Animal Fossils Research Articles

Restoring Maximum Vertical Browsing Reach in Sauropod Dinosaurs.

The ongoing controversy centered on neck posture and function in sauropod dinosaurs is misplaced for a number of reasons. Because of an absence of pertinent data it is not possible to accurately restore the posture and range of motion in long necked fossil animals, only gross approximations are possible. The existence of a single "neutral posture" in animals with long, slender necks may not exist, and its relationship to feeding habits is weak. Restorations of neutral osteological neck posture based on seemingly detailed diagrams of cervical articulations are not reliable because the pictures are not sufficiently accurate due to a combination of illustration errors, and distortion of the fossil cervicals. This is all the more true because fossil cervical series lack the critical inter-centra cartilage. Maximum vertical reach is more readily restorable and biologically informative for long necked herbivores. Modest extension of 10° between each caudal cervical allowed high shouldered sauropods to raise the cranial portion of their necks to vertical postures that allowed them to reach floral resources far higher than seen in the tallest mammals. This hypothesis is supported by the dorsally extended articulation of the only known co-fused sauropod cervicals. Many sauropods appear to have been well adapted for rearing in order to boost vertical reach, some possessed retroverted pelves that may have allowed them to walk slowly while bipedal. A combination of improved high browsing abilities and sexual selection probably explains the unusually long necks of tall ungulates and super tall sauropods. Anat Rec, 2017. © 2017 Wiley Periodicals, Inc. Anat Rec, 300:1802-1825, 2017. © 2017 Wiley Periodicals, Inc.

On the Late Pliocene stone tools of the Quranwala Zone, north-west sub-Himalayas, India

A recent study of the Quranwala Zone (QZ) of the north-west sub-Himalayas, India, presents evidence for anthropic activity during the Pliocene that includes a number of stone tools found in association with fossil animal bones with cut marks. Based on the date of the Pliocene rock outcrop, the tools and bones are suggested to date from 2.6 Ma (Gaillard et al. 2016). There is, however, a question mark over the context of these tools within an outcrop of Pliocene rocks and, hence, over the date of these tools and the fossil bones. The trench from which they were excavated at Masol 2 (Gaillard et al.2016: fig. 3) lies in a depression at the bottom of a slope; the description provided in section 2 of the paper by Gaillard et al. (2016) suggests that the stone tools may not have been in situ within the Pliocene levels, but had accumulated there and were mixed with the fragments of fossil bone due to geological processes. Moreover, many of the stone tools, such as the ‘simple choppers’ found in association with the fossil animal bones (Gaillard et al.2016: figs 6, 8, 9), are usually found on much more recent sites and are therefore unlikely to date from 2.6 Ma.

Plate tectonic regulation of global marine animal diversity

Valentine and Moores [Valentine JW, Moores EM (1970) Nature 228:657-659] hypothesized that plate tectonics regulates global biodiversity by changing the geographic arrangement of continental crust, but the data required to fully test the hypothesis were not available. Here, we use a global database of marine animal fossil occurrences and a paleogeographic reconstruction model to test the hypothesis that temporal patterns of continental fragmentation have impacted global Phanerozoic biodiversity. We find a positive correlation between global marine invertebrate genus richness and an independently derived quantitative index describing the fragmentation of continental crust during supercontinental coalescence-breakup cycles. The observed positive correlation between global biodiversity and continental fragmentation is not readily attributable to commonly cited vagaries of the fossil record, including changing quantities of marine rock or time-variable sampling effort. Because many different environmental and biotic factors may covary with changes in the geographic arrangement of continental crust, it is difficult to identify a specific causal mechanism. However, cross-correlation indicates that the state of continental fragmentation at a given time is positively correlated with the state of global biodiversity for tens of millions of years afterward. There is also evidence to suggest that continental fragmentation promotes increasing marine richness, but that coalescence alone has only a small negative or stabilizing effect. Together, these results suggest that continental fragmentation, particularly during the Mesozoic breakup of the supercontinent Pangaea, has exerted a first-order control on the long-term trajectory of Phanerozoic marine animal diversity.

Bulldozers threaten what may be the world’s oldest animal fossils

Bulldozers threaten what may be the world’s oldest animal fossils

Early animal fossils at risk.

Mining operation in China threatens fossils and embryos that may be the oldest known animals.

High-latitude settings promote extreme longevity in fossil marine bivalves

AbstractOne of the longest-lived, noncolonial animals on the planet today is a bivalve that attains life spans in excess of 500 years and lives in a cold, seasonally food-limited setting. Separating the influence of temperature and food availability on life span in modern settings is difficult, as these two conditions covary. The life spans of fossil animals can provide insights into the role of environment in the evolution of extreme longevity that are not available from studies of modern taxa. We examine bivalves from the unique, nonanalogue, warm and high-latitude setting of Seymour Island, Antarctica, during the greenhouse intervals of the Late Cretaceous and Paleogene. Despite significant sampling limitations, we find that all 11 species examined are both slow growing and long-lived, especially when compared with modern bivalves living in similar temperature settings. While cool temperatures have long been thought to be a key factor in promoting longevity, our findings suggest an important role for caloric restriction brought about by the low and seasonal light regime of the high latitudes. Our life-history data, spanning three different families, emphasize that longevity is in part governed by environmental rather than solely phylogenetic or ecologic factors. Such findings have implications for both modern and ancient latitudinal diversity gradients, as a common correlate of slow growth and long life is delayed reproduction, which limits the potential for evolutionary change. While life spans of modern bivalves are well studied, data on life spans of fossil bivalves are sparse and largely anecdotal. Life histories of organisms from deep time can not only elucidate the controls on life span but also add a new dimension to our understanding of macroevolutionary patterns.

Усть-ишимская кость: минералогогеохимические свойства как источник палеонтологической, палеоантропологической и палеоэкологической информации

Ust-Ishim man was the representative of one of the ancestral groups of the Homo sapiens, Neanderthals and Denisovans. The first results of a comprehensive mineralogical and geochemical study of fossil bones using a wide range of physical, chemical and physico-chemical methods: thermal analysis, optical microscopy, scanning electron microscopy, atomic-force microscopy, nitrogen capillary condensation method, X-ray fluorescence analysis, ISP-MS, gas chromatography method, amino acid chromatography analysis’s, X-ray microprobe method, X-ray diffraction method, Raman and infrared spectroscopy, isotope spectrometry are presented in this article. The studied fragment of the skeleton is of higher preservation rate than the common bone detritus of this age and even the fossils of younger Pleistocene animals that allowed determining almost all its primary properties. The unique preservation presumably was provided by the favorable environment and a special way the Ust-Ishim man originally was buried. Results of study of the chemical and mineral composition of the bone fossils allowed a reconstruction of the Ust-Ishim man life history.

A new terrestrial millipede fauna of earliest Carboniferous (Tournaisian) age from southeastern Scotland helps fill ‘Romer's Gap'

ABSTRACTA diverse millipede (diplopod) fauna has been recovered from the earliest Carboniferous (Tournaisian) Ballagan Formation of the Scottish Borders, discovered by the late Stan Wood. The material is generally fragmentary; however, six different taxa are present based on seven specimens. Only one displays enough characters for formal description and is namedWoodesmus sheariRoss, Edgecombe & Clark gen. & sp. nov. The absence of paranota justifies the erection of Woodesmidae fam. nov. within the Archipolypoda. The diverse fauna supports the theory that an apparent lack of terrestrial animal fossils from ‘Romer's Gap' was due to a lack of collecting and suitable deposits, rather than to low oxygen levels as previously suggested.

A review of the nomenclature of Gyrogona and Gyrogonites (Fossil Algae: Charophyceae)

AbstractAnalysis of the nomenclature of the fossil genus Gyrogonites Lam. (Algae: Charophyceae) shows that the name was first treated by Lamarck (1801) as an incompletely known fossil mollusk from France. The species was given the name Gyrogonites medicaginulus because of its resemblance to the fruit of Medicago sativa (lucern). The gyrogonites were shown to be fossilized charophycean reproductive structures by Leman in 1812, now understood as calcified female gametangia preserved after the escape or the decomposition of protoplasmic material. Differences in the starting date of zoological nomenclature (1 Jannuary 1758) and that of plant fossils (1 January 1820) are resolved by Art. 45.1 of the botanical code, by which Gyrogonites is acceptable as a validly published pre‐1820 fossil charophycean name even though it was originally treated as a fossil animal. Gyrogona Lam. (1805) is a superfluous renaming of Gyrogonites (still considered at that time as a zoological name for a mollusk) and therefore should be rejected under the botanical and zoological codes. The inclusion of the type of Gyrogonites in the later established fossil higher‐plant genus Bechera Sternb. (1825), a repository genus for vegetative verticillate axes and reproductive organs, renders the latter genus name as nomenclaturally superfluous and illegitimate. Six fossil species of Gyrogonites are validated for the first time, 19 species and related 2 subspecies of Gyrogona are formally recombined into Gyrogonites. Two names, G. lemanii and G. oehlertii, are neotypified, and a lectotype is designated for G. wrightii. Precise dates of publication of the taxonomic works on gyrogonites of Bowdich, Brongniart, Fleming, Lamarck and Parkinson, supplementing records of Taxonomic literature II, are given for the first time.

Quest for the Lost World, or palaeontological geotourism

Palaeontological geotourism could be one of many forms of propagating geological values of a country. It can meet the expectations of many tourists. For this broad category of people, paleontological tourism can instill curiosity about the extinct world, offering them places where they can feel like explorers, visiting these sites with a hammer and a chisel. Many of them will cherish the memories of adventures made during the search in the future, and some will find a new passion. Similar practices are used in Germany, for example, in Solnhofen or Holzmaden, where fossil exploration is available for a small fee. In most regions of Poland, you can find numerous places with fossils that anyone can search for. The greatest number of such sites can be found in the south of Poland, in the uplands and mountains, but also at the seaside, where the practice of palaeontological geotourism is possible. In the Holy Cross Mountains, the Sudetes, or in the Silesian-Cracow region, there are places where one finds fossils of plants or animals, including trace fossils. The only effort required in addition to the search for fossils is to develop guidelines and prepare guides for amateurs that quest for the lost world.

Life-restorations of ammonites and the challenges of taxonomic uniformitarianism

Ammonites were among the first life restorations of invertebrate fossil animals. These restorations appeared at around the same time (the 1830s)—and were executed by some of the same artists and scientists—as the earliest restorations of fossil vertebrates. As was the case for many of these vertebrates, ammonite restorations underwent major changes over the next century. These changes were associated with shifts in which living species were used as the basis for comparison with the extinct ammonites. The first models were argonauts (paper nautilus), because at the time they were better known than living Nautilus. By the mid-nineteenth century, Nautilus began to be used as a model, but with an ‘argonaut mode’ of life (floating on the surface). More modern-looking, subsurface restorations first appeared in the late nineteenth and early twentieth centuries. The issue of ‘taxonomic uniformitarianism’ remains a fundamental challenge for efforts to understand ammonite biology today, and this is reflected in the continuing variety of their restorations.

Les sciences géologiques à l’Université de Liège : deux siècles d’évolution

1. Introduction Lors de la creation de l’Universite de Liege en 1817, la constitution geologique de notre pays et des etats voisins etait a peine connue (Fourmarier, 1968a) et la geologie etait une science encore relativement jeune. En effet, la fin du XVIIIe et le debut du XIXe siecles correspondent a ce qu’Ellenberger (1994) appelle la grande eclosion de la geologie (Rudwick, 1997). La geologie moderne emergea alors sur une courte periode de temps (Ellenberger, 1994). Vers 1800, l’etude des fossiles et des mineraux etait encore essentiellement une science des echantillons. Les recherches de beaucoup de naturalistes reposaient sur les echantillons que des paysans, des collectionneurs locaux, des carriers ou des mineurs proposaient de leur vendre (Rudwick, 1997). Les erudits collectaient peu de materiaux eux-memes. Par contre, ils les decrivaient, les identifiaient et les classaient. Les publications qui en resultaient etaient souvent consacrees a un ou plusieurs echantillons recoltes en un lieu precis (Rudwick, 1997). Cette methode d’etude, basee sur des collections, eut pour consequence de separer les fossiles et les mineraux des roches dans lesquelles elles se trouvaient, c’est-a-dire de les separer de leur contexte geologique (Rudwick, 1997). A la meme epoque, une nouvelle branche des sciences minerales basee sur le travail de terrain vit le jour : la geognosie telle qu’enseignee par Abraham Gottlob Werner (1749–1817) a Freiberg. La geognosie, avec son approche en trois

Sea-level changes in the Lopingian (late Permian) of the northwestern Tethys and their effects on the terrestrial palaeoenvironments, biota and fossil preservation

The Lopingian is characterised by an aridisation trend and substantial sea-level changes. Hence, the fossil record of this time interval is strongly affected by ecological and taphonomic factors inherent to these long-term processes. Integrated sedimentological and palaeontological studies in the Bletterbach Gorge (Dolomites, N-Italy) allow discrimination between biological signals and preservational bias, shedding light on the effect of sea-level changes on the preservation potential of terrestrial associations of plant remains and tetrapod footprints. Flora A, composed of more humid elements with larger leaf/shoot fragments, appears close to a sea-level highstand and is interpreted as a (par-)autochthonous assemblage of an intrazonal riparian vegetation. Flora B, dominated by xerophytic elements documented by smaller fragments, corresponds to an allochthonous assemblage of an azonal vegetation preserved in floodplain fines of a progradational fluvial plain associated with a sea-level lowstand. The distribution of vertebrate footprints mirrors that of the plant-bearing horizons and their abundance and morphological diversity strongly increases in correspondence with marine transgressions. This could be related to a more diverse fauna (more complex food-web related to more humid conditions) or more favourable taphonomic conditions. However, the most diversified fauna, recorded during the early phases of the regressive phase, is in our interpretation best explained by the rapid burial of footprints due to the increasing energy. Our study provides an explanation for the change in distribution and preservation of plant and animal fossils in the Bletterbach section and shows how the fossil content of continental successions is deeply influenced by sea-level changes.

Late Pennsylvanian–Early Triassic conchostracan biostratigraphy: a preliminary approach

Abstract Conchostracans are one of the most common fossil animal groups of continental deposits from late Palaeozoic to modern times. Their habitats have ranged from perennial lakes of the Carboniferous and Early Permian to seasonal playa lakes and temporary ponds from the late Early Permian into the Triassic, where they could form mass occurrences. This, together with relatively high speciation rates, makes them ideal guide fossils, especially in otherwise fossil-poor wet and dry red beds. Based on material and data collected since the 1980s from both surface outcrops and well cores in central Europe, a preliminary conchostracan zonation is proposed. We used a conservative approach, erecting assemblage zones comprising two or three species instead of species-range zones with only one or, sometimes, two forms. Assemblage zones are more robust and provide more reliability for each delineated time interval. Isotopically dated occurrences of conchostracan zone species, or co-occurrences of conchostracans, insect zone species and marine index fossils such as conodonts and fusulinids, allow us to correlate our assemblage zones with the marine Standard Global Chronostratigraphic Scale.

Evidence for herbivorous cave bears (Ursus spelaeus) in Goyet Cave, Belgium: implications for palaeodietary reconstruction of fossil bears using amino acid δ15N approaches

ABSTRACTInsights into causes of extinction in fossil animals can contribute to an understanding of how environmental or anthropogenic processes may affect extant animals. Cave bears that went extinct in the late Pleistocene in Europe have been considered largely herbivorous based on tooth, skull and jaw morphology. Nitrogen and carbon isotopic composition (δ15N, δ13C) of bone collagen of many cave bears having values similar to or lower than those of coeval herbivores support an exclusive plant diet and their occurrence in habitats with denser vegetation. A complicating aspect of this hypothesis is that isotopic compositions of bulk collagen, especially those of nitrogen, could reflect environmental fluctuation as well as behavioural and physiological traits, which are not related to trophic position and so may lead to uncertainty in palaeodietary reconstruction. Here we show that δ15N analysis of individual collagen amino acids of fossil bears from Goyet Cave (Belgium) indicates that cave bears had a constant trophic position of 1.9–2.1, indicating purely herbivorous diets, while brown bears had a trophic position of 2.0–2.4, indicating a slightly more omnivorous diet. Results might support the hypothesis of the extinction of cave bear due to the inflexibility in feeding habits.

Mesowear analyses of sympatric ungulates from the late Miocene Maragheh, Iran

This study investigates the palaeoecology of fossil hypsodont equids and bovids from the late Miocene Maragheh Formation, northwestern Iran. No fossil pollen data has been available from Maragheh. Thus, dietary reconstruction of herbivorous ungulates is an important resource for understanding the terrestrial vegetation of the region. Mesowear analysis was applied to fossil cheek teeth of hipparionine horses and bovids with well-described geological contexts from Maragheh (“Hipparion” fauna). Results suggest that the hipparionine horses were not typical grazers, whereas the bovids relied on broader resources from tree leaves to grasses. The report of the site yielding these fossil animals suggests that they were excavated from a single quarry and bed representing their sympatric habitat. Therefore, the diversity of mesowear score represents dietary differentiations of the Maragheh ungulates, which are consistent with the concept of a mosaic vegetational habitat proposed by previous mesowear studies. This study analysed the bovids as composited groups because it was difficult to identify them by individual species. For further palaeoecological discussion, continuous fossil excavation with geological survey is required.

Systematic description of putative animal fossils from the early Ediacaran Lantian Formation of South China

AbstractThe early Ediacaran Lantian Formation in South China contains some of the oldest known representatives of morphologically complex macroorganisms, including various macroalgae and putative animals. The macroalgal fossils have been described previously in several publications, but no taxonomic treatment has been published for the putative animal fossils. This hampers our ability to fully evaluate and communicate the significance of these potentially important Ediacaran macrofossils. To address this deficiency, here we provide a systematic description of these putative animal fossils from the Lantian Formation, including four new genera and five new species: Lantianella laevis gen. et sp. nov., L. annularis gen. et sp. nov., Piyuania cyathiformis gen. et sp. nov., Qianchuania fusiformis gen. et sp. nov. and Xiuningella rara gen. et sp. nov. Morphological comparisons of these fossils and potential modern analogues are provided and critically assessed.

Microbial Origin of Early Animal Trace Fossils?

Abstract Elongate surface trails that abound in late Ediacaran and early Paleozoic sandstone and siltstone are often attributed to early animals. These trails commonly exist on the same beds as wrinkle structures (millimeter- to centimeter-size ridges and pits that are interpreted as evidence of the former presence of microbial mats). Here we show that interactions between oscillatory flow and centimetric microbial aggregates produce elongate trails on the surface of a sediment bed. Trails left by moving microbial aggregates share a number of characteristics with some presumed trace fossils of the earliest animals: elevated edges, zig-zag patterns, smooth curves, reversals, intersections with other trails, series of pits, and paths that terminate abruptly and restart nearby. Under the same flow conditions, millimetric microbial aggregates generate wrinkle structures. Thus, the interaction between flow and microbial aggregates on a sediment bed can produce a number of structures that are commonly interpreted as evidence of early animal locomotion.

An Early Cretaceous anomopod (Crustacea: Branchiopoda) preserved in amber that reveals an unexpected venture during the evolution of the order

ABSTRACTAn anomopod branchiopod crustacean that displays many structural similarities to the extant genera Scapholeberis and Megafenestra (family Daphniidae), fortuitously preserved in amber of Early Cretaceous age, is described. Although most of its appendages have been lost, preservation of several structures is vastly better than in most ‘orthodox’ fossils of these delicate animals. The well-preserved carapace suggests that, like extant representatives of these genera, but in no other daphniid, the animal exploited the surface film, beneath which it suspended itself by means of the straight ventral margins of its functionally bivalved carapace, each of which was armed with a row of close-set setae. Unlike the postabdomen of all the many extant anomopods, which is unsegmented, that of the fossil species, which was well preserved, was segmented; its distal half, or rather more, being clearly divided into four segments. Its topographically ventral margin was armed with pairs of very long spines (relatively longer than in any extant species), and the paired, hook-like terminal spines, clearly homologous with the claws of living species, were modified in a way that has no exact parallel in extant forms. The distal segment shows signs of annulations and may have had slight independent mobility. It is suggested that the long ventral spines of the postabdomen facilitated levering the animal forward over soft substrata. Its minute size reflects the fact that it is a first instar. Moreover, it was possibly squeezed out of the brood pouch prematurely when its parent became trapped in resin. The difficulty of assigning a place to the fossil in the phylogeny of the anomopods, all of which, including fossil forms of greater antiquity, have an unsegmented postabdomen, is briefly noted. The possibility that this attribute represents a very ancient atavism is tentatively suggested.

Simulation of enamel wear for reconstruction of diet and feeding behavior in fossil animals: A micromechanics approach.

The deformation and wear events that underlie microwear and macrowear signals commonly used for dietary reconstruction in fossil animals can be replicated and quantified by controlled laboratory tests on extracted tooth specimens in conjunction with fundamental micromechanics analysis. Key variables governing wear relations include angularity, stiffness (modulus), and size of the contacting particle, along with material properties of enamel. Both axial and sliding contacts can result in the removal of tooth enamel. The degree of removal, characterized by a "wear coefficient," varies strongly with particle content at the occlusal interface. Conditions leading to a transition from mild to severe wear are discussed. Measurements of wear traces can provide information about contact force and particle shape. The potential utility of the micromechanics methodology as an adjunct for investigating tooth durability and reconstructing diet is explored.