Journal articles: 'Fossil bone'

1

Pfretzschner, Hans-Ulrich. "Pyrite in fossil bone." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 220, no. 1 (March 30, 2001): 1–23. http://dx.doi.org/10.1127/njgpa/220/2001/1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

2

Pfretzschner, Hans-Ulrich. "Iron oxides in fossil bone." Neues Jahrbuch für Geologie und Paläontologie - Abhandlungen 220, no. 3 (June 11, 2001): 417–29. http://dx.doi.org/10.1127/njgpa/220/2001/417.

Full text

APA, Harvard, Vancouver, ISO, and other styles

3

BOSKOVIC, DANILO S., URIEL L. VIDAL, KEVIN E. NICK, RAUL ESPERANTE, LEONARD R. BRAND, KENNETH R. WRIGHT, LAWRENCE B. SANDBERG, and BETHANIA C. T. SIVIERO. "STRUCTURAL AND PROTEIN PRESERVATION IN FOSSIL WHALE BONES FROM THE PISCO FORMATION (MIDDLE-UPPER MIOCENE), PERU." PALAIOS 36, no. 4 (April 30, 2021): 155–64. http://dx.doi.org/10.2110/palo.2020.032.

Full text

Abstract:

ABSTRACT Microstructural and biomolecular preservation is reported in fossils as old as the Triassic. Such preservation suggests unusual taphonomic conditions. We collected fragments of fossil whale bone from silty, tuffaceous, and diatomaceous rocks of the middle-upper Miocene portion of the Pisco Formation. The whale fossils within the region are generally well-preserved and mostly articulated, including some specimens with in situ baleen. Due to the depositional setting associated with the preservation of these fossils, they could be expected to be favorable candidates for the preservation of cellular microstructures and/or original biomolecules. To test this hypothesis, fossil whale bone fragments were subjected to microscopic analysis and EDTA-mediated demineralization to release extractable materials. Microscopy of partially demineralized fossil bones revealed quartz-permineralized osteocyte-like and vessel-like structures. Protein assay (micro-Bicinchoninic Acid Assay) of the supernatants obtained from demineralized fossils yielded 12 to 19.5 μg of protein per gram of bone. MALDI-TOF analysis of the extracted protein demonstrated the presence of approximately 5 kD molecules in one fossil sample, consistent with the presence of highly fragmented polypeptides. An LC-MS/MS analysis of the fragmentation pattern of the tryptic digest of extracted protein was performed. However, attempted protein identification was unsuccessful. Nevertheless, this study first documents the microstructural preservation with some silicification of the fossil whale bones of the Pisco Formation, and then quantifies extractable protein from these bones. It adds to the growing body of reports of microstructural and organic preservation in fossils.

APA, Harvard, Vancouver, ISO, and other styles

4

Stafford, Thomas W., P. E. Hare, Lloyd Currie, A. J. T. Jull, and Douglas Donahue. "Accuracy of North American Human Skeleton Ages." Quaternary Research 34, no. 1 (July 1990): 111–20. http://dx.doi.org/10.1016/0033-5894(90)90076-w.

Full text

Abstract:

AbstractAccelerator mass spectrometry (AMS) radiocarbon dates fail to provide conclusive evidence that all New World human fossils are younger than approximately 11,000 yr. Because fossil bones vary widely in preservation, their radiocarbon dates are not equally accurate. Molecular-level radiocarbon dating, which used individual amino acids to assess fossil diagenesis, revealed that dates on known-age, noncollagenous bone were underestimated by at least 2000 to 9000 yr. The significance is that >11,000-yr-old fossil bones with poor preservation would yield Holocene and not Pleistocene radiocarbon ages, regardless of what chemical pretreatment or 14C counting method was used. Irreplaceable evidence for Pleistocene-age fossils in the New World could be lost if the diagenesis of fossil bones is not evaluated before the bones are radiocarbon dated. In contrast, radiocarbon ages for collagenous fossils can be determined more accurately if 14C is measured in several individual amino acids that are isolated from collagenous bone protein. Molecular-level radiocarbon dating will greatly improve not only the accuracy of chronologies for human migrations and animal extinctions, but of all late Quaternary chronologies that are based upon the 14C dating of fossil proteins.

APA, Harvard, Vancouver, ISO, and other styles

5

Newesely, Heinrich. "Fossil bone apatite." Applied Geochemistry 4, no. 3 (May 1989): 233–45. http://dx.doi.org/10.1016/0883-2927(89)90023-1.

Full text

APA, Harvard, Vancouver, ISO, and other styles

6

Denys, Christiane, Olga Otero, Ottmar Kullmer, Oliver Sandrock, Timothy G. Bromage, Friedemann Schrenk, and Yannicke Dauphin. "Biominerals Fossilisation: Fish Bone Diagenesis in Plio–Pleistocene African Hominid Sites of Malawi." Minerals 10, no. 12 (November 25, 2020): 1049. http://dx.doi.org/10.3390/min10121049.

Full text

Abstract:

Fish fossilisation is relatively poorly known, and skeletal element modifications resulting from predation, burial and diagenesis need to be better investigated. In this article, we aim to provide new results about surface, structural and chemical changes in modern and fossil fish bone. Fossil samples come from two distinct localities of roughly the same age in the Pliocene–Pleistocene Chiwondo Beds adjacent to Lake Malawi. Optical and scanning electron microscope (SEM) observations, energy dispersive spectroscopy (EDS) analyses and Fourier transform infrared (FTIR) spectrometry were carried out on three categories of fish bones: (i) fresh modern samples collected in the lake, (ii) extracted from modern fish eagle regurgitation pellets, and (iii) fossils from Malema and Mwenirondo localities. A comparison of these data allowed us to detect various modifications of bone surfaces and structure as well as composition changes. Some differences are observed between fresh bones and modern pellets, and between pellets and fossils. Moreover, fossil fish bone surface modifications, crystallinity, and chemical composition from Malema and Mwenirondo differ despite their chronological and spatial proximities (2.5–2.4 Ma, 500 m). In both sites, the post-predation modifications are strong and may hide alterations due to the predation by bird of prey such as the fish eagle. The combination of the used methods is relevant to analyses of diagenetic alterations in fish bones.

APA, Harvard, Vancouver, ISO, and other styles

7

Goldenberg, Larisa, Lior Regev, Eugenia Mintz, and Elisabetta Boaretto. "Dating Reassembled Collagen from Fossil Bones." Radiocarbon 59, no. 5 (August 3, 2017): 1487–96. http://dx.doi.org/10.1017/rdc.2017.69.

Full text

Abstract:

AbstractInsoluble bone collagen is one of the most common materials used for high-resolution radiocarbon (14C) dating. Unfortunately, in some bones, poor preservation of the insoluble collagen excludes the possibility of dating. During the burial of the bone the collagen sometimes degrades into peptides. These peptides are soluble in the acid used to dissolve the bone mineral. It is known that under appropriate conditions, collagen has the ability to self-assemble. Here we exploit this capability and present a method for reassembling the soluble collagen peptides in archaeological bones and dating them. We treated the acid fraction generated during the demineralization of the bone by desalting and neutralizing the solution by dialysis. During the dialysis, the soluble collagen peptides reassemble and precipitate in the dialysis bag. We used FTIR spectroscopy to determine that the precipitated material is indeed collagen. The14C dates obtained from the reassembled collagen were compared to the dates of “standard” insoluble collagen, extracted in parallel from the same bone. Although there are some divergences of the dates, 3 out of 10 samples could have been dated only by the reassembled collagen. This shows that collagen peptides reassembly can be a valuable tool for dating bones with little or no insoluble collagen.

APA, Harvard, Vancouver, ISO, and other styles

8

Senter, Philip J. "Radiocarbon in Dinosaur Fossils: Compatibility with an Age of Millions of Years." American Biology Teacher 82, no. 2 (February 1, 2020): 72–79. http://dx.doi.org/10.1525/abt.2020.82.2.72.

Full text

Abstract:

The recent discovery of radiocarbon in dinosaur bones at first seems incompatible with an age of millions of years, due to the short half-life of radiocarbon. However, evidence from isotopes other than radiocarbon shows that dinosaur fossils are indeed millions of years old. Fossil bone incorporates new radiocarbon by means of recrystallization and, in some cases, bacterial activity and uranium decay. Because of this, bone mineral – fossil or otherwise – is a material that cannot yield an accurate radiocarbon date except under extraordinary circumstances. Mesozoic bone consistently yields a falsely young radiocarbon “date” of a few thousand to a few tens of thousands of years, despite the fact that it is millions of years old. Science educators need to be aware of the details of these phenomena, to be able to advise students whose acceptance of biological evolution has been challenged by young-Earth creationist arguments that are based on radiocarbon in dinosaur fossils.

APA, Harvard, Vancouver, ISO, and other styles

9

Neil Garland, A. "Microscopical analysis of fossil bone." Applied Geochemistry 4, no. 3 (May 1989): 215–29. http://dx.doi.org/10.1016/0883-2927(89)90021-8.

Full text

APA, Harvard, Vancouver, ISO, and other styles

10

Williams, C. T. "Trace elements in fossil bone." Applied Geochemistry 4, no. 3 (May 1989): 247–48. http://dx.doi.org/10.1016/0883-2927(89)90024-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

11

Ryanskaya, A. D., D. V. Kiseleva, O. P. Shilovsky, and E. S. Shagalov. "XRD study of the Permian fossil bone tissue." Powder Diffraction 34, S1 (March 15, 2019): S14—S17. http://dx.doi.org/10.1017/s0885715619000174.

Full text

Abstract:

This paper is devoted to the X-ray diffraction study of bone fragments of Permian parareptile Deltavjatia vjatkensis obtained from the Kotelnich vertebrate fossil site, one of the richest of the Permian period, which is characterized by the excellent preservation of fossil remains because of their burial in a silty anaerobic environment similar to modern bogs. The bone is well-preserved and consists of fluorapatite, calcite, quartz, and dolomite. The refined apatite unit-cell parameters of a and b-axis (9.3526 ± 0.0001 and 9.3587 ± 0.0001) Å and c-axis (6.8930 ± 0.0001 and 6.8968 ± 0.0001) Å correspond to F-apatite. Crystallinity index determined as the full width at half maximum of the 002 reflection in degrees 2θ is 0.266–0.250, which is typical for Mesozoic vertebrate bones. Apatite crystallite size (length 70.3–74.9 nm, width 30.7–30.3 nm) in fossil pareiasaur bone is larger than in subfossil and recent mammal bone and is in a good agreement with the values for seismosaurus bone. Both crystallite size and aspect ratio (2.3–2.5) are independent of the fossil pareiasaur bone length.

APA, Harvard, Vancouver, ISO, and other styles

12

Long, Austin, A. T. Wilson, R. D. Ernst, B. H. Gore, and P. E. Hare. "AMS Radiocarbon Dating of Bones at Arizona." Radiocarbon 31, no. 03 (1989): 231–38. http://dx.doi.org/10.1017/s0033822200011735.

Full text

Abstract:

Modern bone contains ca 25% protein material, most of which is collagen. Amino acids separated from collagen isolated from bone are suitable for 14C dating of fossil bone, but attempts to carry out this procedure on bones seriously depleted in protein can yield erroneous 14C dates. Amino-acid analysis of fossil bone gives quantitative information on the degree of preservation of its organic component. Also, the relative abundance of the amino-acid components reveal the degree to which the collagen-like pattern has been altered. Alteration may be caused by addition of extraneous material. A 1mg sample of bone material is sufficient for this preliminary analysis. We have developed a series of acceptance criteria for whether a particular specimen is likely to yield the correct 14C age. 14C dating of fossil bones not seriously depleted in protein is a straightforward procedure and yields reliable dates.

APA, Harvard, Vancouver, ISO, and other styles

13

Tankersley, Kenneth B., Michael R. Waters, and Thomas W. Stafford. "Clovis and the American Mastodon at Big Bone Lick, Kentucky." American Antiquity 74, no. 3 (July 2009): 558–67. http://dx.doi.org/10.1017/s0002731600048757.

Full text

Abstract:

Contemporaneity of people and the American mastodon (Mammut americanum) at Big Bone Lick, Kentucky, has been extensively debated for more than two hundred years. Newly interpreted stratigraphic excavations and direct AMS ¹⁴C measurements on mastodon bones from Big Bone Lick, Kentucky, indicate that the megafauna are a palimpsest of fossils spanning at least 1,200 calendar years (11,020 ± 30 to 12,210 ± 35 RC yr B.P.). The radiocarbon evidence indicates that mastodons and Clovis people overlapped in time; however, other than one fossil with a possible cut mark and Clovis artifacts that are physically associated with but dispersed within the bone-bearing deposits, there is no incontrovertible evidence that humans hunted Mammut americanum at the site.

APA, Harvard, Vancouver, ISO, and other styles

14

Elster, Hartwig, Emanuel Gil-Av, and Stephen Weiner. "Amino acid racemization of fossil bone." Journal of Archaeological Science 18, no. 5 (September 1991): 605–17. http://dx.doi.org/10.1016/0305-4403(91)90055-t.

Full text

APA, Harvard, Vancouver, ISO, and other styles

15

ROGERS, RAYMOND R., ANIK K. REGAN, LUCAS N. WEAVER, JEFFREY T. THOLE, and HENRY C. FRICKE. "TRACKING AUTHIGENIC MINERAL CEMENTS IN FOSSIL BONES FROM THE UPPER CRETACEOUS (CAMPANIAN) TWO MEDICINE AND JUDITH RIVER FORMATIONS, MONTANA." PALAIOS 35, no. 3 (March 26, 2020): 135–50. http://dx.doi.org/10.2110/palo.2019.093.

Full text

Abstract:

ABSTRACT Previous studies have yielded mixed results as to whether authigenic mineral infill in fossilized bone tracks specific lithologies or depositional environments, with most suggesting weak to no correlation between infill composition and host lithofacies. This study documents infill patterns in a suite of fossil bones from the Upper Cretaceous Two Medicine and Judith River formations of Montana. The composition and distribution of void-filling materials, including authigenic mineral precipitates (e.g., calcite, chlorite, iron oxides/hydroxides, sulfides, and sulfates) and sedimentary detritus, were identified (petrography and SEM-EDS), imaged (photomicrographs, BSE maps), and quantified on false color maps using ImageJ. The authigenic cement content of fossil bone is distinct at the formation scale, with Two Medicine specimens characterized by pervasive calcite infill (non-ferroan followed by ferroan phase) and local chlorite infill. In contrast, Judith River specimens are characterized by abundant unfilled primary void space, with iron oxides and sulfides, along with rare sulfates, present in all bones, albeit in low abundance. Calcite infills are rare, chlorite is absent, and detrital infill is more abundant in Judith River specimens, presumably reflecting the rapid and more complete permineralization of Two Medicine bones. The sequencing of mineral cements in voids is generally consistent within formations, but is more complex in Two Medicine specimens. Authigenic cement content does not serve to effectively distinguish among facies or localities in either formation. This study compliments previous work on rare earth element (REE) content in the same general suite of fossil bones. In the previous study, patterns in REE uptake also served to readily distinguish fossils at the formation scale, and proved more effective than authigenic cements at differentiating fossils recovered from different facies.

APA, Harvard, Vancouver, ISO, and other styles

16

Barreto, Claudia. "The Dinosaur Growth Plate: A Study in Paleohistology." Paleontological Society Special Publications 7 (1994): 255–60. http://dx.doi.org/10.1017/s2475262200009564.

Full text

Abstract:

Paleontologists study past life through analysis of the fossil record. Vertebrate paleontologists are particularly interested in studying those animals with vertebral columns (backbones). The biology of vertebrates is dictated by the millions of cells that make up these complex animals. Histology is the science concerned with the microscopic anatomy of cells, tissues and organs. All life forms are made of cells (membrane-bound bodies within which the chemical reactions necessary to sustain life occur). In complex animals, such as vertebrates, similar cells work together in associations called tissues. Typically, only the harder tissues of the vertebrate body become preserved as fossils. An example of a hard tissue is bone. Our ability to derive information from a fossil is dependent on how well it is preserved and on the techniques we use to study the specimen. Certain fossilization regimes conserve cellular and sub-cellular structure and microscopic examination of appropriately prepared specimens permits detailed study of fossil bone histology (Barreto and Albrecht 1993). The microscopic structure of bone reflects the activity of the cells that produced it. All organisms on earth, and all the cells that compose them are descended from a common ancestral cell; and we have no reason to believe that cells that produced bone millions of years ago were different from bone cells we can study in living animals today. It is possible to compare the cellular structure of well preserved fossil bone to modern bone. Such research, called “paleohistology,” allows interpretation of the biology of extinct vertebrates (Reid 1984; Ricqles 1976; Ricqles 1980).

APA, Harvard, Vancouver, ISO, and other styles

17

Cadena, Edwin-Alberto. "In situ SEM/EDS compositional characterization of osteocytes and blood vessels in fossil and extant turtles on untreated bone surfaces; different preservational pathways microns away." PeerJ 8 (August 27, 2020): e9833. http://dx.doi.org/10.7717/peerj.9833.

Full text

Abstract:

Osteocytes and blood vessels are the main cellular and tissue components of the bone tissue of vertebrates. Evidence of these soft-tissue microstructures has been widely documented in the fossil record of Mesozoic and Cenozoic turtles. However, all these studies have characterized morphologically and elementally these microstructures via isolation from the fossilized bone matrix where they were preserved or in ground sections, which could raise skepticism about the results due to potential cross-contamination or reagents effects. Fossil turtle bones from three different localities with distinct preservation environments and geological settings, including Mongolemys elegans from the Late Cretaceous of Mongolia, Allaeochelys crassesculpta from the Eocene of Germany, and a podocnemidid indet. from the Miocene of Colombia are studied here. Bone from two extant turtle species, Lepidochelys olivacea, and Podocnemis lewyana, as well as a commercial chicken Gallus gallus were used for comparisons. Scanning Electron Microscopy-Energy Dispersive Spectroscopy analyses performed directly on untreated fresh surfaces show that osteocytes-like in the fossil turtle bone are mostly composed of iron and manganese. In contrast, the in situ blood vessels-like of the fossil turtles, as well as those from the extant taxa are rich in elements typically organic in origin (carbon and nitrogen), which are absent to minimally present in the surrounding bone or rock matrix; this suggests a possible endogenous composition for these fossil structures. Also, the results presented here show that although originally both (osteocytes and blood vessels) are organic soft components of bone as evidenced in the extant turtles and chicken, they can experience completely different preservational pathways only microns away from each other in the same fossil bone.

APA, Harvard, Vancouver, ISO, and other styles

18

Donovan, Stephen K., Daryl P. Domning, Frank A. Garcia, and Harold L. Dixon. "A bone bed in the Eocene of Jamaica." Journal of Paleontology 64, no. 4 (July 1990): 660–62. http://dx.doi.org/10.1017/s0022336000042700.

Full text

Abstract:

Pre-pleistocene fossil vertebrates are rare fossils in the Antillean region. The majority of vertebrate deposits found in the West Indies are of Late Pleistocene age, usually, but not always (MacPhee et al., 1989), dating from after the last interglacial. These faunas are cave and fissure accumulations of disarticulated bones of small terrestrial vertebrates, particularly rodents, birds, and lizards. In contrast, pre-Quaternary vertebrates of the Caribbean islands are particularly poorly known. For example, Jamaica, which has one of the most extensively studied fossil records in the region, has hitherto produced only three Tertiary vertebrates, all aquatic and hitherto known only from unique specimens. These include: the late Early Eocene sirenian Prorastomus sirenoides Owen, 1855, originally described on the basis of the skull, mandible, and atlas vertebra (for a recent discussion of this species, see Savage, 1977); the lower jaw of the early Middle Eocene crocodilian Charactosuchus kugleri Berg, 1969; and a fragment of needlefish jaw from the Pliocene (Caldwell, 1966). It is therefore significant to report the discovery of an early Middle Eocene sequence in which bones are not uncommon, including a bone bed that has produced a moderate diversity of aquatic (marine?) taxa.

APA, Harvard, Vancouver, ISO, and other styles

19

Benchimol, R. E., K. Cooper, Kronberg B.I., and M. Powell. "Reconnaissance study of macrofossils from the upper purus river - Western Amazônia." Acta Amazonica 16 (1986): 327–36. http://dx.doi.org/10.1590/1809-43921986161336.

Full text

Abstract:

Fossils of wood, bone and teeth found along the Upper Purus River οf Amazonia. were studied using conventional microscopy and scanning electron microscopy. Mass spectometry was also used to investigate minor and trace element signatures of bone samples.The microsopy studies showed that there was little alteration of original textures. In the fossil wood samples, identified In thin section as tropical hardwood trees, the replacement of the original material with siderite suggests that fossilization occured in shallow sediments in which interstitial waters were saturated with respect to iron carbenate. In samples of both fossilized bone and wood, precipitation of secondary iron phases was commonly observed in cracks and voids. Other secondary phases Included silica, iron oxides, manganese carbonate. The intimate assοciation οf these secondary phases with the original biological structures could be evidence for a microbiological role in the formation of these phases. The similarity in rare earth element (REE) signatures for 2 fossil bone samples from different modern locations indicates their having shared similar diagenetic histories.The virtually complete preservation of original textures suggests that microscοpic studies could be useful in classifying fossil and even in identifying original materials. Rare carth signatures in fossilized bone may reflect ground water compositions at the time of fossilization.

APA, Harvard, Vancouver, ISO, and other styles

20

Ajie, Henry O., Isaac R. Kaplan, Peter V. Hauschka, Donna Kirner, Peter J. Slota, and R. E. Taylor. "Radiocarbon Dating of Bone Osteocalcin: Isolating and Characterizing a Non-Collagen Protein." Radiocarbon 34, no. 3 (1992): 296–305. http://dx.doi.org/10.1017/s0033822200063451.

Full text

Abstract:

Osteocalcin, a non-collagen bone-matrix protein, has been examined as a possible source of autochthonous 14C data in fossil bones where collagen has been seriously degraded. Extraction procedures for osteocalcin yield a well-characterized product that can be clearly distinguished from collagen. The Gla content indicates that osteocalcin is present in the fossil bones at levels similar to the range present in modern bone. However, it appears to be extracted primarily as proteolytic polypeptide fragments rather than as an intact protein. Concordant 14C determinations are obtained on osteocalcin and gelatin extracts from the same bone when the collagen is relatively well preserved. However, increasing discordances in the 14C values of the osteocalcin and gelatin fractions are associated with reduced concentrations of the gelatin extract in the bone.

APA, Harvard, Vancouver, ISO, and other styles

21

Olesiak, Sara E., Matt Sponheimer, Jaelyn J. Eberle, Michelle L. Oyen, and Virginia L. Ferguson. "Nanomechanical properties of modern and fossil bone." Palaeogeography, Palaeoclimatology, Palaeoecology 289, no. 1-4 (April 2010): 25–32. http://dx.doi.org/10.1016/j.palaeo.2010.02.006.

Full text

APA, Harvard, Vancouver, ISO, and other styles

22

Dalton, Rex. "Hints of bone bounties rile fossil hunters." Nature 416, no. 6879 (March 2002): 356. http://dx.doi.org/10.1038/416356a.

Full text

APA, Harvard, Vancouver, ISO, and other styles

23

Lennie, Kendra I., Sarah L. Manske, Chris F. Mansky, and Jason S. Anderson. "Locomotory behaviour of early tetrapods from Blue Beach, Nova Scotia, revealed by novel microanatomical analysis." Royal Society Open Science 8, no. 5 (May 2021): 210281. http://dx.doi.org/10.1098/rsos.210281.

Full text

Abstract:

Evidence for terrestriality in early tetrapods is fundamentally contradictory. Fossil trackways attributed to early terrestrial tetrapods long predate the first body fossils from the Late Devonian. However, the Devonian body fossils demonstrate an obligatorily aquatic lifestyle. Complicating our understanding of the transition from water to land is a pronounced gap in the fossil record between the aquatic Devonian taxa and presumably terrestrial tetrapods from the later Early Carboniferous. Recent work suggests that an obligatorily aquatic habit persists much higher in the tetrapod tree than previously recognized. Here, we present independent microanatomical data of locomotor capability from the earliest Carboniferous of Blue Beach, Nova Scotia. The site preserves limb bones from taxa representative of Late Devonian to mid-Carboniferous faunas as well as a rich trackway record. Given that bone remodels in response to functional stresses including gravity and ground reaction forces, we analysed both the midshaft compactness profiles and trabecular anisotropy, the latter using a new whole bone approach. Our findings suggest that early tetrapods retained an aquatic lifestyle despite varied limb morphologies, prior to their emergence onto land. These results suggest that trackways attributed to early tetrapods be closely scrutinized for additional information regarding their creation conditions, and demand an expansion of sampling to better identify the first terrestrial tetrapods.

APA, Harvard, Vancouver, ISO, and other styles

24

Potts, Richard. "Temporal span of bone accumulations at Olduvai Gorge and implications for early hominid foraging behavior." Paleobiology 12, no. 1 (1986): 25–31. http://dx.doi.org/10.1017/s0094837300002955.

Full text

Abstract:

Bones of mammals exhibit progressive stages of weathering during their time of subaerial exposure. Consequently, the study of bone weathering in fossil assemblages may help to assess the period represented by an accumulation of bones. Stages of bone decomposition due to subaerial weathering have been identified in assemblages of fossil macromammals from Olduvai Gorge, Tanzania. A modern bone assemblage collected by spotted hyenas is used to devise a method for recognizing attritional accumulations of bones from weathering characteristics. This method, which involves study of long bone diaphyses, is applied to Plio-Pleistocene faunal assemblages from Olduvai, 1.70–1.85 ma old. Previous work indicates that early hominids had an important role in the collection of fauna at five of the six sites studied. It is shown that animal bones were accumulated at each site over a period of probably 5–10 yr or more. The length of this period, along with other taphonomic evidence, suggests that the processes of bone aggregation at these sites differed from those at the short-term campsites of modern, tropical hunter-gatherers.

APA, Harvard, Vancouver, ISO, and other styles

25

Behrensmeyer, Anna K., C. Tristan Stayton, and Ralph E. Chapman. "Taphonomy and ecology of modern avifaunal remains from Amboseli Park, Kenya." Paleobiology 29, no. 1 (2003): 52–70. http://dx.doi.org/10.1666/0094-8373(2003)029<0052:taeoma>2.0.co;2.

Full text

Abstract:

Avian skeletal remains occur in many fossil assemblages, and in spite of small sample sizes and incomplete preservation, they may be a source of valuable paleoecological information. In this paper, we examine the taphonomy of a modern avian bone assemblage and test the relationship between ecological data based on avifaunal skeletal remains and known ecological attributes of a living bird community. A total of 54 modern skeletal occurrences and a sample of 126 identifiable bones from Amboseli Park, Kenya, were analyzed for weathering features and skeletal part preservation in order to characterize preservation features and taphonomic biases. Avian remains, with the exception of ostrich, decay more rapidly than adult mammal bones and rarely reach advanced stages of weathering. Breakage and the percentage of anterior limb elements serve as indicators of taphonomic overprinting that may affect paleoecological signals. Using ecomorphic categories including body weight, diet, and habitat, we compared species in the bone assemblage with the living Amboseli avifauna. The documented bone sample is biased toward large body size, representation of open grassland habitats, and grazing or scavenging diets. In spite of this, multidimensional scaling analysis shows that the small faunal sample (16 out of 364 species) in the pre-fossil bone assemblage accurately represents general features of avian ecospace in Amboseli. This provides a measure of the potential fidelity of paleoecological reconstructions based on small samples of avian remains. In the Cenozoic, the utility of avian fossils is enhanced because bird ecomorphology is relatively well known and conservative through time, allowing back-extrapolations of habitat preferences, diet, etc. based on modern taxa.

APA, Harvard, Vancouver, ISO, and other styles

26

Sanchez, Sophie, Per E. Ahlberg, Katherine M. Trinajstic, Alessandro Mirone, and Paul Tafforeau. "Three-Dimensional Synchrotron Virtual Paleohistology: A New Insight into the World of Fossil Bone Microstructures." Microscopy and Microanalysis 18, no. 5 (October 2012): 1095–105. http://dx.doi.org/10.1017/s1431927612001079.

Full text

Abstract:

AbstractThe recent developments of phase-contrast synchrotron imaging techniques have been of great interest for paleontologists, providing three-dimensional (3D) tomographic images of anatomical structures, thereby leading to new paleobiological insights and the discovery of new species. However, until now, it has not been used on features smaller than 5–7 μm voxel size in fossil bones. Because much information is contained within the 3D histological architecture of bone, including an ontogenetic record, crucial for understanding the paleobiology of fossil species, the application of phase-contrast synchrotron tomography to bone at higher resolutions is potentially of great interest. Here we use this technique to provide new 3D insights into the submicron-scale histology of fossil and recent bones, based on the development of new pink-beam configurations, data acquisition strategies, and improved processing tools. Not only do the scans reveal by nondestructive means all of the major features of the histology at a resolution comparable to that of optical microscopy, they provide 3D information that cannot be obtained by any other method.

APA, Harvard, Vancouver, ISO, and other styles

27

Stathoplos, Linda, and Noreen Tuross. "Preservation of bone proteins and DNA in an ancient fish called ‘Wanda’." Paleontological Society Special Publications 6 (1992): 279. http://dx.doi.org/10.1017/s247526220000839x.

Full text

Abstract:

Skeletal fish remains, including several vertebrae (Teleostei incertae sedis), were recovered from the core catcher section (subbottom depth, 10.5 m) of a piston core taken in the Gulf of California (28° 00.34’ N, 111° 31.32’ W; 460 m water depth). Bottom water temperatures in this area are typically less than 10°. Bone material retained original crystal morphology as well as a chemical composition consistent with hydroxyapatite. Insoluble collagen from one small bone fragment, extracted by decalcification in EDTA, was AMS radiocarbon dated at 28,070 ± 310 years b.p. (TO#2190).Proteins from ancient fish bone fragments were partitioned by sequential extraction into two soluble fractions, non-mineral-associated and mineral-associated, and an insoluble fraction. The amino acid compositions of these extracts were compared to modern fish bone extracts. Soluble fossil fish bone extracts were enriched in collagen, consistent with peptide bond cleavage in this molecule and retention of degradation products by the mineral matrix, as observed previously in other ancient bones.Three non-collagenous bone cell-produced proteins, osteocalcin, osteonectin, and bone sialoprotein, were identified immunochemically by ELISA (enzyme-linked immunosorbent assay) in the mineral-associated fraction from these ancient fish bones. The serum protein albumin was also identified immunochemically, suggesting that hydroxyapatite binding may enhance preservation of biomolecules in the fossil record. DNA, another molecule that binds to hydroxyapatite, was also observed in the mineral-associated ancient fish extract. The DNA showed signs of both in situ cleavage and complexing to an autofluorescent component that has been observed in other ancient specimens. Thus, the continuous presence of water does not by itself preclude preservation of non-collagenous proteins, insoluble collagen, or DNA in bone for tens of thousands of years. Anoxia and low temperatures afforded by burial in this basin slow molecular decay.Small animals are underrepresented in the vertebrate terrestrial fossil record primarily due to differential preservation of skeletal material. Oceanic sediments provide an underexploited source of small vertebrate remains containing molecular as well as morphological information with chronometric and systematic utility.

APA, Harvard, Vancouver, ISO, and other styles

28

Schulp, A. S., R. Schouten, L. Metten, A. van de Sande, and A. Bontenbal. "Tracking consolidant penetration into fossil bone using neutron radiography." Netherlands Journal of Geosciences - Geologie en Mijnbouw 92, no. 2-3 (September 2013): 177–80. http://dx.doi.org/10.1017/s0016774600000123.

Full text

Abstract:

AbstractIn the conservation of fragile fossil bone material, impregnation by solvent-borne consolidant is often required. Understanding the mode of penetration of consolidants into fossil bone is of crucial importance. It is governed by a variety of factors; neutron imaging is a powerful tool to monitor and visualise this penetration (non-destructively). The consolidation of a vertebrate fossil from the Maastrichtian of the southeast Netherlands was imaged at the High Flux Reactor facility at Petten, the Netherlands. The analysis shows current conservation practice to result in a sufficiently deep and isotropic penetration.

APA, Harvard, Vancouver, ISO, and other styles

29

Trueman, C. N., and N. Tuross. "Trace Elements in Recent and Fossil Bone Apatite." Reviews in Mineralogy and Geochemistry 48, no. 1 (January 1, 2002): 489–521. http://dx.doi.org/10.2138/rmg.2002.48.13.

Full text

APA, Harvard, Vancouver, ISO, and other styles

30

Thomas, Daniel B., and Anusuya Chinsamy. "Chemometric analysis of EDXRF measurements from fossil bone." X-Ray Spectrometry 40, no. 6 (October 13, 2011): 441–45. http://dx.doi.org/10.1002/xrs.1364.

Full text

APA, Harvard, Vancouver, ISO, and other styles

31

Abbott, Stephen, Erik Trinkaus, and David B. Burr. "Dynamic bone remodeling in later Pleistocene fossil hominids." American Journal of Physical Anthropology 99, no. 4 (April 1996): 585–601. http://dx.doi.org/10.1002/(sici)1096-8644(199604)99:4<585::aid-ajpa5>3.0.co;2-t.

Full text

APA, Harvard, Vancouver, ISO, and other styles

32

Burky, Richard R., Donna L. Kirner, R. E. Taylor, P. E. Hare, and John R. Southon. "14C Dating of Bone Using γ-Carboxyglutamic Acid and α-Carboxyglycine (Aminomalonate)." Radiocarbon 40, no. 1 (1997): 11–20. http://dx.doi.org/10.1017/s0033822200017823.

Full text

Abstract:

Radiocarbon determinations have been obtained on γ-carboxyglutamic acid [Gla] and α-carboxyglycine (aminomalonate) [Am] as well as acid- and base-hydrolyzed total amino acids isolated from a series of fossil bones. As far as we are aware, Am has not been reported previously in fossil bone and neither Gla nor Am 14C values have been measured previously. Interest in Gla, an amino acid found in the non-collagen proteins osteocalcin and matrix Gla-protein (MGP), proceeds from the suggestion that it may be preferentially retained and more resistant to diagenetic contamination affecting 14C values in bones exhibiting low and trace amounts of collagen. Our data do not support these suggestions. The suite of bones examined showed a general tendency for total amino acid and Gla concentrations to decrease in concert. Even for bones retaining significant amounts of collagen, Gla (and Am extracts) can yield 14C values discordant with their expected age and with 14C values obtained on total amino-acid fractions isolated from the same bone sample.

APA, Harvard, Vancouver, ISO, and other styles

33

Zougrou, I. M., M. Katsikini, F. Pinakidou, E. C. Paloura, L. Papadopoulou, and E. Tsoukala. "Study of fossil bones by synchrotron radiation micro-spectroscopic techniques and scanning electron microscopy." Journal of Synchrotron Radiation 21, no. 1 (November 2, 2013): 149–60. http://dx.doi.org/10.1107/s1600577513025228.

Full text

Abstract:

Earlymost Villafranchian fossil bones of an artiodactyl and a perissodactyl from the Milia excavation site in Grevena, Greece, were studied in order to evaluate diagenetic effects. Optical microscopy revealed the different bone types (fibro-lamellar and Haversian, respectively) of the two fragments and their good preservation state. The spatial distribution of bone apatite and soil-originating elements was studied using micro-X-ray fluorescence (µ-XRF) mapping and scanning electron microscopy. The approximate value of the Ca/P ratio was 2.2, as determined from scanning electron microscopy measurements. Bacterial boring was detected close to the periosteal region and Fe bearing oxides were found to fill bone cavities,e.g.Haversian canals and osteocyte lacunae. In the perissodactyl bone considerable amounts of Mn were detected close to cracks (the Mn/Fe weight ratio takes values up to 3.5). Goethite and pyrite were detected in both samples by means of metallographic microscopy. The local Ca/P ratio determined with µ-XRF varied significantly in metal-poor spots indicating spatial inhomogeneities in the ionic substitutions. XRF line scans that span the bone cross sections revealed that Fe and Mn contaminate the bones from both the periosteum and medullar cavity and aggregate around local maxima. The formation of goethite, irrespective of the local Fe concentration, was verified by the FeK-edge X-ray absorption fine structure (XAFS) spectra. Finally, SrK-edge extended XAFS (EXAFS) revealed that Sr substitutes for Ca in bone apatite without obvious preference to the Ca1or Ca2unit-cell site occupation.

APA, Harvard, Vancouver, ISO, and other styles

34

Cadena, Edwin. "Microscopical and elemental FESEM and Phenom ProX-SEM-EDS analysis of osteocyte- and blood vessel-like microstructures obtained from fossil vertebrates of the Eocene Messel Pit, Germany." PeerJ 4 (January 21, 2016): e1618. http://dx.doi.org/10.7717/peerj.1618.

Full text

Abstract:

The Eocene (∾48 Ma) Messel Pit in Germany is a UNESCO World Heritage Site because of its exceptionally preserved fossils, including vertebrates, invertebrates, and plants. Messel fossil vertebrates are typically characterized by their articulated state, and in some cases the skin, hair, feathers, scales and stomach contents are also preserved. Despite the exceptional macroscopic preservation of Messel fossil vertebrates, the microstructural aspect of these fossils has been poorly explored. In particular, soft tissue structures such as hair or feathers have not been chemically analyzed, nor have bone microstructures. I report here the preservation and recovery of osteocyte-like and blood vessel-like microstructures from the bone of Messel Pit specimens, including the turtlesAllaeochelys crassesculptaandNeochelys franzeni, the crocodileDiplocynodon darwini, and the pangolinEomanis krebsi. I used a Field Emission Scanning Electron Microscope (FESEM) and a Phenom ProX desktop scanning electron microscope (LOT-QuantumDesign) equipped with a thermionic CeB6 source and a high sensitivity multi-mode backscatter electron (BSE) for microscopical and elemental characterization of these bone microstructures. Osteocyte-like and blood vessel-like microstructures are constituted by a thin layer (∾50 nm thickness), external and internal mottled texture with slightly marked striations. Circular to linear marks are common on the external surface of the osteocyte-like microstructures and are interpreted as microbial troughs. Iron (Fe) is the most abundant element found in the osteocyte-like and blood vessel-like microstructures, but not in the bone matrix or collagen fibril-like microstructures. The occurrence of well-preserved soft-tissue elements (at least their physical form) establishes a promising background for future studies on preservation of biomolecules (proteins or DNA) in Messel Pit fossils.

APA, Harvard, Vancouver, ISO, and other styles

35

Arslanov, Kh A., and Yu S. Svezhentsev. "An Improved Method for Radiocarbon Dating Fossil Bones." Radiocarbon 35, no. 3 (1993): 387–91. http://dx.doi.org/10.1017/s0033822200060392.

Full text

Abstract:

We demonstrate here that the use of either the acid-alkali or Longin method alone does not fully extract contaminants from bone-collagen fractions. We present our methods and results of extracting bone collagen that involve successive use of both of these methods.

APA, Harvard, Vancouver, ISO, and other styles

36

Scheyer, Torsten M., and P. Martin Sander. "Shell bone histology indicates terrestrial palaeoecology of basal turtles." Proceedings of the Royal Society B: Biological Sciences 274, no. 1620 (May 22, 2007): 1885–93. http://dx.doi.org/10.1098/rspb.2007.0499.

Full text

Abstract:

The palaeoecology of basal turtles from the Late Triassic was classically viewed as being semi-aquatic, similar to the lifestyle of modern snapping turtles. Lately, this view was questioned based on limb bone proportions, and a terrestrial palaeoecology was suggested for the turtle stem. Here, we present independent shell bone microstructural evidence for a terrestrial habitat of the oldest and basal most well-known turtles, i.e. the Upper Triassic Proterochersis robusta and Proganochelys quenstedti . Comparison of their shell bone histology with that of extant turtles preferring either aquatic habitats or terrestrial habitats clearly reveals congruence with terrestrial turtle taxa. Similarities in the shell bones of these turtles are a diploe structure with well-developed external and internal cortices, weak vascularization of the compact bone layers and a dense nature of the interior cancellous bone with overall short trabeculae. On the other hand, ‘aquatic’ turtles tend to reduce cortical bone layers, while increasing overall vascularization of the bone tissue. In contrast to the study of limb bone proportions, the present study is independent from the uncommon preservation of appendicular skeletal elements in fossil turtles, enabling the palaeoecological study of a much broader range of incompletely known turtle taxa in the fossil record.

APA, Harvard, Vancouver, ISO, and other styles

37

Showers, William J., Bernard Genna, Reese E. Barrick, and Alfred G. Fischer. "A new method for the determination of the δ18O composition of bone phosphate: applications to the thermal physiology of vertebrates." Paleontological Society Special Publications 6 (1992): 269. http://dx.doi.org/10.1017/s2475262200008297.

Full text

Abstract:

A new method for the preparation of bone samples for δ18O-PO4 analysis has been developed. The phosphate from bone samples is separated and purified using ion exchange chromatography, and then precipitated as silver phosphate using the Firsching method. O2 is then extracted by reaction with bromine pentafluoride and converted to CO2 for isotopic analysis. Advantages of the silver phosphate technique over the bismuth phosphate technique are (1) the simplicity of the method, (2) silver phosphate is not hygroscopic so atmospheric water is not an oxygen contaminate, and (3) very small samples (2 mg to 10 mg) can be analyzed with an increase of precision compared to previous techniques. Iron and silica oxides added to Ag3PO4 standards produce no offset, which suggests that this new technique is not sensitive to interferences from cements commonly found in fossil bone material. Analyses have been performed on standards ranging in size from 30 mg to 2 mg with a σ1 of ± 0.05 per mil.The δ18O-PO4 compositional pattern of the bones of modern vertebrates have been analyzed to provide a base for the interpretation of the δ18O-PO4 pattern of fossil vertebrates. The average %PO4 in modern mammals and reptiles is approximately 15% with a σ1 of 2-3 %. The average %PO4 of fossil reptiles range from 10 to 25% with σ1 variations of up to 10%. The %PO4 variation can be related to cementation of void spaces in the bone material. XRD analysis reveals that calcite, dolomite, ankerite, and silica cements are commonly present. FTIR (Fourier Transform Infrared Spectroscopy) yields low indices calculated according to the formula of Shemesh, 1990 [GCA 54(9):2433]. Thin sections of the fossil bone material show detailed structures. All this evidence suggests that the fossil bone δ18O-PO4 composition is pristine and not altered by diagenesis. The total δ18O-PO4 σ1 variation of 10 or more skeletal elements analyzed for each individual specimen varies from 0.1 per mil for a domestic cow (Bos) to 0.8 per mil for a Komodo dragon (Varanus). Variations in between appear to be related to thermal physiology and variations in drinking water δ18O due to seasonality or migration.

APA, Harvard, Vancouver, ISO, and other styles

38

Ermatsans, I. A., Yu L. Bolotsky, I. Yu Bolotsky, and G. N. Gataulina. "Dinosaurs from the location of Gilchins vertebrates of the late Mesozoic era (Russia, Amur region)." SOCIALNO-ECOLOGICHESKIE TECHNOLOGII 9, no. 1 (2019): 9–26. http://dx.doi.org/10.31862/2500-2961-2019-9-1-9-26.

Full text

Abstract:

Currently there are six locations of Cretaceous continental fauna and flora in Amur region: Blagoveshchensk, Kundur and Astashikha, Gilchin, Dim, Bureinsky Belogory. Gilchin is the location of the Cretaceous dinosaurs, the potential of which still requires evaluation. The article provides new information about the history of its discovery, as well as the description of the fossils from the Gilchin collection presented in the exposition of the Paleontological Museum of the Amur Scientific Center of the Far East Branch of the Russian Academy of Sciences. The fauna of Gilchin, established by fossil bone remains, includes hadrosaurs, carnivorous dinosaurs, a dinosaur whose identity it is difficult to determine, and turtles (Trionychidae indet). Most of the definable bone remains of the collection belong to the hadrosaurs. In terms of preservation, the fossil material is close to that of the Chinese locations of Ulaga and Jiayin / Longu Shan. The article assumes similarity of the genesis of the locations of Gilchin and Jiayin / Longu Shan (China).

APA, Harvard, Vancouver, ISO, and other styles

39

Strydonck, Mark Van, Mathieu Boudin, and Guy De Mulder. "The Carbon Origin of Structural Carbonate in Bone Apatite of Cremated Bones." Radiocarbon 52, no. 2 (2010): 578–86. http://dx.doi.org/10.1017/s0033822200045616.

Full text

Abstract:

In order to reveal a possible carbon exchange between carbon dioxide of the fuel and the bone apatite during the cremation process an experiment was set up using fossil fuel. Two setups were constructed, one using natural gas and one using coal. In both experiments, a carbon substitution in the apatite was revealed.

APA, Harvard, Vancouver, ISO, and other styles

40

Buckley, Michael, Stacey Warwood, Bart van Dongen, Andrew C. Kitchener, and Phillip L. Manning. "A fossil protein chimera; difficulties in discriminating dinosaur peptide sequences from modern cross-contamination." Proceedings of the Royal Society B: Biological Sciences 284, no. 1855 (May 31, 2017): 20170544. http://dx.doi.org/10.1098/rspb.2017.0544.

Full text

Abstract:

A decade ago, reports that organic-rich soft tissue survived from dinosaur fossils were apparently supported by proteomics-derived sequence information of exceptionally well-preserved bone. This initial claim to the sequencing of endogenous collagen peptides from an approximately 68 Myr Tyrannosaurus rex fossil was highly controversial, largely on the grounds of potential contamination from either bacterial biofilms or from laboratory practice. In a subsequent study, collagen peptide sequences from an approximately 78 Myr Brachylophosaurus canadensis fossil were reported that have remained largely unchallenged. However, the endogeneity of these sequences relies heavily on a single peptide sequence, apparently unique to both dinosaurs. Given the potential for cross-contamination from modern bone analysed by the same team, here we extract collagen from bone samples of three individuals of ostrich, Struthio camelus . The resulting LC–MS/MS data were found to match all of the proposed sequences for both the original Tyrannosaurus and Brachylophosaurus studies. Regardless of the true nature of the dinosaur peptides, our finding highlights the difficulty of differentiating such sequences with confidence. Our results not only imply that cross-contamination cannot be ruled out, but that appropriate measures to test for endogeneity should be further evaluated.

APA, Harvard, Vancouver, ISO, and other styles

41

Cushing, John, Adrian M. Wenner, Elmer Noble, and Marla Daily. "A Groundwater Hypothesis for the Origin of “Fire Areas” on the Northern Channel Islands, California." Quaternary Research 26, no. 2 (September 1986): 207–17. http://dx.doi.org/10.1016/0033-5894(86)90105-5.

Full text

Abstract:

Pleistocene areas of red sediments and carbonized vegetation on the Northern Channel Islands, California, have in the past been interpreted as caused by fires of either natural or human origin. Some are associated with darkened mammoth and bird fossils, and these fossils have been considered as having been burned by early man. Reevaluation of these so-called “fire areas” indicates that the above phenomena are the result of low-temperature (≤100°C), nonheating processes occurring in groundwater. Evidence for this conclusion is derived from field observations on fossil carbonized vegetation, and the geology of the areas. Additional evidence derives from experiments on the red sediments and fossil wood, X-ray diffraction analyses, magnetic analyses, studies on the clay minerals smectite and illite, and the demonstration that fossil mammoth bone contains sufficient Fe and Mn to account for their discoloration. Much of the carbonization of vegetation probably occurred in water rather than in fire. Radiocarbon dates from the islands will probably need to be reevaluated. These data provide evidence contrary to the concept of the occurrence of significant fires, either natural or set by early man, on the Northern Channel Islands.

APA, Harvard, Vancouver, ISO, and other styles

42

Silaev, V. I., D. V. Ponomarev, S. N. Shanina, I. V. Smoleva, E. M. Tropnikov, and A. F. Khazov. "Current research of fossil bone detritus: paleontology, mineralogy, geochemistry." Vestnik of Institute of Geology of Komi Science Center of Ural Branch RAS 5 (2016): 19–31. http://dx.doi.org/10.19110/2221-1381-2016-5-19-31.

Full text

APA, Harvard, Vancouver, ISO, and other styles

43

Gauld, Suellen C. "Allometric patterns of cranial bone thickness in fossil hominids." American Journal of Physical Anthropology 100, no. 3 (July 1996): 411–26. http://dx.doi.org/10.1002/(sici)1096-8644(199607)100:3<411::aid-ajpa8>3.0.co;2-w.

Full text

APA, Harvard, Vancouver, ISO, and other styles

44

Ksepka, Daniel T., Sarah Werning, Michelle Sclafani, and Zachary M. Boles. "Bone histology in extant and fossil penguins (Aves: Sphenisciformes)." Journal of Anatomy 227, no. 5 (September 11, 2015): 611–30. http://dx.doi.org/10.1111/joa.12367.

Full text

APA, Harvard, Vancouver, ISO, and other styles

45

Gurley, L. R., J. G. Valdez, W. D. Spall, B. F. Smith, and D. D. Gillette. "Proteins in the fossil bone of the dinosaur, seismosaurus." Journal of Protein Chemistry 10, no. 1 (February 1991): 75–90. http://dx.doi.org/10.1007/bf01024658.

Full text

APA, Harvard, Vancouver, ISO, and other styles

46

Rae, Angela M., and Miro Ivanovich. "Successful application of uranium series dating of fossil bone." Applied Geochemistry 1, no. 3 (May 1986): 419–26. http://dx.doi.org/10.1016/0883-2927(86)90026-0.

Full text

APA, Harvard, Vancouver, ISO, and other styles

47

Schoeninger, Margaret J., Katherine M. Moore, Matthew L. Murray, and John D. Kingston. "Detection of bone preservation in archaeological and fossil samples." Applied Geochemistry 4, no. 3 (May 1989): 281–92. http://dx.doi.org/10.1016/0883-2927(89)90030-9.

Full text

APA, Harvard, Vancouver, ISO, and other styles

48

Rae, Angela, Robert E. M. Hedges, and Miro Ivanovich. "Further studies for uranium-series dating of fossil bone." Applied Geochemistry 4, no. 3 (May 1989): 331–37. http://dx.doi.org/10.1016/0883-2927(89)90038-3.

Full text

APA, Harvard, Vancouver, ISO, and other styles

49

Kiel, S., J. L. Goedert, W. A. Kahl, and G. W. Rouse. "Fossil traces of the bone-eating worm Osedax in early Oligocene whale bones." Proceedings of the National Academy of Sciences 107, no. 19 (April 27, 2010): 8656–59. http://dx.doi.org/10.1073/pnas.1002014107.

Full text

APA, Harvard, Vancouver, ISO, and other styles

50

Canoville, Aurore, Mary H. Schweitzer, and Lindsay Zanno. "Identifying medullary bone in extinct avemetatarsalians: challenges, implications and perspectives." Philosophical Transactions of the Royal Society B: Biological Sciences 375, no. 1793 (January 13, 2020): 20190133. http://dx.doi.org/10.1098/rstb.2019.0133.

Full text

Abstract:

Medullary bone (MB) is a sex-specific tissue produced by female birds during the laying cycle, and it is hypothesized to have arisen within Avemetatarsalia, possibly outside Avialae. Over the years, researchers have attempted to define a set of criteria from which to evaluate the nature of purported MB-like tissues recovered from fossil specimens. However, we argue that the prevalence, microstructural and chemical variability of MB in Neornithes is, as of yet, incompletely known and thus current diagnoses of MB do not capture the extent of variability that exists in modern birds. Based on recently published data and our own observations of MB distribution and structure using computed tomography and histochemistry, we attempt to advance the discourse on identifying MB in fossil specimens. We propose: (i) new insights into the phylogenetic breadth and structural diversity of MB within extant birds; (ii) a reevaluation and refinement of the most recently published list of criteria suggested for confidently identifying MB in the fossil record; (iii) reconsideration of some prior identifications of MB-like tissues in fossil specimens by taking into account the newly acquired data; and (iv) discussions on the challenges of characterizing MB in Neornithes with the goal of improving its diagnosis in extinct avemetatarsalians. This article is part of the theme issue ‘Vertebrate palaeophysiology’.

APA, Harvard, Vancouver, ISO, and other styles

Journal articles on the topic 'Fossil bone'

Create a spot-on reference in APA, MLA, Chicago, Harvard, and other styles