Carnivorous Taxa Research Articles

Lynxes and foxes among hyenas, bears and humans. Unit 3 of the Cova del coll Verdaguer Upper Pleistocene site (Barcelona, Iberian Peninsula)

Zooarchaeological and palaeontological assemblages, especially those located in karst cavities, are usually the product of the activity of several taphonomic biological agents. This is also the case of the Upper Pleistocene site of Cova del Coll Verdaguer (Barcelona, Iberian Peninsula), where hyenas accumulated most of the ungulates, bears used the cave to hibernate and for birthing cubs, and humans occasionally visited the cave. The main aim of this study is to investigate the role played by medium-sized mammalian carnivores in the formation of Unit 3 (the Sala Sal de Llop chamber). For this purpose, we analysed Lynx pardinus and Vulpes vulpes remains, on the one hand, and leporid remains, on the other, applying different taphonomic (breakage and surface modifications) zooarchaeological (skeletal parts frequencies, age at death) and spatial methods (GIS, geostatistics, refits). Regarding medium-sized carnivores, the results indicate a predominance of adult individuals, a fairly complete anatomical representation (especially in the case of the lynx), the refitting of several elements (in the case of the lynx, many of them clustered in the same area), and the presence of tooth marks on some remains. This data points to the natural death of these animals inside the cave, and suggests they were subsequently scavenged by other carnivores. With respect to leporids, adult individuals predominate, the most abundant elements are innominate bones and those from the distal segment of the appendicular skeleton, and there is evidence of carnivore damage on several remains. In accordance with these results, the leporid assemblage is interpreted mainly as a non-ingested assemblage caused by the feeding activity of the Iberian lynx and, to a lesser extent, the red fox. Thus, the combination of all these analyses indicates that the medium-sized terrestrial carnivores did not play a merely passive role, but were also accumulators and modifying agents, at least in terms of the leporid remains. Although ungulates are not the focus of this study, we have also discussed the potential role of Iberian lynx and red fox in accumulating and modifying them. This work adds to previously published studies indicating that Cova del Coll Verdaguer is the product of mixed occupations of different carnivore taxa, suggesting that lynxes and foxes used the cave as a safe place to rest, transport their prey and consume it. Therefore, this study will shed more light on the relationships between human groups and different carnivore taxa at Cova del Coll Verdaguer and, by extension, in the European Upper Pleistocene, demonstrating that the study of fossil collections can contribute significantly towards extending our knowledge on past carnivore and human behaviour.

A space‐for‐time framework for forecasting the effects of ocean stratification on zooplankton vertical habitat use and trait composition

AbstractThe effects of environmental change on zooplankton communities, and more broadly, pelagic ecosystems are difficult to predict due to the high diversity of ecological strategies and complex interspecific interactions within the zooplankton. Trait‐based approaches can define zooplankton functional groups with distinct responses to environmental change. Analyses across multiple mesozooplankton groups can help identify key organizing traits. Here, we use the pronounced cross‐shore environmental gradient within the California Current Ecosystem in a space‐for‐time substitution to test potential effects of ocean warming and increased stratification on zooplankton communities. Along a horizontal gradient in sea‐surface temperature, water column stratification, and light attenuation, we test whether there are changes in zooplankton species composition, trait composition, and vertical habitat use. We employ DNA metabarcoding at two loci (18S‐V4 and COI) and digital ZooScan imaging of zooplankton sampled in a Lagrangian manner. We find that vertical distributions of many mesozooplankton taxa shift to deeper depths in the cross‐shore direction, and light attenuation is the strongest predictor of magnitude of change. Vertical habitat shifts vary among functional groups, with changes in vertical distribution most pronounced among carnivorous taxa. Herbivorous taxa remain associated with the chlorophyll maximum, especially in clear offshore waters. Our results suggest that increased stratification of this ocean region will lead to deeper depths occupied by some components of epipelagic mesozooplankton communities, and may result in zooplankton communities with more specialized feeding strategies, increased egg brooding, and more asexual reproduction.

Benthic invertebrate biodiversity enhancement with reef cubes®, evidenced by environmental DNA analysis of sediment samples

Nature inclusive design (NID) is an “eco-friendly” approach to the construction of manmade infrastructure. reef cubes® are patented construction products designed to be used as NID options for marine developments. Artificial reefs can be made with reef cubes® when used either as replacements of or additions to conventional marine manmade structures in marine construction projects. The first long-term, marine research station with reef cubes® is in Torbay, Devon, UK. A goal of the installation, to enhance biodiversity, is assessed here in regards to the benthic invertebrate community, with a novel method of sedimentary environmental DNA (eDNA) analysis. There are two primary aims targeted in this study: firstly to use sedimentary eDNA metabarcoding to assess if the enhancement of invertebrate biodiversity has been achieved and secondly to assess if the reef cubes have a negative impact on the infaunal diversity of exposed sediments in their vicinity. Sediment samples were taken in and away from, the reef cube® test site, in periods before and after their installation. Genetic material in the samples was amplified, sequenced, and amplicon sequence variants (ASVs) assigned to taxonomic ranks. Invertebrate metazoan biodiversity was analysed in terms of taxonomic richness, taxonomic diversity, genetic diversity of ASVs per taxa and species richness of: orders, functional feeding groups and positional lifestyle groups (infauna, epifauna or plankton). A significantly higher biodiversity of invertebrates was found at the reef sites across all measures. Benthic epifauna, suspension feeders and carnivore taxa in particular exhibited higher diversity. Mussels, barnacles, anemones, hydrozoans and copepods were the most distinguishing taxa. Benthic infauna were similarly diverse inside and around the reef cubes® to surrounding sediments. The results suggest that at least for the reef cubes® sampled here the goal of enhancing invertebrate biodiversity at the test site has been achieved. There was no negative effect found on the infaunal diversity in exposed sediments inside and beside the reef cubes®. Application of eDNA analyses to sediment samples represents a promising and efficient method for assessing such ecological goals with the installation of NIDs and artificial reefs.

The topography of diet: Orientation patch count predicts diet in turtles.

Use of quantitative morphological methods in biology has increased with the availability of 3D digital data. Rotated orientation patch count (OPCr) leverages such data to quantify the complexity of an animal's feeding surface, and has previously been used to analyze how tooth complexity signals diet in squamates, crocodilians, and mammals. These studies show a strong correlation between dental complexity and diet. However, dietary prediction using this technique has not been tested on the feeding structures of edentulous (toothless) taxa. This study is the first to test the applicability of OPCr to the triturating surface morphology of a beaked clade. Fifty-five turtle specimens, 42 of which preserved both the skull and rhamphotheca, were categorized into dietary categories based on the food sources comprising 90% or 60% of their diets. Photogrammetric models of each specimen were read into molaR, producing OPCr results. Comparison of bone and rhamphotheca OPCr values shows no significant difference in complexity, implying that bone can suffice for predicting diet from morphology when keratin is absent. Carnivorous taxa have significantly lower OPCr values than herbivorous or omnivorous taxa, showing that feeding surface complexity in edentulous animals varies with diet similarly to tooth complexity in toothed taxa. Comparison of bone OPCr values by family shows that Testudinidae (tortoises) are more complex than Cheloniidae (sea turtles) and Chelydridae (snapping turtles), but that Cheloniidae and Chelydridae are not significantly different from each other. We therefore find that OPCr can be used to differentiate between carnivores and other dietary categories in edentulous taxa.

Alternative or cytochrome? Respiratory pathways in traps of aquatic carnivorous bladderwort Utricularia reflexa

ABSTRACT Carnivorous plants of the genus Utricularia (bladderwort) form modified leaves into suction bladder traps. The bladders are metabolically active plant tissue with high rates of mitochondrial respiration (RD). In general, plants possess two mitochondrial electron transport pathways to reduce oxygen to water: cytochrome and an alternative. Due to the high metabolic rate in the bladders, it is tempting to assume that the bladders prefer the cytochrome c oxidative pathway. Surprisingly, we revealed that alternative oxidase (AOX), which yields only a little ATP, is much more abundant in the bladders of Utricularia reflexa in comparison with the shoots. This pattern is similar to the carnivorous plants with passive pitcher traps (e.g. Sarracenia, Nepenthes) and seems to be widespread across many carnivorous taxa. The exact role of AOX in the traps of carnivorous plants remains to be investigated.

Laughter, play faces and mimicry in animals: evolution and social functions.

Human laughter and laugh faces show similarities in morphology and function with animal playful expressions. To better understand primordial uses and effects of human laughter and laugh faces, it is important to examine these positive expressions in animals from both homologous and analogous systems. Phylogenetic research on hominids provided empirical evidence on shared ancestry across these emotional expressions, including human laughter and laugh faces. In addition, playful expressions of animals, in general, arguably have a key role in the development of social cognitive skills, a role that may help explain their polyphyletic history. The present work examines the evolution and function of playful expressions in primates and other animals. As part of this effort, we also coded for muscle activations of six carnivore taxa with regard to their open-mouth faces of play; our findings provide evidence that these carnivore expressions are homologues of primate open-mouth faces of play. Furthermore, our work discusses how the expressions of animal play may communicate positive emotions to conspecifics and how the motor resonance of these expressions increases affiliation and bonding between the subjects, resembling in a number of ways the important social–emotional effects that laughter and laugh faces have in humans.This article is part of the theme issue ‘Cracking the laugh code: laughter through the lens of biology, psychology and neuroscience’.

The Kromdraai early hominin-bearing site. A review of recent findings

The Kromdraai archaeological site is located in a fossiliferous paleokarst situated in the UNESCO World Heritage Site referred to as the “Cradle of Humankind” in the Gauteng Province of South Africa. Kromdraai is noteworthy because it features among the three southern African early hominin-bearing sites considered to represent distinct temporal periods within the same stratigraphic succession. Kromdraai also yielded a partial skull and dentition (TM 1517) in 1938 that was designated as the holotype of a new genus and species, Paranthropus robustus. Although the hominin fossil assemblage collected from Kromdraai between 1938 and 2014 is rather paltry, morphometric and cladistic analyses of this material suggested that it represented a somewhat less-derived form of P. robustus than the considerably larger assemblage from the nearby site of Swartkrans. However, the geochronological and biotic relationships among the P. robustus-bearing sites in South Africa are not resolved. Since 2014, the previously unknown, albeit densely fossiliferous Unit P produced 51 individually catalogued hominin fossils (36 craniodental and 15 postcranial) that currently represent 13% of the faunal assemblage from this unit with a minimum number of 10 juvenile and 9 adult individuals. P. robustus and early Homo coexisted at the time of the accumulation of Unit P at Kromdraai, with a relative abundance of 89% and 11%, respectively. P. robustus and early Homo are associated with a highly diverse fauna that includes several water-dependent species, and a large variety of bovid and carnivore taxa. Biochronological data from Unit P and an interval of reversed polarity measured in younger deposits above it are interpreted in the context of the regional chronological framework to infer that it represents a deposit that was likely accumulated prior to 2 Ma.

Feeding habits of the Middle Triassic pseudosuchian Batrachotomus kupferzellensis from Germany and palaeoecological implications for archosaurs

AbstractBite traces on fossil bones are key to deciphering feeding ecology and trophic interactions of vertebrate past ecosystems. However, similarities between traces produced by different carnivorous taxa with similar dentitions, and misidentifications due to equifinality, hinder confident identifications of the bite makers. Here, we correlate bite traces with macroscopic wear and microanatomy of the teeth of the pseudosuchian archosaur Batrachotomus kupferzellensis from the Triassic Lower Keuper fossil lagerstätten (southern Germany), untangling its feeding habits and shedding light on the bite traces generated by ziphodont teeth (teeth with serrated carinae). Individually, bite traces reflect tooth morphology, whereas composite bite traces and their frequency are related to feeding behaviour and explain tooth macroscopic wear and microanatomy. Therefore the identification of the bite maker is possible by analysing composite bite traces, their location on bones, and their relative abundance. In addition, tooth macroscopic wear and microanatomy are proven as independent lines of evidence of feeding ecology. Comparing bite traces on fossil and present‐day bone assemblages, we observe that bone modifications by the crocodylomorph lineage (from Triassic pseudosuchian archosaurs to extinct and extant crocodylians) are strikingly similar, including taxa with and without ziphodont teeth. Such a set of features differs from bone modification assemblages produced by taxa with similar ziphodont teeth outside the pseudosuchian lineage, such as theropod dinosaurs and the Komodo monitor, suggesting phylogeny is a better predictor of feeding ecology among saurian reptiles than tooth morphology.

A NEW SEMI-QUANTITATIVE METHOD FOR CODING CARNIVORE CHEWING DAMAGE WITH AN APPLICATION TO MODERN AFRICAN LION-DAMAGED BONES

ABSTRACT The ability to distinguish between the taphonomic patterns inflicted by different carnivore taxa in the fossil record is currently underdeveloped. Previous efforts to identify taxon-specific taphonomic damage to prey bones inflicted by larger felids have largely focused on tooth marks. Recent work, however, which considers patterns of chewing damage are only beginning to yield methods that can consistently distinguish between species, or even families, of large predators. Here we present a new low-cost, low-tech, semi-quantitative method for coding carnivore-inflicted chewing damage patterns using a basic 5-stage scale (0 = no damage, 1 = tooth marks only, 2 = minimal chewing damage, 3 = moderate chewing damage, 4 = severe chewing damage, fragmentation, or destruction), including a photographic guide to different levels of bone damage inflicted on different skeletal elements and portions. An independent test of this method by three experienced taphonomic analysts indicates that this method is easy to use and results in consistent data across analysts. We also apply this method to document and describe the intensity of damage that free-ranging African lions inflicted on a sample of zebra bones. This method can be used in conjunction with efforts to distinguish taxon-specific tooth mark shapes or patterns to more confidently infer the identity of different predators based on their chewing damage.

Coprolites from the Neogene Sahabi Formation, northeastern Sirt Basin of Libya

A large number of coprolites are newly documented from the As Sahabi area in the Sirt Basin of Libya. They are collected from the fossiliferous horizon within the Late Miocene sediments belonging primarily to the lower member (member “U1”) of the Sahabi Formation. Some of the coprolite specimens were subjected to microscopic examination and geochemical analysis to determine the possible producer and food type. The study proved that carnivores are the major producers as understood from both the observed undigested material such as bone and tooth fragments by reference to the known carnivore taxa present. The collected coprolite specimens are classified into a number of ichnomorphotypes in order to facilitate their study.

The effects of phylogeny, body size, and locomotor behavior on the three-dimensional shape of the pelvis in extant carnivorans.

The mammalian pelvis is thought to exhibit adaptations to the functional demands of locomotor behaviors. Previous work in primates has identified form-function relationships between pelvic shape and locomotor behavior; few studies have documented such relationships in carnivorans, instead focusing on long bones. Most work on the functional morphology of the carnivoran pelvis, in particular, has used univariate measures, with only a few previous studies incorporating a three-dimensional (3D) analysis. Here we test the hypothesis that carnivoran taxa that are characterized by different locomotor modes also differ in 3D shape of the os coxae. Using 3D geometric morphometrics and phylogenetic comparative methods, we evaluate the phylogenetic, functional, and size-related effects on 3D pelvis shape in a sample of 33 species of carnivorans. Using surface models derived from laser scans, we collected a suite of landmarks (N = 24) and curve semilandmarks (N = 147). Principal component analysis on Procrustes coordinates demonstrates patterns of shape change in the ischiopubis and ilium likely related to allometry. Phylogenetic generalized least squares analysis on principal component scores demonstrates that phylogeny and body size have greater effects on pelvic shape than locomotor function. Our results corroborate recent research finding little evidence of locomotor specialization in the pelvis of carnivorans. More research on pelvic morphological integration and evolvability is necessary to understand the factors driving pelvic evolution in carnivorans.

Hindlimb myology of the kinkajou (Potos flavus )

The kinkajou (Potos flavus) is a common exotic pet in the United States, and is also found in many zoo collections. However, basic information about its anatomy, which is essential for proper veterinary care, is poorly documented. Captive kinkajous often suffer from metabolic bone disorders resulting from inappropriate captive diet. Unfortunately, these bone diseases are difficult to diagnose due to a lack of understanding of baseline anatomy and available references, such as normal radiographs. There is also little understanding of kinkajou locomotion, which is important for understanding how they interact with their environment. The kinkajou can plantarflex and invert its pes (hindfoot) around multiple ankle and pes joints in order to fully reverse the pes 180°; however the myological and osteological adaptions that facilitate this behavior are unclear. Well‐developed plantarflexor and invertor muscles were recently hypothesized in species exhibiting hindfoot reversal. However, recent studies of other procyonids do not support this hypothesis.To address the issue of the lack of understanding of basic kinkajou anatomy and its locomotor behaviors, the left and right hindlimbs of an adult male kinkajou were dissected. A detailed description, and documentation of the hindlimb muscles in P. flavus was conducted. Here, we present the first comprehensive review of the muscular anatomy of the hindlimb of P. flavus including detailed anatomical description, muscle maps of the pelvis, long bones, and pes, and comparisons to other documented species of the Carnivoran order.Our dissections revealed that the anatomy of the hindlimb muscles was generally consistent with previous descriptions of other carnivoran taxa, although we observed a few interesting differences. In the thigh, the kinkajou had three bellies of m. semimembranosus, in contrast to two bellies in another procyonid, the ringtail (Bassariscus astutus), giant panda, and the domestic dog. The only other taxa with three bellies were the lesser grison and red panda. In the quadriceps femoris group, the kinkajou most closely resembled the red panda; however, it also shared some similarities in the quadriceps femoris with the ringtail and lesser grison. In the leg, the kinkajou closely resembles the domestic dog and lesser grison in the morphology of the m. gastrocnemius. In m. popliteus, the kinkajou most closely resembles the ringtail.Having this baseline understanding of kinkajou hindlimb functional anatomy, can provide insight into adaptations for its unique locomotor style. This understanding also has implications for proper husbandry by lending itself to the development of more exceptional habitats and enrichments for captive specimens and creating awareness for how any potential changes to environmental habitat could affect their health and well‐being.Support or Funding InformationThis study was funded by the Department of Biomedical Sciences, Midwestern University.This abstract is from the Experimental Biology 2019 Meeting. There is no full text article associated with this abstract published in The FASEB Journal.

Composition of the canid auditory bulla and a new look at the evolution of carnivoran entotympanics

The higher carnivoran taxa significantly differ in the morphology of the auditory bulla, but little is known about its non-ectotympanic elements and their contribution to phylogenetically informative bullar characters. The ventral entotympanic sinus, a principal hypotympanic compartment unique to Canidae, expands in post-ossification ontogeny from a distinct portion, rather than the whole, of what is considered the ‘caudal entotympanic’. To trace the earlier development of this sinus and to clarify the potential roles of individual entotympanics in formation of the canid auditory bulla, osteological observations were made on younger skulls of Canis lupus and four additional species. The ventral entotympanic sinus was found to invariably originate at a separate bone provisionally designated the ventral entotympanic. The rest of the caudal entotympanic is a fusion of the posterior (or the proper) caudal entotympanic ossifying near the tympanohyal, and the anterior caudal entotympanic ossifying between the ectotympanic and rostral entotympanic. Examination of the rostral entotympanic also revealed previously unknown details. In sum, the canid auditory bulla includes at least four rather than earlier recognised two (or suspected three) entotympanics. Based on these findings, the composition of the canid intrabullar septum and the homologies of the carnivoran entotympanics are discussed. Within the established phylogenetic framework, the rostral entotympanic and posterior caudal entotympanic appear as plesiomorphic for crown-group Carnivora, while the anterior caudal entotympanic is synapomorphic for Caniformia, and the ventral entotympanic is autapomorphic for Cynoidea. This hypothesis implies that the carnivoran entotympanic patterns may have emerged before complete fusions of bullar bones observed in the fossil record.

Geometric-morphometric analysis of tooth pits and the identification of felid and hyenid agency in bone modification

Carnivore bone modification has been one of the targets of taphonomic research during the last decades. Discerning carnivore involvement in the archaeo-paleontological record during the Plio-Pleistocene is especially important due to the capability of several carnivores of creating bone assemblages, to the interaction with other species in the modification of bones across the landscape and to the potential interspecific competition (e.g., with other carnivores or hominins). Several variables have been explored to discern the carnivore taxa involved in bone modification, but most of them led to equifinality. Recently, the application of computer vision and geometric morphometric techniques for the reconstruction of tooth mark morphology has provided satisfactory results in terms of differentiating among carnivore taxa with similar body size. Here we apply this new technique to the study of pits from the Olduvai Carnivore site (OCS), which has been interpreted as the first bone assemblage generated by lions and subsequently ravaged by hyenas. Results support the lions' involvement and post-ravaging action of hyenas in the OCS assemblage. Lastly, we also explore the potential of applying these new techniques to other bone assemblages in which different carnivore taxa were involved in their modification.

New Material and Revision of the Carnivora, Mammalia from the Lower Pleistocene Locality Apollonia 1, Greece

During the last field campaigns in the mammal fossiliferous site Apollonia 1 (Macedonia, Greece), new carnivoran material has been discovered. The new collection added two new carnivoran taxa, Homotherium latidens and Panthera gombaszögensis. The new canid material and the revision of the old one (a) suggest the presence of two Canis species, C. etruscus and C. apolloniensis; (b) confirm the presence of the hypercarnivore Lycaon lycaonoides, and (c) allow for re-classifying the vulpine material to Vulpes praeglacialis. The taxonomic status of the species C. apolloniensis and Meles dimitrius is discussed. The composition and diversity of the Apollonia carnivoran assemblage are estimated and compared to those of various Greek and European Villafranchian ones. The results suggest close similarity to the Venta Micena (Spain) and Dmanisi (Georgia) carnivoran assemblages. The biochronological evidence indicates that Apollonia 1 is younger than Venta Micena and older than Untermassfeld (Germany), suggesting an age of 1.3–1.0 Ma. The study of the carnivoran guild structure of Apollonia 1 in comparison to the modern ones from known environments, as well as their functional morphology, suggest an open habitat, agreeing with previous interpretations.

Evaluating the adaptive evolutionary convergence of carnivorous plant taxa through functional genomics.

Carnivorous plants are striking examples of evolutionary convergence, displaying complex and often highly similar adaptations despite lack of shared ancestry. Using available carnivorous plant genomes along with non-carnivorous reference taxa, this study examines the convergence of functional overrepresentation of genes previously implicated in plant carnivory. Gene Ontology (GO) coding was used to quantitatively score functional representation in these taxa, in terms of proportion of carnivory-associated functions relative to all functional sequence. Statistical analysis revealed that, in carnivorous plants as a group, only two of the 24 functions tested showed a signal of substantial overrepresentation. However, when the four carnivorous taxa were analyzed individually, 11 functions were found to be significant in at least one taxon. Though carnivorous plants collectively may show overrepresentation in functions from the predicted set, the specific functions that are overrepresented vary substantially from taxon to taxon. While it is possible that some functions serve a similar practical purpose such that one taxon does not need to utilize both to achieve the same result, it appears that there are multiple approaches for the evolution of carnivorous function in plant genomes. Our approach could be applied to tests of functional convergence in other systems provided on the availability of genomes and annotation data for a group.

From the epipelagic zone to the abyss: Trophic structure at two seamounts in the subtropical and tropical Eastern Atlantic - Part I zooplankton and micronekton

Specific mechanisms, driving trophic interactions within the pelagic community may be highly variable in different seamount systems. This study investigated the trophic structure of zooplankton and micronekton above and around Ampère and Senghor, two shallow seamounts in the subtropical and tropical Eastern Atlantic, and over the adjacent abyssal plains. For the identification of food sources and trophic positions stable isotope ratios (δ13C and δ15N) were used. δ13C ranged from −24.7‰ to −15.0‰ and δ15N covered a total range of 0.9–15.9‰. Based on epipelagic particulate organic matter, zooplankton and micronekton usually occupied the 1st–3rd trophic level, including herbivorous, omnivorous and carnivorous taxa. δ13C and δ15N values were generally lower in zooplankton and micronekton of the subtropical waters as compared to the tropical region, due to the differing nutrient availability and phytoplankton communities. Correlations between δ13C and δ15N values of particulate organic matter, zooplankton, micronekton and benthopelagic fishes suggest a linear food chain based on a single energy source from primary production for Ampère Seamount, but no evidence was found for an autochthonus seamount production as compared to the open ocean reference site. Between Senghor Seamount and the open ocean δ13C signatures indicate that hydrodynamic effects at seamounts may modify the energy supply at times, but evidence for a seamount effect on the trophic structure of the pelagic communities was weak, which supports the assumption that seamount communities rely to a large extent on advected food sources.

Which tooth to sample? A methodological study of the utility of premolar/non-carnassial teeth in the microwear analysis of mammals

Low magnification dental microwear constitutes one of the most important proxies on the ecology and evolution of diet in mammals. Numerous studies have been established on the reconstruction of dietary ecology of even-toed and carnivorous taxa. To date, these studies have used the second permanent molars or carnassials exclusively, for ungulates or carnivores, respectively. In this study, for the first time, premolars and non-carnassials of artiodactyls and carnivores, respectively, were used. Tooth samples from nine artiodactyl and eight carnivore taxa, covering the largest dietary spectrum possible, were evaluated and the microwear signal of the premolars/non-carnassials compared with known data of the second permanent molars and carnassials. The results reveal an almost identical statistical microwear signal of the premolars and molars for artiodactyls and the non-carnassials and carnassials for carnivores. Based on the even-toed taxa, new expanded morphospaces for both browsers and grazers are depicted on an average scratches versus average pits scatterplot. Additionally, dietary tendencies were delineated for the carnivore taxa with low or high counts of small and large pits for specific preferences such as a meat/bone, frugivorous or mixed carnivore diets in non-carnassial tooth positions as well. Lastly, low scratch and low large pit score plots for the ungulate and carnivore taxa, respectively, reveal an even clearer separation between the main dietary categories.

Carnivore taphonomy in South America: a review of actualistic studies and their implications in the southern Neotropics

Actualistic studies on mammalian carnivore taphonomy in southern South America are reviewed here, including pumas, small cats, foxes, and other, smaller carnivores. Patterns for different carnivore taxa and their variation are elicited. Also temporal and spatial variability is analysed, and comparisons are made to other carnivores and regions. While generally these Neotropical carnivores produce low damage intensity, stronger modifications and their implications are described as well. These patterns and their variation are put in context by taking into account the particular physical and biotic conditions in the southern Neotropics.

Organic enrichment simplifies marine benthic food web structure

AbstractFood web structure is a key determinant for community functioning and stability. Still, the architecture of trophic interactions is often ignored in assessments of stressor‐ or disturbance‐induced changes in ecological communities. We established anthropogenic structuring of trophic networks by revisiting the Pearson‐Rosenberg paradigm on changing benthic communities along gradients of organic enrichment. Using monitoring data from two sites with point‐source organic loading, acknowledging associated changes in, e.g., water chemistry, we studied network topology of soft‐sediment macroinvertebrate communities. We found that organic enrichment led to a progressive simplification of food web structure. The simplification manifested both horizontally and vertically in the web, and networks at impacted sites consisted of fewer nodes, fewer links, and had lower linkage density than more pristine communities. Contrary to our expectation, organic enrichment did not change the directed connectance of the networks, nor affect proportions of top‐level species and carnivorous taxa in the assemblages. There were, however, changes in the proportions of basal‐level and intermediate‐level nodes, which together with decreasing mean trophic height further reveal a disintegration of the trophic network. We suggest the Pearson‐Rosenberg model is expanded to include a progressive simplification of benthic food webs. Adding a dimension of interactions (in this case feeding links) to existing biodiversity assessments enhances our understanding of the consequences of environmental degradation.