Rusingoryx atopocranion is an extinct alcelaphin bovid from the late Pleistocene of Kenya, known for its distinctive hollow nasal crest. A bonebed of R. atopocranion from the Lake Victoria Basin provides a unique opportunity to examine the nearly complete postcranial ecomorphology of an extinct species, and yields data that are important to studying paleoenvironments and human-environment interaction. With a comparative sample of extant African bovids, we used discriminant function analyses to develop statistical ecomorphological models for 18 skeletal elements and element portions. Forelimb and hindlimb element models overwhelmingly predict that R. atopocranion was an open-adapted taxon. However, the phalanges of Rusingoryx are remarkably short relative to their breadth, a morphology outside the range of extant African bovids, which we interpret as an extreme open-habitat adaptation. It follows that even recently extinct fossil bovids can differ in important morphological ways relative to their extant counterparts, particularly if they have novel adaptations for past environments. This unusual phalanx morphology (in combination with other skeletal indications), mesowear, and dental enamel stable isotopes, demonstrate that Rusingoryx was a grassland specialist. Together, these data are consistent with independent geological and paleontological evidence for increased aridity and expanded grassland habitats across the Lake Victoria Basin.

Bat flies (Streblidae) are diverse, obligate blood-feeding insects and probably the most conspicuous ectoparasites of bats. They show preferences for specific body regions on their host bat, which are reflected in behavioural characteristics. In this study, we corroborate the categorization of bat flies into three ecomorphological groups, focusing only on differences in hind leg morphology. As no detailed phylogeny of bat flies is available, it remains uncertain whether these morphological differences reflect the evolutionary history of bat flies or show convergent adaptations for the host habitat type. We show that the division of the host bat into three distinct habitats contributes to the avoidance of interspecific competition of bat fly species. Finally, we found evidence for density-dependent competition between species belonging to the same ecomorphological group.

Bat guano deposits are common in the Mammoth Cave system (Kentucky, USA). Paleontological remains associated with these deposits are important records of local landscape changes. Recent excavations in the cave suggest that vertebrate remains in most of these deposits are dominated by Chiroptera. Although no extinct fauna were identified, the presence of a large roost of Tadarida brasiliensis in the Chief City section is beyond the northern extent of its current range suggesting that this deposit dates to an undetermined interglacial period. Stable isotope analyses of Tadarida-associated guano indicate a C3 prey signature characteristic of forested habitat. This was unexpected since this species is typically associated with open environments. Further ecomorphological analysis of wing shape trends in interglacial, Holocene, and historic-aged assemblages indicate that interglacial faunas are dominated by fast-flying, open-space taxa (T. brasiliensis) while late Holocene and Historic assemblages contain more taxa that utilized closed forest or forest gaps.

Rusingoryx atopocranion is a poorly known extinct alcelaphine bovid, documented in Pleistocene deposits associated with Middle Stone Age artifacts on Rusinga Island, Kenya. Following its initial description, Rusingoryx was subsumed into Megalotragus, which includes the extinct giant wildebeests, on the basis of its cranial architecture. Renewed investigations of the Pleistocene deposits on Rusinga Island recovered a large sample of Rusingoryx specimens that provide new taxonomic and paleoecological insight. This study (1) reviews the morphological and phylogenetic evidence concerning the taxonomic status of Rusingoryx and (2) evaluates its paleoecology and dietary habits. The morphology and phylogenetic data indicate that Rusingoryx is distinct from Megalotragus; they likely shared a common ancestor in the late Pliocene. Ecomorphology and mesowear analysis point to a specialized grazing adaptation, and its association with arid-adapted ungulates suggests a preference for arid grasslands. The confirmation of Rusingoryx as a valid taxonomic entity, together with the presence of other extinct taxa (including Megalotragus) on Rusinga Island, suggests an increasingly complex pattern of ungulate biogeography and extinctions in the late Quaternary of East Africa. Rusingoryx appears to have been part of an arid-adapted faunal community that potentially persisted in East Africa until the onset of the Holocene.

The procyonid †Cyonasua is endemic to South America and recorded from the Late Miocene to the Early Pleistocene. This paper studies the forelimb of †Cyonasua sp. (late Pliocene of Miramar, Argentina), using an ecomorphological approach to infer morphological adaptations linked to substrate preference and locomotory mode, as well as to grasping and digging ability. Twenty linear measurements of forelimb and pectoral girdle were taken from †Cyonasua sp. and a sample of 87 specimens of extant carnivoran families (Procyonidae, Mustelidae, Ursidae, Viverridae, Canidae and Felidae). Raw values were transformed to minimise the effect of size. Morphological variation was explored by principal component analysis (PCA); substrate preference and locomotory mode were further analysed by multivariate analysis of variance (MAV) and discriminant analysis (DA); grasping and digging ability were analysed by DA. In the PCA morphospace, †Cyonasua sp. occupied a unique position, close to extant procyonids. DA classified it as non-specialised digger with poor grasping ability. The results lead to the interpretation of †Cyonasua sp. as having a moderately stabilised elbow joint with poor pronation–supination, although some climbing skills cannot be ruled out. Thus, †Cyonasua sp. could have had generalised habits, in agreement with reconstructed palaeoenvironmental conditions.

The hind limbs of birds have long been considered a key feature in the conquest of different environments. However, the high level of morphological diversity encountered complicates the foundation of a good theoretical correlation between morphology, locomotor habits and substrate preference and this, in turn, complicates palaeobiological interpretations. Phorusrhacids (Aves, Cariamiformes) are a good example, since they have been unequivocally categorised as terrestrial birds due to their reduced forelimbs; and as apex predators with the ability to pursue prey based only on their hind limb morphology. Multivariate techniques (PCA and discriminant analysis), based on traditional metrics and geomorphometrics of the hind limb and pelvis, were applied in order to explore terrestriality and cursoriality in phorusrhacids. Although several groups of birds could be identified, when looking solely at hind limb metrics, some phorusrhacids appear to be associated with walking birds, while others are associated with cursorial birds. However, the pelvis separates cursorial birds and phorusrhacids from walking and wading birds. This scenario is complicated further by a lack of clear definition of the different locomotor modes and substrate preferences in extant birds, and this makes it difficult to confirm phorusrhacid cursoriality based solely on morphometrics. However, some qualitative features of the pelvis and foot make the picture a little clearer. To study limb adaptations in fossil birds, a more holistic study, with an emphasis on qualitative features of the whole posterior locomotor module, is necessary, since morphometrics leaves some issues unresolved. A comparison with the wings is also needed, in order to make a more complete analysis of locomotor behaviour.

In the present work we describe nine saccular otolith morphometric indices (circularity, rectangularity, aspect ratio, percentage of the otolith surface occupied by the sulcus, percentage of the sulcus length occupied by the cauda length and ostium length, otolith length relative to the length of the fish, rostrum aspect ratio and percentage of the rostrum length occupied by the otolith length) of 41 species of the Tripterygiidae family collected mainly from New Zealand, Australia, Chile, South Africa, Mediterranean Sea and North America. The principal component of analysis showed that the indices that best explain the variability between species were related to sulcus and rostrum morphometry. According to cluster analysis, otolith morphometry could reflect the diversity of microenvironments for some genera such as Notoclinops and Forsterygion, while this does not happen to genera like Enneapterygius and Ruanoho. The discriminant analysis showed that the species Helcogrammoides cunninghami, Karalepis stewarti, Lepidoblennius haplodactylus, Notoclinus compressus, Ucla xenogrammus can be discriminated by using the morphometric indices. Two new indices related to the sulcus that were of great value for the discrimination of these species are described for the first time. This information will be a useful tool for palaeontological, taxonomic and trophic ecology studies.

Although many studies have been made on fish community changes in reservoirs, the diversity of situations means that general models are still difficult to construct. In order to be useful to managers, the information gathered in these studies must cover the regional taxonomic peculiarities. The inclusion of ecological strategies allows the detection of general patterns of fish community change. In the present study, multivariate analyses and non-parametric tests were used in order to detect relationships between ecological traits of 39 fish species and pelagic fish assemblages. We used gillnet captures of fish made in the Sinnamary River before filling of the Petit-Saut Reservoir and in the reservoir 8 years after closure of the dam and published data on fish species diet, life history parameters and morphology. Significant relationships were detected between fish assemblages and every ecological trait, which would have allowed the forecast of the type of species able to colonize the Petit-Saut Reservoir. Provided that the general characteristics of a river before damming are taken into account, it seems that feeding strategies can be used to predict future fish population and species changes on a general basis. Conversely, the lack of published data prevents definitive conclusions from being drawn concerning life-history and swimming strategies.

In the present study gut type was described and intestinal indices (i.e. mean gut length, relative gut length and Zihler's index) were estimated and compared for 58 fish species from the North Aegean Sea. A strong relationship between gut length (GL) and total length (TL) (significant relationships (P < 0.05) for 52 species) was found, whereas the hypothesis of the allometric growth of GL with TL was confirmed for 27 out of the 52 species. For the same TL, GL differs for species with different feeding habits (in omnivores > carnivores), as previously reported. Finally, for the same TL, GL also differs for species with different habitats (reef-associated > pelagic > benthopelagic > demersal) and gut types (Z-shaped with multiple loops > looped Z-shaped > Z-shaped >straight > convoluted > short with spiral valve).

To better understand the effects of perturbations (e.g. global change) or habitat restorations on fish population dynamics, it is crucial to improve the knowledge about strategies of habitat use (especially in terms of velocity use) by fish. Many recent studies accurately describe kinematics or energetic budgets of swimming activities, which are often species-specific and hardly transferable to other species. The main goal of the present study was to revive more general ecomorphological relationships between body shape and strategies of velocity use by highlighting a functional aspect of fish morphology: the hydrodynamic potential. For this purpose, potential relationships between minimum drag coefficients (Cdmin, constant at high Reynolds numbers), velocity use, fish morphology and drag in given flow conditions were investigated. To assess these relationships, dead drag values (i.e. drag values measured on dead, straight individuals) of 27 riverine species (108 individuals in total) common in France were experimentally measured under various flow conditions. These values served to estimate the Cdmin of fish. For pelagic species, Cdmin values were related to both preferred and near-maximum flow velocity used by the fish in nature. Explaining 61% of its variability, Cdmin was described using six morphological variables, which demonstrates the functional link between fish morphology and velocity use. For all studied species, a model explained 94% of drag variability using the Reynolds number of fish and three morphological variables. The link between morphology and drag force at given velocity conditions provides simple elements for modelling fish energetics in the context of physical habitat use. Moreover, the relationships between fish velocity use and their Cdmin open many applied perspectives, such as assessing the species abilities to withstand discharge modulations.

We investigated the global relationship between diet and morphology for 42 fish species from a medium-sized river in French Guiana and checked the influence of the species taxonomic proximity on the implication of individual morphological traits in that relation. The 42 species were classified in eight trophic guilds based on analysis of more than 4000 stomach contents. Taxonomic proximity between species was accounted for by an autoregressive model applied to original data of diet and morphology. Original and taxonomic-free data were then submitted to a Canonical Correspondence Analysis in order to detect the relationship between diet and morphology. We compared the results obtained by analyzing the original data and the corrected data. The results confirm the existence of a significant global relationship between diet and morphology. However, morphological traits responsible for that relation were different when considering the taxonomic-free data. Particularly the well known relationship between gut length and detritivory was not observed on the taxonomic free analysis. It is concluded that controlling for phylogeny is essential to the detection of relationships between diet and morphology. It is also concluded that, despite the robustness of some relationships between morphology and diet, many diets cannot be inferred by a ecomorphological approach.

Patterns of morphological variation in the skulls of extant bears were studied as they relate to diet and feeding behaviour. Measurements of craniodental features were used to compute indices that reflect dietary adaptations of the dentition and biomechanical properties of the skull, jaw and related musculature. Species were classified as either carnivores, omnivores, herbivores or insectivores. Differences among dietary groups were assessed with analysis of variance and discriminant factor analysis. Results demonstrated significant morphological separation among all four groups. Carnivores were distinguished by, among other features, molar size reduction, flexible mandibles and, most surprisingly, relatively small carnassial blades. In contrast, herbivores displayed, among other features, large molar grinding areas, rigid mandibles and large carnassial blades. The insectivorous sloth bear was characterized by extreme reduction of the post-canine teeth. As expected, omnivores tended to have morphology intermediate between that of carnivorous and herbivorous ursids. Comparison with previous studies revealed that bears exhibit a different set of morphological specializations for diet than other carnivoran groups. Carnivorous ursids, for example, were found to share aspects of craniodental morphology with omnivorous canids. The relatively weak adaptations for carnivory observed in bears may be the result of selection for the ability to cope with temporal fluctuations in dietary components. The giant panda Ailuropoda melanoleuca was found to have a relatively stiff jaw and great mechanical advantage of the jaw-closing muscles, features previously observed in carnivorous canids and unexpected in this herbivorous bear. Comparison of patterns of morphological variation and patterns of phylogenetic relationships among species revealed surprisingly strong congruence between morphology and phylogenetics.

Nearly all animals show altered musculo-skeletal phenotypes when subjected to captive conditions. Whether such changes affect biomechanical performance is for the most part unknown. In American alligators Alligator mississippiensis such modifications include shortened jaws, more robust body form, and broadened heads. Bite-force performance was assessed for a variety of sizes of wild-captured alligator specimens and the results correlated with morphological indices. Bite forces ranged from 217 to 13 172 N, with the latter being the highest value ever measured for a living animal. These data were statistically compared with those for long-term captive specimens using ANCOVA. Bite-force performance showed similar patterns of increase between captive and wild-reared animals, and bite forces with respect to snout–vent length and body mass were statistically indistinguishable. Nevertheless, with respect to head size, captive alligators were found to bite more forcefully than their wild counterparts. These findings illustrate the importance of considering biomechanical performance differences between wild and captive individuals if meaningful ecological ties are to be made. Furthermore, before concluding that wild-reared or captive animals show similar or different biomechanical performances, it is important to understand that standardization to different morphological parameters can reveal conflicting results. Consideration as to which measures are the most germane to the question at hand is essential.

Several molluscs that have been introduced world-wide have become economically important for coastal communities. As far as it is known, at least four scallop species (Argopecten irradians, Argopecten purpuratus, Patinopecten yessoensis, Pecten maximus) have been moved between different biological provinces and it is possible there will be further such movements. Making an introduction involves responsibilities and so requires careful consideration. This is because there have been several unwanted impacts with movements of molluscs in the past. The International Council for the Exploration of the Sea's (ICES) 1995 Code of Practice on the Introductions and Transfers of Marine Organisms and recent revision provides a basis for undertaking such an action wisely. In this review, scallops that may be used in future cultivation or in fisheries as potential candidates are examined in relation to the first phase of an introduction—the prospectus. This prospectus should take account of the purposes and objectives of the introduction, including relevant biological, pathological and ecological conditions in the donor region and the potential impacts of the species in the expected range occupied in the recipient region. This may require a study visit to the donor region to evaluate concerns relating to potential hazards. The ecomorphology of five different scallop shell morphs is discussed in relation to their behaviour and occupied habitat. Such information may provide an indication of their interaction with native scallop species in advance of their introduction.

American alligators Alligator mississippiensis undergo major transformations in morphology and ecology during development. These include several thousand-fold changes in body mass, modified snout and dental proportions, and shifts in diet from small, delicate foodstuffs to the inclusion of increasingly larger, more robust prey. How these changes in anatomical form contribute to actual physical performance and niche use is largely unknown. In the present study, bite-force measurements for 41 specimens of A. mississipiensis, were made throughout ontogeny (hatchling–older adults) using a series of precision force transducers. How this performance indicator scaled with respect to cranial and whole-body measurements was determined. Bite-force production throughout development was contrasted with ontogenetic changes in trophic ecology. The influences of this performance measure on these changes were then analysed. The results showed a 800-fold range (12–9452 N) of bite forces with values positively correlating with increases in body size. Scaling of biting forces through ontogeny showed positive allometry with respect to body mass, head length, jaw length, snout–vent length and total length. These patterns may be attributable to allometric growth of individual skeletal elements (and associated musculature), and/or progressive fusion and ossification of skull and jawbones during development. The overall pattern of force increase throughout ontogeny did not vary in association with major shifts in diet. Notably, the bite-force values for adult A. mississippiensis are the highest measured for any living animal and represent the first measures for a large crocodilian. Additionally, these data provide the first documentation of how bite force changes during ontogeny in a reptile. By bridging the rich morphological and ecological databases for these animals, this study opens the door to a comprehensive understanding of feeding in A. mississippiensis. Furthermore, it provides groundwork for standardized comparative studies of feeding among crocodilian, reptilian, or other gnathostome vertebrates.

We tested the hypothesis that the number of presacral vertebrae in lacertid lizards has evolved to meet requirements set by the structural habitat. The idea was that lizards from cluttered habitats (densely vegetated areas, stony walls and hills, rocks) would be aided by a flexible backbone with many vertebrae, ensuring manoeuvrability, whereas lizards from open habitats would require stiffer vertebrate columns, with relatively few vertebrae, favouring speed and acceleration capacity. In contrast to earlier findings in fishes and snakes, evolution of vertebral number and body size was uncorrelated in lacertid lizards. Body size also did not differ between structural habitat types (open areas, densely vegetated areas, vertical elements). Traditional analysis of variance suggests strong differences in vertebral counts between species from open areas and cluttered areas, the latter having higher numbers of presacral vertebrae. When adequate phylogenetic analyses are used, differences remain significant although the level of significance is considerably lower. Tests of the mechanistic relationships between vertebral number, bending ability, and manoeuvrability, and assessment of the relative importance of manoeuvrability and speed in habitats with varying degrees of impediment are needed to reveal the evolutionary path that has led to the differences in vertebral number.

This work examines whether stepwise discriminant function analysis of a suite of craniodental variables enables feeding behaviour and habitat preferences to be identified in fossil ungulates. There are several morphological features of the ungulate skull, mandible and dentition that are well correlated with dietary adaptations, and thus can be used for estimating the feeding ecology of extinct taxa. However, most studies have followed an univariate approach for characterizing the relationship between diet and craniodental structure in extant ungulates (but see Pérez-Barberia & Gordon, 2001), even though such a relationship has been revealed to be complex because of functional, phylogenetic and biomechanical constraints. In this paper a multivariate perspective is followed, developing quadratic discriminant functions for pairwise comparisons of dietary/habitat groups in modern species. Given that the stepwise method for selecting the morphological variables to be included in the algorithms was used, alternative discriminant functions are provided. Results obtained show that these algorithms reclassify correctly the species according to their feeding and habitat ecology, and thus may be useful for obtaining reliable palaeoautecological inferences (i.e. those related to the life style of extinct species, such as feeding ecology and habitat preferences) when applied to extinct ungulate taxa.

The Neotropical pitviper genus Bothrops comprises about 40 species, which occur in all main ecosystems of cis-Andean South America. We explored the relationships of body size and form (tail length and stoutness) with macrohabitat use in 20 forms of Bothrops. Semi-arboreal habits appeared only in forest forms. Semi-arboreals are significantly more slender and have longer tails than terrestrials; body size is not significantly different between terrestrials and semi-arboreals. Within Bothrops, independent contrasts for macrohabitat use were significantly correlated with contrasts of tail size (positively) and stoutness (negatively); thus, the more arboreal the species, the longer its tail and the more slender its body. Contrasts of adult body size seems to remain constant over the lower range of macrohabitat use, but to decrease in species of Bothrops which are more arboreal. Reconstructions of character states indicate that: (1) the ancestor of Bothrops was a small, stout, terrestrial species; (2) semi-arboreal habits appeared one to three times in the genus; (3) a decrease in stoutness and an increase in tail length occurred along with an increase in arboreality in some clades. Although macrohabitat use seems to be important in determining body form in Bothrops, our results also indicate that tail size, stoutness and body size may also be affected by selective agents other than macrohabitat use. The selective agents responsible for the shifts in macrohabitat use in Bothrops are still uncertain, although they may have included prey availability and/or predation pressure. The plasticity of macrohabitat use, morphology and body size described in this study may have been key features that facilitated the highly successful ecological diversification of Bothrops in South America.