Modern Animals Research Articles

Synchronized moulting behaviour in trilobites from the Cambrian Series 2 of South China

The study of moulting behaviour in the fossil record is relatively well known in arthropods and this is especially true for trilobites. Nevertheless, while studies focusing on the style of moulting in social and semi-social groups of modern animals (e.g. arthropods) are common, very few works investigate moulting adaptations in deep time. Here we report a trilobite assemblage from the Cambrian Series 2 “Tsinghsutung” Formation of South China. Around 850 specimens were used for this study from three different levels across one section near Balang (SE Guizhou Province, South China). These levels preserve numerous trilobite clusters in some cases containing around 400 individual specimens. Up to four species have been found in these clusters, but two species are more common. Trilobite clusters bear a high percentage of disarticulated specimens that we interpret as moults. Additionally, measurements of bioclast orientation and the dorsoventral attitude suggests very quiet water conditions followed by rapid burial events, prior to scavenger disturbance. Together, this indicates that the fossil assemblages were a result of a biological phenomenon rather than mechanical processes, allowing us to interpret the position of the fossil parts as different moulting configurations. Since the trilobite assemblage seems to be in situ, the large number of exuviae suggests a local place of migration. This was triggered by the need for group protection while moulting, which is suggestive of gregarious behaviour, possibly synchronized. These trilobites from the Cambrian Epoch 2, Age 4 constitute one of the earliest known gregarious community of trilobites and has important implications for understanding the ecology of this group during their emergence in the Cambrian.

A Natural History of the Kitchen

On the evidence of early modern European cookbooks, the wild birds deemed edible around 1600 included cranes, herons, swans, and cormorants. By 1750, none of these were considered palatable. While culinary historians have explored the transition from medieval to modern food marked by François Pierre de La Varenne’s Le cuisinier françois (1651), less attention has been afforded to another major transition in the European diet—that of eating a large variety of wild and domesticated animals to eating only a few. Historians of science in particular have largely ignored this transition, yet this shift in the definition of what was edible held profound implications for the changing roles of animals in both diets and scientific study. Two kinds of printed sources that are not commonly consulted together—cookery books and works on natural history—afford a new comparative glimpse of early modern animals and their varied meanings. In 1600, cookbooks and natural histories included many of the same animals and talked about some of the same things, since the category of “use” applied to both. By the time Vincent La Chapelle’s The Modern Cook appeared in 1733, these works had entirely diverged in content. Animals in cookbooks became a means to an end rather than a topic of study, while natural histories ceased to talk about uses and considered instead comparative anatomy and classification. Looking particularly at birds, this article tracks changing meanings surrounding both animals and diets in early modern Europe. The turkey emerges as the critical indicator of these changes in its naturalization from a wild exotic species to a familiar farmyard animal.

Lichen mimesis in mid-Mesozoic lacewings.

Animals mimicking other organisms or using camouflage to deceive predators are vital survival strategies. Modern and fossil insects can simulate diverse objects. Lichens are an ancient symbiosis between a fungus and an alga or a cyanobacterium that sometimes have a plant-like appearance and occasionally are mimicked by modern animals. Nevertheless, lichen models are almost absent in fossil record of mimicry. Here, we provide the earliest fossil evidence of a mimetic relationship between the moth lacewing mimic Lichenipolystoechotes gen. nov. and its co-occurring fossil lichen model Daohugouthallus ciliiferus. We corroborate the lichen affinity of D. ciliiferus and document this mimetic relationship by providing structural similarities and detailed measurements of the mimic's wing and correspondingly the model's thallus. Our discovery of lichen mimesis predates modern lichen-insect associations by 165 million years, indicating that during the mid-Mesozoic, the lichen-insect mimesis system was well established and provided lacewings with highly honed survival strategies.

Discovery of the oldest bilaterian from the Ediacaran of South Australia

Analysis of modern animals and Ediacaran trace fossils predicts that the oldest bilaterians were simple and small. Such organisms would be difficult to recognize in the fossil record, but should have been part of the Ediacara Biota, the earliest preserved macroscopic, complex animal communities. Here, we describe Ikaria wariootia gen. et sp. nov. from the Ediacara Member, South Australia, a small, simple organism with anterior/posterior differentiation. We find that the size and morphology of Ikaria match predictions for the progenitor of the trace fossil Helminthoidichnites-indicative of mobility and sediment displacement. In the Ediacara Member, Helminthoidichnites occurs stratigraphically below classic Ediacara body fossils. Together, these suggest that Ikaria represents one of the oldest total group bilaterians identified from South Australia, with little deviation from the characters predicted for their last common ancestor. Further, these trace fossils persist into the Phanerozoic, providing a critical link between Ediacaran and Cambrian animals.

Reductions in the dietary niche of southern sea otters (Enhydra lutris nereis) from the Holocene to the Anthropocene.

The sea otter (Enhydra lutris) is a marine mammal hunted to near extinction during the 1800s. Despite their well‐known modern importance as a keystone species, we know little about historical sea otter ecology. Here, we characterize the ecological niche of ancient southern sea otters (E. lutris nereis) using δ13C analysis and δ15N analysis of bones recovered from archaeological sites spanning ~7,000 to 350 years before present (N = 112 individuals) at five regions along the coast of California. These data are compared with previously published data on modern animals (N = 165) and potential modern prey items. In addition, we analyze the δ15N of individual amino acids for 23 individuals to test for differences in sea otter trophic ecology through time. After correcting for tissue‐specific and temporal isotopic effects, we employ nonparametric statistics and Bayesian niche models to quantify differences among ancient and modern animals. We find ancient otters occupied a larger isotopic niche than nearly all modern localities; likely reflecting broader habitat and prey use in prefur trade populations. In addition, ancient sea otters at the most southerly sites occupied an isotopic niche that was more than twice as large as ancient otters from northerly regions. This likely reflects greater invertebrate prey diversity in southern California relative to northern California. Thus, we suggest the potential dietary niche of sea otters in southern California could be larger than in central and northern California. At two sites, Año Nuevo and Monterey Bay, ancient otters had significantly higher δ15N values than modern populations. Amino acid δ15N data indicated this resulted from shifting baseline isotope values, rather than a change in sea otter trophic ecology. Our results help in better understanding the contemporary ecological role of sea otters and exemplify the strength of combing zooarchaeological and biological information to provide baseline data for conservation efforts.

What is on the menu today? Creating a microwear reference collection through a controlled-food trial to study feeding management systems of ancient agropastoral societies

The study of ancient herd-feeding systems is essential to investigate livestock management and the interactions of humans with domestic animals and past environments. This topic for historic periods has recently been investigated through dental microwear analyses. This approach, however, must be used with caution, as it is based on comparisons of established microwear patterns of modern wild animals. Here we present an experimental reference collection of dental microwear for domestic sheep (Ovis aries), created by a controlled-food trial to fill this methodological gap. Fifty sheep were split into five groups of ten, fed with four different types of vegetation potentially used by agropastoral societies (alfalfa, ray-grass, forage, and barley), and administrated following different techniques of processing (wet, dried and fresh). After being fed with a specific and controlled diet, the animals were slaughtered and the microwear patterns on the enamel surface of the lower molars were analysed via standard light stereomicroscopy. The differences found in our experiment between the different diets and processed plants have allowed us to characterize each dietary group and feeding management system. This information is extremely important to correctly interpret the archaeological record.

Latest Middle Miocene fauna and flora from Kumkol Basin of northern Qinghai-Xizang Plateau and paleoenvironment

We report 7 mammalian and 16 pollen species from the top of the Shimagou Formation in Kumkol Basin of northern Qinghai-Xizang Plateau, whose age is latest Middle Miocene (about 12.5 Ma). We erect a new species of fossil rodent, Spermophilinus kumkolensis sp. nov. The micromammalian fauna from the Kumkol Basin shares high similarities with contemporary faunas from Europe and northern China, indicating the existence of active zoogeographic exchange between Europe and northern Asia. Trees are dominant in pollen fossils, and herbs and shrubs are minorities. Broadleaved Quercus and Fagus predominate in tree pollens. The flora reconstructed by pollens displays a mixture of evergreen broadleaved forest and dry and warm steppe landscape. Compared to the modern vegetation in Yunnan region, the latest Middle Miocene flora in the Kumkol Basin represents a distinct vertical distribution. The ecotypes of the latest Middle Miocene fauna and flora in the Kumkol Basin, as a whole, are markedly different from those of modern animals and vegetation, the past climate being more suitable than today.

Co-expression of synaptic genes in the sponge Amphimedon queenslandica uncovers ancient neural submodules

The synapse is a complex cellular module crucial to the functioning of neurons. It evolved largely through the exaptation of pre-existing smaller submodules, each of which are comprised of ancient sets of proteins that are conserved in modern animals and other eukaryotes. Although these ancient submodules themselves have non-neural roles, it has been hypothesized that they may mediate environmental sensing behaviors in aneural animals, such as sponges. Here we identify orthologues in the sponge Amphimedon queenslandica of genes encoding synaptic submodules in neural animals, and analyse their cell-type specific and developmental expression to determine their potential to be co-regulated. We find that genes comprising certain synaptic submodules, including those involved in vesicle trafficking, calcium-regulation and scaffolding of postsynaptic receptor clusters, are co-expressed in adult choanocytes and during metamorphosis. Although these submodules may contribute to sensory roles in this cell type and this life cycle stage, total synaptic gene co-expression profiles do not support the existence of a functional synapse in A. queenslandica. The lack of evidence for the co-regulation of genes necessary for pre- and post-synaptic functioning in A. queenslandica suggests that sponges, and perhaps the last common ancestor of sponges and other extant animals, had the ability to promulgate sensory inputs without complete synapse-like functionalities. The differential co-expression of multiple synaptic submodule genes in sponge choanocytes, which have sensory and feeding roles, however, is consistent with the metazoan ancestor minimally being able to undergo exo- and endocytosis in a controlled and localized manner.

Senescence in immunity against helminth parasites predicts adult mortality in a wild mammal.

Our understanding of the deterioration in immune function in old age-immunosenescence-derives principally from studies of modern human populations and laboratory animals. The generality and significance of this process for systems experiencing complex, natural infections and environmental challenges are unknown. Here, we show that late-life declines in an important immune marker of resistance to helminth parasites in wild Soay sheep predict overwinter mortality. We found senescence in circulating antibody levels against a highly prevalent nematode worm, which was associated with reduced adult survival probability, independent of changes in body weight. These findings establish a role for immunosenescence in the ecology and evolution of natural populations.

Grazing high and low: Can we detect horse altitudinal mobility using high-resolution isotope (δ13 C and δ15 N values) time series in tail hair? A case study in the Mongolian Altai.

Carbon and nitrogen stable isotope time series performed in continuously growing tissues (hair, tooth enamel) are commonly used to reconstruct the dietary history of modern and ancient animals. Predicting the effects of altitudinal mobility on animal δ13 C and δ15 N values remains difficult as several variables such as temperature, water availability or soil type can contribute to the isotope composition. Modern references adapted to the region of interest are therefore essential. Between June 2015 and July 2018, six free-ranging domestic horses living in the Mongolian Altaï were fitted with GPS collars. Tail hairs were sampled each year, prepared for sequential C and N isotope analysis using EA-IRMS. Isotopic variations were compared with altitudinal mobility, and Generalized Additive Mixed (GAMMs) models were used to model the effect of geographic and environmental factors on δ13 C and δ15 N values. Less than half of the pasture changes were linked with a significant isotopic shift while numerous isotopic shifts did not correspond to any altitudinal mobility. Similar patterns of δ13 C and δ15 N variations were observed between the different horses, despite differences in mobility patterns. We propose that water availability as well as seasonal availability of N2 fixing type plants primarily controlled horse hair δ13 C and δ15 N values, overprinting the influence of altitude. Our study shows that altitudinal mobility is not the main factor that drives the variations in horse tail hair δ13 C and δ15 N values and that seasonal change in the animal dietary preference also plays an important role. It is therefore risky to interpret variations in δ13 C and δ15 N values of animal tissues in terms of altitudinal mobility alone, at least in C3 -dominated environments.

Bioturbation in matgrounds at Lake Bogoria in the Kenya Rift Valley: implications for interpreting the heterogeneous early Cambrian seafloor

Modern burrowing organisms feed on microbial organic matter in matgrounds near hot springs on the margins of Lake Bogoria, a saline alkaline lake in the Kenya Rift Valley. The burrowers produce a low-diversity trace assemblage similar to those produced by undermat miners during the Ediacaran–Cambrian transition. Despite obvious differences in body plans and phylogenetic affinities, these modern animals feed on microbes in similar ways to those inferred for primitive bilaterians. With increasing distance from hot-spring vents, outflow channels and adjacent matgrounds, the diversity and depth of the traces increase and mixgrounds become dominant. This modern extreme environment gives clues for interpreting the heterogeneous early Cambrian seafloor, with: (1) the restriction of ‘pre-agronomic revolution’ matground substrates; and (2) expansion of adjacent ‘post-agronomic revolution’ mixground areas.

Collagen turnover and isotopic records in cortical bone

Bone collagen of modern and ancient animals is a useful tissue for isotope analyses because it is stable over time. However, uncertainty regarding metabolic turnover processes of bone collagen can make isotope analysis difficult to correlate with relevant life history information. We used radiocarbon (14C) dating to examine turnover within cortical bone and to investigate retrospective isotope ratios along the growth direction of mid-shaft femurs of several large mammals with long life-span, including brown bear (Ursus arctos), sika deer (Cervus nippon), Japanese serow (Capricornis crispus), and Japanese macaque (Macaca fuscata). The individuals examined died between 1971 and 1986, and their bones were thus expected to contain radiocarbon generated by nuclear bomb testing, which led to an atmospheric 14C spike around 1964. Therefore, 14C dating could be used to date sections of cortical bone at fine scale. The 14C ages in the bone sections of all specimens except the Japanese serow specimen showed similar trends; perimedullary bone sections contained younger carbon, which has depleted 14C after the peak of the 14C spike, whereas 14C ages became rapidly older in midcortical sections before gradually becoming younger towards the bone surface. We observed metabolic turnover of collagen driven by bone remodelling in perimedullary bone sections, but we observed no evidence of remodelling in midcortical and pericortical sections. Thus, our results confirm that bone collagen in femoral cortical bone records retrospective isotopic information during skeletal growth of mammals and suggest that entire femoral cortical bone of aged terrestrial mammals represents isotopic values during adolescence rather than an average value from several years prior to death.

Fascinated by the elephant

The description of childhood and the main stages of life of Vadim Evgenevich Garutt, as well as the fate of his parents, is given. The stages of making up of his personality as a specialist on modern and ancient animals, including elephants, are shown. His fate is closely intertwined with the history of Russia of the 20th century. It was influenced by revolutionary events in Russia and the Great Patriotic War, evacuation and difficult post-war years, suffered contusion and serious illnesses. Beginning from the school age, when he visited a study group of Young Zoologists and worked up at the Leningrad Zoo, the life confronted him with interesting people and situations that allowed Garutt to become an expert in morphology and evolution of mammoths and other Quaternary proboscideans. Such personalities as B.V. Pestinsky, A.P. Bystrov, Yu.A. Orlov, L.V. Oshanin, M.M. Gerasimov, B.E. Bykhovsky and other scientists played an important role in his fate. In addition to studying the teeth and bone remains of ancient elephants, he carried out an active museum work, mounting and restoration of fossil elephants and rhinoceroses’ skeletons. The results of his research are published in a number of important monographs and articles that are important for the systematic of the Eurasian proboscides and biostratigraphy of the Pleistocene.

Strontium and Oxygen Isotope Profiles of Sequentially Sampled Modern Bison (<i>Bison bison bison</i>) Teeth from Interior Alaska as Proxies of Seasonal Mobility

Studies addressing prehistoric mobility in animals typically use isotopic analyses of sequentially formed tissues, such as the growth layers in teeth, to infer physical movement on the landscape. Strontium isotope ratios (87Sr/86Sr values), which vary geographically, are particularly useful for this purpose, especially when paired with stable oxygen isotope ratios (δ18O), which vary seasonally. Together, these two isotope systems can provide information about past animal movement patterns on a seasonal scale. However, while many studies have used 87Sr/86Sr and δ18O values from analyses of sequentially formed tissues for this purpose, there have been limited analyses on modern animals of known movement patterns across high-latitude regions. In this pilot study, we sequentially sampled and analyzed one second molar (M2) and two third molars (M3) from two bison (Bison bison bison) from the Delta bison herd, which resides in interior Alaska and has known and documented seasonal mobility patterns. The resulting 87Sr/86Sr values from the teeth were compared to a high-resolution 87Sr/86Sr isoscape for the region and were paired with δ18O analyses to determine whether the seasonal 87Sr/86Sr values matched the predicted values for each of the seasonal bison habitat areas. The results indicate that the 87Sr/86Sr and δ18O values reliably reflected the known seasonal mobility patterns of bison and suggest that this approach could be used to investigate the mobility patterns of prehistoric bison in Alaska and surrounding high-latitude regions.

Tyrannosaurus Rex Running? Estimations of Efficiency, Speed and Acceleration

Background. The estimations of maximum speed of Tyrannosaurus Rex vary from 5 20 m/s and higher and still are the subject of scientific discussion. Some scientists consider T. Rex the largest terrestrial super-predator that needed speeds greater than60 km/h (17 m/s) to capture its prey. Some recent publications indicate that it wasn’t able to run at all due to its large mass and significant loads on the skeleton and limit its walking speed to 5–7.5 m/s. Objective. We will try to answer the question of whether large animal or robot sizes are an obstacle to rapid running and to evaluate the maximum possible speed of T. Rex. Methods. We will use: a) two energy efficiency indicators - the drag-to-weight ratio or the cost of motion and the recently developed capacity-efficiency (connected with the power-to-weight ratio or metabolic rate); b) the vertical acceleration estimations; c) the available data about the speed, the stride and the leg length of human and animals. Results. The drag-to-weight ratio and the capacity-efficiency were estimated for running of different animals and humans. It was shown that the maximal running speed of T. Rex may reach the values 21–29 m/s. The values of its vertical acceleration are typical for bipedal running. Conclusions. Large dimensions of Tyrannosaurus Rex couldn’t be an obstacle to achieving rather high speeds during short intervals of fast running. Such conclusions allow us not to abandon the assertion that the dinosaur was a super-predator. Presented approach could be useful for studying locomotion in modern and fossil animals, human sport activity and for design of fast bipedal robots.

Sheep and cattle population dynamics based on ancient and modern DNA reflects key events in the human history of the North-East Baltic Sea Region

Genetic data from ancient and modern domestic animals holds tremendous potential to reveal long term trends in population histories. Reconstruction of effective population sizes based on temporally well covered data may reveal the effects of particular events in the early history of animal populations as well as reflect the changes in the lifestyle and society of past human populations. We used an Extended Bayesian Skyline Plot approach to estimate the effective population sizes (Ne) and their temporal changes in sheep and cattle from Late Bronze Age to present in North-East Baltic Sea Region (NEBSR). The results support previous results from ancient DNA analyses (mtDNA, Y-chromosome, MC1R) in the NEBSR for cattle and reveal previously unidentified temporal fluctuation for sheep (mtDNA, Y-chromosome). The sheep and cattle Ne increased during the Iron Age, reaching their maximum at the Late Iron Age/Medieval period followed by deep decline in sizes until the present. Decline in Ne simultaneously with increase in total population sizes indicate selection and increasing inbreeding from the beginning of Post Medieval period to the middle of the 20th century. The timing of the increase in sheep and cattle Ne is roughly the same as the timing of transition from hunting-gathering to farming in Iron Age (400–1000CE).

Dimensions of the Modern Pig

Abstract. It is important to know the physical dimensions of livestock to properly design confined animal housing facilities as well as feeding and drinking equipment. An engineering standard for the dimensions of livestock and poultry published by ASABE reports swine dimensions that were originally published in 1968. Changes in animal husbandry practices for swine, such as improved and new genetic lines, nutrition and feed form, and improved facility and equipment design, make it necessary to validate or update these dimensions for modern animals. The objective of this study was to evaluate dimension data for the grow-finish stages of modern pigs. A total of 150 growing-finishing pigs were sampled at five approximate ages: 4, 8, 12, 16, and 20 weeks old (30 animals at each age). The animals equally represented three commercial sire lines (Landrace, Duroc, and Yorkshire), and equal numbers of barrows and gilts were sampled. Dorsal and lateral color digital and depth images were collected using a Kinect sensor as the pigs were held individually in a stanchion or scale, and the images were analyzed by manual and automated methods. Measured physical dimensions included height from top of back to the floor, length from nose to base of the tail, width at shoulders, jowl length, front leg height, body depth from top of back to lowest point of the belly, and others. It was determined that the conformation of modern pigs has changed from the dimensions reported in current engineering standards such that modern pigs tend to be wider (15.1%) and shorter in height (-10.2%) and length (-4.9% on average) between 4 and 20 weeks of age. These updated pig dimensions will enable engineers to better design modern swine equipment and facilities. Keywords: Depth sensor, Dimensions, Image analysis, Precision livestock farming, Swine.

An isotopic investigation into the origins and husbandry of Mid-Late Bronze Age cattle from Grimes Graves, Norfolk

Bioarchaeological evidence suggests that the site of Grimes Graves, Norfolk, characterised by the remains of several hundred Late Neolithic flint mineshafts, was a permanently settled community with a mixed farming economy during the Mid-Late Bronze Age (c. 1400BCE–c. 800BCE). The aim of this study was to investigate, through isotope ratio analysis (87Sr/86Sr, δ13C and δ18O), the origins and husbandry of Bronze Age cattle (Bos taurus) excavated from a mineshaft known as the “1972 shaft”. Strontium isotope ratios from the molar enamel of ten Grimes Graves cattle were compared with eight modern animals from the Chillingham Wild White cattle herd, Northumberland. The range of 87Sr/86Sr values for the modern cattle with known restricted mobility was low (0.00062) while the values for the Grimes Graves cattle varied much more widely (range=0.00357) and suggest that at least five of the cattle were not born locally. Two of these animals were likely to have originated at a distance of ≥150km. Intra-tooth δ13C profiles for eight of the Grimes Graves cattle show higher δ13C values compared to those of Early Bronze Age cattle from central England. Most of these profiles also display pronounced shifts in δ13C during the period of enamel formation. One possible interpretation is that the cattle were subject to dietary change resulting from movement between habitats with different vegetation δ13C values. More comparative data, both archaeological and modern, is required to validate this interpretation. The multi-isotope approach employed in this study suggests that certain cattle husbandry and/or landscape management practices may have been widely adopted throughout central Britain during the Mid-Late Bronze Age.

Long-term ecological changes in marine mammals driven by recent warming in northwestern Alaska.

Carbon and nitrogen isotopes analyses were performed on marine mammal bone collagen from three archaeological sites (ad 1170-1813) on Cape Espenberg (Kotzebue Sound, northwestern Alaska) as well as modern animals harvested from the same area to examine long-term trends in foraging ecology and sea ice productivity. We observed significant and dramatic changes in ringed seal stable isotope values between the early 19th and early 21st centuries, likely due to changing sea ice productivity and reduced delivery of organic matter to the benthos driven by recent warming in the Arctic. These data highlight the importance of the archaeological record for providing a long-term perspective on environmental variation and interpreting recent changes driven by anthropogenic processes.

Joyce’s “Force” and His Tuskers as Modern Animals

Focusing on those animals that have been overlooked in reading Joyce’s work opens up new perspectives for understanding his writing. One of his earliest essays, “Force” (1898), written at the age of sixteen, shows his so far unexplored concern about the domestication of animals and extinction of species, and develops a theory of subjugation. The essay provides a useful mainstay for considering the “tuskers,” (the mammoth and mastodon, the elephants, their tusks, and ivory) in the context of the cultural discourses of modern society. The game-changer discovery of the notion of extinction; representation of mammoths and mastodons as fearful creatures; the novelty of elephants exposed to curious gaze on exhibition; the sculpture of Elvery’s Elephant House in Sackville street; a circus elephant and “terrible queer creature” episode in Stephen Hero; the forced labor perpetrated in the Congo Free State to exploit rubber and the ivory of wild elephants. These seemingly disparate topics deeply wedded to modernity will be interrelated with each other in “Force,” shaping a constellation of “Joyce’s tuskers.”