Osteomorphological features of the hind limb bones of Saiga antelope (Saiga tatarica).

The intralimb indices and calcaneal linear metrics are known as the reliable predictors of locomotor adaptation in artiodactyls. The osteological features of hindlimb in adult Saiga (Saiga tatarica) were described, and its correlation with cursoriality and habitat adaptation was discussed. Gross anatomy data showed Saiga owned the deep acetabulum as a broad lunate surface, the large acetabular anteversion, the well-developed ischiatic tuberosity and the prominent gluteal lines. It also presented the robust rough line and the strong gluteal tuberosity. A proximodistally elongated eminence located on the cranially distal tibia, which had not been found in goat. The tibial extensor groove was deep. The calcaneal tuberosity was robust. Digital anatomy data showed Saiga owned the higher metatarsal-femur ratio than forest musk deer and sheep. Comparing with wild bovids and sheep, Saiga presented a transitional variation in calcaneal form. The mean greatest length of the calcaneus (GLC) and the height of the sustentacular facet (HSF) in Saiga were shorter than that in sheep and longer than that in wild bovids respectively (F = 587.492; F = 10.264, p < .05). The wild bovids had longer cubonavicular facets than the other two groups (F = 18.587, p < .05). The great metatarsal-femur ratio of Saiga implied a superior cursorial ability and high conservation confronting the different habitats. The calcaneal linear metrics might shed light on lifestyle-related functional adaptation over decades of short-term evolution in the semi-free range environment.

A three-dimensional pelvimetric assessment on pelvic cavity of gazelle (Gazella subgutturosa) by computed tomography.

The gazelles (Gazella subgutturosa), which are at the risk of extinction and are legally protected, have a cultural and aesthetic value in Turkey. It becomes incredibly important to increase their numbers in order to ensure their survival. In this context, it is required to examine thoroughly the pelvic cavity which contains reproductive organs and is used as the birth canal, as well. This study was conducted to determine the pelvimetric data of the gazelles by scanning their pelvic cavity via a multidetector computed tomography (MDCT) and preparing three-dimensional models of the pelvic cavity. Twelve adult (6 females, 6 males) gazelle carcasses were used in the study. After the pelvic cavity was scanned using the MDCT device with 64 detectors at 80 kV, 200 mA, 639 mGY and 0.625 mm cross-section thickness, the MDCT images were obtained. The three-dimensional models of the images obtained using MIMICS 20.1 (The Materialise Group, Leuven, Belgium) program were prepared. Pelvimetric measurements of the pelvic cavity were taken using these models. It was determined based on the pelvimetric examinations that there was a significant difference between the female and male gazelles in terms of conjugate diameter, vertical diameter, intermediate traversal diameter, and cranial and medial transverse diameter data at p < .05. Also, there was a significant difference in their data related to caudal transverse diameter and ischial arch at p < .01. Consequently, it is thought that the use of pelvimetric values belonging to the pelvic cavity of gazelles would reveal the sexual dimorphism of the species and its differences with other species and would contribute to clinical sciences.

Placentation and hormonal maintenance of pregnancy in the impala (Aepyceros melampus).

INTRODUCTION: The impala is a widely distributed African ungulate. Detailed studies of the placenta and ovaries in impala undertaken in the 1970s did not address the endocrine functions of the placenta. METHODS: The uteri of 25 pregnant impala estimated to be between 49 and 113 days of the 190 day gestation were examined grossly, histologically and immunohistochemically. RESULTS: A single corpus luteum was present in either maternal ovary but the conceptus was always situated in the right uterine horn. The fetal membranes extended to the tips of both uterine horns. The amnion was in intimate contact with, but not fused to, the allantochorion. Placentation was typically ruminant with fetal macrocotyledons attached to the rows of maternal caruncles. The fetal villi were highly branched, especially in the centre of each placentome where the attenuated maternal epithelium lining the placental crypts was absent in some places. Both the corpus luteum and the uninucleate trophoblast cells of the interplacentomal allantochorion stained strongly for 3-ß hydroxysteroid dehydrogenase, and progestagen concentrations in allantoic and amniotic fluids increased significantly as gestation progressed, with a tendency to do likewise in maternal serum. Binucleate trophoblast cells stained positively for bovine placental lactogen, but neither the placenta nor the maternal corpus luteum showed evidence of oestrogen synthesis. DISCUSSION: Despite exhibiting the same basic type of placentation, both the gross and histological structure of the impala placenta, along with its immunohistochemical properties, demonstrates that great variation exists across ruminant placentas.

Three-dimensional modelling of computed tomography images of limb bones in gazelles (Gazella subgutturosa).

The objective of the present study was to model in 3D the detailed morphometric features of the thoracic and pelvic limb bones of the gazelle (Gazella subgutturosa), whose natural habitat is only in the Sanliurfa province, by using multidetector computerized tomography (MDCT) images. Materials from 14 (7 male and 7 female) dead gazelles were collected from the Harran University Veterinary Medicine Faculty clinics during or after treatment. MDCT images of the gazelles were taken and saved as DICOM (Digital Imaging and Communications in Medicine) files. MIMICS 20.1 software was used to generate a 3D reconstruction of the data, and morphological and morphometrical evaluation was performed. In respect of morphological features, the combined metacarpus (Mc) III and metacarpus Mc IV were the main weight-bearing metacarpal bone, while Mc II and Mc V were rudimentary. On the femur, the lateral condyle was bigger than the medial condyle at the caudodistal end and the medial wing of the trochlea femoris was larger than the lateral. As with the thoracic limb, the combined metatarsus (Mt) III and metatarsus Mt IV were the main weight-bearing metacarpal bone and they displayed a synostosis structure. There was no secondary metatarsus in the gazelles' pelvic limb. Based on digital measurements, the tibia was the longest bone of the gazelles' skeletal system, and there was a statistically significant sexual dimorphism throughout the skeleton at the levels of p < .05, p < .01 and p < .001. As a result, the present study's findings are useful as reference data for further studies on anatomy, surgery and archaezoology, while also being useful for classifying species and for forensic sciences.

Savannah roars: The vocal anatomy and the impressive rutting calls of male impala (Aepyceros melampus) - highlighting the acoustic correlates of a mobile larynx.

A retractable larynx and adaptations of the vocal folds in the males of several polygynous ruminants serve for the production of rutting calls that acoustically announce larger than actual body size to both rival males and potential female mates. Here, such features of the vocal tract and of the sound source are documented in another species. We investigated the vocal anatomy and laryngeal mobility including its acoustical effects during the rutting vocal display of free-ranging male impala (Aepyceros melampus melampus) in Namibia. Male impala produced bouts of rutting calls (consisting of oral roars and interspersed explosive nasal snorts) in a low-stretch posture while guarding a rutting territory or harem. For the duration of the roars, male impala retracted the larynx from its high resting position to a low mid-neck position involving an extensible pharynx and a resilient connection between the hyoid apparatus and the larynx. Maximal larynx retraction was 108 mm based on estimates in video single frames. This was in good concordance with 91-mm vocal tract elongation calculated on the basis of differences in formant dispersion between roar portions produced with the larynx still ascended and those produced with maximally retracted larynx. Judged by their morphological traits, the larynx-retracting muscles of male impala are homologous to those of other larynx-retracting ruminants. In contrast, the large and massive vocal keels are evolutionary novelties arising by fusion and linear arrangement of the arytenoid cartilage and the canonical vocal fold. These bulky and histologically complex vocal keels produced a low fundamental frequency of 50 Hz. Impala is another ruminant species in which the males are capable of larynx retraction. In addition, male impala vocal folds are spectacularly specialized compared with domestic bovids, allowing the production of impressive, low-frequency roaring vocalizations as a significant part of their rutting behaviour. Our study expands knowledge on the evolutionary variation of vocal fold morphology in mammals, suggesting that the structure of the mammalian sound source is not always human-like and should be considered in acoustic analysis and modelling.

Remarkable muscles, remarkable locomotion in desert-dwelling wildebeest.

Large mammals that live in arid and/or desert environments can cope with seasonal and local variations in rainfall, food and climate1 by moving long distances, often without reliable water or food en route. The capacity of an animal for this long-distance travel is substantially dependent on the rate of energy utilization and thus heat production during locomotion-the cost of transport2-4. The terrestrial cost of transport is much higher than for flying (7.5 times) and swimming (20 times)4. Terrestrial migrants are usually large1-3 with anatomical specializations for economical locomotion5-9, because the cost of transport reduces with increasing size and limb length5-7. Here we used GPS-tracking collars10 with movement and environmental sensors to show that blue wildebeest (Connochaetes taurinus, 220 kg) that live in a hot arid environment in Northern Botswana walked up to 80 km over five days without drinking. They predominantly travelled during the day and locomotion appeared to be unaffected by temperature and humidity, although some behavioural thermoregulation was apparent. We measured power and efficiency of work production (mechanical work and heat production) during cyclic contractions of intact muscle biopsies from the forelimb flexor carpi ulnaris of wildebeest and domestic cows (Bos taurus, 760 kg), a comparable but relatively sedentary ruminant. The energetic costs of isometric contraction (activation and force generation) in wildebeest and cows were similar to published values for smaller mammals. Wildebeest muscle was substantially more efficient (62.6%) than the same muscle from much larger cows (41.8%) and comparable measurements that were obtained from smaller mammals (mouse (34%)11 and rabbit (27%)). We used the direct energetic measurements on intact muscle fibres to model the contribution of high working efficiency of wildebeest muscle to minimizing thermoregulatory challenges during their long migrations under hot arid conditions.

Scaling of morphology and ultrastructure of hearts among wild African antelope.

The hearts of smaller mammals tend to operate at higher mass-specific mechanical work rates than those of larger mammals. The ultrastructural characteristics of the heart that allow for such variation in work rate are still largely unknown. We have used perfusion-fixation, transmission electron microscopy and stereology to assess the morphology and anatomical aerobic power density of the heart as a function of body mass across six species of wild African antelope differing by approximately 20-fold in body mass. The survival of wild antelope, as prey animals, depends on competent cardiovascular performance. We found that relative heart mass (g kg-1 body mass) decreases with body mass according to a power equation with an exponent of -0.12±0.07 (±95% confidence interval). Likewise, capillary length density (km cm-3 of cardiomyocyte), mitochondrial volume density (fraction of cardiomyocyte) and mitochondrial inner membrane surface density (m2 cm-3 of mitochondria) also decrease with body mass with exponents of -0.17±0.16, -0.06±0.05 and -0.07±0.05, respectively, trends likely to be associated with the greater mass-specific mechanical work rate of the heart in smaller antelope. Finally, we found proportionality between quantitative characteristics of a structure responsible for the delivery of oxygen (total capillary length) and those of a structure that ultimately uses that oxygen (total mitochondrial inner membrane surface area), which provides support for the economic principle of symmorphosis at the cellular level of the oxygen cascade in an aerobic organ.

Microanatomy of the digestive tract, hooves and some visceral organs of addax antelope (Addax nasomaculatus) following a concentrate or forage feeding regime.

Subacute ruminal acidosis is a common disease in captive non-domesticated ruminants and is mainly diagnosed by rumen fluid pH and rumen histology. Furthermore, differences in ruminant gastrointestinal histology have been hypothesized to correlate with the browser-grazer continuum. Twelve surplus addax antelope (Addax nasomaculatus) were divided into two groups, fed either their usual diet, consisting of a concentrate feed with a limited amount of hay, or a diet of unlimited hay only, for 3 months. After culling, descriptive and morphometric histology and pH measurements were compared between groups. Significant variations in cellular subpopulations were noted between groups, with roughage-fed individuals presenting primarily with balloon cells of the Stratum corneum and living layer cell vacuolization, whereas parakeratosis and intermediate-type cells were more frequent in the concentrate-fed group. Lesions typical of subacute ruminal acidosis were significantly more pronounced in concentrate-fed individuals. Ruminal pH measurements did not differ significantly, but were more consistent in forage-fed individuals, indicating a more stable reticuloruminal environment. The results indicate that ruminal histology may be more appropriate in assessing ruminal health compared to a single post-mortem pH measurement. It is proposed that Stratum corneum balloon cells may indicate cell maturation and not, as previously assumed, hyperfunction. Concentrate-fed individuals scored higher on the presence of inflammatory cells on hoof corium histology. The study further emphasizes the adaptability of ruminant digestive tract microanatomy in adult animals even after a short period of time and the positive effects an increased roughage diet may have in populations of captive grazing ruminants.

Ecomorphological analysis of bovid mandibles from Laetoli Tanzania using 3D geometric morphometrics: Implications for hominin paleoenvironmental reconstruction.

The current study describes a new method of mandibular ecological morphology (ecomorphology). Three-dimensional geometric morphometrics (3D GM) was used to quantify mandibular shape variation between extant bovids with different feeding preferences. Landmark data were subjected to generalized Procrustes analysis (GPA), principal components analysis (PCA), and discriminant function analysis (DFA). The PCA resulted in a continuum from grazers to browsers along PC1 and DFA classified 88% or more of the modern specimens to the correct feeding category. The protocol was reduced to a subset of landmarks on the mandibular corpus in order to make it applicable to incomplete fossils. The reduced landmark set resulted in greater overlap between feeding categories but maintained the same continuum as the complete landmark model. The DFA resubstitution and jackknife analyses resulted in classification success rates of 85% and 80%, respectively. The reduced landmark model was applied to fossil mandibles from the Upper Laetolil Beds (∼4.3-3.5 Ma) and Upper Ndolanya Beds (∼2.7-2.6 Ma) at Laetoli, Tanzania in order to assess antelope diet, and indirectly evaluate paleo-vegetation structure. The majority of the fossils were classified by the DFA as browsers or mixed feeders preferring browse. Our results indicate a continuous presence of wooded habitats and are congruent with recent environmental studies at Laetoli indicating a mosaic woodland-bushland-grassland savanna ecosystem.

Unusually high-pitched neonate distress calls of the open-habitat Mongolian gazelle (Procapra gutturosa) and their anatomical and hormonal predictors.

In neonate ruminants, the acoustic structure of vocalizations may depend on sex, vocal anatomy, hormonal profiles and body mass and on environmental factors. In neonate wild-living Mongolian gazelles Procapra gutturosa, hand-captured during biomedical monitoring in the Daurian steppes at the Russian-Mongolian border, we spectrographically analysed distress calls and measured body mass of 22 individuals (6 males, 16 females). For 20 (5 male, 15 female) of these individuals, serum testosterone levels were also analysed. In addition, we measured relevant dimensions of the vocal apparatus (larynx, vocal folds, vocal tract) in one stillborn male Mongolian gazelle specimen. Neonate distress calls of either sex were high in maximum fundamental frequency (800-900 Hz), but the beginning and minimum fundamental frequencies were significantly lower in males than in females. Body mass was larger in males than in females. The levels of serum testosterone were marginally higher in males. No correlations were found between either body mass or serum testosterone values and any acoustic variable for males and females analysed together or separately. We discuss that the high-frequency calls of neonate Mongolian gazelles are more typical for closed-habitat neonate ruminants, whereas other open-habitat neonate ruminants (goitred gazelle Gazella subgutturosa, saiga antelope Saiga tatarica and reindeer Rangifer tarandus) produce low-frequency (<200 Hz) distress calls. Proximate cause for the high fundamental frequency of distress calls of neonate Mongolian gazelles is their very short, atypical vocal folds (4 mm) compared to the 7-mm vocal folds of neonate goitred gazelles, producing distress calls as low as 120 Hz.

Gross Measurements of the Digestive Tract and Visceral Organs of Addax Antelope (Addax nasomaculatus) Following a Concentrate or Forage Feeding Regime.

Differences in macroscopic measurements of the gastrointestinal tract have been hypothesized to correlate with the browser-grazer continuum in the natural diet of ruminants. However, to what extent these characteristics represent species-specific traits, or respond to the actually ingested diet, remains to be investigated. Twelve surplus addax antelope (Addax nasomaculatus) were divided into two groups and fed, for 3 months, either their usual diet, consisting of a concentrate feed with a limited amount of hay, or a diet of unlimited hay only. After culling, macroscopic measurements were compared between groups. The macroscopic anatomy of the addax showed many characteristics considered typical for grazing or 'cattle-type' ruminants. While both diet groups had mesenteric, pericardial and perirenal adipose tissue, these depots were subjectively more pronounced in concentrate-fed animals. Hay-fed animals had significantly heavier filled forestomach compartments, with corresponding significantly longer linear measurements. Masseter muscles and the surface of first-order omasal leaves were significantly more prominent in hay-fed animals, reflecting possible adaptations to overcome resistance of grass forage and to reabsorb fluid from increased rumination, but differences were not as distinct as reported between 'cattle-type' and 'moose-type' ruminants. Some measurements such as reticular crests and empty foregut mass remained stable between groups, indicating possibly genetically pre-defined characteristics less prone to change in adult life. The results emphasize the adaptability of ruminant digestive tract anatomy in adult animals even after a short period of time, but also suggest limits to this adaptability that reveals a species-specific anatomy regardless of the diet actually consumed.

Gross anatomy of the stomach of the dorcas gazelle (Gazella Dorcas, Linnaeus, 1758) / Anatomía macroscópica del estómago de la gacela dorcas (Gazella Dorcas, Linnaeus, 1758)

The macroscopic anatomy of the stomach in four adult dorcas gazelle was described. Four adult, two male and two female dorcas gazelle (Gazella dorcas) of the Frigya Zoological Park, Enfidha, Tunisie, were used in this study. The ruminal papillae were distributed unequally in the rumen, and were larger and more abundant within the atrium and in the two saccus cecus. The papillae were absent in dorsal part of the dorsal sac. The ruminal pillars had no papillae. The cellulae reticuli were divided and contained secondary and tertiary crests. The curvatura omasi measured 12.1±0.1 cm. A comparison with literature data for sand gazelles (Gazella subgutturosa marica) emphasises that differences between closely related species that fill similar niches cannot be expected to follow a clear pattern, but yield an inhomogenous picture, with some measurements more tending towards a specific feeding type in the one, and some other measurements tending more towards that feeding type in the other species.We concluded that the stomach morphology of the dorcas gazelle indicates the'cattle-type' morphophysiology representative for intermediate feeders.

En este estudio se describe la anatomía macroscópica del estómago de cuatro gacelas dorcas adultas. Se utilizaron cuatro animales adultos, dos machos y dos hembras (Gazella dorcas) del Parque Zoológico Frigya, Enfidha, Túnez. Las papilas ruminales estaban distribuidas de manera desigual en el rumen, y se observaron de mayor tamaño y abundantes dentro de la aurícula, y en ambos saccus cecus. No se observaron papilas en la parte dorsal del saco dorsal. Los reticuli cellulae se dividieron y contenían crestas secundarias y terciarias. La curvatura omasi media 12,1±0,1 cm. Una comparación con los datos de la literatura en gacelas de arena (Gazella subgutturosa marica) indica que no se puede esperar un patrón exacto en las especies estrechamente relacionadas que llenan nichos similares, pero no cuentan con una imagen homogénea. En algunas de las mediciones se observa la tendencia hacia un tipo específico de alimentación en una especie, mientras que otras medidas tienden a asociar este tipo de alimentación a otras especies. La morfología del estómago de la gacela dorcas indica que la morfofisiologia de este tipo de ganado es representativa de alimentadores intermedios.

Morphological and radiographic studies on the skull of Indian blackbuck (Antilope cervicapra) / Estudios morfológicos y radiográficos del craneo del antilope negro (Antilope cervicapra) de la India

The phenotypic appearance of the head of animal species depends strongly on the shape of the skull. The present study has been carried out on morphological and radiographic characteristics of skull of the Indian Blackbuck. The skull comprised of cranial and facial bones. The cranial bones included occipital, sphenoid, ethmoid, interparietal, parietal, frontal and temporal. The occipital was a single bone surrounding the foramen magnum. The sphenoid was a single bone and situated between the occipital posteriorly and the ethmoid anteriorly. The ethmoid was a single bone laid ventral to the frontal and nasal bones. The interparietal was a small quadrilateral bone wedged in between the parietal anterio-laterally and the supraoccipital posteriorly. The parietal was a paired bone. The frontal bone was a paired and formed the roof of the cranial cavity. The occipital bone was roughly pentagonal in shape. The temporal was a paired bone and formed the part of the lateral wall of the cranial cavity. The facial bones included maxilla, premaxilla, palatine, pterygoid, nasal, lacrimal, zygomatic, vomer, turbinates, mandible and hyoid. The maxilla was a roughly triangular flat paired bone. The paired incisive bones were placed on the lower part of the face. The palatine was a paired bone. The pterygoid was a paired, small, slightly curved, flat plate of bone and situated on either side of the posterior nares. The nasal was a paired bone and formed the roof of nasal cavity. The lacrimal was a paired bone and located on the anterior margin of the orbit. The zygomatic was a paired bone and irregularly triangular in outline. The vomer was a single medial bone. The turbinate bone was delicate, scroll-like, complex bony plates, placed vertically in the nasal cavity, being attached to the lateral walls. The mandible was a paired bone. The hyoid bone was situated between the vertical parts of the rami of the mandible.

La apariencia fenotípica de la cabeza de las especies animales depende principalmente de la forma del cráneo. El objetivo fue estudiar las características morfológicas y radiográficas del cráneo del antílope negro de la India. El cráneo consta de los huesos craneales y faciales. Los huesos craneales incluyen occipital, esfenoides, etmoides, interparietal, parietal, frontal y temporal. El occipital es un hueso singular que circunda el foramen occipital. El esfenoides se sitúa entre el occipital posterior y el etmoidal anterior. El etmoidal es un hueso singular situado de forma ventral a los huesos frontal y nasal. El interparietal es un pequeño hueso cuadrilátero ubicado entre el parietal anterolateral y posterior del supraoccipital. El parietal es un hueso bilateral. El hueso bilateral frontal cubría la cavidad craneal. El hueso occipital era más o menos de forma pentagonal. El hueso temporal formaba parte de la pared lateral de la cavidad craneal. Los huesos faciales incluyen el hueso maxilar, premaxila, palatina, pterigoideo, nasal, lacrimal, cigomático, vómer, conchas nasales, mandíbula y el hueso hioides. El maxilar se presentó como un hueso bilateral plano más o menos triangular. Los huesos incisivos estaban colocados en la parte inferior de la cara. El hueso palatino es un hueso bilateral. El hueso pterigoideo bilateral, plano pequeño, de hueso y situado a ambos lados de las fosas posteriores. El hueso nasal en ambos lados formaba la cubierta de la cavidad nasal. El lagrimal es un hueso asociado y situado en el margen anterior de la órbita. El cigomático es un hueso irregular de contorno triangular. El vómer esun solo hueso medial. La concha nasal delgada con forma de espiral, placas óseas complejas y colocadas verticalmente en la cavidad nasal unidas a las paredes laterales. La mandíbula es un hueso bilateral. El hueso hioides estaba situado entre las partes verticales de las ramas de la mandíbula.

The postnatal ontogeny of the sexually dimorphic vocal apparatus in goitred gazelles (Gazella subgutturosa).

This study quantitatively documents the progressive development of sexual dimorphism of the vocal organs along the ontogeny of the goitred gazelle (Gazella subgutturosa). The major, male-specific secondary sexual features, of vocal anatomy in goitred gazelle are an enlarged larynx and a marked laryngeal descent. These features appear to have evolved by sexual selection and may serve as a model for similar events in male humans. Sexual dimorphism of larynx size and larynx position in adult goitred gazelles is more pronounced than in humans, whereas the vocal anatomy of neonate goitred gazelles does not differ between sexes. This study examines the vocal anatomy of 19 (11 male, 8 female) goitred gazelle specimens across three age-classes, that is, neonates, subadults and mature adults. The postnatal ontogenetic development of the vocal organs up to their respective end states takes considerably longer in males than in females. Both sexes share the same features of vocal morphology but differences emerge in the course of ontogeny, ultimately resulting in the pronounced sexual dimorphism of the vocal apparatus in adults. The main differences comprise larynx size, vocal fold length, vocal tract length, and mobility of the larynx. The resilience of the thyrohyoid ligament and the pharynx, including the soft palate, and the length changes during contraction and relaxation of the extrinsic laryngeal muscles play a decisive role in the mobility of the larynx in both sexes but to substantially different degrees in adult females and males. Goitred gazelles are born with an undescended larynx and, therefore, larynx descent has to develop in the course of ontogeny. This might result from a trade-off between natural selection and sexual selection requiring a temporal separation of different laryngeal functions at birth and shortly after from those later in life. J. Morphol. 277:826-844, 2016. © 2016 Wiley Periodicals, Inc.

Unexpected Convergent Evolution of Nasal Domes between Pleistocene Bovids and Cretaceous Hadrosaur Dinosaurs.

The fossil record provides tangible, historical evidence for the mode and operation of evolution across deep time. Striking patterns of convergence are some of the strongest examples of these operations, whereby, over time, similar environmental and/or behavioral pressures precipitate similarity in form and function between disparately related taxa. Here we present fossil evidence for an unexpected convergence between gregarious plant-eating mammals and dinosaurs. Recent excavations of Late Pleistocene deposits on Rusinga Island, Kenya, have uncovered a catastrophic assemblage of the wildebeest-like bovid Rusingoryx atopocranion. Previously known from fragmentary material, these new specimens reveal large, hollow, osseous nasal crests: a craniofacial novelty for mammals that is remarkably comparable to the nasal crests of lambeosaurine hadrosaur dinosaurs. Using adult and juvenile material from this assemblage, as well as computed tomographic imaging, we investigate this convergence from morphological, developmental, functional, and paleoenvironmental perspectives. Our detailed analyses reveal broad parallels between R. atopocranion and basal Lambeosaurinae, suggesting that osseous nasal crests may require a highly specific combination of ontogeny, evolution, and environmental pressures in order to develop.

Phylogenetic analyses of gazelles reveal repeated transitions of key ecological traits and provide novel insights into the origin of the genus Gazella.

African bovids are a famous example of a taxonomic group in which the correlated evolution of body size, feeding mode, gregariousness, and social organization in relation to the preferred habitat type has been investigated. A continuum has been described ranging from small-bodied, sedentary, solitary or socially monogamous, forest- or bush-dwelling, browsing species that seek shelter from predation in dense vegetation, to large-bodied, migratory, highly gregarious, grazing taxa inhabiting open savannahs and relying on flight or group-defense behaviors when facing predators. Here, we examined a geographically widespread clade within the Bovidae (the genus Gazella) that shows minimal interspecific variation in body size and asked if we could still uncover correlated changes of key ecological and behavioral traits during repeated transitions from open-land to mountain-dwelling. Our study used a multi-locus phylogeny (based on sequence variation of Cytb and six nuclear intron markers) of all extant members of the genus Gazella to infer evolutionary patterns of key ecological and behavioral traits and to estimate ancestral character states using Bayesian inference. At the base of the Gazella-phylogeny, open plains were inferred as the most likely habitat type, and three independent transitions toward mountain-dwelling were uncovered. Those shifts coincided with shifts from migratory to sedentary lifestyles. Character estimation for group size was largely congruent with movement patterns in that species forming large groups tended to be migratory, while small group size was correlated with a sedentary lifestyle. Evolutionary patterns of two other conspicuous traits (twinning ability vs. exclusive singleton births and hornless vs. horned females) did not follow this trend in the Gazella-phylogeny. Furthermore, we inferred the genus Gazella to have emerged in the Late Miocene to Pliocene (10-3Mya), and estimating ancestral ranges based on a Dispersal-Extinction-Cladogenesis model found the Middle East to be the most likely origin of the genus.

Macroscopic digestive tract anatomy of two small antelopes, the blackbuck (Antilope cervicapra) and the Arabian sand gazelle (Gazella subgutturosa marica).

The digestive tract anatomy of 14 blackbucks (Antilope cervicapra) and seven Arabian sand gazelles (Gazella subgutturosa marica) was quantified by dimensions, area and weight. Data from the two small-sized antilopinae were evaluated against a larger comparative data set from other ruminants classified as having either a 'cattle-type' or 'moose-type' digestive system. The digestive anatomy of the blackbuck resembled that of 'cattle-type' ruminants, which corresponds to their feeding ecology and previous studies of solute and particle retention time; however, a surprising exception was the remarkably small omasum in this species, which makes the blackbuck stand out from the general rule of a relatively large omasum in grazing ruminants. Sand gazelles had morphological features that corresponded more to the 'moose type' or an intermediate position, although previous studies of solute and particle retention time had led to the expectation of a more 'cattle-type' anatomy. The results show that outliers to general morphological trends exist, that findings on physiology and anatomy do not always match completely and that differences in the digestive morphology among ruminant species are more difficult to demonstrate at the lower end of the body mass range.

Morphology of the lingual papillae of the eland (Taurotragus oryx).

We examined the dorsal lingual surfaces of an adult eland (Taurotragus oryx) by scanning electron microscopy. Filiform, fungiform and vallate papillae were observed. The filiform papillae of the lingual apex consisted of a larger main papilla and smaller secondary papillae. The connective tissue core of the filiform papilla was U-shaped. The fungiform papillae were round in shape. The connective tissue core of the fungiform papilla was flower-bud shaped. The filiform papillae of the lingual body consisted of a main papilla and were big as compared to that of the lingual apex. The connective tissue core of the filiform papilla resembled that of the lingual apes. The lenticular papillae of large size were limited on the lingual prominence. The connective tissue core of the lenticular papilla consisted of numerous small spines. The vallate papillae were located on both sides of the posterolateral aspects. The vallate papillae were flattened-oval shaped and the papillae were surrounded by a semicircular trench. The connective tissue core of the vallate papilla was covered with numerous small spines. The lingual surface of the eland closely resembled that of the family Bovidae.

Morphometrical studies on the skull of indian blackbuck (Antelope cervicapra) / Estudios morfológicos en el cráneo del antílope indio (Antelope cervicapra)

The phenotypic appearance of the head of animal species depends strongly on the shape of the skull. The morphometric studies of the skull show that variability in the shape and proportions of bones is influenced by genetic and environmental factors. The present study was carried out first time on the morphometrical characteristics on skull of Indian Blackbuck. Craniometric measurements for 48 different parts of the skulls of Indian blackbuck were made in this study. All investigated features were expressed as Mean±SE. The craniometric measurements and cephalic indices had been compared with ruminants. The mean lengths of the skulls were found to be 20.68±0.02 cm, with the width and cephalic index to the magnitude of 9.54±0.03 cm and 46.12±0.12 cm, respectively. The cranial length, width and height in blackbuck were 10.40±0.02 cm, 6.13±0.02 cm and 7.13±0.02 cm, respectively. The cranial index was 59.00±0.11. The mean facial length, facial width and facial index were 11.53±0.08 cm, 9.30±0.01 cm and 80.67±0.44 cm, respectively. The mean weight of the skull with mandible in blackbuck was 182.37±0.54.

La apariencia fenotípica de la cabeza de especies animales depende principalmente de la forma del cráneo. Los estudios morfométricos del cráneo muestran que la variabilidad en la forma y proporciones de los huesos está influenciada por factores genéticos y ambientales. El presente estudio se llevó a cabo por primera vez en las características morfométricas en el cráneo del antílope indio. En este estudio se efectuaron mediciones craneométricas en 48 partes de los cráneos de antílope indio. Todas las características investigadas se expresaron como Media±EE. Las mediciones craneométricas e índices cefálicos fueron comparados con los rumiantes. Se encontró que las longitudes medias de los cráneos eran de 20,68±0,02 cm, con el ancho y el índice cefálico de 9,54±0,03 cm y 46,12±0,12 cm, respectivamente. La longitud del cráneo, ancho y alto en antílope indio eran 10,40±0,02 cm, 6,13±0,02 cm y 7,13±0,02 cm, respectivamente. El índice craneal era 59,00±0,11. La longitud media del rostro, ancho facial e índice facial eran 11,53±0,08 cm, 9,30±0,01 cm y 80,67±0,44 cm, respectivamente. El peso medio del cráneo con la mandíbula en el antílope indio fue de 182,37±0,54.

Bovid ecomorphology and hominin paleoenvironments of the Shungura Formation, lower Omo River Valley, Ethiopia.

The Shungura Formation in the lower Omo River Valley, southern Ethiopia, has yielded an important paleontological and archeological record from the Pliocene and Pleistocene of eastern Africa. Fossils are common throughout the sequence and provide evidence of paleoenvironments and environmental change through time. This study developed discriminant function ecomorphology models that linked astragalus morphology to broadly defined habitat categories (open, light cover, heavy cover, forest, and wetlands) using modern bovids of known ecology. These models used seven variables suitable for use on fragmentary fossils and had overall classification success rates of >82%. Four hundred and one fossils were analyzed from Shungura Formation members B through G (3.4-1.9 million years ago). Analysis by member documented the full range of ecomorph categories, demonstrating that a wide range of habitats existed along the axis of the paleo-Omo River. Heavy cover ecomorphs, reflecting habitats such as woodland and heavy bushland, were the most common in the fossil sample. The trend of increasing open cover habitats from Members C through F suggested by other paleoenvironmental proxies was documented by the increase in open habitat ecomorphs during this interval. However, finer grained analysis demonstrated considerable variability in ecomorph frequencies over time, suggesting that substantial short-term variability is masked when grouping samples by member. The hominin genera Australopithecus, Homo, and Paranthropus are associated with a range of ecomorphs, indicating that all three genera were living in temporally variable and heterogeneous landscapes. Australopithecus finds were predominantly associated with lower frequencies of open habitat ecomorphs, and high frequencies of heavy cover ecomorphs, perhaps indicating a more woodland focus for this genus.