoic marine diversity record is a true global record, or is instead biased toward North America and Western ...
The claim that fossils document evolution is simply not true. ICR geologist Dr. John Morris and zoologist Frank Sherwin unearth the evidence of earths history and conclude that the fossil record is incompatible with evolution, but remarkably consistent with the biblical account of creation and the great Flood of Noahs day.. To order The Fossil Record, click here.. ...
Fossils have not been a very important source of information about the transition that we are discussing, because the earliest multicellular animals were small and soft-bodied and did not leave a fossil record. They may have appeared between -600 and -800 Myr, or even earlier. Extensive biomineralization by animals began at the beginning of the Cambrian era ( -540 Myr) and by -520 Myr (the Burgess shale) already show a great diversity of animal types that are unlikely to be the most primitive forms. Many of the present day phyla appear to be represented at this time. Some fossils have been found from the late PreCambrian (known as the Ediacaran faunas, from about -575 Myr). In this assemblage, radial symmetry appears to be predominant. This could support the idea that radially symmetric, diploblastic animals that were ancestors of present Cnidarians evolved at a very early stage. However, it could also mean that sessile animals evolved protective coverings that were preserved as fossils before ...
4. Sudden Appearance or Face Value Interpretation. The known fossil record is assumed reasonably complete. The gaps show that while some species may have arisen by gradual change, at least the major taxa did not, and perhaps many species didnt either. The fossil record shows that most organisms remain essentially unchanged. The conclusion to be drawn is that major groups of plants and animals have coexisted on the earth independent of each other in their origins, which must be explained in some way other than Darwinian evolution.. Scientists should not accept the face value interpretation of the fossil record without also exploring the other possibilities, and even then, only if the evidence continues to support it. The imperfect record and incomplete research interpretations above are attempts to make the fossil record compatible with the Darwinian view of origins, which teaches step-wise evolution from one form of life to another. Both of these views acknowledge that the present existence of ...
Free Geological Time Units sofware download and review at SoftList.Net, Free downloads of Geological Time Units freeware and shareware programs.
Publishing in the Chinese Science Bulletin, three paleontologists described the fossils as being well-preserved as articulated skeletons, even retaining soft tissue impressions. The fossils showed more than just impressions in mudstone, however. The study authors wrote, It is obvious that more organic residue (shown by the darker color) is preserved on the surfaces of the carapaces in the gut of the salamander than on those outside, providing further evidence for their being the food of the predator.1. They did not test whether the dark fossil material was original and not mineralized soft tissue, but other fossils from the same area appear to have original organics. For example, researchers described lizard skin impressions that may preserve original skin in dark patches.2 Also, two different Daohugou spider fossils have dark-colored exoskeleton outlines,3,4 and one Daohugou specimen contains pterodactyl skin fibers.5 If direct tests verify biological materials such as protein and chitin, ...
The Swedish Government said it is targeting to become one of the first countries in the world to be free of fossil fuels.. It has pledged to boost investment in clean energy projects, with plans for 4.5 billion krona (£0.3bn) in climate projects next year to support its goal.. The government announced it wants to increase aid for solar to 390 million krona (£30m) every year from 2017 to 2019, with a total of 1.4 billion (£0.1bn) krona.. It also plans to focus on electricity storage, with 25 million krona (£1.9m) to be invested next year and 50 million krona per year between 2017 and 2019.. It will also spend 10 million krona (£0.8m) on smart grids and one billion krona (£0.07bn) in energy efficiency.. ...
Tapinosaurus" is Pliosaurus?- Unfortunately, the alpha level taxonomy of Pliosaurus is currently controversial, and most proposed distinguishing characters are cranial. The only axial character currently used to distinguish Pliosaurus species is the median ventral keel on cervical centra of P. brachydeirus. Rabecks specimen lacks this, as do P. brachyspondylus (both current and proposed neotypes), P. funkei (paratype), P. macromerus (lectotype), P. rossicus (holotype) and P. westburyensis. Yet this morphology is plesiomorphic, also being found in e.g. Brachauchenius, Simolestes and "P." andrewsi. Pliosaurus archiaci is based on a mandible (MNHN 24.1) also discovered in the Kimmeridgian deposits of Le Havre, but cannot be compared to "Tapinosaurus". Another method would be to correlate the "Tapinosaurus" specimens stratigraphically with known Pliosaurus species. According to Lepage et al., at least Rabecks specimen derives from the Aulacostephanus mutabilis zone of the Late Kimmeridgian. This ...
Tapinosaurus" is Pliosaurus?- Unfortunately, the alpha level taxonomy of Pliosaurus is currently controversial, and most proposed distinguishing characters are cranial. The only axial character currently used to distinguish Pliosaurus species is the median ventral keel on cervical centra of P. brachydeirus. Rabecks specimen lacks this, as do P. brachyspondylus (both current and proposed neotypes), P. funkei (paratype), P. macromerus (lectotype), P. rossicus (holotype) and P. westburyensis. Yet this morphology is plesiomorphic, also being found in e.g. Brachauchenius, Simolestes and "P." andrewsi. Pliosaurus archiaci is based on a mandible (MNHN 24.1) also discovered in the Kimmeridgian deposits of Le Havre, but cannot be compared to "Tapinosaurus". Another method would be to correlate the "Tapinosaurus" specimens stratigraphically with known Pliosaurus species. According to Lepage et al., at least Rabecks specimen derives from the Aulacostephanus mutabilis zone of the Late Kimmeridgian. This ...
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Although primarily a pre-eminent palaeoichthyologist, Arthur Smith Woodwards research and publications ranged across all major tetrapod groups: nevertheless, his contributions in this area have generally been overshadowed by involvement in the Piltdown Man affair. Smith Woodward published on fossil amphibians, every major group of reptiles and on mammals. Most of the new taxa he named remain valid, a testament to his wide knowledge and understanding of fossil vertebrates beyond his principal speciality, although some of these have now been extensively revised. He travelled widely in Europe and the Americas, resulting in some of the earliest work on Gondwanan Cretaceous reptiles. Several of his taxa revealed the existence of previously unknown groups (e.g. notosuchian crocodiles) or provided important character data that have fuelled various phylogenetic debates (e.g. snake and tyrannosauroid origins). His influence extended beyond his own scientific efforts to incorporate his role as a senior ...
A 500 million-year-old bacteria has been brought back to life in a laboratory at Georgia Tech in an experiment with echoes of Jurassic Parks disastrous recreation of the dinosaurs.
The fossil record does not show a gradual, linear progression from Hyracotherium (Eohippus) to Equus. Nor is there any reason to think it should. The fossil record of equids shows that various lineages split into several branches. Evolution was not smooth and gradual; traits evolved at different rates and occasionally reversed. Some species arose gradually, others suddenly. All of this is in accord with the messiness we expect from evolution and from biology in general ...
Our picture of global diversification and extinction on long time scales is mostly based on generalized data for Phanerozoic marine macroinvertebrates. While every effort was made to guarantee the comprehensiveness of this data set, the community has been aware that sampling artifacts may contribute to the observed trends. Until now, we have been unable to remove these effects. Several robust methods for doing this are now available, but these methods use locality-specific data that are not a part of the existing, more generalized compilations. In order to confirm the reality of the major observed patterns, a collaborative data compilation project needs to be initiated. We wish to form a working group to do this. As a first step, we propose a workshop this August involving workers who have specialized in analyzing paleontological diversity data. This workshop will determine the scope, goals, structure, and time table of a database project. Immediately after the workshop, a post-doc who will ...
Although represented by at least seven specimens from the Lossiemouth Sandstone Formation, no Scleromochlus is well preserved (Benton 1999). Most specimens comprise shallow sediment molds rather than actual bones, and none are complete. But we should consider ourselves lucky we know of this animal at all: the delicate, 180 mm long bodies of Scleromochlus occur in sandstone deposits representing an ancient, wind-blown desert with 20 m high dunes. Such deposits are often devoid of fossil remains, but the Lossiemouth Sandstones actually preserve a diverse reptile fauna (Benton and Walker 1985). Still, its remarkable that the tiny bones of these reptiles preserved at all in these harsh conditions and in relatively coarse (fine - medium) sands - the grains preserving Scleromochlus are each as large as Scleromochlus teeth. As is typical of Lossiemouth Sandstone specimens, most Scleromochlus fossils are more-or-less articulated and many appear to have been crouching at death. With little indication of ...
An interpretation of 2D and newer 3D depth sections in the Kwanza basin, highlights the rift morphology and enables a better understanding of the structure and stratigraphy of the pre-salt sequences.
ERC grant 310763: GeneFlow The goal of the project is to investigate the importance of nuclear gene flow between populations for the evolution of Pleistocene mammalian species. To achieve this, we need to obtain genomic data from ancient DNA samples, which is generally hampered by the low quality and quantity of ancient DNA. So far, we were able, due to a combination of published and self-developed approaches, to establish an analysis pipeline that makes it possible to obtain not only genomic data but entire nuclear genomes at affordable costs from fossil specimens. Our investigations also showed that each step during the analysis process has a major influence not only on the quantity of DNA recovered, but also on qualitative measures such as average read length and read length distribution. We also found, together with collaborators, that the petrous part of the temporal bone contains substantially higher percentages of endogenous DNA than any other part of the mammalian skeleton. We have used ...
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Stratigraphy can can be divided into several subfields: Lithiostratigraphy is the classification of rock units on the basis of their physical and mineralogical properties and relationships to other, surrounding rocks. A lithiostratigraphic unit comprises a sedimentary, igneous or metamorphic-equivalent layer that is defined on the basis of the layers composition and position in a succession of layers. The basic principle is that younger layers are deposited over older layers.
A key piece in the puzzle of the evolution of vertebrates has been identified, after the discovery of fossilised fish specimens, dating from the Cambrian period (around 505 million years old), in the Canadian Rockies. The fish, known as Metaspriggina, shows pairs of exceptionally well-preserved arches near the front of its body. The first of these pairs, closest to the head, eventually led to the evolution of jaws in vertebrates, the first time this feature has been seen so early in the fossil record.
Cathaya: Cathaya,, genus of evergreen coniferous trees of the family Pinaceae, containing two living species native to China and one fossil species found in Germany. Both living forms are about 20 metres (65 feet) tall and have two types of branchlets: long terminal shoots and short secondary shoots. The
About 540 million years ago, things were looking pretty rosy for complex life on Earth. Conditions were favorable, and the diversity of multicellular organisms took off during the so-called Cambrian Explosion. Trilobites frolicked. Brachiopods abounded. And then, things went south.. Between 490 million and 520 million years ago, a swift extinction event wiped out many of the Cambrian lifeforms. Geologists Benjamin Gill and Graham Shields-Zhou thinks they have found the trigger right in the midst of that era. According to their study in this weeks Nature, the oceans oxygen level plunged and the sulfur levels rose sharply 499 million years ago, killing off species that could not quickly adapt. That included some, but not all, of the trilobites that ruled the seas of the time.. Gills team decided to look at a specific subset of Cambrian extinctions that began 499 million years ago and lasted for 2 million to 4 million years. Other researchers had proposed that low oxygen levels - a condition ...
Our global carbon reserves (including coal, oil, oil shale, tar sands, gas and coal-seam gas) contain considerably more than 10,000 billion tonnes of carbon (see Figure 5). This amount of carbon, if released into the atmosphere, is capable of raising atmospheric CO2 levels to higher than 1,000 ppm. Such a rise in atmospheric radiative forcing will be similar to that of the Paleocene-Eocene boundary thermal maximum (PETM), which happened about 55 million years ago (see Figures 1, 2 and 4). But the rate of rise surpasses those of this thermal maximum by about ten times. ...
Join the Parker family on their annual fossil hunting adventure. Dr. Gary Parker and his wife Mary explain to their children what fossils support Noahs Flood and…
Earliest known fossils date back to the Cambrian (600 million years ago-but probably more), but the time of the brachiopod was in the Paleozoic! (bear in mind how vast a time period 250 million years is.. thats MUCH older than humanity..). They dominated in diversity and abundance. This was their "time"... Sadly, most brachiopods underwent a huge extinction at the end of the Paleozoic ...
The length of the canine and the width at the base and at the tip of the canine, as well as the backward curvature of the tooth, most closely resemble those of the gorgonopsian taxa Cyonosaurus (Figures 2c and 2d) and Aelurognathus (Figures 2e and 2f). The tip of the unidentified tooth appears to have broken off during the predators lifetime and through subsequent use the top part of the remaining tooth became smooth and rounded (Figure 2b). Similar patterns of wear and tear can be seen in the Cyonosaurus and Aelurognathus specimens in Figures 2c and 2e. The 0.5-mm square serrations on the unidentified tooth most closely match those of Aelurognathus (Figure 2f) and are different to those of Cyonosaurus, which are rectangular and significantly smaller at 0.16-mm wide and 0.2-mm long (Figure 2d).. Discussion. Our taphonomic analysis of the large dicynodont skeleton presents evidence of a carnivore-prey interaction in the Late Permian. The broken carnivore tooth strongly suggests that, soon ...
I have been reading through the palaeoclimate chapter in the new IPCC report, in part so I can write a post on transfer functions in the report for Victor Venemas climate scientists reviews. This post is not that review, instead I want to focus on half a sentence in section 5.5.5 on megadroughts and floods. while lake-sediment…
We here present a comparative study of the Montmaurin-LN Middle Pleistocene mandible (Haute-Garonne, France). This mandible, of which its right and left molar series are preserved in situ, was found in La Niche cave (Montmaurins karst system) in 1949, and was first attributed to the `Mindel-Riss interglacial (= MIS 9 to 11) based on its geological context. Later studies based on geological and faunal evidence have attributed the Montmaurin-LN mandible to MIS 7. Following a detailed morphological and metric comparative study of the mandible in the 1970s, it was interpreted in the light of a still limited fossil record and the prevailing paradigm back then. Waiting for geochronological studies in the forthcoming years, here we review the main morphological and metrical features of this mandible and its molars, which have been reassessed in the framework of a remarkably enlarged Pleistocene fossil record since the mandible was first described, and our current, more in-depth understanding of human ...
441 Publications. ANGELONE, C., S. ČERMÁK and L. ROOK (2017). "New insights on Paludotona, an insular endemic Lagomorph (Mammalia) from the Tusco-Sardinian Palaeobioprovince (Italy, Turolian, Late Miocene)." Rivista Italiana di Paleontologia e Stratigrafia 123 (3): 455-473 BERNOR, R., U. GÖHLICH, M. HARZHAUSER and G. SEMPREBON (2017). "The Pannonian C hipparions from the Vienna Basin." Palaeogeography Palaeoclimatology Palaeoecology 476: 28-41 DENYS, C., E. STOETZEL, P. ANDREWS, S. BAILON, A. RIHANE, J. B. HUCHET, Y. FERNANDEZ-JALVO and V. LAROULANDIE (2017). "Taphonomy of Small Predators multi-taxa accumulations: paleoecological implications." Historical Biology: KAYA, F. (2017). Paleobiogeographic and Paleoecologic Development of the Old World Savanna Paleobiome during the Neogene. University of Helsinki, 185 KOUFOS, G. D., S. MAYDA and T. KAYA (2017). "New carnivoran remains from the Late Miocene of Turkey." Paläontologische Gesellschaft: LU, X., X. JI, S. HOU, S. WANG, Q. SHI, S. CHEN, ...
Geologic time divides Earths history based on the succession of rock layers and the fossils within them. How do we link geologic time with actual dates?
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Shimmield, Graham (2004): Determination of the carbon and nitrogen system at station CD53_28#5. PANGAEA, https://doi.org/10.1594/PANGAEA.197294, In: Lowry, Roy K; Machin, P (2016): Compilation of the results of EU-project BOFS. PANGAEA, https://doi.org/10.1594/PANGAEA.859221
Your ideas on the relationship between morphology and evolution have not been without controversy. You told me once about a colleagues phrase this self-serving paper of Campbell in this respect. What was that all about? This fellow had a Chinese PhD student who, putting bits and pieces together, had come to the conclusion that the early fishes were all air-breathing. In my view he had no functional evidence to show this. He was saying, The relationships are this and this. That thing is air-breathing. You cant have air breathing developed independently, therefore it must have been a primitive character which has been carried all through. There is no morphological support for that view.. Let me demonstrate what I mean with these fossil specimens. First, this is a palate of Neoceratodus, which comes from the Mary River, in Queensland. These are the teeth, this is where the lower jaw fits on, and the teeth match together for grinding. A structure in here (the parasphenoid) makes the roof of ...
Lyrics to Pangaea by August Burns Red: Closed off, we wake from the dusk... (the dusk) / Only to step out into open air, just to see the
page] 18. examine a large series of fossil specimens from the Coralline Crag of England, and others from northern Italy, from Portugal, and from the southern United States, I at once discovered that the form of the denticuli on the striæ of the scuta was quite a worthless character,-that in young specimens the scuta were simply striated,-that the prominence of the adductor scutorum ridge and the depth of the cavity for the lateral depressor muscle varied much (as in the case of the recent specimens), owing apparently to the varying thickness of the valve,-that in the terga the spur varied considerably in length and breadth, the latter character being in part determined by the varying extent to which the edges of the longitudinal furrow are folded in,-and lastly, that in young specimens the basal end of the spur is much more abruptly truncated than in the old. Hence I was led to throw the three recent forms, originally considered by me as specifically distinct, into one species; but I may repeat ...
Palaeontological models can address questions of varying complexity at numerous hierarchical levels [6]. The majority of studies focus on specimen-specific questions, in part owing to the time required to construct some computational models. These studies address classic functional questions: how hard could an animal bite [13], how fast could it run [14] or even how crinoids were able to support themselves in the water column [15]. A fruitful line of enquiry is comparative analyses of form-function, such as analysing changes in posture across therapsid groups [16] and three-dimensional dynamic projections of locomotion in extinct vertebrates [17]. By virtually manipulating geometry in computer-based FE models, researchers may make morphological changes whose effects on model performance can be evaluated [18]. This can involve the simple addition or removal of features such as sutures or fenestrae in a skull [19] or altering the morphology to mimic that of closely related groups [20]. It is ...
Not everything in a fossil actually fossilizes, according to researchers who discovered pigment and feather cells in an early bird fossil.
Most fossils are millions of years in the making, but a new technique is allowing scientists to simulate the process of fossilization in about 24 hours. The laboratory-based method, described in a study published in the journal Palaeontology, sheds light on how exceptionally preserved fossils form generally over geologic time and may provide custom samples for research projects investigating specific conditions under which certain fossils formed.
Autodesk gave a grant to help world renowned Paleontologist Louise Leakey to help develop one of her goals to bring many of the rare fossil specimens in Kenya to the world by the web, The website http://www.Africanfossils.org by Louise Leakey has been updated with several new features since its launch at Autodesk University 2011.
A new international analysis of marine fossils shows that warming of the polar oceans during the Eocene, a greenhouse period that provides a glimpse of Earths potential future climate, was greater than previously thought.
This misinterpretation of some fossil materials might contribute to "a widespread but currently unrecognized bias in our understanding of the early evolution of a number of phyla" because failure to recognize that some important features might have disappeared before fossilization. This can be interpreted to suggest that many ancient animals belonged to very primitive and bizarre groups when they might actually have shared more features with modern animals than previously thought. "In some organisms that have been interpreted there has been way too much speculation and the data have been extended beyond what is scientifically acceptable," Dr Purnell stated. He also pointed out earlier in a review paper that it is important to recognize that some fossil organisms are simply too just incompletely preserved for their evolutionary significance to be realized (DOI: 10.1002/bies.200800128). Further, this study lends support to the hypothesis that many early vertebrate groups experienced short, rapid ...
Janie & Geoff. Hiking the Burgess Shale: 500 Million Years Ago in the Canadian Rockies. Many people travel to the Canadian Rockies and end up in popular spots such as Banff, Jasper, and Lake Louise. The Rockies are so magnificently beautiful its hard to imagine that there could be even more awesome experiences there than gazing at those mountains and lakes. But if you make it to Lake Louise, Alberta, take the time to travel another 30 kilometers to a World Heritage site that is awesome in the original sense of the word. It is well worth the drive and an overnight stay to take the guided hike the next day to the Burgess Shale, located in Yoho National Park on the British Columbia side of the Rockies.. If youve ever been to natural science museums, most notably the Smithsonian, and seen fossils from the Cambrian Age (540 million years ago), chances are that they came from the Burgess Shale. Steven J. Goulds book Wonderful Life describes the discovery of the site and how it changed our notions ...
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The discovery of new fossils in Africa, Asia, and Europe, and the recognition of a greater diversity in the middle Pleistocene fossil record, has led to a reconsideration of the species Homo heidelbergensis. This nomen, formulated by Schoetensack in 1908 to describe the Mauer jaw (Germany), was almost forgotten during most of the past century. Numerous fossils have been attributed to it but no consensus has arisen concerning their classification. The holotype anatomical traits are still poorly understood, and numerous fossils with no mandibular remains have been placed in the taxon. Some researchers propose H. heidelbergensis as an Afro-European taxon that is ancestral to both modern humans and Neandertals whereas others think it is a strictly European species that is part of the Neandertal lineage. We focus on the validity of H. heidelbergensis, using the traditional basis of species recognition: anatomical description. We provide a comparative morphological analysis using 47 anatomical traits ...
The size and flight mechanics of giant pterosaurs have received considerable research interest for the last century but are confused by conflicting interpretations of pterosaur biology and flight capabilities. Avian biomechanical parameters have often been applied to pterosaurs in such research but, due to considerable differences in avian and pterosaur anatomy, have lead to systematic errors interpreting pterosaur flight mechanics. Such assumptions have lead to assertions that giant pterosaurs were extremely lightweight to facilitate flight or, if more realistic masses are assumed, were flightless. Reappraisal of the proportions, scaling and morphology of giant pterosaur fossils suggests that bird and pterosaur wing structure, gross anatomy and launch kinematics are too different to be considered mechanically interchangeable. Conclusions assuming such interchangeability-including those indicating that giant pterosaurs were flightless-are found to be based on inaccurate and poorly supported assumptions
Jason Poole, who oversees the lab and has participated in dinosaur digs around the world, says the fossils were unearthed in Wyoming in 2011 by a team from the New Jersey State Museum in Trenton. Scientists already know the fossils belong to a 25-foot-long, duck-billed, plant-eating dinosaur that lived 67 to 70 million years ago. Its of the hadrosaur family, the same family as the famous Hadrosaurus foulkii, the worlds first nearly complete dinosaur, which the Academy displayed in 1868 as the worlds first mounted dinosaur.. But scientists wont know what species of hadrosaur the mystery dinosaur is until they can fully see and examine the fossils. Even though they have found only a small portion of the dinosaur, scientists are confident they will be able to identify it, especially since they have parts of the skull, which often is not recovered.. "From neck to tail, all hadrosaurids look alike," Poole says. "But we have a good bit of the skull, which makes it a lot easier to identify the ...
To discover interordinal relationships of living and fossil placental mammals and the time of origin of placentals relative to the Cretaceous-Paleogene (K-Pg) boundary, we scored 4541 phenomic characters de novo for 86 fossil and living species. Combining these data with molecular sequences, we obtained a phylogenetic tree that, when calibrated with fossils, shows that crown clade Placentalia and placental orders originated after the K-Pg boundary. Many nodes discovered using molecular data are upheld, but phenomic signals overturn molecular signals to show Sundatheria (Dermoptera + Scandentia) as the sister taxon of Primates, a close link between Proboscidea (elephants) and Sirenia (sea cows), and the monophyly of echolocating Chiroptera (bats). Our tree suggests that Placentalia first split into Xenarthra and Epitheria; extinct New World species are the oldest members of Afrotheria.
In order to investigate mid-Cretaceous terrestrial climates of low paleolatitudes, Moroccan, Tunisian and Brazilian vertebrate apatites have been analyzed for their oxygen and carbon isotope compositions of phosphates (delta O-18(p)) and carbonates (delta O-18(c), delta C-18(c)). At each site, coexisting theropod dinosaurs, titanosaurid sauropods, pterosaurs, crocodilians, turtles and fish have distinct delta O-18(p) and delta C-18(c) values reflecting their ecologies, diets and foraging environments. Oxygen isotope compositions of surface waters (delta O-18(w)) estimated from turtle and crocodile delta O-18(p) values range from -5.0 +/- 1.0 parts per thousand to -2.4 +/- 1.0 parts per thousand, which do not differ from mean annual rainwater values occurring today under inter-tropical sub-arid to arid climates. High water temperatures ranging from 21 +/- 6 degrees C to 34 +/- 2 degrees C deduced from fish delta O-18(p) values are in agreement with those published for mid-Cretaceous low ...
Identified as Mystacodon selenensis, the fossil whale is described as a small to medium-sized creature that had teeth, but in other ways resembled modern humpbacks and blue whales, they explained - hence its name, which Science News said translates to "toothed mysticete.". The remains were discovered in the deserts of Peru by a team led by Royal Belgian Institute of Natural Sciences paleontologist Olivier Lambert. It was approximately four meters long, or about as big as a modern-day pilot whale, and like primitive whales, still had a protruding hip bone indicating that it still had hind legs left over from when its ancestors were terrestrial quadrupeds.. However, the creature also had a flat snout similar to those of modern-day baleen whales, and while ancient whales had elbow-like joints in its front flippers, M. selenensis does not - nor do modern-day baleen whales, according to the authors of the new Current Biology paper.. Lamberts team believes that M. selenensis might have used ...
redOrbit Staff & Wire Reports - Your Universe Online. Neanderthal men likely adorned themselves with bird feathers, a new study suggests.. The researchers believe the feathers were stripped from the remains of birds and worn as decorative ornaments or jewelry, a theory that further suggests early hominids had a strong sense of tradition and culture.. The scientists studied bird bones found at European sites used by Neanderthal man, and discovered that bird wings containing large feathers had consistently been cut and carved by the inhabitants.. Gibraltar Museum researchers Clive Finlayson and Kimberly Brown said the study´s findings provide further evidence that Neanderthals´ thinking ability was similar to that of modern man.. The research even suggests that Neanderthal man had a preference for dark feathers selected from birds of prey and corvids, such as ravens and rooks.. The researchers said they are not suggesting that humans learned the practice of adorning themselves from Neanderthals, ...