Fossil Samples Research Articles

The enamel characteristics of fossil and modern first lower molars of the European water vole (Arvicola amphibius, Arvicolinae, Rodentia) of the Perm Pre-Urals

This article presents data on the enamel characteristics (thickness, enamel differentiation coefficient (SDQ)) of the first lower molars of the European water vole (based on the conditional groups “juvenile” and “adult”) from fossil and modern samples from the Perm Pre-Urals (Russia). Among the “adult” group teeth, samples from the Eemian (Mikulino) interglacial deposits had the highest mean SDQ values (91.5–94.8), while samples from the end of the Bryansk Interstadial, the Late Glacial, the Early Holocene deposits had the lowest (76.3–84.9).

Early Pleistocene amphibians and squamates from Copăceni (Dacian Basin, southern Romania)

This paper describes an Early Pleistocene amphibian and squamate assemblage from the Dacian Basin, southern Romania. The fossil sample allows for the identification of a moderately diverse assemblage, which includes representatives of 13 genera of the families Salamandridae (Lissotriton vulgaris, Triturus sp.), Bombinatoridae (Bombina sp.), Hylidae (Hyla aff. Hyla arborea), Bufonidae (Bufo bufo), Pelobatidae (Pelobates syriacus), Ranidae (Ranidae indet., Pelophylax sp., Rana ?temporaria, Rana sp.), Lacertidae (Lacertidae indet.), Anguidae (Pseudopus sp.), Natricidae (Natrix natrix), and Colubridae (Coronella austriaca, Zamenis longissimus). The taxonomic composition of the Early Pleistocene amphibian and squamate assemblage from Copăceni is similar to the one reported from other Romanian sites of the same age, and also to that of Recent Romanian herpetofaunas. The amphibian and squamate assemblage from Copăceni supports the existence of a permanent freshwater body, of neighbouring forests or shrubberies, and thick soil, in an Early Pleistocene climate that was warmer than the present one.

Tooth chipping prevalence and patterns in extant primates.

A tooth chip occurs when a hard object forcefully contacts the surface of the tooth, typically removing enamel from the occlusal edge. In this study, chipping patterns in extant primates were compared, and hard-object-feeding assessed alongside other factors (e.g., grit mastication and dental properties), to elucidate dietary and behavioral inferences in archeological and paleontological samples. Thirteen species of extant primates were studied, including eight species within the Cercopithecidae, two within the Ceboidea, and three within the Hominoidea. Four additional species were also incorporated from the literature for some of the analyses. The severity (Grade 1-3), position (buccal, lingual, mesial, and distal) and number of tooth fractures were recorded for each specimen. Species considered hard-object-feeding specialists presented higher rates of chipping, with sakis, mandrills, sooty mangabeys and Raffles' banded langurs having high chipping rates (28.3%, 36.7%, 48.4%, and 34.7% of teeth, respectively). Species that seasonally eat harder foods had intermediate chipping frequencies (e.g., brown woolly monkeys: 18.5%), and those that less commonly consume hard food items had the lowest chipping frequencies (e.g., Kloss gibbon: 7.3%; chimpanzees: 4.4%). The results suggest hard food mastication influences differences in chipping prevalence among the species studied. Although Homo fossil samples show high rates of chipping comparable to hard-object-feeding extant primates, they display a different pattern of chipping, supporting the hypothesis that these fractures are mostly non-food related (e.g., grit mastication in Homo naledi; non-masticatory tooth use in Neanderthals).

Endocranial Cast Anatomy of the Extinct Hipposiderid Bats Palaeophyllophora and Hipposideros (Pseudorhinolophus) (Mammalia: Chiroptera)

Bat fossil endocasts have been little studied in the literature (nine published works, only one in the XXIth century), and macromorphology of the brain of extant bats has only been characterized at the family-level. We describe here in detail the endocranial casts of four fossil hipposiderid species based on μCT-scans data and propose a revised nomenclature of the hipposiderid brain structures that leave their imprint on endocranial casts. Exhaustive comparisons of the external morphology of our fossil cranial endocast sample allow us to discuss the distribution of both qualitative and quantitative features in this family for different epochs. A conservatism of the brain is considered to be the rule during bats evolution. Indeed, we found that encephalization did not increase since the Eocene in hipposiderid bats (contrary to other mammals) and that macromorphology of the brain is close between Paleogene, Miocene, and extant hipposiderid species. However, subtler but promising fine anatomical characters might allow distinguishing genera and species. Eventually, expanding the fossil sample and/or adding extant species could shake the paradigm of temporal homogeneity and bring new light on the morpho-anatomical evolutionary history of Hipposideridae.

Isotopic calcium biogeochemistry of MIS 5 fossil vertebrate bones: application to the study of the dietary reconstruction of Regourdou 1 Neandertal fossil

The calcium isotopic composition (δ44/42Ca) of bone and tooth enamel can be used for dietary reconstructions of extant and extinct mammals. In natural conditions, the δ44/42Ca value of bone and teeth varies according to dietary intake with a constant isotopic offset of about −0.6‰. Owing to the poor conservation of collagen, carbon (C), and nitrogen (N) isotopic compositions of the Regourdou Mousterian site (MIS 5, Dordogne, France) previously failed to provide any paleodietary information. Therefore, to reconstruct the trophic chain, we have measured calcium (Ca) isotopes from fossil bone samples of the fauna from the Regourdou site, as well as from three bone samples of the Regourdou 1 Neandertal specimen. The results show a taxon-dependent patterning of the Ca isotopic compositions: herbivores generally have higher δ44/42Ca values than carnivores. All the δ44/42Ca values of Regourdou 1 are low (<-1.6‰), placing this specimen amid carnivores. Using a bone-muscle Ca isotopic offset determined on extant animals, we further show that the δ44/42Ca value of the Regourdou 1 diet, and that of most carnivores, cannot be accounted for by the consumption of meat only, as plants and meat have indistinguishable δ44/42Ca values. Mass balance calculations indicate that the low δ44/42Ca values of the Neandertal's carnivorous diet are explained by the ingestion of bone marrow containing as little as 1% trabecular bone. Our results show that the Regourdou 1 Neanderthal consumed a mixture of various herbivorous prey, as well as trabecular bone, which probably occurred when marrow was ingested, by accident or intentionally.

ОБ ИСТОЧНИКАХ ИЗУЧЕНИЯ ЛЯОНИНСКОГО ПАЛЕОНТОЛОГИЧЕСКОГО МУЗЕЯ

The article covers a poorly studied topic about the sources of museum science study. The authors of the article rely on the prominent Russian researcher S.O. Schmidt’ opinion that the elaboration of source study is a guarantor of the accuracy of historical knowledge. They used Schmidt's scientific classification of sources and applied it to identifying and systematizing the sources of study of Liaoning Paleontological Museum in China. The article deals with such typological groups of sources as written, material, visual and electronic sources. The group of written sources includes legislative acts and documents of office-work. Such important act documents as the Constitution of the People's Republic of China, the Law of the People's Republic of China on the Protection of Cultural Relics contain the information on museum work and protection of cultural values. Orders and resolutions of the State Council of the People's Republic of China, and the Ministry of Culture of the People's Republic of China, and the National Administration of Cultural Heritage Regulations include this information as well. The administrative documents of the leadership of Shenyang Pedagogical University, in which the Liaoning Paleontological Museum was opened in 2011, have no small importance too. The Charter of the Academic Committee of the Liaoning Paleontological Museum has direct relation to the creation and activities of the museum at Shenyang University. Documents of officework were deposited in the archival funds of the Liaoning Museum. They include planning materials, and reports on the activities of the museum departments. The reports on the search and conservation of fossils, on work with museum visitors, on cooperation between the museum and schools in Liaoning Province contain an important information about Liaoning Museum. The article characterizes a group of material sources that play a major role in the formation of the source base for Liaoning Museum study. These are paleontological fossils – samples of flora and fauna of antiquity. The museum contains 30158 paleontological fossils. The author reported that 707 fossils are of unique scientific value and are authentic sources of study of the museum. Visual sources include photographs, restoration drawings and sculptures made of resin of fossil samples. These historical monuments are used in the museum exposition; contain important information about the activities of the museum. Electronic sources and multimedia resources are created in order to popularize scientific knowledge about the ancient world of China, they are used in working with visitors, contain important information about the museum and its collections. The identified and characterized sources have a high degree of reliability, they are distinguished by information saturation. They provide a solid documentary base for the study of the Liaoning Paleontological Museum.

Coleção científica de Paleontologia e a capacidade de comunicação de um blog sobre a disciplina

To enhance the teaching of Paleontology, due to the lack of tools to assist it in the undergraduate course in Geology at the Federal University of Uberlândia, Brazil, we developed a blog using the existing resources on a free online platform, as well as additional features developed in HTML, CSS, and JavaScript languages. To accomplish this task, the fossil samples from the Laboratory of Stratigraphic Paleontology (LAPE) of the Federal University of Uberlândia, Monte Carmelo Campus needed to be identified, recorded, grouped according to taxonomic proximity, and analyzed quantitatively and qualitatively. We evaluated the communication capacity of the tool to reach the most diverse readers, according to statistical data provided internally by the platform, highlighting the moment of social distancing caused by the COVID-19 Pandemic.

Low-frequency integrated radio spectra of diffuse, steep-spectrum sources in galaxy clusters: palaeontology with the MWA and ASKAP

AbstractGalaxy clusters have been found to host a range of diffuse, non-thermal emission components, generally with steep, power law spectra. In this work we report on the detection and follow-up of radio halos, relics, remnant radio galaxies, and other fossil radio plasmas in Southern Sky galaxy clusters using the Murchison Widefield Array and the Australian Square Kilometre Array Pathfinder. We make use of the frequency coverage between the two radio interferometers—from 88 to$\sim\!900$MHz—to characterise the integrated spectra of these sources within this frequency range. Highlights from the sample include the detection of a double relic system in Abell 3186, a mini-halo in RXC J0137.2–0912, a candidate halo and relic in Abell 3399, and a complex multi-episodic head-tail radio galaxy in Abell 3164. We compare this selection of sources and candidates to the literature sample, finding sources consistent with established radio power–cluster mass scaling relations. Finally, we use the low-frequency integrated spectral index,$\alpha$($S_v \propto v^\alpha$), of the detected sample of cluster remnants and fossil sources to compare with samples of known halos, relics, remnants and fossils to investigate a possible link between their electron populations. We find the distributions of$\alpha$to be consistent with relic and halo emission generated by seed electrons that originated in fossil or remnant sources. However, the present sample sizes are insufficient to rule out other scenarios.

Frontal bone virtual reconstruction and geometric morphometric analysis of the mid-Pleistocene hominin KNM-OG 45500 (Olorgesailie, Kenya).

KNM-OG 45500 is a hominin fossil composed of parts of a frontal bone, left temporal bone, and cranial vault pieces. Since its discovery along the Olorgesailie Formation (Kenya) in 2003, it has been associated with the Homo erectus hypodigm. The specimen, derived from a geological context dated to ca. 900 Ka BP, has been described as a very small individual of probable female sex. However, despite its status as an important hominin specimen, it has not been used in a quantitative comparative framework because of its fragmentary condition. Here, we undertake a virtual reconstruction of the better-preserved fragment, the frontal bone. We additionally apply geometric morphometric analyses, using a geographically diverse fossil and modern human sample, in order to investigate the morphological affinities of KNM-OG 45500. Our results show that the frontal shape of KNM-OG 45500 exhibits similarities with Early Pleistocene fossils from Eurasia and Africa that are assigned to H. erectus sensu lato (s.l.). Its size, on the other hand, is notably smaller than most other Homo erectus fossils and modern humans and similar to the specimens from Dmanisi (Georgia) and to Homo naledi. Taken together, our analyses of the frontal bone suggest a taxonomic attribution of KNM-OG 45500 to H. erectus s.l. and extend even further the range of size variability associated with this taxon around 900 Ka BP.

The age of the Palaeolithic sedimentary layer of Hyangmokri cave site in the democratic People’s Republic of Korea

Hyangmokri cave site was newly excavated in Kangdong County, Pyongyang City a few years ago. The sedimentary deposits in the cave consist of seven different layers. According to the composition of sediments and features of archaeological finds, it is clear that Layers 4 and 5 are of the late Palaeolithic, Layer 6 is of the Neolithic and Layer 7 is of the Bronze Age. We determined dates of some samples from Layer 4 by using thermoluminscence (TL) and electron spin resonance (ESR) dating. We found out by using TL method that three calcite samples from Layer 4 date back to 34,780 ± 3,890, 31,490 ± 3,930 and 36,020 ± 4,160a respectively, while ESR ages of three bear fossil tooth enamel samples from Layer 4 are 35,680 ± 3,860, 31,910 ± 3,430 and 34,700 ± 3,760a respectively. There is good agreement between morphological research on archaeological finds and chronological research on several samples collected from Layer 4, the first sedimentary layer which contained lots of relics.

Biominerals Fossilisation: Fish Bone Diagenesis in Plio–Pleistocene African Hominid Sites of Malawi

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.

Elucidation of the macromolecular composition of fossil biopolymers using Py-GC×GC-TOFMS

In recent times, the limits of traditional Py-GC-MS techniques in evaluating the macromolecular compositions of biopolymers have proved to be more apparent – particularly in those samples containing complex, structurally similar organic molecules, often producing large areas of unresolved complex mixtures (UCM). In this paper, we compare the use of pyrolysis comprehensive two-dimensional gas chromatography coupled with time-of-flight mass spectrometry (Py-GC×GC-TOFMS) with conventional Py-GC-MS analyses and attempt to showcase the full potential of this technique by analyzing different fossil organic materials – algal-derived Tasmanites, Ordovician microfossil Gloeocapsomorpha prisca and terrestrial plant-derived resin. With all three fossil samples, Py-GC×GC-TOFMS was able to offer a higher degree of compound separation and detection of more complex compounds. Sulphur and oxygen-bearing polar compounds were clearly separated into different homologous series. Thus, this method bypassed the problem created by the UCMs in traditional Py-GC-MS in the case of G. prisca and Tasmanites, while resolving several biomarkers in the case of the resin which aided chemotaxonomic classification. We find that Py-GC×GC-TOFMS provides a greater variety of compounds at enhanced resolution levels than conventional Py-GC-MS methods and is more suited to analyzing samples with larger variety of chemical structures and functional groups with greater confidence, particularly in unknown samples. It can thus provide the analytical capability to better characterize the chemistry of kerogens, which will help in assessments of hydrocarbon source properties and may provide new avenues to interpretation in paleobiological studies.

First data on the structure of tubes formed by phoronids

Phoronids are marine benthic animals that live in tubes in soft sediment or hard substrata; the phoronids form the tubes by digging or boring. Epidermal glands produce much of the material of the tube, which is completely imbedded in the soft sediment or hard substrata. The structure of phoronid tubes has not been previously studied in detail. In the current research, the morphology and microstructure of the tubes were studied by light microscopy, histology, and scanning electron microscopy for the following species: Phoronis ijimai, Phoronis svetlanae, Phoronis hipporcrepia, Phoronis australis, and Phoronopsis harmeri. In most of these species, the tube consists of an inner organic cylinder and an external layer. The inner organic cylinder is formed by three layers (inner, middle, and outer) of thin films. Each film is formed by fibers, whose thickness differs in different species. These fibers form a net, whose density is higher in digging phoronids than in boring phoronids. The middle layer is formed by highly compressed thin films. The outer layer is the densest portion of the inner cylinder and is associated with the external layer. The external layer is absent in some species (P. australis) but is well developed in digging phoronids. The differences in the organization of tube are consistent with the biology of each species and depend on the type of substrata and on the life style of the animal. Tube organization substantially differs between phoronids and sedentary annelids: the inner organic cylinder is much thicker in phoronid than in annelid tubes, and the fibers that form films are randomly oriented in phoronids but regularly oriented in annelids. In annelids but not in phoronids, inorganic particles in the external layer are usually surrounded and glued together by organic material. These differences may be used to distinguish phoronid tubes from annelid tubes in present-day benthic samples and also in fossil samples.

Taxonomic differences in deciduous lower first molar crown outlines of Homo sapiens and Homo neanderthalensis

Recent studies have demonstrated that the outline shapes of deciduous upper and lower second molars and the deciduous upper first molar are useful for diagnosing hominin taxa—especially Homo neanderthalensis and Homo sapiens. Building on these studies, we use geometric morphometric methods to assess the taxonomic significance of the crown outline of the lower first deciduous molar (dm1). We test whether the crown shape of the dm1 distinguishes H. neanderthalensis from H. sapiens and explore whether dm1 crown shape can be used to accurately assign individuals to taxa. Our fossil sample includes 3 early H. sapiens, 7 Upper Paleolithic H. sapiens, and 13 H. neanderthalensis individuals. Our recent human sample includes 103 individuals from Africa, Australia, Europe, South America, and South Asia. Our results indicate that H. neanderthalensis dm1s cluster fairly tightly and separate well from those of Upper Paleolithic H. sapiens. However, we also found that the range of shapes in the recent human sample completely overlaps the ranges of all fossil samples. Consequently, results of the quadratic discriminant analysis based on the first 8 principal components (PCs) representing more than 90% of the variation were mixed. Lower dm1s were correctly classified in 87.3% of the individuals; the combined H. sapiens sample had greater success (90.2%) in assigning individuals than did the H. neanderthalensis sample (61.5%). When the analysis was run removing the highly variable recent human sample, accuracy increased to 84.6% for H. neanderthalensis, and 57.1% of Upper Paleolithic H. sapiens were classified correctly by using the first 4 PCs (70.3%). We conclude that caution is warranted when assigning isolated dm1 crowns to taxa; while an assignment to H. neanderthalensis has a high probability of being correct, assignment to Upper Paleolithic H. sapiens is less certain.

A Total-Evidence Dated Phylogeny of Echinoidea Combining Phylogenomic and Paleontological Data.

Phylogenomic and paleontological data constitute complementary resources for unraveling the phylogenetic relationships and divergence times of lineages, yet few studies have attempted to fully integrate them. Several unique properties of echinoids (sea urchins) make them especially useful for such synthesizing approaches, including a remarkable fossil record that can be incorporated into explicit phylogenetic hypotheses. We revisit the phylogeny of crown group Echinoidea using a total-evidence dating approach that combines the largest phylogenomic data set for the clade, a large-scale morphological matrix with a dense fossil sampling, and a novel compendium of tip and node age constraints. To this end, we develop a novel method for subsampling phylogenomic data sets that selects loci with high phylogenetic signal, low systematic biases, and enhanced clock-like behavior. Our results demonstrate that combining different data sources increases topological accuracy and helps resolve conflicts between molecular and morphological data. Notably, we present a new hypothesis for the origin of sand dollars, and restructure the relationships between stem and crown echinoids in a way that implies a long stretch of undiscovered evolutionary history of the crown group in the late Paleozoic. Our efforts help bridge the gap between phylogenomics and phylogenetic paleontology, providing a model example of the benefits of combining the two. [Echinoidea; fossils; paleontology; phylogenomics; time calibration; total evidence.].

A late Neanderthal tooth from northeastern Italy

The site of Riparo Broion (Vicenza, northeastern Italy) preserves a stratigraphic sequence documenting the Middle-to-Upper Paleolithic transition, in particular the final Mousterian and the Uluzzian cultures. In 2018, a human tooth was retrieved from a late Mousterian level, representing the first human remain ever found from this rock shelter (Riparo Broion 1). Here, we provide the morphological description and taxonomic assessment of Riparo Broion 1 with the support of classic and virtual morphology, 2D and 3D analysis of the topography of enamel thickness, and DNA analysis. The tooth is an exfoliated right upper deciduous canine, and its general morphology and enamel thickness distribution support attribution to a Neanderthal child. Correspondingly, the mitochondrial DNA sequence from Riparo Broion 1 falls within the known genetic variation of Late Pleistocene Neanderthals, in accordance with newly obtained radiocarbon dates that point to approximately 48 ka cal BP as the most likely minimum age for this specimen. The present work describes novel and direct evidence of the late Neanderthal occupation in northern Italy that preceded the marked cultural and technological shift documented by the Uluzzian layers in the archaeological sequence at Riparo Broion. Here, we provide a new full morphological, morphometric, and taxonomic analysis of Riparo Broion 1, in addition to generating the wider reference sample of Neanderthal and modern human upper deciduous canines. This research contributes to increasing the sample of fossil remains from Italy, as well as the number of currently available upper deciduous canines, which are presently poorly documented in the scientific literature.

Temporal lobe evolution in Javanese Homo erectus and African Homo ergaster: Inferences from the cranial base

Increased brain size is a characteristic of the Homo erectus hypodigm compared to early fossil hominins with changes in cerebral reorganization of evolutionary importance for the genus Homo. The close spatial proximity of the temporal lobes of the brain to the cranial base, specifically, the middle cranial fossa (MCF), provides inference of temporal lobe evolution. To date, differences in MCF proportions and relative scaling in the H. erectus hypodigm compared to extant Homo sapiens is unknown. A total sample (n = 51) of cranial Computed Tomography scans (CT) from extant H. sapiens and fossil specimens attributed to African Homo ergaster and Javanese H. erectus were generated into three-dimensional (3D) virtual models with three linear metrics digitally measured on the MCF and two metrics to approximate cranial size. Reduced Major Axis (RMA) log-log regressions and resampling with permutations determined if relative MCF scaling in the fossil sample was greater than observed among extant H. sapiens. An increase or decrease in MCF proportions in the fossil sample compared to extant H. sapiens was used to determine potential changes in temporal lobe size. There were no differences in the allometric trend of relative MCF scaling with no statistically significant differences suggesting that the fossil sample were beyond the range observed for extant H. sapiens, but the effects of the small fossil sample size could not be excluded. However, relative MCF proportions showed extant H. sapiens had a larger MCF to relative to cranial size, while specimens attributed to Javanese H. erectus which had a relatively longer and wider MCF compared to African H. ergaster. These findings indicate that despite sampling limitations, the fossil sample did not show differences in allometric scaling compared to extant H. sapiens, but these specimens attributed to Javanese H. erectus and African H. ergaster share the same total cranial size but had different MCF proportions relative to cranial size. The paleoneurological implications are that these specimens attributed to Javanese H. erectus had longer and wider temporal lobes relative to total brain size compared to African H. ergaster suggesting different patterns of cerebrocranial organization within the Homo erectus hypodigm.

Mammal functional diversity and habitat heterogeneity: Implications for hominin habitat reconstruction

Hominin habitats are frequently described as ‘mosaic’ based on interpretations of fossil assemblages comprising taxa with divergent functional adaptations (e.g., both grazers and browsers). This interpretation rests on an assumption that mammal functional diversity is positively associated with habitat heterogeneity. We test this assumption using modern mammal data for 141 sites in Africa. Species average body mass and locomotor and dietary information was compiled for all species >500 g. The functional diversity of each species assemblage was measured using five metrics: locomotor richness, trophic richness, functional richness, functional divergence, and functional evenness. We used a high-resolution woody cover estimate for sub-Saharan Africa to compute the coefficient of variation of percentage of woody cover for each site. We used a published land cover classification to compute the number of habitat patches and the number of distinct habitat types at each site. Multiple regressions were conducted at 9 different spatial resolutions (pixel size ranging from 100 m to 30 km) to explore the relationship between functional diversity and habitat heterogeneity metrics. The overall number of species found at a site is strongly positively associated with functional richness, locomotor richness, and trophic richness at all spatial resolutions. The number of habitat types at a site and the density of habitat patches show a modest positive relationship with most functional diversity metrics at most spatial resolutions. The coefficient of variation in woody cover is a very poor predictor of functional diversity. The locomotor and trophic richness of mammal communities are positively associated with habitat heterogeneity and may be useful for reconstructing aspects of heterogeneity at hominin sites. However, the overall number of species is an important confounding variable, which in turn depends on the sample size of the overall fossil sample. Researchers should carefully consider impacts of sample size on faunal reconstructions of habitat heterogeneity.

Human manual distal phalanges from the Middle Stone Age deposits of Klasies River Main Site, Western Cape Province, South Africa

Two new distal manual phalanges from the Middle Stone Age deposits of Klasies River Main Site are described. One (SAM-AP 6387) likely derives from ray II or ray III, whereas the other (SAM-AP 6388) is from the thumb. Both derive from a late adolescent or fully adult individual. They were recovered by H. Deacon from the same stratigraphic unit (submember W or possibly submember R) of the Shell and Sand Member of Cave 1, which places them between 100 and 90 ka. Both are comparatively small elements, and the possibility that they came from the same hand cannot be discounted at this time. These bones add to the meager and all too fragmentary postcranial human fossil sample from the Late Pleistocene of South Africa. These two specimens provide some additional evidence pertaining to the morphological attributes of the distal phalanges of the Middle Stone Age inhabitants of South Africa. Together with the distal pollical phalanx from Die Kelders (SAM-AP 6402), they are relatively small in comparison with homologs from recent human samples as well as Late Pleistocene specimens from Eurasia. Given their small sizes, the distal pollical phalanges from Klasies and Die Kelders are not dissimilar to Holocene Khoesan homologs. As expected, the Klasies elements differ noticeably from Neandertal homologs, especially in the narrowness of their shafts and distal tuberosities.

Composition and radioactivity of Oligocene fossil bones and their country rocks in Gabal Qatrani, Fayoum, Egypt

Several pieces of fossil bones of scute (scutum), shells, teeth, ribs, and vertebra belonging to turtle, crocodile, hippo, and other unidentified mammals were collected from the Oligocene Qatrani Formation, Fayoum, Egypt. Natural radioactivity was measured to all samples of the country rocks (mainly sandstone, calcareous muddy sandstone and dolostone), in addition to the bone samples. Petrographic examination, XRD, SEM, and complete chemical analyses were done with an emphasis on the more radioactive samples that comprise both fossil bone samples and dolostone. The main mineral composition of these bones is carbonate fluorapatite (francolite), while dolostone consists of microcrystalline dolomite, which is cemented by gypsum and/or silica. The complete chemical analysis indicates that Ca and P are the main components of fossil bone. The high content of the redox-sensitive elements such as Cu, Zn, Se, Mo, Cd, Sn, and Pb is a diagnostic feature of the fossil bones. The total rare earth elements (REE) in fossil bones ranges between 635 and 4984 ppm but decreases to 90 ppm in the dolostone bed. The high content of the REE in fossil bones seems to be a result of interaction with fluids that were heated by the thermal gradients prevailed during the Oligocene volcanic eruptions. The available data indicate that the fossil bones are more enriched in their uranium contents (from 42 to 457 ppm), while the contents in the country rocks include the dolostone range from 1 to 31 ppm. The fraction of heavy minerals of the studied sandstone is generally enriched in magnetite, ilmenite, and leucoxene as opaques especially magnetite and ilmenite (> 50%) and contains a wide variety of non-opaques such as zircon, rutile, garnet, and kyanite among others. These non-opaque minerals have variable but insignificant impacts on the REE pattern and the natural radioactivity of the bone-bearing sediments.