Large Horn Research Articles

Does Headbutting Cause Traumatic Brain Injury? The Case of Combative Bovids

Forceful headbutting clashes occur every year during the rut for most bovids. Bighorn sheep (Ovis aries) and muskoxen (Ovibos moschatus) show extreme examples of this behavior, exerting head-to-head forces of over 3000 N. Their large horns are commonly thought to protect them from these impacts, to the extent of inspiring football equipment. However, whether their horns or thick skull successfully prevent brain trauma has not been investigated experimentally until now. The aim of our research is to study anatomical adaptations of animals with extreme behaviors in order to provide solutions to human problems. A better understanding of brain injury, or the prevention thereof in these animals, will provide insight for the reduction of traumatic brain injury (TBI) in humans at a time where clinical translation of experimental therapies is limited. In a preliminary study, we found early signs of chronic brain injury in a male muskox using immunohistochemistry staining for abnormally phosphorylated tau and high-resolution MRI. Applying the same techniques to bighorn sheep is complicated, as their tau expression is not well understood. Despite the possibility of brain trauma, the capacity to survive such forceful impacts and continue to thrive is not negligible. Thus, alongside the brain, we simultaneously investigated anatomical properties of the skull of both species, using an ontogenetic series of skulls and skull CT scans, respectively. The skulls of six muskoxen and six bighorn sheep were bisected to describe the braincase in detail for the first time. The differences between juveniles, adults, males, and females were especially important because of the sexually dimorphic nature of headbutting behavior. In muskoxen for example, the male skull is approximately 300% larger than that of the female. Although the large pneumatized sinuses of species such as the bighorn sheep have been suspected to contribute to force mitigation, they may simply be a scaffolding supporting the rapid growth of large horns. Furthermore, bighorn sheep horn cores are proven to have similar biomechanical properties to that of regular cortical bone. These findings indicate that the horns and sinuses may not be the main means of protection and we instead hypothesize that the brain's position within the braincase, its connection to meninges, and the rough inner-surface of the cranium are what allow these animals to survive such extreme forces. Anatomical descriptions will serve to increase our knowledge of bovid inner-cranial anatomy all while aiming to determine which anatomical features are most likely to protect bovid brains, which in turn could be translated to humans as a preventive strategy for TBI.

An updated population status of Astor Markhor (Capra falconeri falconeri) in Gilgit-Baltistan, Pakistan

Gilgit-Baltistan (Northern Pakistan) has a rich diversity of wild caprinae and is one of key area for caprinae community-based conservation programs. In this program, selective hunting of small proportion of adult males with large horns is done on annual basis to generate money for the conservation, habitat improvement and livelihood of local communities. The current study aimed at collecting reliable data about population status of Astor Markhor (Capra falconeri falconeri). For this purpose, fixed-point direct count method was used for estimation of Astor Markhor population in 16 catchments including 15 Community-Controlled Hunting Areas (CCHAs). A total of 1087 animals were counted, comprising of 266 (24%) males (including sixty-two (6%) trophy-sized males), 388 (36%) females, 227 (21%) yearling and 206 (19%) kids. Population density of Astor Markhor was estimated 0.13 individuals/km2, with male to female ratio 0.69:1, yearling to female 0.54:1 and kids to female 0.51:1. CCHA/catchment wise assessments showed that Kargah area has highest population (211 animals). It is suggested that consequences of trophy hunting should be strictly contingent upon population data obtained through robust methods, duly verified by a panel of conservation experts and may be extended to other areas also for fruitful results.

Стоянка Очью катище на р. Ижма

The Mesolithic archaeological site Ochyu katishche is located on the right bank of the Izhma river in the environs of the village Tom of the Izhma region of the Komi Republic. It is located on the pine forested terrace with a height of 12,5 m. The site was discovered in 2017 and then surveyed in 2018-2019. At the archaeological site the concentration of finds was revealed, where there was a joint occurrence of flint artefacts and a large number of faunal remains of good preservation, including small bones and fragments of large bones and horns, that were identified. The bones of beaver absolutely predominated, the bones of reindeer and elk were also found. There were single fragments of the bones of lynx and marten, as well as those of birds. The presence of a large number of segments and fragments of very large blades was noted. Short proximal segments and middle parts of large blades with irregular edge retouch and small burin spalls were serially presented. The cores in the final knapping stage and the so-called core-burins were presented. According to these indicators, the material of the site Ochyu katishche is similar to the collections of Mesolithic horizons of the archaeological site Vylys Tom 2, located 2 km to the north. Both sites are included in the so-called Izhma-Tom geoarchaeological microregion, where there are other Mesolithic sites with fundamentally different technical and typological indicators of the industry. These are the sites of Lek-Lesa 1, Turunnyur 1 and Ulys Tom 4.

Digest: Sexually selected weapons: Winning the fight, but losing the war for reproduction on a changing battlefield*

What conditions favor the evolution of large animal weapons? In the Japanese rhinoceros beetle, Trypoxylus dichotomus, del Sol et al. found that selection favors large horns in populations where males compete over guardianship of scarce female feeding territories. However, in other populations, an abundance of female feeding territories reduces the chance of mating success for these guarding males, leading to the evolution of relatively shorter horn sizes. This finding illustrates that female habitat and resource use have the potential to influence evolution of male weapon size through sexual selection.

Morphogenesis and formation of the human hyoid bone

Background. Morphogenesis of hyoid bone in early intrauterine development of human is a topical question of anatomical research that is aimed to improve methods of surgical interventions in neck and mandible regions and to supplement data in forensic practice. Objective. To investigate peculiarities of development and morphological transformations of hyoid bone in the early period of human ontogenesis. Methods. 15 specimens of human embryos and prefetuses of 12,0-80,0 mm parietal-coccygeal length (PCL) were investigated by using a set of morphological methods. Results. In human embryos 12,0-13,5 mm PCL, rudiment of hyoid bone is seen as s mesenchymal condensation in second pharyngeal arch area above the level of cervical sinus. In 13,0-13,5 mm PCL embryos, hyoid bone anlage is on prechondrification stage: caudal segment of Reichert’s cartilage forms small horns and mesodermal condensation of III pharyngeal arch forms large horns and body of hyoid. In 50,0-80,0 mm PCL human prefetuses, hyoid part of Reichert’s cartilage, which forms small horns, reaches chondrification stage. The body and large horns of hyoid are connected to small horns, and are found lower the level of tongue anlage. At this stage hyoid bone is an attachment site for the hyoid neck muscles. Conclusions. 1. Rudiment of the hyoid bone is found at the end of embryonic period as a prechondrificational mesenchymal condensation of II and III pharyngeal arches 2. During prefetal period, small horns loose contact with the cranial part of Reichert’s cartilage. 3. Anlage of the hyoid bone during prefetal period is on chondrification stage and is a site of attachment for supra- and infrahyoid muscles.

Male mating behaviour affects growth of secondary sexual traits: a mechanism for rapid phenotypic change

Intra- and intersexual selection drives the evolution of secondary sexual traits, leading to increased body size, trait size and generally increased reproductive success in bearers with the largest, most attractive traits. Evolutionary change through natural selection is often thought of primarily in terms of genetic changes through mutations and adaptive selection. However, this view ignores the role of the plasticity in phenotypes and behaviour and its impact on accelerating or decelerating the expression of sexually selected traits. Here, we argue that sudden changes in selection pressures (e.g. predation pressure) may cause a cascade of behavioural responses, leading to a rapid change in the size of such traits. We propose that selective removal of individuals with the most prominent traits (such as large antlers or horns in male ungulates) induces behavioural changes in the surviving males, leading to a reduction in the growth of these traits (phenotypic expression). To test this idea, we used an individual-based simulation, parametrized with empirical data of male bighorn sheep, Ovis candensis. Our model shows that the expression (phenotype, not genotype) of the trait under selection (here horn size) can be negatively impacted, if the biggest, most dominant males in the population are removed. While the selective removal of prime males opens breeding opportunities for younger, smaller males, we predicted that it would come at the expense of growth and maintenance. As predicted, we observed a rapid decline in average male horn length in our model. We argue that this decline happens because smaller males, instead of allocating energy into growth, divert this energy towards participation in mating activities that are typically exclusively available to prime males. While our model deals with ecological life-history trade-offs, it cannot predict evolutionary outcomes. However, this nongenetic mechanism is important for the understanding of evolutionary processes because it describes how heritable traits can rapidly change because of behavioural plasticity, long before any genetic changes might be detectable.

Laparoscopic Excision of a Noncommunicating Uterine Horn Pregnancy

Study Objective To describe the diagnostic challenge and surgical management of a noncommunicating uterine horn pregnancy. Design Clinical history, brief literature review, and video documentation. Setting Patient was placed in dorsal lithotomy for laparoscopic resection of a uterine horn pregnancy in a tertiary care center. Patients or Participants The patient was a 29 year old G1P0 female presenting with a live 11-week extrauterine pregnancy. Radiologic work-up with both pelvic ultrasound and MRI could not fully ascertain diagnosis. Differential diagnosis included tubal ectopic, horn pregnancy of a bicornuate uterus, interstitial pregnancy, and broad ligament pregnancy. Given this was a wanted pregnancy, intra-sac potassium chloride was not administered pre-operatively and the patient was consented for a diagnostic laparoscopy and possible removal of ectopic pregnancy. Interventions Laparoscopy Measurements and Main Results Diagnostic laparoscopy was undertaken where pelvic inspection revealed a right-sided normal appearing unicornuate uterus and a large left rudimentary noncommunicating horn distended by the pregnancy. The pregnancy was connected to the unicornuate uterus via a thick fibrous band. This confirmed a pregnancy in a Type II-B Mullerian anomaly as per the ASRM classification system. Such pregnancies are rare ranging from 1 in 75,000-150,000. Our video demonstrates a stepwise approach for the excision of such pregnancies including isolation of the ureter retroperitoneally, bladder dissection, use of peritoneal landmarks to ensure safe transection of the fibrous band, and use of hemostatic techniques such as vasopressin and advanced bipolar devices. In addition, we demonstrate a simple technique for oophoropexy where we stabilize a hypermobile ovary to the round ligament pedicle using a laparoscopic ligature device. Conclusion Rudimentary horn pregnancies are rare and pose a diagnostic challenge. Complications are common with >50% of such pregnancies presenting ruptured, thus resection is often recommended. We demonstrate that laparoscopy is a safe and feasible option to manage such pregnancies.

Formation and phenotypic performance of the new breed POGASI Agrinak cattle

To increase domestic meat production is needed beef cattles which can be cultivated in marginal areas with feed conditions that are limited in quality and quantity. The new breed of POGASI (PO Grati Hasil Seleksi) Agrinak cattle is formed to have optimal productivity in provision of low-quality feed. Ongole Crossed (OC) cattle from selection at farmers in 2002– 2003, are developed in experimental stall at Beef Cattle Research Station by gradually selected and regulation of mating into optimum excellence in providing low quality feed (low crude protein and energy but high crude fiber, made from agricultural by-products and by-products of processing agricultural products), continuously extorting for 14 years. In 2017, the new breed beef cattle, POGASI Agrinak, is formed which is the fourth generation. POGASI cattle has penotypic performance specific, likes body color is yellowish white, short and large horns, hump grows upward, screw is small but wide, body weight and size are greater and ability to utilize feed nutrients is better than compared to OC cattle. POGASI cattle are suitable to be cultivated in marginal areas where feed availability is limited in quality and quantity.

Anatomical and histological observations on a musk ox brain (Ovibos moschatus)

Musk oxen are large tundra‐dwelling bovids that, when in rut, can strike heads at speeds around 30 mph. The wide base of their large horns armor their skull against such impacts, although it is unknown if they sustain brain trauma. There is no literature describing concussion, or other adverse repercussions of severe cranial contact in musk oxen. Our research explores the brain and skull anatomy of combative bovids, specifically focusing on whether these animals sustain brain injury after head‐butting, and if not, what features most likely provide protection. Achieving a better understanding of how these extreme animals may avoid brain injury will provide insight to develop strategies for the reduction of traumatic brain injury in humans.An archived brain of an adult male musk ox was used in this preliminary study. It had been collected after humane euthanasia and preserved in formalin following a goring injury in the wild where it had been observed clashing heads with another musk ox bull in the moments before its death. The brain was MR scanned and examined histologically for evidence of traumatic brain injury. The right hemisphere was fixed in paraformaldehyde (4%, buffered) and prepared using a variety of exploratory histological protocols, to investigate abnormalities in neurons, microglia, astrocytes, and blood vessels. Specifically, Tau protein, a biomarker found in the cerebrospinal fluid and in neurodegenerative lesions, was used to detect any brain trauma‐related cellular consequence of chronic or acute head clashing. Preliminary histological results indicate no apparent abnormalities. A high‐resolution 7‐T MRI scan additionally revealed no abnormal neuropathological changes. This brain being a single sample does not allow us to make sweeping assumptions. However, these preliminary investigations lead us to believe that musk oxen do not appear to suffer from chronic or acute brain trauma after head clashing. A more in‐depth exploration with a larger sample size is proposed to better understand the combination of anatomical structures contributing to brain protection in these animals.Support or Funding InformationNLA is a fellow of the Swiss National Science Foundation

Histamine H3 Receptors Expressed in Ventral Horns Modulate Spinal Motor Output.

Motoneuron activity is modulated by histamine receptors. While H1 and H2 receptors have been widely explored, H3 histamine receptors (H3Rs) have not been sufficiently characterized. This paper targets the effects of the selective activation of H3Rs and their expression on the membranes of large ventral horn cells. The application of selective pharmacological agents to spinal cords isolated from neonatal rats was used to identify the presence of functional H3Rs on the membrane of physiologically identified lumbar motoneurons. Intra and extracellular recordings revealed that H3R agonist, α-methylhistamine, depolarized both single motoneurons and ventral roots, even in the presence of tetrodotoxin, an effect prevented by H3R antagonist, thioperamide. Finally, immunohistochemistry located the expression of H3Rs on a subpopulation of large cells in lamina IX. This study identifies H3Rs as a new exploitable pharmacological target against motor disturbances.

The multistep morphing of beetle horns.

Genes that specify insect wings initiate horn development in dung beetles

Density-dependent decline of early horn growth in European mouflon

The development of horns in Caprinae can be largely influenced by food-limiting factors such as population density and climate, as well as by negative evolutionary responses to size-selective harvesting. In this study, we investigated the effects of population density, environmental covariates and trophy hunting on horn development in a population of European mouflon Ovis aries musimon introduced to the Mediterranean region of Croatia in the early 1980s. The study population was subject to commercial trophy hunting on males since the mid-1980s. This allowed to analyse the temporal trend in early horn growth in 341 rams legally culled. Cohort-based linear model and analysis of deviance (ANODEV) revealed a significant negative trend in early horn growth, with a decline of ca. 10% over only 15 cohorts (1993–2007). The increase in population density (by ca. 600%) and summer temperature, selected via LASSO regression, explained about 61% and 13% of the decline in early horn growth, as revealed by the ANODEV R2. Our results suggest a prominent role of food-limiting factors in the decline of weapon size. We also found a negative relationship between age at death and early horn growth in our study population, which suggests the occurrence of hunters’ selectivity towards large horns. The effect of trophy hunting on the decline in horn size, however, is difficult to quantify. Our analysis was largely influenced by the rapid increase of mouflon density after introduction, thereby limiting the possibility to detect potential effects of hunting selection, although the large number of rams shot before 5 years of age may possibly lead to undesirable consequences of trophy hunting on mating success. To clarify the consequences of commercial trophy hunting on the mouflon population, the long-term pattern of horn growth and the age-dependent male siring success should be further investigated.

Biological relevance of antler, horn, and pronghorn size in records programs

AbstractLong-term datasets are becoming increasingly important for assessing population- and species-level responses to a changing environment. Programs that record morphological measurements of horns, antlers, and pronghorns were established in the early- to mid-20th century to collect biological information about animals that possess large horns, antlers, or pronghorns, which could be used to assess the effectiveness of conservation efforts for large mammals in North America. The general relevance of record books has been questioned because of the minimum size requirements for inclusion in a record book, which may mask trends when changes in the population occur. We compared trends in size of antlers, horns, and pronghorns through time using records from three records programs with different minimum size requirements to evaluate the influence of entry requirements on temporal trends. We also investigated whether horn, antler, or pronghorn size affected the probability of specimens being submitted to a records program. Only two of 17 categories exhibited less-pronounced trends in the record book with the highest size requirements for entry, and in two categories trends were more pronounced. Although societal interest in submitting eligible specimens increased slightly over time in one of six categories, the probability of voluntary entry was largely random and not affected by year of harvest or size of specimen. In contrast to previous criticisms, trends in record books should not be expected to represent the size of all males within a population. Instead, our evaluation indicates that the records programs we examined can provide a useful resource for assessing long-term changes in phenotypic characteristics of ungulates, but importantly, they represent the respective range of sizes within which each program collects data.

Hunting and mountain sheep: Do current harvest practices affect horn growth?

The influence of human harvest on evolution of secondary sexual characteristics has implications for sustainable management of wildlife populations. The phenotypic consequences of selectively removing males with large horns or antlers from ungulate populations have been a topic of heightened concern in recent years. Harvest can affect size of horn‐like structures in two ways: (a) shifting age structure toward younger age classes, which can reduce the mean size of horn‐like structures, or (b) selecting against genes that produce large, fast‐growing males. We evaluated effects of age, climatic and forage conditions, and metrics of harvest on horn size and growth of mountain sheep (Ovis canadensis ssp.) in 72 hunt areas across North America from 1981 to 2016. In 50% of hunt areas, changes in mean horn size during the study period were related to changes in age structure of harvested sheep. Environmental conditions explained directional changes in horn growth in 28% of hunt areas, 7% of which did not exhibit change before accounting for effects of the environment. After accounting for age and environment, horn size of mountain sheep was stable or increasing in the majority (~78%) of hunt areas. Age‐specific horn size declined in 44% of hunt areas where harvest was regulated solely by morphological criteria, which supports the notion that harvest practices that are simultaneously selective and intensive might lead to changes in horn growth. Nevertheless, phenotypic consequences are not a foregone conclusion in the face of selective harvest; over half of the hunt areas with highly selective and intensive harvest did not exhibit age‐specific declines in horn size. Our results demonstrate that while harvest regimes are an important consideration, horn growth of harvested male mountain sheep has remained largely stable, indicating that changes in horn growth patterns are an unlikely consequence of harvest across most of North America.

Grating lobe suppression using grid cover structures on horn arrays with linear and circular polarizations

AbstractIn this letter, a 2 × 2 pyramidal horn antenna array is presented to accomplish linear and circular polarizations with suppressed grating lobes using removable grid cover structures (GCSs) mounted on the top of the antenna array. The spacing between the unit cells becomes farther than a wavelength due to electrically large pyramidal horns and the feeding network. The proposed GCSs, called linear and circular GCS, in this arrangement act as a spacing reducer between the apertures of the horn antennas without the need of physical change of the spacings. Thereby, the desired array factor with newly created apertures can be realized. Although using both GCSs benefit to suppress the highest‐level grating lobe, the circular GCS also converts the polarization to circular. The feeding network, which also prevents a formal array factor due to its massive structure, is made up of equal power dividers with T‐junction waveguides. The proposed horn arrays, the feeding network, and both GCSs are fabricated, and the total antenna is measured to validate the simulation results. A good agreement is achieved between simulations and measurements.

Intercomparison of Soil Moisture Retrieved from GNSS-R and from Passive L-Band Radiometry at the Valencia Anchor Station.

In this paper, the SOMOSTA (Soil Moisture Monitoring Station) experiment on the intercomparison of soil moisture monitoring from Global Navigation Satellite System Reflectometry (GNSS-R) signals and passive L-band microwave radiometer observations at the Valencia Anchor Station is introduced. The GNSS-R instrument has an up-looking antenna for receiving direct signals from satellites, and a dual-pol down-looking antenna for receiving LHCP (left-hand circular polarization) and RHCP (right-hand circular polarization) reflected signals from the soil surface. Data were collected from the three different antennas through the two channels of Oceanpal GNSS-R receiver and, in addition, calibration was performed to reduce the impact from the differing channels. Reflectivity was thus measured, and soil moisture could be retrieved. The ESA (European Space Agency)-funded ELBARA-II (ESA L Band Radiometer II) is an L-band radiometer with two channels with 11 MHz bandwidth and respective center frequencies of 1407.5 MHz and 1419.5 MHz. The ELBARAII antenna is a large dual-mode Picket horn that is 1.4 m wide, with a length of 2.7 m with −3 dB full beam width of 12° (±6° around the antenna main direction) and a gain of 23.5 dB. By comparing GNSS-R and ELBARA-II radiometer data, a high correlation was found between the LHCP reflectivity measured by GNSS-R and the horizontal/vertical reflectivity from the radiometer (with correlation coefficients ranging from 0.83 to 0.91). Neural net fitting was used for GNSS-R soil moisture inversion, and the RMSE (Root Mean Square Error) was 0.014 m3/m3. The determination coefficient between the retrieved soil moisture and in situ measurements was R2 = 0.90 for Oceanpal and R2 = 0.65 for Elbara II, and the ubRMSE (Unbiased RMSE) were 0.0128 and 0.0734 respectively. The soil moisture retrievals by both L-band remote sensing methods show good agreement with each other, and their mutual correspondence with in-situ measurements and with rainfall was also good.

Habitat utilization by an intertidal isopod, Dynoides dentisinus Shen, 1929 (Isopoda, Sphaeromatidae)

Abstract Intertidal isopods use a variety of living or non-living objects as habitats, although only a few studies have been made on their ecological function and significance. In the present study, the habitat utilization by the sphaeromatid isopod, Dynoides dentisinus was recorded based on observations on intertidal rocky shores in the warm temperate zone of Japan during the period from 2014 to 2018. The adults of this species have a remarkable sexual dimorphism in the morphology of their armature: adult males possess an elongate pleonal process, like a large horn, on the dorsal side of the pleon and have large uropods. On the other hand, females do not have such a horn, and the uropods are small. Differences in habitat use were seen according to the stage in the life history of the species. Juveniles lived on, or amongst, algae and were sometimes associated with molluscs such as chitons, limpets and whelks. Adults inhabited the cryptic habitats such as gaps in algal holdfasts, oscula of demosponges, dead barnacle shells, cavities of dead corals, and crevices in sand rocks. Generally, a single adult male was present in each cryptic habitat, keeping head in down position, and one or more females cohabited inside with the male. These suggest that D. dentisinus has a biphasic life history; juveniles live and feed on algal cover or use the spaces between the ventral sides of the molluscs and the surfaces of the rocks as a refuge from desiccation. Adults breed in the cryptic habitats, forming a polygynous group.

Long-term effects of direct current are reproduced by intermittent depolarization of myelinated nerve fibers.

Direct current (DC) potently increases the excitability of myelinated afferent fibers in the dorsal columns, both during DC polarization of these fibers and during a considerable (>1 h) postpolarization period. The aim of the present study was to investigate whether similarly long-lasting changes in the excitability of myelinated nerve fibers in the dorsal columns may be evoked by field potentials following stimulation of peripheral afferents and by subthreshold epidurally applied current pulses. The experiments were performed in deeply anesthetized rats. The effects were monitored by changes in nerve volleys evoked in epidurally stimulated hindlimb afferents and in the synaptic actions of these afferents. Both were found to be facilitated during as well as following stimulation of a skin nerve and during as well as following epidurally applied current pulses of 5- to 10-ms duration. The facilitation occurring ≤2 min after skin nerve stimulation could be linked to both primary afferent depolarization and large dorsal horn field potentials, whereas the subsequent changes (up to 1 h) were attributable to effects of the field potentials. The findings lead to the conclusion that the modulation of spinal activity evoked by DC does not require long-lasting polarization and that relatively short current pulses and intrinsic field potentials may contribute to plasticity in spinal activity. These results suggest the possibility of enhancing the effects of epidural stimulation in human subjects by combining it with polarizing current pulses and peripheral afferent stimulation and not only with continuous DC. NEW & NOTEWORTHY The aim of this study was to define conditions under which a long-term increase is evoked in the excitability of myelinated nerve fibers. The results demonstrate that a potent and long-lasting increase in the excitability of afferent fibers traversing the dorsal columns may be induced by synaptically evoked intrinsic field as well as by epidurally applied intermittent current pulses. They thus provide a new means for the facilitation of the effects of epidural stimulation.

Horn size and nutrition in mountain sheep: Can ewe handle the truth?

ABSTRACTHorns, antlers, and other horn‐like structures are products of sexual selection, confer reproductive advantages, and are heritable and honest indicators of individual quality. In addition to serving key biological functions, horns and antlers garner societal interest that, when combined with the powerful motivation to acquire trophy animals, likely has spawned a growing hornographic culture fixated on males with exceptional horn‐like structures. The concern that harvest of large, fast‐growing males may cause evolutionary change to the very trait being sought has been the source of controversy in the popular and scientific literature over the past 2 decades. Mountain sheep (i.e., bighorn and thinhorn; Ovis spp.), possibly the only large ungulates in North America managed almost exclusively as trophy species throughout their ranges, embody this controversy, which has led to polarizing views among scientists and stakeholders as to how mountain sheep should be managed. Our goal in this commentary was to discuss the relative contributions of the key ecological and intrinsic factors that influence horn growth, how those factors might interact with harvest strategies, and identify what determinants of horn size are most amenable to management and most effective in achieving desired outcomes. Despite repeated results demonstrating that age or nutrition frequently override genetic contributions to size of horns, attention has been given to the role of genetics and its relationship to harvest of mountain sheep. Given the hyperbole surrounding trophy management and big horns, we suggest the importance of females in the management of mountain sheep has been largely forgotten. Maternal condition can instigate life‐long effects on size and growth of males (via maternal effects), and abundance of females, in turn, affects nutritional limitation within populations through density‐dependent feedbacks. If production of males with large horns is an objective, we contend that management programs should, integrate monitoring of nutritional status of populations, and where evidence indicates nutritional limitation through density dependence, seek to regulate abundance and per capita nutrition via harvest of females. We propose that extrinsic regulation (i.e., removal by harvest or translocation) is the most effective way to manage per capita availability of forage resources and, thus, nutritional limitation on growth of males. Not only can female harvest improve growth in body size and horns of males through enhanced nutrition of growing males and their mothers, such management also 1) may yield a nutritional buffer against environmental stochasticity and erratic population fluctuations, 2) be employed in areas where other management alternatives such as habitat manipulation may not be feasible, 3) may reduce frequency or magnitude of epizootic die‐offs, and 4) will increase hunter opportunity and involvement in management. Ultimately, we call for greater recognition of the pervasive role of the ewe, and other female ungulates, in the production of trophy males, and that accordingly, females be better integrated into harvest and management programs. © 2017 The Wildlife Society.

A new horned and long-necked herbivorous stem-archosaur from the Middle Triassic of India

The early evolution of archosauromorphs (bird- and crocodile-line archosaurs and stem-archosaurs) represents an important case of adaptive radiation that occurred in the aftermath of the Permo-Triassic mass extinction. Here we enrich the early archosauromorph record with the description of a moderately large (3–4 m in total length), herbivorous new allokotosaurian, Shringasaurus indicus, from the early Middle Triassic of India. The most striking feature of Shringasaurus indicus is the presence of a pair of large supraorbital horns that resemble those of some ceratopsid dinosaurs. The presence of horns in the new species is dimorphic and, as occurs in horned extant bovid mammals, these structures were probably sexually selected and used as weapons in intraspecific combats. The relatively large size and unusual anatomy of Shringasaurus indicus broadens the morphological diversity of Early–Middle Triassic tetrapods and complements the understanding of the evolutionary mechanisms involved in the early archosauromorph diversification.