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Tyrannosaurid dinosaurs dominated as predators in the Late Cretaceous of Laurasia, culminating in the evolution of the giant Tyrannosaurus rex, both the last and largest tyrannosaurid. Where and when Tyrannosaurini (T. rex and kin) originated remains unclear. Competing hypotheses place tyrannosaurin origins in Asia, or western North America (Laramidia). We report a new tyrannosaurin, Tyrannosaurus mcraeensis, from the Campanian-Maastrichtian Hall Lake Formation of New Mexico, based on a fossil previously referred to T. rex. T. mcraeensis predates T. rex by ~ 6-7 million years, yet rivaled it in size. Phylogenetic analysis recovers T. mcraeensis as sister to T. rex and suggests Tyrannosaurini originated in southern Laramidia. Evolution of giant tyrannosaurs in southern North America, alongside giant ceratopsians, hadrosaurs, and titanosaurs suggests large-bodied dinosaurs evolved at low latitudes in North America., (© 2023. The Author(s).)

Tyrannosaurids were large carnivorous dinosaurs that underwent major changes in skull robusticity and body proportions as they grew, suggesting that they occupied different ecological niches during their life span. Although adults commonly fed on dinosaurian megaherbivores, the diet of juvenile tyrannosaurids is largely unknown. Here, we describe a remarkable specimen of a juvenile Gorgosaurus libratus that preserves the articulated hindlimbs of two yearling caenagnathid dinosaurs inside its abdominal cavity. The prey were selectively dismembered and consumed in two separate feeding events. This predator-prey association provides direct evidence of an ontogenetic dietary shift in tyrannosaurids. Juvenile individuals may have hunted small and young dinosaurs until they reached a size when, to satisfy energy requirements, they transitioned to feeding on dinosaurian megaherbivores. Tyrannosaurids occupied both mesopredator and apex predator roles during their life span, a factor that may have been key to their evolutionary success.

Counts of the number of skeletal specimens of "adult" megaherbivores and large theropods from the Morrison and Dinosaur Park formations-if not biased by taphonomic artifacts-suggest that the big meat-eaters were more abundant, relative to the number of big plant-eaters, than one would expect on the basis of the relative abundance of large carnivores and herbivores in modern mammalian faunas. Models of megaherbivore population density (number of individuals per square kilometer) that attempt to take into account ecosystem productivity, the size structure of megaherbivore populations, and individual megaherbivore energy requirements, when combined with values of the large theropod/megaherbivore abundance ratio, suggest that large theropods may have been more abundant on the landscape than estimates extrapolated from the population density versus body mass relationship of mammalian carnivores. Models of the meat production of megaherbivore populations and the meat requirements of "adult" large theropods suggest that herbivore productivity would have been insufficient to support the associated number of individuals of "adult" large theropods, unless the herbivore production/biomass ratio was substantially higher, and/or the large theropod meat requirement markedly lower, than expectations based on modern mammals. Alternatively, or in addition to one or both of these other factors, large theropods likely included dinosaurs other than megaherbivores as significant components of their diet., (© 2022 The Authors. The Anatomical Record published by Wiley Periodicals LLC on behalf of American Association for Anatomy.)

Dromaeosaurids (Theropoda: Dromaeosauridae), a group of dynamic, swift predators, have a sparse fossil record, particularly at the end of the Cretaceous Period. The recently described Dineobellator notohesperus, consisting of a partial skeleton from the Upper Cretaceous (Maastrichtian) of New Mexico, is the only diagnostic dromaeosaurid to be recovered from the latest Cretaceous of the southwestern United States. Reinterpreted and newly described material include several caudal vertebrae, portions of the right radius and pubis, and an additional ungual, tentatively inferred to be from manual digit III. Unique features, particularly those of the humerus, unguals, and caudal vertebrae, distinguish D. notohesperus from other known dromaeosaurids. This material indicates different physical attributes among dromaeosaurids, such as use of the forearms, strength in the hands and feet, and mobility of the tail. Several bones in the holotype exhibit abnormal growth and are inferred to be pathologic features resulting from an injury or disease. Similar lengths of the humerus imply Dineobellator and Deinonychus were of similar size, at least regarding length and/or height, although the more gracile nature of the humerus implies Dineobellator was a more lightly built predator. A new phylogenetic analysis recovers D. notohesperus as a dromaeosaurid outside other previously known and named clades. Theropod composition of the Naashoibito Member theropod fauna is like those found in the more northern Late Cretaceous North American ecosystems. Differences in tooth morphologies among recovered theropod teeth from the Naashoibito Member also implies D. notohesperus was not the only dromaeosaurid present in its environment., (© 2022 American Association for Anatomy.)

Isolated teeth, previously referred to Aves, are more common than other bird fossils from the Late Cretaceous of Alberta. However, there are no known morphological synapomorphies that distinguish isolated bird teeth, and features of these teeth are generally shared with those of non-avian theropods and crocodilians. Here, specimens ranging from Late Santonian to Late Maastrichtian in age are described and qualitatively categorized into morphotypes, most of which strongly resemble teeth of extant juvenile and some fossil crocodilians. Variation within this sample of teeth may therefore reflect the heterodont dentition of crocodilians, rather than avian species diversity. Quantitative analysis Principal Component Analysis was mostly uninformative, with limited overlap between putative avian teeth and those of known Cretaceous birds, crocodilians, and non-avian theropods. The reassignment of these putative avian teeth to Crocodylia has important ramifications for our understanding of the evolutionary history of Cretaceous birds., Competing Interests: The authors have declared that no competing interests exist., (Copyright: © 2023 Mohr et al. This is an open access article distributed under the terms of the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.)

In the present study, we investigated the effects of the glucagon-like peptide-1 (GLP-1) agonist exendin-4 (Ex-4) on the stimulatory action of neuropeptide Y (NPY) and ghrelin. These effects were examined in relation to operant responding for palatable food or voluntary ethanol intake in a two-bottle limited access paradigm. Male Sprague Dawley rats, each with ventral tegmental area (VTA) unilateral guide cannulae, were used. Ex-4 was paired with either NPY, ghrelin, or combined NPY and ghrelin treatment. Our results indicated that while NPY and ghrelin reliably stimulated operant responding for sucrose pellets and increased ethanol intake, Ex-4 suppressed intake and, most importantly, significantly reduced the effects of NPY and ghrelin. Overall, this work provides compelling evidence that VTA GLP-1, NPY, and ghrelin systems interact within the brain to modulate reward salience., (Copyright © 2022 Elsevier B.V. All rights reserved.)

Streamlining a body is a major adaptation for aquatic animals to move efficiently in the water. Whereas diving birds are well known to have streamlined bodies, such body shapes have not been documented in non-avian dinosaurs. It is primarily because most known non-avian theropods are terrestrial, barring a few exceptions. However, clear evidence of streamlined bodies is absent even in the purported semiaquatic groups. Here we report a new theropod, Natovenator polydontus gen. et sp. nov., from the Upper Cretaceous of Mongolia. The new specimen includes a well-preserved skeleton with several articulated dorsal ribs that are posterolaterally oriented to streamline the body as in diving birds. Additionally, the widely arched proximal rib shafts reflect a dorsoventrally compressed ribcage like aquatic reptiles. Its body shape suggests that Natovenator was a potentially capable swimming predator, and the streamlined body evolved independently in separate lineages of theropod dinosaurs., (© 2022. The Author(s).)

In this study, we use an exceptional skeleton of the pachycephalosaur Stegoceras validum (UALVP 2) to inform a comprehensive appendicular muscle reconstruction of the animal, with the goal of better understanding the functional morphology of the pachycephalosaur postcranial skeleton. We find that S. validum possessed a conservative forelimb musculature, particularly in comparison to early saurischian bipeds. By contrast, the pelvic and hind limb musculature are more derived, reflecting peculiarities of the underlying skeletal anatomy. The iliotibialis, ischiocaudalis, and caudofemoralis muscles have enlarged attachment sites and the caudofemoralis has greater leverage owing to the distal displacement of the fourth trochanter along the femur. These larger muscles, in combination with the wide pelvis and stout hind limbs, produced a stronger, more stable pelvic structure that would have proved advantageous during hypothesized intraspecific head-butting contests. The pelvis may have been further stabilized by enlarged sacroiliac ligaments, which stemmed from the unique medial iliac flange of the pachycephalosaurs. Although the pubis of UALVP 2 is not preserved, the pubes of other pachycephalosaurs are highly reduced. The puboischiofemoralis musculature was likely also reduced accordingly, and compensated for by the aforementioned improved pelvic musculature., Competing Interests: The authors have declared that no competing interests exist.

Modern birds are typified by the presence of feathers, complex evolutionary innovations that were already widespread in the group of theropod dinosaurs (Maniraptoriformes) that include crown Aves. Squamous or scaly reptilian-like skin is, however, considered the plesiomorphic condition for theropods and dinosaurs more broadly. Here, we review the morphology and distribution of non-feathered integumentary structures in non-avialan theropods, covering squamous skin and naked skin as well as dermal ossifications. The integumentary record of non-averostran theropods is limited to tracks, which ubiquitously show a covering of tiny reticulate scales on the plantar surface of the pes. This is consistent also with younger averostran body fossils, which confirm an arthral arrangement of the digital pads. Among averostrans, squamous skin is confirmed in Ceratosauria (Carnotaurus), Allosauroidea (Allosaurus, Concavenator, Lourinhanosaurus), Compsognathidae (Juravenator), and Tyrannosauroidea (Santanaraptor, Albertosaurus, Daspletosaurus, Gorgosaurus, Tarbosaurus, Tyrannosaurus), whereas dermal ossifications consisting of sagittate and mosaic osteoderms are restricted to Ceratosaurus. Naked, non-scale bearing skin is found in the contentious tetanuran Sciurumimus, ornithomimosaurians (Ornithomimus) and possibly tyrannosauroids (Santanaraptor), and also on the patagia of scansoriopterygids (Ambopteryx, Yi). Scales are surprisingly conservative among non-avialan theropods compared to some dinosaurian groups (e.g. hadrosaurids); however, the limited preservation of tegument on most specimens hinders further interrogation. Scale patterns vary among and/or within body regions in Carnotaurus, Concavenator and Juravenator, and include polarised, snake-like ventral scales on the tail of the latter two genera. Unusual but more uniformly distributed patterning also occurs in Tyrannosaurus, whereas feature scales are present only in Albertosaurus and Carnotaurus. Few theropods currently show compelling evidence for the co-occurrence of scales and feathers (e.g. Juravenator, Sinornithosaurus), although reticulate scales were probably retained on the mani and pedes of many theropods with a heavy plumage. Feathers and filamentous structures appear to have replaced widespread scaly integuments in maniraptorans. Theropod skin, and that of dinosaurs more broadly, remains a virtually untapped area of study and the appropriation of commonly used techniques in other palaeontological fields to the study of skin holds great promise for future insights into the biology, taphonomy and relationships of these extinct animals., (© 2022 Cambridge Philosophical Society.)

In order to further elucidate the role of mesolimbic peptides in the expression of ethanol reward, the present study investigated the effects of ghrelin and glucagon-like peptide-1 (GLP-1) on ethanol intake, in addition to ethanol intake stimulated by systemic d-amphetamine or cocaine treatment. While a number of studies suggest that ghrelin plays an important role in mesolimbic reward, emerging data now indicate that GLP-1 receptor mechanisms inhibit reward signaling, possibly by directly or indirectly inhibiting ghrelinergic activity within the mesolimbic system. In the present study all rats were initially habituated to a 6% ethanol solution. We then demonstrated that intraperitoneal injections of d-amphetamine and cocaine increased ethanol intake compared to the vehicle condition. In subsequent testing we examined the effects of ventral tegmental area (VTA) ghrelin or vehicle paired with a fixed dose of d-amphetamine or vehicle. In separate rats we then investigated the impact of the GLP-1 agonist exendin-4 (Ex-4), injected into the VTA, on ethanol intake alone, or when Ex-4 was co-administered with d-amphetamine or cocaine. Our results indicated that VTA ghrelin significantly increased ethanol intake, and most importantly, potentiated the effect of d-amphetamine and cocaine on ethanol consumption. Conversely, VTA Ex-4 inhibited ethanol intake and antagonized the stimulatory effect of d-amphetamine and cocaine on ethanol consumption. In a final study we further demonstrated that VTA Ex-4 treatment significantly inhibited the combined stimulatory effects of ghrelin paired with d-amphetamine or ghrelin paired with cocaine. Overall our findings are consistent with a critical role for both ghrelin and GLP-1 receptor mechanisms in mesolimbic ethanol reward circuitry. Moreover, our results further suggest that ghrelin and GLP-1 modulate the stimulatory effect of psychostimulants on ethanol intake., (Copyright © 2021 Elsevier B.V. All rights reserved.)

A growing body of evidence links prenatal and early postnatal acetaminophen (APAP) exposure to atypical development of brain and behavior. In adult rodents, APAP is known to produce oxidative stress and lower anxiety-related behavior following acute exposure. In models of early-life exposure, APAP has also been shown to alter anxiety-related and other behaviors. Since the neuropeptide ghrelin has been recently shown to reduce oxidative stress markers and act as a neuroprotectant, we hypothesized that exposure to ghrelin prior to exposure to APAP would mitigate the behavioral effects of APAP exposure. On postnatal day 7, pups were administered doses of either APAP (51.97 mg/kg), ghrelin (1 mg/kg/ml), ghrelin + APAP, or vehicle only. As adults, anxiety-related behavior was assessed in the open field and elevated plus maze. Behavior differed based upon treatment condition. In rats unexposed to ghrelin, APAP treatment resulted in increased exploration (i.e., reduced anxiety) in the open field relative to controls. Rats co-administered APAP and ghrelin did not differ from vehicle-only controls. No significant effects of APAP or interactions between APAP and ghrelin exposures were observed in the elevated plus maze. These results are the first to demonstrate that ghrelin can mitigate the effects of perinatal APAP exposure in rats., (© 2022 Wiley Periodicals LLC.)

Michael Benton and colleagues reminisce about the discovery of Sinosauripteryx, the first feathered dinosaur., (Copyright © 2021 Elsevier Inc. All rights reserved.)

The Nemegt Formation of the Gobi Desert of Mongolia has produced one of the most abundant and diverse oviraptorosaur records globally. However, the caenagnathid component of this fauna remains poorly known. Two caenagnathid taxa are currently recognized from the Nemegt Formation: Elmisaurus rarus and Nomingia gobiensis. Because these taxa are known from mostly non-overlapping material, there are concerns that they could represent the same animal. A partial, weathered caenagnathid skeleton discovered adjacent to the holotype quarry of Nomingia gobiensis is referable to Elmisaurus rarus, revealing more of the morphology of the cranium, mandible, pectoral girdle, and pubis. Despite metatarsals clearly exhibiting autapomorphies of Elmisaurus rarus, overlapping elements are identical to those of Nomingia gobiensis, and add to a growing body of evidence that these taxa represent a single morphotype. In the absence of any positive evidence for two caenagnathid taxa in the Nemegt Formation, Nomingia gobiensis is best regarded as a junior synonym of Elmisaurus rarus. Low caenagnathid diversity in the Nemegt Formation may reflect broader coexistence patterns with other oviraptorosaur families, particularly oviraptorids. In contrast to North America, competition with the exceptionally diverse oviraptorids may have restricted caenagnathids to marginal roles in Late Cretaceous Asian ecosystems., Competing Interests: The authors have declared that no competing interests exist.

The question why non-avian dinosaurs went extinct 66 million years ago (Ma) remains unresolved because of the coarseness of the fossil record. A sudden extinction caused by an asteroid is the most accepted hypothesis but it is debated whether dinosaurs were in decline or not before the impact. We analyse the speciation-extinction dynamics for six key dinosaur families, and find a decline across dinosaurs, where diversification shifted to a declining-diversity pattern ~76 Ma. We investigate the influence of ecological and physical factors, and find that the decline of dinosaurs was likely driven by global climate cooling and herbivorous diversity drop. The latter is likely due to hadrosaurs outcompeting other herbivores. We also estimate that extinction risk is related to species age during the decline, suggesting a lack of evolutionary novelty or adaptation to changing environments. These results support an environmentally driven decline of non-avian dinosaurs well before the asteroid impact.

A new articulated postcranial specimen of an indeterminate ankylosaurid dinosaur from the Upper Cretaceous (middle-upper Campanian) Baruungoyot Formation from Hermiin Tsav, southern Gobi Desert, Mongolia includes twelve dorsal vertebrae, ribs, pectoral girdles, forelimbs, pelvic girdles, hind limbs, and free osteoderms. The new specimen shows that Asian ankylosaurids evolved rigid bodies with a decreased number of pedal phalanges. It also implies that there were at least two forms of flank armor within Ankylosauridae, one with spine-like osteoderms and the other with keeled rhomboidal osteoderms. Unique anatomical features related to digging are present in Ankylosauridae, such as dorsoventrally flattened and fusiform body shapes, extensively fused series of vertebrae, anteroposteriorly broadened dorsal ribs, a robust humerus with a well-developed deltopectoral crest, a short robust ulna with a well-developed olecranon process, a trowel-like manus, and decreased numbers of pedal phalanges. Although not fossorial, ankylosaurids were likely able to dig the substrate, taking advantage of it for self-defence and survival.

Locomotion is a fundamental aspect of palaeobiology and often investigated by comparing osteological structures and proportions. Previous studies document a stepwise accumulation of avian-like features in theropod dinosaurs that accelerates in the clade Maniraptora. However, the soft tissues that influenced the skeleton offer another perspective on locomotory adaptations. Examination of the pelvis for osteological correlates of hind limb and tail musculature allowed reconstruction of primary locomotory muscles across theropods and their closest extant relatives. Additionally, the areas of pelvic muscle origins were quantified to measure relative differences within and between taxa, to compare morphological features associated with cursoriality, and offer insight into the evolution of locomotor modules. Locomotory inferences based on myology often corroborate those based on osteology, although they occasionally conflict and indicate greater complexity than previously appreciated. Maniraptoran pelvic musculature underscores previous studies noting the multifaceted nature of cursoriality and suggests that a more punctuated step in caudal decoupling occurred at or near the base of Maniraptora., Competing Interests: The authors declare there are no competing interests., (©2021 Rhodes et al.)

A characteristic fauna of dinosaurs and other vertebrates inhabited the end-Cretaceous European archipelago, some of which were dwarves or had other unusual features likely related to their insular habitats. Little is known, however, about the contemporary theropod dinosaurs, as they are represented mostly by teeth or other fragmentary fossils. A new isolated theropod metatarsal II, from the latest Maastrichtian of Spain (within 200,000 years of the mass extinction) may represent a jinfengopterygine troodontid, the first reported from Europe. Comparisons with other theropods and phylogenetic analyses reveal an autapomorphic foramen that distinguishes it from all other troodontids, supporting its identification as a new genus and species, Tamarro insperatus. Bone histology shows that it was an actively growing subadult when it died but may have had a growth pattern in which it grew rapidly in early ontogeny and attained a subadult size quickly. We hypothesize that it could have migrated from Asia to reach the Ibero-Armorican island no later than Cenomanian or during the Maastrichtian dispersal events.

Approximately 14.4 million Americans are experiencing alcohol use disorder (AUD) and about two-thirds of people who experience drug addiction will relapse, highlighting the need to develop novel and effective treatments. Glucagon-like peptide-1 (GLP-1) is a peptide hormone implicated in the mesocorticolimbic reward system and has become a peptide of interest with respect to its putative inhibitory effects on drug reward. In order to further develop treatments for those diagnosed with AUD, the interplay between GLP-1 receptor signaling and ethanol consumption must be elucidated. In the present study, we investigated the ability of the GLP-1 analogue, exendin-4 (Ex-4), to alter alcohol intake and operant responding for sucrose pellets in order to further understand the role of this compound in mediating reward. We selected multiple sites throughout the prosencephalic and mesencephalic regions of the brain, where we directly administered various doses of Ex-4 to male Sprague Dawley rats. In alcohol investigations, we utilized a two-bottle choice intermittent access protocol. In separate groups of rats, we adopted an operant paradigm in order to examine the effect of Ex-4 on motivated responding for palatable food. Results indicated that GLP-1 receptor signaling effectively suppressed voluntary alcohol intake when injected into the ventral tegmental area (VTA), the accumbens core (NAcC) and shell (NAcS), the dorsomedial hippocampus (DMHipp), and the lateral hypothalamus (LH), which are all structures linked to brain reward mechanisms. The arcuate nucleus (ARcN) and the paraventricular nucleus (PVN) of the hypothalamus were unresponsive, as was the basolateral amygdala (BLA). However, Ex-4 treatment into the ArcN and PVN suppressed operant responding for sucrose pellets. In fact, the VTA, NAcC, NAcS, LH, and the DMHipp all showed comparable suppression of sucrose responding. Overall, our findings suggest that these central structures are implicated in brain reward circuitry, including alcohol and appetitive motivation, which may be mediated by GLP-1 receptor mechanisms. GLP-1, therefore, may play a critical role in modifying addictive behaviors via activation of multiple GLP-1 systems throughout the brain.

Background: Throughout the United Kingdom, there have been sweeping changes to the practice of medicine due to the COVID-19 pandemic. For the surgical speciality, there have been changes to both elective and emergency practice. Concern regarding potential aerosolisation during invasive procedures have been raised - including the use of pneumoperitoneum to facilitate laparoscopy. The aim of this study is to systematically review the data available to date regarding the potential risk posed to theatre staff by laparoscopy., Method: A systematic review and meta-analysis was carried out in accordance with PRISMA guidelines. Only publications in peer-reviewed journals were considered. PubMed, Ovid Embase, SCOPUS, and Cochrane Library were searched. The search period was between 1st January 1980 and 27th April 2020. Bias was assessed using the ROBINS-I tool., Results: 4209 records were identified, resulting in 9 unique studies being selected. The included studies examined viral DNA aerosoliation generated by electrosurgery and CO 2 laser ablation, with one study examining viral DNA aerosolisation following laparoscopy. Each of these demonstrated that viral DNA (Hepatitis B Virus and Human Papilloma Virus) was detectable in the surgical smoke plume., Conclusion: The data and analysis reported in this study reflect the most up-to-date evidence available for the surgeon to assess risk towards healthcare staff. It was constrained by heterogeneity of reporting for several outcomes and lack of comparable studies. There is currently insufficient data to recommend open or a minimally invasive surgical approach with regard to theatre team safety in the COVID-19 era., (Copyright © 2020 Royal College of Surgeons of Edinburgh (Scottish charity number SC005317) and Royal College of Surgeons in Ireland. All rights reserved.)

Late Cretaceous trends in Asian dinosaur diversity are poorly understood, but recent discoveries have documented a radiation of oviraptorosaur theropods in China and Mongolia. However, little work has addressed the factors that facilitated this diversification. A new oviraptorid from the Late Cretaceous of Mongolia sheds light on the evolution of the forelimb, which appears to have played a role in the radiation of oviraptorosaurs. Surprisingly, the reduced arm has only two functional digits, highlighting a previously unrecognized occurrence of digit loss in theropods. Phylogenetic analysis shows that the onset of this reduction coincides with the radiation of heyuannine oviraptorids, following dispersal from southern China into the Gobi region. This suggests expansion into a new niche in the Gobi region, which relied less on the elongate, grasping forelimbs inherited by oviraptorosaurs. Variation in forelimb length and manus morphology provides another example of niche partitioning in oviraptorosaurs, which may have made possible their incredible diversity in the latest Cretaceous of Asia., Competing Interests: The authors declare no competing interests., (© 2020 The Authors.)

Several published censuses have noted the presence of two tyrannosaurids, Daspletosaurus sp. and Albertosaurus sarcophagus, within the Upper Cretaceous Horseshoe Canyon Formation of Alberta. Although A. sarcophagus is known from more than a dozen major discoveries in these strata, Daspletosaurus sp. is known from just a single problematic skeleton (lacking most of the skull) of a young individual. Here we describe and figure this skeleton, and marshal a variety of osteohistologic, morphometric, and phylogenetic methods to accurately determine its taxonomic status. Although none of these methods individually provides convincing evidence regarding the affinities of the specimen, together (and including other historical and biostratigraphic considerations) they strongly imply that the skeleton instead pertains to a young A. sarcophagus. In this way, we show that only a single species of tyrannosaurid is definitively present in the Horseshoe Canyon Formation, greatly simplifying interpretations of tyrannosaurid evolution and ecology in this setting. Anat Rec, 303:673-690, 2020. © 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists., (© 2019 The Authors. The Anatomical Record published by Wiley Periodicals, Inc. on behalf of American Association of Anatomists.)

The fossil record of caenagnathid oviraptorosaurs consists mainly of their fused, complexly sculptured dentaries, but little is known about the growth and development of this diagnostic structure. Previous work has suggested that the ridges and grooves on the occlusal surface are either the vestiges of teeth and their alveoli or were adaptations to increase shearing action during mastication. In addition, the distinctiveness of the dentaries has led to their use for species-level taxonomy, without a complete understanding of their variation through ontogeny. Here, we describe additional caenagnathid mandibles from the Dinosaur Park Formation of Alberta, Canada, and perform histological analyses to assess relative ontogenetic stage and the nature of the occlusal elaborations. The results show that the mandibular symphysis is synostosed early in ontogeny and does not accurately reflect ontogenetic stage in caenagnathids. In contrast, the presence of cyclical growth marks in a large specimen shows that mandibles can be used for relative histological maturity estimation. Histological features of the ridges of bone surrounding the lingual groove indicate that they are not the vestiges of tooth-bearing tissues and that caenagnathids did not lose their teeth through ontogeny as suggested in previous work. Instead, increased secondary remodeling in these structures is consistent with their use for food processing. Unexpectedly advanced maturity in a small specimen suggests that at least three caenagnathid species of varying body sizes coexisted in the Dinosaur Park Formation. These results stress the necessity of histological analysis when assessing maturity or ontogenetic trends in fossil material. Anat Rec, 303:918-934, 2020. © 2019 Wiley Periodicals, Inc., (© 2019 Wiley Periodicals, Inc.)

The femoral fourth trochanter is the attachment site of the caudofemoralis musculature, which is the primary hindlimb retractor in most non-avian dinosaurs. Early ornithischian dinosaurs are uniquely characterized by a fourth trochanter with a prominent pendant process. Throughout the evolution of ornithischians, the fourth trochanter repeatedly converged on two major morphological changes: (1) the distal migration of the trochanter down the femoral shaft and (2) the loss of the pendant process. Both changes, as well as the original evolution of the pendant form, relate to a single major functional shift emphasizing caudofemoral leverage. Direct evidence of muscle scarring across the surface of the pendant process affirms that it served to extend the attachment of the primary caudofemoralis brevis tendon distally. A proximally located fourth trochanter is the basal condition in dinosaurs and other archosaurs, and the development of a pendant process lengthened the functional lever arm with regard to the insertion of the caudofemoralis. This adaptation afforded improved mechanical advantage, perhaps beneficial in the context of the newly assumed herbivorous diets of basal ornithischians. As some derived ornithischians increased in body size, a high-leverage system with a more distal caudofemoralis attachment evolved. In some groups, the fourth trochanter as a whole descended down the femur, eventually reaching a point where the pendant process was unnecessary. Sauropodomorphs, the other great lineage of dinosaur herbivores, converged on the same high-leverage distal fourth trochanter arrangement, but without first transitioning through a prominent pendant form. Anat Rec, 303:1146-1157, 2020. © 2019 Wiley Periodicals, Inc., (© 2019 Wiley Periodicals, Inc.)

Here we describe an extremely large and relatively complete (roughly 65%) skeleton of Tyrannosaurus rex (RSM P2523.8). Multiple measurements (including those of the skull, hip, and limbs) show that RSM P2523.8 was a robust individual with an estimated body mass exceeding all other known T. rex specimens and representatives of all other gigantic terrestrial theropods. Histological sampling of the fibula confirms that RSM P2523.8 is skeletally mature. The prevalence of incompletely coossified elements contradicts previous assertions that such unfused elements can be taken as indicators of somatic immaturity. As an extreme example of both ontogenetic maturity and osteological robustness, RSM P2523.8 offers support for prior hypotheses that a sampling bias occurs throughout the Dinosauria, making it likely that most taxa grew to significantly greater size than current known specimens indicate. Anat Rec, 303:656-672, 2020. © 2019 Wiley Periodicals, Inc., (© 2019 Wiley Periodicals, Inc.)

The holotype of the dromaeosaurid Saurornitholestes langstoni was described in 1978 on the basis of fewer than 30 associated cranial and postcranial bones of a single individual from Dinosaur Provincial Park. Four additional partial skeletons of Saurornitholestes were recovered from Campanian (Upper Cretaceous) beds of Alberta and Montana over the next 25 years, although reasonably complete skeletons remained elusive, and virtually nothing was known about the skull. The lack of truly diagnostic material has been problematic, and the relationships of Saurornitholestes to other dromaeosaurids have been difficult to resolve because of the incomplete knowledge of its anatomy. In 2014, an almost complete skeleton, including the skull, was collected less than a kilometer from where the holotype had been found. Although similar in body size to Velociraptor, the facial region of the skull is relatively shorter, taller, and wider. The nasals are pneumatic. The premaxillary teeth are distinctive, and teeth previously identified in the Dinosaur Park Formation as Zapsalis abradens can now be identified as the second premaxillary tooth of S. langstoni. Morphology and wear patterns suggest that these may have been specialized for preening feathers. Many traits define a Campanian North American clade, Saurornitholestinae, that is distinct from an Asian clade that includes Velociraptor (Velociraptorinae). This new information on the skull allows a more complete evaluation of its systematic position within the Dromaeosauridae and supports the suggestion of at least two major faunal interchanges between Asia and North America during the Cretaceous. Anat Rec, 303:691-715, 2020. © 2019 American Association for Anatomy., (© 2019 American Association for Anatomy.)

Background: Binge alcohol drinking has been characterized as a key feature of alcoholism. The drinking-in-the-dark (DID) preclinical model, a procedure that promotes high levels of ethanol (EtOH) intake in short periods of time, has been extensively used to investigate neuropharmacological and genetic determinants of binge-like EtOH consumption. Using DID methodology, alcohol-preferring strains of mice such as C57BL/6J (B6) mice consume enough EtOH to achieve blood concentrations (≥1.0 mg/ml) associated with behavioral intoxication (i.e., motor incoordination). DID procedures typically involve the use of socially isolated animals (single-housed prior to and during the experiment). Previous research indicates that stress associated with social isolation can induce anxiety-like behavior and promote increases in EtOH intake. The present study investigates the role of housing conditions in anxiety-like behavior and binge-like EtOH intake using a DID procedure., Methods: Male and female B6 mice were isolated or pair-housed for a period of 6 weeks prior to evaluation of anxiety-like (elevated plus maze, light and dark box, open field) and drinking (water, 10% sucrose, 10 to 30% EtOH) behavior. In order to measure intake, a variation of the standard DID procedure using a removable, transparent, and perforated plastic barrier strip (designed to temporarily divide the cage in 2) was introduced. This allowed for individual intake records (2-hour test) of isolated and socially housed animals., Results: Increased anxiety-like behavior and reduced sucrose consumption were found in isolated mice. The effects of housing conditions on EtOH intake were sex- and concentration-dependent. In male mice, isolation increased 20 and 30% EtOH intake. In females, however, an increased intake of EtOH (30%) was found in socialized animals. No effects of housing or sex were found at EtOH 10%., Conclusions: Together with previous literature, the present study suggests that social isolation can promote anxiety-associated behavior and produce sex-dependent changes in binge-like EtOH consumption., (Copyright © 2019 by the Research Society on Alcoholism.)

Avimimids were unusual, birdlike oviraptorosaurs from the Late Cretaceous of Asia. Initially enigmatic, new information has ameliorated the understanding of their anatomy, phylogenetic position, and behaviour. A monodominant bonebed from the Nemegt Formation of Mongolia showed that some avimimids were gregarious, but the site is unusual in the apparent absence of juveniles. Here, a second monodominant avimimid bonebed is described from the Iren Dabasu Formation of northern China. Elements recovered include numerous vertebrae and portions of the forelimbs and hindlimbs, representing a minimum of six individuals. Histological sampling of two tibiotarsi from the bonebed reveals rapid growth early in ontogeny followed by unexpectedly early onset of fusion and limited subsequent growth. This indicates that avimimids grew rapidly to adult size, like most extant birds but contrasting other small theropod dinosaurs. The combination of adults and juveniles in the Iren Dabasu bonebed assemblage provides evidence of mixed-age flocking in avimimids and the onset of fusion in young individuals suggests that some of the individuals in the Nemegt Formation bonebed may have been juveniles. Regardless, these individuals were likely functionally analogous to adults, and this probably facilitated mixed-age flocking by reducing ontogenetic niche shift in avimimids.

Despite being known from every continent, the geological record of pterosaurs, the first group of vertebrates to develop powered flight, is very uneven, with only a few deposits accounting for the vast majority of specimens and almost half of the taxonomic diversity. Among the regions that stand out for the greatest gaps of knowledge regarding these flying reptiles, is the Afro-Arabian continent, which has yielded only a small number of very fragmentary and incomplete materials. Here we fill part of that gap and report on the most complete pterosaur recovered from this continent, more specifically from the Late Cretaceous (~95 mya) Hjoûla Lagerstätte of Lebanon. This deposit is known since the Middle Ages for the exquisitely preserved fishes and invertebrates, but not for tetrapods, which are exceedingly rare. Mimodactylus libanensis gen. et sp. nov. differs from the other Afro-Arabian pterosaur species named to date and is closely related to the Chinese species Haopterus gracilis, forming a new clade of derived toothed pterosaurs. Mimodactylidae clade nov. groups species that are related to Istiodactylidae, jointly designated as Istiodactyliformes (clade nov.). Istiodactyliforms were previously documented only in Early Cretaceous sites from Europe and Asia, with Mimodactylus libanensis the first record in Gondwana.

Hadrosaurian dinosaurs were abundant in the Late Cretaceous of North America, but their habitats remain poorly understood. Cretaceous amber is also relatively abundant, yet it is seldom found in direct stratigraphic association with dinosaur remains. Here we describe an unusually large amber specimen attached to a Prosaurolophus jaw, which reveals details of the contemporaneous paleoforest and entomofauna. Fourier-transform Infrared spectroscopy and stable isotope composition (H and C) suggest the amber formed from resins exuded by cupressaceous conifers occupying a coastal plain. An aphid within the amber belongs to Cretamyzidae, a Cretaceous family suggested to bark-feed on conifers. Distinct tooth row impressions on the amber match the hadrosaur's alveolar bone ridges, providing some insight into the taphonomic processes that brought these remains together.

Daspletosaurus is a large tyrannosaurine found in upper Campanian deposits of Alberta and Montana. Although several large subadult and adult individuals of this taxon are known, only one juvenile individual, TMP 1994.143.1, has been identified. This specimen has played a key role in the idea that juvenile tyrannosaurid individuals are difficult to differentiate among species. Here the taxonomic affinity of TMP 1994.143.1 is reassessed in light of a juvenile tyrannosaurine postorbital recently discovered in the Dinosaur Park Formation of Alberta. Anatomical comparisons and phylogenetic analyses reveal that TMP 1994.143.1 is referable to the albertosaurine Gorgosaurus libratus, whereas the new postorbital belongs to a small juvenile Daspletosaurus. This taxonomic reassignment of TMP 1994.143.1 results in the juvenile ontogenetic stage of Daspletosaurus being known only from two isolated cranial elements. The new postorbital provides insights into early Daspletosaurus ontogeny, revealing that the cornual process developed earlier or faster than in other tyrannosaurids. Although some ontogenetic changes in the postorbital are found to be unique to Daspletosaurus, overall changes are most consistent with those of other large tyrannosaurines. Our results also show that diagnostic features develop early in ontogeny, such that juveniles of different tyrannosaurid species are easier to differentiate than previously thought.

Preserved labile tissues (e.g., skin, muscle) in the fossil record of terrestrial vertebrates are increasingly becoming recognized as an important source of biological and taphonomic information. Here, we combine a variety of synchrotron radiation techniques with scanning electron and optical microscopy to elucidate the structure of 72 million-year-old squamous (scaly) skin from a hadrosaurid dinosaur from the Late Cretaceous of Alberta, Canada. Scanning electron and optical microscopy independently reveal that the three-dimensionally preserved scales are associated with a band of carbon-rich layers up to a total thickness of ∼75 microns, which is topographically and morphologically congruent with the stratum corneum in modern reptiles. Compositionally, this band deviates from that of the surrounding sedimentary matrix; Fourier-transform infrared spectroscopy and soft X-ray spectromicroscopy analyses indicate that carbon appears predominantly as carbonyl in the skin. The regions corresponding to the integumentary layers are distinctively enriched in iron compared to the sedimentary matrix and appear with kaolinite-rich laminae. These hosting carbonyl-rich layers are apparently composed of subcircular bodies resembling preserved cell structures. Each of these structures is encapsulated by calcite/vaterite, with iron predominantly concentrated at its center. The presence of iron, calcite/vaterite and kaolinite may, independently or collectively, have played important roles in the preservation of the layered structures., Competing Interests: James J. Dynes is employed by Canadian Light Source Inc., (©2019 Barbi et al.)

The present study examined the ability of ghrelin administration into either the ventral tegmental area (VTA) or nucleus accumbens (NAc) to potentiate cocaine-induced conditioned place preference (CPP). Additionally, we examined the impact of co-injection of the ghrelin 1a antagonist JMV 2959 with ghrelin in order to evaluate the potential attenuation of ghrelin's effects on cocaine-induced CPP. Adult male Sprague-Dawley rats were allowed simultaneous access to either side of the CPP apparatus to establish baseline chamber preferences. The rats were then restricted to either their non-preferred or preferred side over the course of conditioning which lasted for a total of 8 consecutive days. On days in which rats were restricted to their non-preferred side, systemic cocaine (0.5-5.0 mg/kg IP) followed by central ghrelin (300 pmol), or co-administration of ghrelin (300 pmol) with JMV 2959 (10 μg), was administered either into the VTA or NAc immediately prior to the conditioning period. On alternate days rats were treated with vehicle then placed into what was initially determined to be their preferred side. CPP was calculated as the difference in the percentage of total time spent in the treatment-paired compartment during the post-conditioning session and the pre-conditioning session. Our results indicated that ghrelin potentiated cocaine-induced CPP and that this effect was attenuated by JMV 2959. Overall, these findings provide further evidence that mesolimbic ghrelin signaling is indeed critically involved in mediating the rewarding effects of cocaine., (Copyright © 2019 Elsevier B.V. All rights reserved.)

Over the last two decades, paleontologists have pieced together the early evolutionary history of feathers. Simple hair-like feathers served as insulating pelage, but the first feathers with complex branching structures and a plainer form evolved for the purpose of sexual display. The evolution of these complex display feathers was essential to the later evolution of flight. Feathers illustrate how sexual selection can generate complex novel phenotypes, which are then available for natural selection to modify and direct toward novel functions. In the longstanding metaphor of the adaptive landscape, sexual selection is a means by which lineages resting on one adaptive peak may gradually bridge a gap to another peak, without the landscape itself being first altered by environmental changes., (© 2019 The Author(s). Evolution © 2019 The Society for the Study of Evolution.)

Background: Inguinal hernia repair is a common low-risk intervention. Patient-reported outcomes (PROs) are being used increasingly as primary outcomes in clinical trials. The aim of this study was to review and meta-analyse the PROs in RCTs comparing laparoscopic versus open inguinal hernia repair techniques in adult patients., Methods: A systematic review and meta-analysis was carried out in accordance with PRISMA guidelines. Only RCTs in peer-reviewed journals were considered. PubMed, Ovid Embase, Scopus and the Cochrane Library were searched. In addition, four trial registries were searched. The search interval was between 1 January 1998 and 1 May 2018. Identified publications were reviewed independently by two authors. The review was registered in the PROSPERO database (CRD42018099552). Bias was assessed using the Cochrane Collaboration risk-of-bias tool., Results: Some 7192 records were identified, from which 58 unique RCTs were selected. Laparoscopic hernia repair was associated with significantly less postoperative pain in three intervals: from 2 weeks to within 6 months after surgery (risk ratio (RR) 0·74, 95 per cent c.i. 0·62 to 0·88), 6 months to 1 year (RR 0·74, 0·59 to 0·93) and 1 year onwards (RR 0·62, 0·47 to 0·82). Paraesthesia (RR 0·27, 0·18 to 0·40) and patient-reported satisfaction (RR 0·91, 0·85 to 0·98) were also significantly better in the laparoscopic repair group., Conclusion: The data and analysis reported in this study reflect the most up-to-date evidence available for the surgeon to counsel patients. It was constrained by heterogeneity of reporting for several outcomes., (© 2019 BJS Society Ltd Published by John Wiley & Sons Ltd.)

Synopsis: Tyrannosaurid dinosaurs had large preserved leg muscle attachments and low rotational inertia relative to their body mass, indicating that they could turn more quickly than other large theropods., Methods: To compare turning capability in theropods, we regressed agility estimates against body mass, incorporating superellipse-based modeled mass, centers of mass, and rotational inertia (mass moment of inertia). Muscle force relative to body mass is a direct correlate of agility in humans, and torque gives potential angular acceleration. Agility scores therefore include rotational inertia values divided by proxies for (1) muscle force (ilium area and estimates of m. caudofemoralis longus cross-section), and (2) musculoskeletal torque. Phylogenetic ANCOVA (phylANCOVA) allow assessment of differences in agility between tyrannosaurids and non-tyrannosaurid theropods (accounting for both ontogeny and phylogeny). We applied conditional error probabilities a ( p ) to stringently test the null hypothesis of equal agility., Results: Tyrannosaurids consistently have agility index magnitudes twice those of allosauroids and some other theropods of equivalent mass, turning the body with both legs planted or pivoting over a stance leg. PhylANCOVA demonstrates definitively greater agilities in tyrannosaurids, and phylogeny explains nearly all covariance. Mass property results are consistent with those of other studies based on skeletal mounts, and between different figure-based methods (our main mathematical slicing procedures, lofted 3D computer models, and simplified graphical double integration)., Implications: The capacity for relatively rapid turns in tyrannosaurids is ecologically intriguing in light of their monopolization of large (>400 kg), toothed dinosaurian predator niches in their habitats., Competing Interests: The authors declare that they have no competing interests.

Current literature indicates that the orexigenic peptide ghrelin increases appetitive motivation via signaling in the mesolimbic reward system. Another gastric peptide, glucagon-like peptide-1 (GLP-1), and the neurotransmitter 5-hydroxytryptamine (5-HT), are both known to suppress operant responding for food by acting on key mesolimbic nuclei, including the ventral tegmental area (VTA). In order to investigate the interaction effects of ghrelin, GLP-1, and 5-HT within the VTA, we measured operant responding for sucrose pellets after the administration of ghrelin, the GLP-1 receptor agonist exendin-4 (Ex-4), and the 5-HT 2c receptor agonist Ro60-0175 in male Sprague-Dawley rats. Following training on a progressive ratio 3 (PR3) schedule, animals were first injected with ghrelin into the VTA at doses of 3 to 300 pmol. In subsequent testing, separate rats were administered intraperitoneal (IP) Ex-4 (0.1⁻1.0 µg/kg) or VTA Ex-4 (0.01⁻0.1 µg) paired with 300 pmol ghrelin. In a final group of rats, the 5-HT 2c agonist Ro60-0175 was injected IP (0.25⁻1.0 mg/kg) or into the VTA (1.5⁻3.0 µg), and under both conditions paired with 300 pmol ghrelin delivered into the VTA. Our results indicated that ghrelin administration increased operant responding for food reward and that this effect was attenuated by IP and VTA Ex-4 pretreatment as well as pre-administration of IP or VTA Ro60-0175. These data provide compelling evidence that mesolimbic GLP-1 and serotonergic circuitry interact with the ghrelinergic system to suppress ghrelin's effects on the mediation of food reinforcement.

Hagfish depart so much from other fishes anatomically that they were sometimes considered not fully vertebrate. They may represent: ( i ) an anatomically primitive outgroup of vertebrates (the morphology-based craniate hypothesis); or ( ii ) an anatomically degenerate vertebrate lineage sister to lampreys (the molecular-based cyclostome hypothesis). This systematic conundrum has become a prominent case of conflict between morphology- and molecular-based phylogenies. To date, the fossil record has offered few insights to this long-branch problem or the evolutionary history of hagfish in general, because unequivocal fossil members of the group are unknown. Here, we report an unequivocal fossil hagfish from the early Late Cretaceous of Lebanon. The soft tissue anatomy includes key attributes of living hagfish: cartilages of barbels, postcranial position of branchial apparatus, and chemical traces of slime glands. This indicates that the suite of characters unique to living hagfish appeared well before Cretaceous times. This new hagfish prompted a reevaluation of morphological characters for interrelationships among jawless vertebrates. By addressing nonindependence of characters, our phylogenetic analyses recovered hagfish and lampreys in a clade of cyclostomes (congruent with the cyclostome hypothesis) using only morphological data. This new phylogeny places the fossil taxon within the hagfish crown group, and resolved other putative fossil cyclostomes to the stem of either hagfish or lamprey crown groups. These results potentially resolve the morphological-molecular conflict at the base of the Vertebrata. Thus, assessment of character nonindependence may help reconcile morphological and molecular inferences for other major discords in animal phylogeny., Competing Interests: The authors declare no conflict of interest., (Copyright © 2019 the Author(s). Published by PNAS.)

In the current study we investigated the interaction of hypothalamic paraventricular nucleus (PVN) glucagon-like peptide-1 (GLP-1) and ghrelin signaling in the control of metabolic function. We first demonstrated that acylated ghrelin injected directly into the PVN reliably altered the respiratory exchange ratio (RER) of adult male Sprague Dawley rats. All testing was carried out during the initial 2 h of the nocturnal cycle using an indirect open circuit calorimeter. Results indicated that acylated ghrelin induced a robust increase in RER representing a shift toward enhanced carbohydrate oxidation and reduced lipid utilization. In contrast, treatment with comparable dosing of des-acyl ghrelin failed to significantly impact metabolic activity. In separate groups of rats we subsequently investigated the ability of exendin-4 (Ex-4), a GLP-1 analogue, to alter acylated ghrelin's metabolic effects. Rodents were treated with either systemic or direct PVN Ex-4 followed by acyl ghrelin microinjection. While our results showed that both systemic and PVN administration of Ex-4 significantly reduced RER, importantly, Ex-4 pretreatment itself reliably inhibited the impact of ghrelin on RER. Overall, these findings provide increasingly compelling evidence that GLP-1 and ghrelin signaling interact in the neural control of metabolic function within the PVN., (Copyright © 2018 Elsevier Inc. All rights reserved.)

The present study investigated the relationship between accumbal ghrelin and glucagon-like peptide 1 (GLP-1) signaling in alcohol reward in female rats. Animals with guide cannulae targeting the nucleus accumbens core (NAcC) and shell (NAcS) were habituated to alcohol for 12 weeks through a two-bottle intermittent access paradigm. JMV2959, a ghrelin antagonist, and exendin-4 (Ex-4), a GLP-1 agonist, were microinjected at the onset of the nocturnal cycle. Alcohol, food, water, and total fluid intake were measured 2, 6, and 24 h postinjection. Results indicated that JMV2959 reduced alcohol consumption when injected into both the NAcC and NAcS. Ex-4 administration as well as combined JMV2959 and Ex-4 treatment reduced intake when injected into the NAcS, but not the NAcC. These effects were time-dependent. JMV2959 had no effect on food intake when administered into either the NAcC or the NAcS, whereas Ex-4 decreased food intake when injected separately into both structures. The combination of JMV2959 and Ex-4 decreased food intake when administered only into the NAcC. These effects were also time-dependent. No estrous-related effects on alcohol or food intake were found. However, water and total fluid intake were increased during the metestrus and diestruses phases of the estrous cycle compared with the proestrus and estrus phases. Overall, these findings demonstrate the importance of accumbal ghrelin and GLP-1 signaling in alcohol reward and appetitive motivation.

The teeth of putatively carnivorous dinosaurs are often blade-shaped with well-defined serrated cutting edges (Figure 1). These ziphodont teeth are often easily differentiated based on the morphology and density of the denticles [1, 2]. A tearing function has been proposed for theropod denticles in general [3], but the functional significance of denticle phenotypic variation has received less attention. In particular, the unusual hooked denticles found in troodontids suggest a different feeding strategy or diet compared to other small theropods. We used a two-pronged approach to investigate the function of denticle shape variation across theropods with both congruent body shapes and sizes (e.g., dromaeosaurids versus troodontids) and highly disparate body shapes and sizes (e.g., troodontids versus tyrannosaurids), using microwear and finite element analyses (Figure 1). We found that many toothed coelurosaurian theropods employed a puncture-and-pull feeding movement, in which parallel scratches form while biting down into prey and oblique scratches form as the head is pulled backward with the jaws closed. In finite element simulations, theropod teeth had the lowest stresses when bite forces were aligned with the oblique family of microwear scratches. Different denticle morphologies performed differently under a variety of simulated biting angles: Dromaeosaurus and Saurornitholestes were well-adapted for handling struggling prey, whereas troodontid teeth were more likely to fail at non-optimal bite angles. Troodontids may have favored softer, smaller, or immobile prey., (Copyright © 2018 Elsevier Ltd. All rights reserved.)

Maniraptora includes birds and their closest relatives among theropod dinosaurs. During the Cretaceous period, several maniraptoran lineages diverged from the ancestral coelurosaurian bauplan and evolved novel ecomorphologies, including active flight, gigantism, cursoriality and herbivory. Propagation X-ray phase-contrast synchrotron microtomography of a well-preserved maniraptoran from Mongolia, still partially embedded in the rock matrix, revealed a mosaic of features, most of them absent among non-avian maniraptorans but shared by reptilian and avian groups with aquatic or semiaquatic ecologies. This new theropod, Halszkaraptor escuilliei gen. et sp. nov., is related to other enigmatic Late Cretaceous maniraptorans from Mongolia in a novel clade at the root of Dromaeosauridae. This lineage adds an amphibious ecomorphology to those evolved by maniraptorans: it acquired a predatory mode that relied mainly on neck hyperelongation for food procurement, it coupled the obligatory bipedalism of theropods with forelimb proportions that may support a swimming function, and it developed postural adaptations convergent with short-tailed birds.

Dinosaur community composition data for eleven fossil localities in the Late Cretaceous Nemegt Basin of Mongolia are compiled from field observations and records in the literature. Counts were generated from skeletons and represent numbers of individuals preserved in each locality. These data were used in the analyses of Funston et al. [1] "Oviraptorosaur anatomy, diversity, and ecology in the Nemegt Basin" in the Nemegt Ecosystems Special Issue of Palaeogeography, Palaeoclimatology, Palaeoecology, where the results are discussed.

The first histological study of an entire hadrosaurid dental battery provides a comprehensive look at tooth movement within this complex structure. Previous studies have focused on isolated teeth, or in-situ batteries, but this is the first study to examine an entire dental battery of any dinosaur. The absence of direct tooth-to-tooth contact across the entire battery and a unique arrangement of the dental tissues in hadrosaurids led us to compare their teeth with the ever-growing incisors of mammals. The similarity in the distributions of tissues along the incisor, coupled with continuous eruption, make for helpful comparisons to hadrosaurid teeth. The mammalian ever-growing incisor can be used as a model to extrapolate the soft tissue connections and eruptive mechanisms within the hadrosaurid dental battery. Serial sections across the adult dental battery reveal signs of gradual ontogenetic tooth migration. Extensive remodeling of the alveolar septa and the anteroposterior displacement of successive generations of teeth highlight the gradual migration of tooth generations within the battery. These eruptive and ontogenetic tooth movements would not be possible without a ligamentous connection between successive teeth and the jaws, underscoring the dynamic nature of one of the most unique and complex dental systems in vertebrate history.

Insulin detemir (DET) is a basal insulin analog that, in contrast to other long-acting forms of insulin, has significant weight-gain-sparing effects in diabetic patients. We hypothesized that this effect of DET may be due to its enhanced catabolic action in the central nervous system. We investigated the long-term effects of single third ventricular (3V) microinjections of equimolar doses of DET and regular insulin in normal male rats on feeding, body weight, energy expenditure (EE), and respiratory quotient (RQ). Also, in acute testing, we assessed the ability of lower doses of DET to alter feeding, EE, and RQ when microinjected directly into the paraventricular nucleus (PVN). The anabolic peptide ghrelin served as a positive control in acute testing. 3V administration of both DET (0.5-2.0 mU) and regular insulin (2.0-8.0 mU) significantly reduced feeding and body weight over 48 and 120 h, respectively, with DET yielding greater inhibitory effects. DET also stimulated greater elevations of EE and reductions of RQ over 72 and 48 h postinjection, respectively. In acute (4 h) testing, microinjections of DET (0.5 mU) into the PVN reduced feeding, increased EE, and reduced RQ, while ghrelin (100 pmol) had the opposite effects. When administered sequentially into the PVN, DET (0.25 and 0.5 mU) reversed ghrelin-induced feeding, EE, and RQ effects. These data support the notion that the weight-sparing effect of DET is at least in part based on its central catabolic action and that enhanced EE and reduced RQ may participate in this effect., (Copyright © 2017 the American Physiological Society.)

Eating disorders are associated with impaired decision-making and dysfunctional reward-related neurochemistry. The present study examined the potential contributions of dopamine and opioid signaling to these processes using two different decision-making tasks. In one task, Long Evans Rats chose between working for a preferred food (high-carbohydrate banana-flavored sucrose pellets) by lever pressing on a progressive-ratio schedule of reinforcement vs. obtaining less preferred laboratory chow that was concurrently available. In a second (effort-free) task, rats chose between the same two reinforcers when they were both available freely. Rats were trained in these tasks before receiving haloperidol (0.00, 0.05, 0.10mg/kg, intraperitoneally (i.p.)) or naloxone (0.0, 1.5, 3.0mg/kg, i.p.). In the first task, haloperidol decreased breakpoint, lever presses, number of reinforcers earned, and increased chow intake, whereas naloxone decreased breakpoint and number of reinforcers earned but had no effect on chow consumption. In the effort-free task, haloperidol reduced intakes of both foods without affecting preference, whereas naloxone selectively reduced the consumption of banana-pellets. The present findings support converging evidence suggesting that DA signaling affects processes more closely related to appetitive motivation, leaving other components of motivation unchanged. By contrast, opioid signaling appears to mediate aspects of hedonic feeding by selectively altering intakes of highly palatable foods. For preferred foods, both appetitive and consummatory aspects of food intake were altered by opioid receptor antagonism. Our findings argue against a general suppression of appetite by either compound, as appetite manipulations have been shown to unselectively alter intakes of both types of food regardless of the task employed., (Copyright © 2017 Elsevier Inc. All rights reserved.)