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Turtles and tortoises (Order Testudines) are facing an extinction crisis, and ecosystems are at risk of collapsing with the loss of key roles they play. Hatching failure is a crucial barrier to population growth and persistence, but its causes are poorly understood, and it is unknown whether fertilization rates are declining as many populations become smaller and more female‐biased. Here, we show that very few studies of turtle and tortoise hatching success consider fertilization rates, and those that do use unreliable methods to determine egg fertility. We also show that studies of hatching success are biased towards marine turtles, as opposed to freshwater and terrestrial species, and wild rather than captive populations. To address the lack of reliable methods for assessing fertilization rates in turtles and tortoises, a microscopy‐based method (originally designed for bird eggs) for detecting perivitelline membrane (PVM) bound sperm and embryonic nuclei in the germinal disc of unhatched eggs has been developed and tested (in turtle and tortoise eggs). We demonstrate that this method provides unequivocal evidence of egg fertilization in five different turtle and tortoise species from both captive and wild populations, even after eggs have been left in wild nests for the full incubation period. This methodological approach represents a valuable tool for monitoring egg fertility and embryo survival rates in turtles and tortoises, with the potential to provide important insights into the underlying drivers of reproductive failure in threatened captive and wild populations. [ABSTRACT FROM AUTHOR]

Recent advancements in stress physiology, driven by the relevance of the stress response in animal welfare and conservation, have focused on alternative techniques beyond blood sampling for measuring glucocorticoids (GC). While blood samples have been traditionally used, practical and ethical concerns have spurred exploration into minimally invasive media like saliva, feces, milk, hair, and feathers. This review addresses the dearth of research on reptile endocrinology, offering insights into measuring GC or their metabolites in reptiles through various biological tissues. It underscores the importance of considering temporal dynamics in stress response evaluation and advocates for further exploration of alternative tools to enhance our understanding of reptilian stress responses. [ABSTRACT FROM AUTHOR]

Wildlife trade is driving species extinctions globally, and the Asian Turtle Crisis is posing a threat in China as turtle species are collected from the wild and sold at high prices. Local ecological knowledge is increasingly used to determine the status of threatened taxa, but there is little understanding of wider relationships between indices of ecological knowledge and other conservation‐relevant factors such as market values of traded species. To assess whether local people's awareness of potentially traded turtles might indicate direct interaction with trade in these species, we conducted 185 interviews in rural villages around Bawangling National Nature Reserve, Hainan, China. Interviewees were asked to free‐list native turtles to determine species salience and then were shown photographs of the species to assess recognition and knowledge. We investigated relationships between species' salience, whether species were recognized, named and/or perceived to be traded by more people, and independently obtained market prices. Indices of species awareness varied among interviewees, but all species were reported to be traded by at least some people. There was no correlation between indices of awareness and market value, indicating that more valuable species were no more likely to be well known. However, the perception that turtles are traded irrespective of species is a concern for conservation because all species are then vulnerable to exploitation. Our results highlight that local communities should not be assumed to have accurate knowledge of traded species, with implications for the management of wildlife trade and conservation at the community level. [ABSTRACT FROM AUTHOR]

Sea turtles use olfaction to detect volatile and water‐soluble substances. The nasal cavity of green turtles (Chelonia mydas) comprises morphologically defined the anterodorsal, anteroventral, and posterodorsal diverticula, as well as a single posteroventral fossa. Here, we detailed the histological features of the nasal cavity of a mature female green turtle. The posterodorsal diverticulum contained spongy‐like venous sinuses and a wave‐shaped sensory epithelium that favored ventilation. Secretory structures that were significant in sensory and non‐sensory epithelia were probably involved in protection against seawater. These findings suggested that green turtles efficiently intake airborne substances and dissolve water‐soluble substances in mucous, while suppressing the effects of salts. In addition, positive staining of Gαs/olf that couples with olfactory, but not vomeronasal, receptors was predominant in all three types of sensory epithelium in the nasal cavity. Both of airborne and water‐soluble odorants seemed to be detected in cells expressing Gαolf and olfactory receptors. [ABSTRACT FROM AUTHOR]

Mojave desert tortoises (Gopherus agassizii), a threatened species under the US Endangered Species Act, are long‐lived reptiles that experience a chronic respiratory disease. The virulence of primary etiologic agent, Mycoplasma agassizii, remains poorly understood, but it exhibits temporal and geographic variability in causing disease outbreaks in host tortoises. Multiple attempts to culture and characterize the diversity of M. agassizii have had minimal success, even though this opportunistic pathogen chronically persists in nearly every population of Mojave desert tortoises. The current geographic range and the molecular mechanisms of virulence of the type‐strain, PS6T, are unknown, and the bacterium is thought to have low‐to‐moderate virulence. We designed a quantitative polymerase chain reaction (qPCR) targeting three putative virulence genes annotated on the PS6T genome as exo‐α‐sialidases, enzymes which facilitate growth in many bacterial pathogens. We tested 140 M. agassizii‐positive DNA samples collected from 2010 to 2012 across the range of Mojave desert tortoises. We found evidence of multiple‐strain infections within hosts. We also found the prevalence of these sialidase‐encoding genes to be highest in tortoise populations surrounding southern Nevada, the area from which PS6T was originally isolated. We found a general pattern of loss or reduced presence of sialidase among strains, even within a single host. However, in samples that were positive for any of the putative sialidase genes, one particular gene (528), was positively associated with bacterial loads of M. agassizii and may act as a growth factor for the bacterium. Our results suggest three evolutionary patterns: (1) high levels of variation, possibly due to neutral changes and chronic persistence, (2) a trade‐off between moderate virulence and transmission, and (3) selection against virulence in environmental conditions known to be physiologically stressful to the host. Our approach of quantifying genetic variation via qPCR represents a useful model of studying host–pathogen dynamics. [ABSTRACT FROM AUTHOR]

Global urban expansion has multiple impacts on biodiversity and ecosystem functioning. Still, urban centres may play an important role in the conservation of reptiles, an undersampled, megadiverse and unevenly distributed group especially vulnerable to anthropogenic impacts. However, major gaps in research on the urban ecology of reptiles and species responses to urbanisation persist, which may limit our capacity to guide suitable conservation policies. We conducted a global systematic literature review to evaluate biogeographic, taxonomic and ecological research biases in the urban ecology of reptiles and ultimately to detect major gaps and steer future sampling efforts. Our database comprised 278 articles dealing with biological responses to urbanisation of 493 species across 45 countries, comprising 658 cases between a given species and specific biological response. Research on the urban ecology of reptiles was geographically and taxonomically biased. Developed countries within temperate regions were better sampled, whereas developing tropical and megadiverse countries were mostly undersampled or neglected. Among reptile orders, Testudines and Crocodylia were proportionally more studied than Squamata. Across lower groups within Squamata, lizards were present in most studies and were the biological model most commonly used. Studies evaluating biological responses associated with landscape‐level processes, behaviour and/or population dynamics were prevalent, whereas conservation, human–reptile conflicts and wildlife management were the least considered topics. Our results show that research on urban ecology of reptiles is unevenly distributed across regions and lineages. Overcoming these major gaps is an important step towards the improvement of the conservation of reptiles worldwide under the upcoming biodiversity loss scenario. Beyond spreading sampling efforts across undersampled countries, taxa and research topics to meet conservation objectives, we recommend more multidisciplinary approaches to evaluate and compare the actual performance of reptiles in urban environments and to achieve the equilibrium between human well‐being and species conservation. [ABSTRACT FROM AUTHOR]

Bite force is important in understanding how feeding biomechanics impacts the life‐history of vertebrates. Bite force has been measured in many lizards and crocodilians but fewer turtles and snakes. Few comparative interspecific studies exist of the inter‐relationships between body size, jaw musculature and bite force. This study collated data reported in the literature for bite force and mass of the jaw musculature in reptiles and explored the relationships between these variables and body mass and size. Two hypotheses were explored: (1) bite force and mass of the jaw musculature scale with body size irrespective of order (as a broad taxonomic grouping) when controlled for phylogeny, and (2) bite force and jaw musculature mass would be directly related and be unrelated to order. Phylogenetically controlled Bayesian analyses showed that in relation to body mass there were different relationships with bite force for testudines compared to saurians and crocodilians. For snout–vent length, squamates and crocodilians exhibited a single relationship, but for head length, all reptile orders exhibited different allometric patterns. Although there was a strong phylogenetic signal in all cases, indicating that there are clusters of closely related species for a measure of size, there was no effect of order on the relationships between measures of body size and mass of the jaw musculature. The relationship between bite force and jaw muscle mass was isometric and did not differ among reptile orders. Several ecological factors may correlate with head morphology and bite force in reptiles. Further studies could explore the evolutionary drivers that shape the relationship between head size, jaw musculature and bite force. Similarities for the relationships between bite force and body size in different reptilian orders suggests that this could be a model system to demonstrate fundamental biomechanical principles of how jaw muscles generate a bite force. [ABSTRACT FROM AUTHOR]

Turtles have been prominent subjects of sexual size dimorphism (SSD) analyses due to their compact taxonomy, mating systems, and habitat diversity. In prior studies, marine turtles were grouped with fully aquatic non‐marine turtles (NMATs). This is interesting because it is well‐established that the marine environment imposes a distinct selective milieu on body form of vagile vertebrates, driven by convergent adaptations for energy‐efficient propulsion and drag reduction. We generated a comprehensive database of adult marine turtle body sizes (38,569 observations across all species), which we then used to evaluate the magnitude of SSD in marine turtles and how it compares to SSD in NMAT. We find that marine turtles are only minimally sexually size dimorphic, whereas NMAT typically exhibit female‐biased SSD. We argue that the reason for this difference is the sustained long‐distance swimming that characterizes marine turtle ecology, which entails significant energetic costs incurred by both sexes. Hence, the ability of either sex to allocate proportionately more to growth than the other is likely constrained, meaning that sexual differences in growth and resultant body size are not possible. Consequently, grouping marine turtles with NMAT dilutes the statistical signature of different kinds of selection on SSD and should be avoided in future studies. [ABSTRACT FROM AUTHOR]

Various morphological proxies have been used to infer habitat preferences among fossil turtles and their early ancestors, but most are tightly linked to phylogeny, thereby minimizing their predictive power. One particularly widely used model incorporates linear measurements of the forelimb (humerus + ulna + manus), but in addition to the issue of phylogenetic correlation, it does not estimate the likelihood of habitat assignment. Here, we introduce a new model that uses intramanual measurements (digit III metacarpal + non‐ungual phalanges + ungual) to statistically estimate habitat likelihood and that has greater predictive strength than prior estimators. Application of the model supports the hypothesis that stem‐turtles were primarily terrestrial in nature and recovers the nanhsiungchelyid Basilemys (a fossil crown‐group turtle) as having lived primarily on land, despite some prior claims to the contrary. [ABSTRACT FROM AUTHOR]

Pubenza is a remarkable palaeontological site of Colombia, and a place that could hold some of the potentially oldest evidence of humans in northern South America. Previous palaeontological research at this site has mainly focused on the megafauna. Here we describe and establish the systematic palaeontology for the small fauna that inhabited this ancient lacustrine ecosystem, including the first report of birds, tortoises and vipers for the Late Pleistocene in Colombia. Furthermore, exceptionally well preserved fossilised wasp nests are morphologically and elementally characterised, which is the first report of an ichnofossil of this kind in northern South America. In addition, new material of kinosternid turtles, armadillos and rodents is also described. Our results reveal that the Bogotá River Basin, where Pubenza is located, was a rich ecosystem during the Late Pleistocene and a region of great interest for future articulated palaeontological and archaeological studies. [ABSTRACT FROM AUTHOR]

Archosaurs displayed an evolutionary trend toward increasing bipedalism in their evolutionary history, that is, forelimbs tend to be reduced in contrast to the development of hindlimbs becoming major weight‐bearing and locomotor appendages. The archosaurian locomotion has been extensively discussed based on their limb morphology because the latter reflects their locomotor modes very well. However, despite some attempts of reconstructing the hindlimb musculature in Archosauria, that of the most distal portion, the pes, has often been neglected. In order to rectify this trend, detailed homologies of pedal muscles among sauropsids were established based on dissections and literature reviews of adult conditions. As a result, homologies of some pedal muscles between non‐avian sauropsids and avians were revised, challenging classical hypotheses. The present new hypothesis postulates that the avian m. tibialis cranialis and non‐avian m. extensor digitorum longus, as well as the avian m. extensor digitorum longus and non‐avian m. tibialis anterior, are homologous with each other, respectively. This is more plausible because it requires no drastical change in the attachment sites between the avian and non‐avian homologues unlike the classical hypothesis. Many interosseous muscles in non‐archosaurian sauropsids that have long been regarded as a part of short digital extensors or flexors are also divided into multiple distinct muscles so that they can be homologized with short pedal muscles among all sauropsids. In addition, osteological correlates of attachments are identified for most of the pedal muscles, contributing to future attempts of reconstruction of this muscle system in fossil archosaurs. [ABSTRACT FROM AUTHOR]

Freshwater turtle species are suffering from anthropocentric‐caused population declines, making preservation of professionally managed populations increasingly important. Turtles under professional care have an increased risk to develop hepatic lipidosis, potentially resulting in early death. Computed tomography can provide an antemortem screening for increased fatty liver composition. A goal of this prospective analytical cross‐sectional study was to assess the hepatic attenuation measured as Hounsfield units (HU) in a wild population of a freshwater turtle species, and then compare hepatic HU to freshwater turtles under professional care. Ninety‐five wild Blanding's turtles (BT; Emydoidea blandingii) as well as 10 Vietnamese Pond turtles (VPT; Mauremys annamensis) and six Northern Snake‐Necked turtles (NSNT; Chelodina oblonga) under professional care underwent CT with quantification of hepatic HU. Hepatic HU were correlated to serum chemistry findings and the presence of follicles was recorded in BT. The mean (±SD) hepatic attenuation for 95 wild BT was 97.5 HU ±9.6. There were significant differences in hepatic attenuation among VPT, NSNT, and BT, with median HU values (range) of 5.39 HU (–6.45 to 61.50), 71.74 HU (59.44‐94.49), and 95.43 HU (74.41‐124.56), respectively. Aspartate aminotransferase (AST) values had a weak negative correlation to HU with a coefficient of –0.85 (P <.001). The hepatic attenuation was significantly higher for individuals undergoing folliculogenesis (P =.007). The decreased HU values were significantly negatively correlated with AST values. Findings supported the use of CT as an aid for guiding future management practices in freshwater turtles. [ABSTRACT FROM AUTHOR]

In recent years, it has become clear that frugivory and seed dispersal (FSD) by turtles and tortoises is much more common than previously thought. We here review published and unpublished records of chelonian FSD, and assess the role of chelonians as seed dispersers, from individual species to the community level. We first discuss the distribution of chelonian FSD and the characteristics of the fruit and/or seed species eaten and dispersed by chelonians. We then use the seed dispersal efficiency framework to explore the quantitative and qualitative components of seed dispersal by tortoises and turtles, embarking on a journey from when the fruits and/or seeds are consumed, to when and where they are deposited, and assess how efficient chelonians are as seed dispersers. We finally discuss chelonian FSD in the context of communities and of chelonians as megafauna. A substantial proportion of the world's aquatic and terrestrial turtles and a major part of testudinid tortoises (71 species in 12 families) include fruits and/or seeds in their diet; fruits of at least 588 plant species in 121 families are ingested and/or dispersed by chelonians. For some chelonians, overall or in certain seasons, fruit may even form the largest part of their diet. Contrary to seed dispersal by lizards, the other major reptilian frugivores, chelonian FSD is not an island phenomenon in terms of geographic distribution. Nevertheless, on islands tortoises are often among the largest native terrestrial vertebrates – or were until humans arrived. We synthesise our knowledge of chelonian FSD, and discuss the relevance of our findings for conservation and restoration, especially in relation to rewilding with large and giant tortoises. [ABSTRACT FROM AUTHOR]

The middle ear of turtles differs from other reptiles in being separated into two distinct compartments. Several ideas have been proposed as to why the middle ear is compartmentalized in turtles, most suggesting a relationship with underwater hearing. Extant turtle species span fully marine to strictly terrestrial habitats, and ecomorphological hypotheses of turtle hearing predict that this should correlate with variation in the structure of the middle ear due to differences in the fluid properties of water and air. We investigate the shape and size of the air‐filled middle ear cavity of 56 extant turtles using 3D data and phylogenetic comparative analysis to test for correlations between habitat preferences and the shape and size of the middle ear cavity. Only weak correlations are found between middle ear cavity size and ecology, with aquatic taxa having proportionally smaller cavity volumes. The middle ear cavity of turtles exhibits high shape diversity among species, but we found no relationship between this shape variation and ecology. Surprisingly, the estimated acoustic transformer ratio, a key functional parameter of impedance‐matching ears in vertebrates, also shows no relation to habitat preferences (aquatic/terrestrial) in turtles. We suggest that middle ear cavity shape may be controlled by factors unrelated to hearing, such as the spatial demands of surrounding cranial structures. A review of the fossil record suggests that the modern turtle ear evolved during the Early to Middle Jurassic in stem turtles broadly adapted to freshwater and terrestrial settings. This, combined with our finding that evolutionary transitions between habitats caused only weak evolutionary changes in middle ear structure, suggests that tympanic hearing in turtles evolved as a compromise between subaerial and underwater hearing. [ABSTRACT FROM AUTHOR]

Gastrointestinal disorders are an important cause of morbidity in box turtles (Terrapene carolina Carolina), however published information is currently lacking on the normal radiographic anatomy, transit, and emptying times of the gastrointestinal tract. A total of 15 healthy box turtles were recruited for this prospective, anatomic, reference interval study. Three‐view radiographic series (vertical beam dorsoventral, horizontal beam latero‐lateral, and horizontal beam rostrocaudal views) were acquired prior to contrast administration, and following contrast administration at 0, 20, 40, 60, and 90 min, 2, 4, 8, 12, and 24 h post administration, and every 24 h thereafter until all contrast was eliminated (15 mL/kg barium sulfate diluted to 30% weight per volume was administered via orogastric gavage). Vertical beam dorsoventral and horizontal beam latero‐lateral views were of excellent quality to identify gastrointestinal structures. The horizontal beam rostrocaudal view immediately postcontrast administration provided gastric and pyloric identification but had lesser diagnostic use at later time points due to anatomical superimposition. The gastrointestinal tract was composed of a tubular stomach, a pyloric sphincter near midline, a duodenum with a cranial flexure in the right cranial coelomic cavity, small intestines within the right coelom, a small cecal bulb, and a transverse and descending colon. Contrast media entered the large intestine by 24 h in all turtles, and a pyloro‐colic indentation was noted at the proximal descending colon. The large intestinal emptying was highly variable due to the interindividual variability of contrast sequestration within the cecal bulb. Findings from the current study serve as a reference on the gastrointestinal anatomy, transit, and emptying times in healthy eastern box turtles; and introduce a novel, horizontal beam, rostrocaudal view for gastrointestinal contrast studies in chelonians. [ABSTRACT FROM AUTHOR]

Extant sea turtles develop and lay pliable (flexible) eggs; however, it is unknown whether they inherited this reproductive strategy from their closer fossil relatives or if it represents an evolutionary novelty. Here, we describe the first undisputable gravid marine fossil turtle ever found, from the early Cretaceous of Colombia, belonging to Desmatochelys padillai Cadena & Parham, which constitutes a representative of the Protostegidae. Using thin sectioning of one of the eggs, as well as scanning electron microscopy coupled with elemental characterization, cathodoluminescence, and computer tomography, we established that Desmatochelys padillai produced rigid eggs similar to those associated with some extant and fossil freshwater and terrestrial turtles. At least 48 spherical eggs were preserved inside this gravid turtle. We suggest that the development of rigid eggs in the extinct marine turtle Desmatochelys padillai resulted as an adaptation for egg‐embryo requirements dictated by the physical attributes of the nesting site. [ABSTRACT FROM AUTHOR]

Sharpey's fibers are considered the anatomical structures integrated to the muscles. Since these fibers leave marks at the microscopic level, their presence and distribution are used as evidence of muscle attachment in extinct and extant forms. In recent years, studies have been focusing on muscle–bone and tendon–bone interaction mostly on mammals. The main objective of this work is to contribute to the morphological and histological knowledge of muscle attachment in other amniotes, such as reptiles, and their variation related to different locomotor habits. In this way, a study was performed on terrestrial and aquatic turtles. The musculature related to the movement of the humerus, and pectoral girdle in Chelonoidis chilensis, Phrynops hilarii and Hydromedusa tectifera was analyzed. Dissections were performed mapping the origins and insertions of each muscle and undecalcified thin sections were performed in specific muscular attachment sites. We found some differences which were not previously reported, related to the insertion of the m. pectoralis, the m. coracobrachialis magnus and the origin of the m. tractor radii. The osteohistology revealed the presence of Sharpey's fibers in the cortex of all the bone elements analyzed. Patterns were established in relation to the orientation and density of Sharpey's fibers, which were used for the categorization of each muscle attachment site. The comparative micro‐anatomical study of these areas did not reveal any important differences between terrestrial and freshwater turtles in muscles involved with the rotation, abduction and adduction of the humerus. In this way, the preliminary results suggest an absence of correlation between the distribution and density of Sharpey's fibers between different habitat forms, at least in the bones and species analyzed. [ABSTRACT FROM AUTHOR]

Aim: This study aims to evaluate phylogenetic structure of turtle communities and their potential correlates on a global scale. More specifically, we tested whether cold temperatures and low precipitation could act as potential environmental filters of turtle communities and whether the dispersal limitation caused by altitudinal range could generate phylogenetic clustered patterns in these communities. Location: Global. Taxon: Turtles. Methods: We used phylogenetic and distributional data of 257 species of turtles on a grid of 100 km × 100 km to generate measures of phylogenetic structure (mean nearest taxon distance and the mean pairwise distance, and their standardized effect sizes—SES) of turtle communities using three different species pools. We evaluated the relationship between SESs with climatic and altitudinal data in order to evaluate our hypotheses. Finally, we inspected whether there was phylogenetic signal in the climatic variables classified as potential filters, as it is a basic assumption for using phylogenetic structure metrics to infer assembly rules. Results: Phylogenetic clustering was generally stronger than phylogenetic overdispersion in turtle communities. There was a positive relationship between minimum temperature and the phylogenetic structure metrics, while minimum precipitation and altitudinal range were negatively related to these metrics. We found a strong phylogenetic signal in the minimum temperature, while precipitation had a weak signal. Main conclusions: The positive correlation between phylogenetic community structure metrics and minimum temperature and the phylogenetic signal present in this climatic variable are in accordance with our initial hypothesis regarding minimum temperature acting as an environmental filter for turtles. However, we did not find evidence to support minimum precipitation as a filter. Altitudinal range followed the expected patterns, suggesting that it increases dispersal limitation and allows a concentration of closely related species. [ABSTRACT FROM AUTHOR]

Abstract: A new stem cheloniid turtle, Cabindachelys landanensis, gen. et sp. nov., is represented by a nearly complete skull and partial hyoid collected in lower Paleocene shallow marine deposits, equivalent to the offshore Landana Formation, near the town of Landana in Cabinda, Angola. A partial chelonioid carapace previously reported from this locality is referred here to C. landanensis. Cabindachelys landanensis possesses clear synapomorphies of Pan‐Cheloniidae, including a rod‐like rostrum basisphenoidale, V‐shaped basisphenoid crest, and secondary palate, but also retains a reduced foramen palatinum posterius, unlike most other pan‐cheloniids. Phylogenetic analysis suggests that C. landanensis forms a weakly‐supported clade with Erquelinnesia gosseleti, Euclastes acutirostris, Euclastes wielandi and Terlinguachelys fischbecki, although a close relationship between the protostegid T. fischbecki and these durophagous pan‐cheloniids is unlikely. The Paleocene–Eocene strata near Landana have produced a number of turtle fossils, including the holotype specimen of the pleurodire Taphrosphys congolensis. A turtle humerus collected c. 1 m above the holotype skull of C. landanensis differs from humeri of chelonioids and Taphrosphys, indicating that a third turtle taxon is present at Landana. Cheloniid fossil material is rare in the Landana assemblage, in comparison with the abundant remains of Taphrosphys congolensis found throughout the stratigraphic section. This disparity implies that C. landanensis preferred open marine habitats, whereas Taphrosphys congolensis spent more time in nearshore environments. The appearance of new durophagous species such as C. landanensis in the early Paleocene reflects the rapid radiation of pan‐cheloniids as they diversified into open niches following the K–Pg extinction. [ABSTRACT FROM AUTHOR]

The common snapping turtle ( Chelydra serpentina) is a well studied and broadly distributed member of Testudines; however, very little is known concerning developmental anomalies and soft tissue pathologies of turtles and other reptiles. Here, we present an unusual case of unilateral pulmonary aplasia, asymmetrical carapacial kyphosis, and mild scoliosis in a live adult C. serpentina. The detailed three-dimensional (3D) anatomy of the respiratory system in both the pathological and normal adult C. serpentina, and a hatchling are visualized using computed tomography ( CT), micro CT, and 3D digital anatomical models. In the pathological turtle, the right lung consists of an extrapulmonary bronchus that terminates in a blind stump with no lung present. The left lung is hyperinflated relative to the normal adult, occupying the extra coelomic space facilitated by the unusual mid-carapacial kyphotic bulge. The bronchial tree of the left lung retains the overall bauplan of the normal specimens, with some minor downstream variation in the number of secondary airways. The primary difference between the internal pulmonary structure of the pathological individual and that of a normal adult is a marked increase in the surface area and density of the parenchymal tissue originating from the secondary airways, a 14.3% increase in the surface area to volume ratio. Despite this, the aplasia has not had an impact upon the ability of the turtle to survive; however, it did interfere with aquatic locomotion and buoyancy control under water. This turtle represents a striking example of a non-fatal congenital defect and compensatory visceral hypertrophy. [ABSTRACT FROM AUTHOR]

Aim Ecological communities may be structured by deterministic processes commonly related to climatic conditions or to neutral processes commonly associated with dispersal limitation. This study aims to evaluate the processes responsible for structuring the composition of turtle communities across different biogeographical realms. Location Global Methods We used distribution maps of 290 non-marine turtle species to determine the components of beta diversity (turnover and nestedness/richness difference) within the biogeographical realms. We also used a recently published phylogeny to calculate phylogenetic beta diversity. Then, we used partial Mantel tests and multiple regressions on distance matrices ( MRM) to evaluate the importance of ecological and spatial factors in determining turtle beta diversity. We also used multiple regressions to evaluate whether temperature instability since the Last Glacial Maximum ( LGM) or topographical heterogeneity was the main driver of beta diversity. Results The beta diversity of turtles in all realms was mainly influenced by the turnover component. However, the nestedness/richness difference component was also important, mainly in realms subject to large climatic variations since the LGM. Environmental distance was positively related to beta diversity in some realms, but this effect was generally low. Geographical distance explained a higher amount of variance than environmental distances in all the realms. Phylogenetic beta diversity provided similar results to taxonomic beta diversity. Temperature instability since the LGM was a strong driver of taxonomic beta diversity in the Nearctic realm, but its effect on the Neotropical realm was mainly concentrated in the turnover component. Main conclusions Spatial processes such as dispersal may be more important than climatic differences in structuring the composition of turtle communities in the distinct biogeographical realms. However, when climate is also important, the effect of environmental processes such as temperature instability since the LGM and topographical heterogeneity are not the same in the different biogeographical realms. [ABSTRACT FROM AUTHOR]

Abstract: The late Pliocene (early Villafranchian, MN 16a) locality of Milia (Grevena, Greece) has yielded numerous remains of mammals, such as zygodons, mastodons, rhinocerotids, hipparions, bovids, cervids, suids, carnivorans and tapirs. Several specimens of chelonians have also been discovered and comprise a small testudinid, a geoemydid and a giant tortoise. The presence of a giant tortoise and the presence of a geoemydid with large dimensions are further examples of the trend towards gigantism evidenced by the diverse fauna of Milia. In terms of taxonomic abundance of extinct turtles, this is the richest locality in Greece. The small testudinid is of particular importance because it preserves a posteriorly flared carapace, as in the extant Testudo marginata, but the posterior carapace is much taller and anteroposteriorly shorter. These characters allow us to erect a new species, Testudo brevitesta sp. nov., and to discuss the presence of the marginated tortoise and closely related forms in Greece. The new taxon is analysed in a phylogenetic context within other extant and extinct testudinids, providing new information on the clade Testudona. [ABSTRACT FROM AUTHOR]

Background: This multi‐institutional retrospective study evaluated the feasibility and safety of endoscopic sex identification in 467 turtles and tortoises, representing 10 species. Methods: Medical records of turtles and tortoises that underwent endoscopic sex identification at the University of Georgia, New England Aquarium and Turtle Conservancy were reviewed for presurgical management, anaesthesia, endoscopic equipment and surgical techniques, endoscopic results and complications. Results: The majority of animals weighed less than 200 g, were fasted and anaesthetised using an injectable combination of ketamine, dexmedetomidine and morphine or hydromorphone, supplemented by local lidocaine at the prefemoral site. Anaesthetic reversal using atipamezole alone or in combination with naloxone was routine. For uncomplicated procedures, mean total anaesthesia, surgery and recovery times were 22, 4 and 18 minutes, respectively. All animals were placed in lateral recumbency for a prefemoral endoscopic approach to the coelom using a rigid telescope and sterile fluid infusion to visualise the gonads. Sex identification was definitive in 99.4% (n = 464) of the animals. Iatrogenic bladder perforation was the most common complication (n = 5), which necessitated extended anaesthesia and surgical time for repair. Only a single anaesthetic‐related death was reported, which was associated with human error and drug overdose. Conclusions: This is the first large‐scale study to retrospectively evaluate endoscopic sex identification in multiple chelonian species. Results suggest that endoscopic sexing is a safe, accurate and practical means for sex identification in turtles and tortoises, and represents a valuable tool in their reproductive management. [ABSTRACT FROM AUTHOR]

Maternal body size can have notable consequences on reproductive success. For example, fecundity often increases with body size. Less is known, however, about the relationship between maternal size and factors affecting offspring fitness, including size, growth and survival. Here, we examined the relationship between hatchling and maternal body size in the Mojave Desert tortoise G opherus agassizii. We further examined the relationships between survival and growth after 1 year and size at hatching. We found that larger females tended to produce larger offspring; post-hatching growth and survival also correlated positively with size at hatching. Our results suggest that, in desert tortoises, maternal body size may indirectly influence offspring fitness via growth and survival for at least the first year of life. Such an advantage early in life may confer long-term benefits for individuals, especially in species thought to have high juvenile mortality or that inhabit highly variable environments. [ABSTRACT FROM AUTHOR]

Background The role of noradrenergic system in the control of nociception is documented in some vertebrate animals. However, there are no data showing the role of this system on nociception in the marsh terrapins. Methodology In this study, the antinociceptive action of intrathecal administration of the α2-adrenoreceptor agonist clonidine and α2-adrenoreceptor antagonist yohimbine was evaluated in the African marsh terrapin using the formalin test. The interaction of clonidine and yohimbine was also evaluated. Results Intrathecal administration of clonidine (37.5 or 65 μg/kg) caused a significant reduction in the mean time spent in pain-related behavior. Yohimbine, at a dose of 25 μg/kg, significantly blocked the effect of clonidine (65 μg/kg). However, administration of yohimbine (40 or 53 μg/kg) caused a significant reduction in the mean time spent in pain-related behavior. Intrathecal administration of yohimbine (53 μg/kg) followed immediately by intrathecal injection of the serotonergic methysergide maleate (20 μg/kg) resulted in a significant reversal of the antinociceptive effect of yohimbine. Conclusion The present study documented the intrathecal administration of drugs in the marsh terrapin, a technique that can be applied in future studies on these animals. The data also suggest the involvement of both α2-adrenoreceptors and 5 HT receptors in the modulation of nociception in testudines. [ABSTRACT FROM AUTHOR]

Aim The island rule describes a trend toward dwarfism of large animals and gigantism of small animals on islands. Studies of vertebrates, including reptiles, report conflicting results regarding the generality of this evolutionary pattern. We studied the size evolution of insular turtles at the intra- and interspecific levels, as well as the clade level. We examined the evolutionary patterns, the relationship of habitat preferences and insular turtle size and whether the island rule extends to turtles. Location Islands world-wide and adjacent continents. Methods We collected data from the literature and expanded our database by measuring turtle specimens in museum collections. We used reduced major axis regression to test the island rule at the inter- and intraspecific levels, after accounting for phylogenetic effects. In addition, we compared body size frequency distributions of insular versus mainland turtles at the clade level. Results Our analyses revealed no support for the island rule in turtles. Intraspecifically, we found no systematic pattern of body size evolution. Interspecifically, large turtle species tend to become larger on islands, in contrast to the island rule predictions. Islands generally harbour larger turtles than mainland regions. This pattern is especially apparent when recently extinct species are considered. We found no impact of habitat preferences on the evolution of body size on islands. Main conclusions Turtles on islands do not follow the island rule. We suggest that both physiological and ecological factors drive turtle body size evolution on islands, and their tendency for insular gigantism. Large turtles can survive longer periods of water or food shortage on small oceanic islands. Increased intraspecific competition and reduced interspecific competition and predation on islands may favour large body size. A non-mutually exclusive explanation is that the presence of giant tortoises on islands may reflect founder effects rather than evolution - large turtles are better island colonizers. [ABSTRACT FROM AUTHOR]

Clinically healthy reptiles may shed Salmonella and therefore act as a potential zoonotic threat. Most people in Northern European countries are rarely exposed to reptiles, but many zoos have education departments where children have direct contact with this group of animals. The objectives of this study were to determine the prevalence and serotype distribution of Salmonella among reptiles in the Education Department ( n = 55) at Copenhagen Zoo and compare it to the Zoo's main reptile collection ( n = 145) to evaluate the zoonotic risk. Salmonella was isolated from cloacal swabs by selective enrichment, and a single isolate from each positive sample was further identified by biochemical tests and serotyped. The overall prevalence was 35% (69/200) with significant difference between the Education Department (64%, 35/55) and the main reptile collection (23%, 34/145). A total of 28 serotypes were detected. Ten serotypes were isolated from more than one specimen and four from more than one species. Salmonella enterica subsp. enterica serovar Eastbourne was the predominant serotype (32%, 22/69) and was also the serotype isolated from most reptile species ( n = 7). Transmission of serotypes from one department to another was very limited indicated by the serotype distribution. Despite the relative high prevalence observed among the reptiles in the Zoo's Education Department compared to the reptiles in the Zoo's main reptile collection, no Salmonella cases have been linked to the Zoo, and Salmonella ser. Eastbourne is very rarely isolated from humans in Denmark. Simple hygienic procedures such as hand washing which is consistently carried out following handling of reptiles at the Education Department may reduce the risk and therefore contribute to this low prevalence. [ABSTRACT FROM AUTHOR]

DNA barcoding facilitates the identification of species and the estimation of biodiversity by using nucleotide sequences, usually from the mitochondrial genome. Most studies accomplish this task by using the gene encoding cytochrome oxidase subunit I ( COI; Entrez COX1). Within this barcoding framework, many taxonomic initiatives exist, such as those specializing in fishes, birds, mammals, and fungi. Other efforts center on regions, such as the Arctic, or on other topics, such as health. DNA barcoding initiatives exist for all groups of vertebrates except for amphibians and nonavian reptiles. We announce the formation of Cold Code, the international initiative to DNA barcode all species of these 'cold-blooded' vertebrates. The project has a Steering Committee, Coordinators, and a home page. To facilitate Cold Code, the Kunming Institute of Zoology, Chinese Academy of Sciences will sequence COI for the first 10 specimens of a species at no cost to the steward of the tissues. [ABSTRACT FROM AUTHOR]

Joyce, W.G. and Sterli J. 2010. Congruence, non-homology, and the phylogeny of basal turtles.- Acta Zoologica (Stockholm) Modern cladistic analysis is characterized by the assembly of increasingly larger data sets coupled with the use of congruence as the final test of homology. Some critics of this development have recently called for a return to more detailed primary homology analysis while questioning the utility of congruence. This discussion appears to be central to the debate regarding the phylogenetic relationships of basal turtles, as the large data sets developed by us have been criticized recently for utilizing poorly constructed characters and including too many homoplasy-prone characters. Our analysis of this critique reveals that (1) new information regarding poorly understood taxa has a greater impact on the outcome of turtle phylogenies than the characters under dispute; (2) most current turtle phylogenies differ in taxon sampling, not character sampling, and so it appears illogical to condemn a particular analysis for its character sampling; (3) even evolutionary taxonomists should agree that key characters utilized to resolve basal turtle relationships cannot be thought to be 'infallible'; (4) whereas various criteria provide positive evidence for homology, only congruence provides positive evidence for non-homology; and (5) a stalemate between conflicting camps within a congruence frame work is preferable to the ad hoc dismissal of data sets, because authoritative statements are untestable. [ABSTRACT FROM AUTHOR]

The present study represents the first comprehensive contribution to the knowledge of the skeletal development of a pleurodiran turtle, Phrynops hilarii (Pleurodira, Chelidae). The most remarkable features found are: (1) absence of ascending process on pterygoquadrate cartilage; (2) presence of ossification centres for the epiotics; (3) as in other pleurodirans, dorsal ribs IX and X are ‘sacralized’; (4) contact between ilium and carapace occurs later in ontogenetic development; (5) suture between ischia, pubes and plastron occurs in posthatching specimens; (6) contrary to previous interpretations, the phalangeal formula of the pes of P.  hilarii is 2 : 3 : 3 : 3 : 5; (7) the hooked bone represents the fifth metatarsal. [ABSTRACT FROM AUTHOR]

Survival rates of juvenile reptiles are critical population parameters but are difficult to obtain through mark-recapture programs because these small, secretive animals are rarely caught. This scarcity has encouraged speculation that survival rates of juveniles are very low, and we test this prediction by estimating juvenile survival rates indirectly. A simple mathematical model calculates the annual juvenile survival rate needed to maintain a stable population size, using published data on adult survival rates, reproductive output, and ages at maturity in 109 reptile populations encompassing 57 species. Counter to prediction, estimated juvenile survival rates were relatively high (on average, only about 13% less than those of conspecific adults) and highly correlated with adult survival rates. Overall, survival rates during both juvenile and adult life were higher in turtles than in snakes, and higher in snakes than in lizards. As predicted from life history theory, rates of juvenile survival were higher in species that produce large offspring, and higher in viviparous squamates than in oviparous species. Our analyses challenge the widely held belief that juvenile reptiles have low rates of annual survival and suggest instead that sampling problems and the elusive biology of juvenile reptiles have misled researchers in this respect. [ABSTRACT FROM AUTHOR]

Carpal and tarsal anatomy was documented based on the observation of dry skeletons of adult specimens representing 25 species in 15 genera and on data taken from the literature. In addition, histological sections and cleared and double-stained autopodia of recently hatched and juvenile specimens representing seven chelid and pelomedusoid species were studied. There is much more morphological diversity in the manus than in the pes. Variation in autopodial skeletons includes: the astragalus and calcaneum are either separated or fused; fusion of distal carpals 3–4−5 or just 4–5; number of centralia in the carpus; and presence/absence of a pisiform and of an accessory radial element. The widespread and probably basal phalangeal formula for Pleurodira is 2.3.3.3.3. Deviations are Pelomedusa subrufa, exhibiting a reduction to 2.2.2.2.2, Pelusios spp. with one phalanx less in digit I and for one species in digit V as well, and Acanthochelys pallidipectoris with an additional phalanx in the fourth finger. Six discrete characters itemizing some of the morphological variation observed were plotted on a composite pleurodire phylogeny, revealing not only homoplastic patterns but also the utility of some characters in supporting the monophyly of several clades. The pisiform is the last carpal element to ossify in Chelus fimbriatus. We hypothesize that the so-called fifth hooked metatarsal represents the fusion of distal tarsal 5 with metatarsal V. The accessory radial element that was occasionally present in the turtles examined may represent an atavism of the otherwise lost radiale of turtles. [ABSTRACT FROM AUTHOR]

A new, unusually well-preserved juvenile specimen of Ctenochelys stenoporus from the Niobrara Formation is described. The skull has come apart at its sutures and all bones of the braincase and ear region are preserved three-dimensionally. This allows a detailed reconstruction of the important brain structures of a basal juvenile cheloniid turtle. It is compared with adult Ctenochelys specimens, and the major ontogenetic changes in the skull and postcranial skeleton are described. Furthermore, the specimen is compared with other fossil and extant cheloniids with well-known braincases and the differences between basal and advanced cheloniids turtles are specified. [ABSTRACT FROM AUTHOR]

We re-examine the type series of ‘ Sinemys’ wuerhoensis Yeh (at least 20 specimens, including several shells and skulls on three slabs of matrix and one isolated skull) from the Early Cretaceous Tugulu Group of China. Our study shows that the type series of ‘ S.’ wuerhoensis is actually a chimera made up of at least three distinct taxa. The holotype of this taxon should be assigned to the basal eucryptodire genus Xinjiangchelys Yeh. As there are no characters that distinguish ‘ S.’ wuerhoensis from Xinjiangchelys species, we consider it to be a nomen dubium. This new assignment of ‘ S.’ wuerhoensis expands the temporal range of Xinjiangchelys from the Late Jurassic into the Early Cretaceous in Asia. The majority of the paratypes of ‘ S.’ wuerhoensis (several shells in dorsal and ventral aspect and skulls) are referred to the basal eucryptodire genus Ordosemys Brinkman and Peng. We establish a new name for these specimens, Ordosemys brinkmania sp. nov. One additional specimen in the type series of ‘ S.’ wuerhoensis, a skull, is referred to cf. Pantrionychia Joyce, Parham and Gauthier indet. [ABSTRACT FROM AUTHOR]

Ecological and genetic studies of marine turtles generally support the hypothesis of natal homing, but leave open the question of the geographical scale of genetic exchange and the capacity of turtles to shift breeding sites. Here we combine analyses of mitochondrial DNA (mtDNA) variation and recapture data to assess the geographical scale of individual breeding populations and the distribution of such populations through Australasia. We conducted multiscale assessments of mtDNA variation among 714 samples from 27 green turtle rookeries and of adult female dispersal among nesting sites in eastern Australia. Many of these rookeries are on shelves that were flooded by rising sea levels less than 10 000 years ( c. 450 generations) ago. Analyses of sequence variation among the mtDNA control region revealed 25 haplotypes, and their frequency distributions indicated 17 genetically distinct breeding stocks (Management Units) consisting either of individual rookeries or groups of rookeries in general that are separated by more than 500 km. The population structure inferred from mtDNA was consistent with the scale of movements observed in long-term mark–recapture studies of east Australian rookeries. Phylogenetic analysis of the haplotypes revealed five clades with significant partitioning of sequence diversity (Φ = 68.4) between Pacific Ocean and Southeast Asian/Indian Ocean rookeries. Isolation by distance was indicated for rookeries separated by up to 2000 km but explained only 12% of the genetic structure. The emerging general picture is one of dynamic population structure influenced by the capacity of females to relocate among proximal breeding sites, although this may be conditional on large population sizes as existed historically across this region. [ABSTRACT FROM AUTHOR]

The olive ridley is the most abundant seaturtle species in the world but little is known of the demography of this species. We used skeletochronological data on humerus diameter growth changes to estimate the age of North Pacific olive ridley seaturtles caught incidentally by pelagic longline fisheries operating near Hawaii and from dead turtles washed ashore on the main Hawaiian Islands. Two age estimation methods [ranking, correction factor (CF)] were used and yielded age estimates ranging from 5 to 38 and 7 to 24 years, respectively. Rank age-estimates are highly correlated ( r = 0.93) with straight carapace length (SCL), CF age estimates are not ( r = 0.62). We consider the CF age-estimates as biologically more plausible because of the disassociation of age and size. Using the CF age-estimates, we then estimate the median age at sexual maturity to be around 13 years old (mean carapace size c. 60 cm SCL) and found that somatic growth was negligible by 15 years of age. The expected age-specific growth rate function derived using numerical differentiation suggests at least one juvenile growth spurt at about 10–12 years of age when maximum age-specific growth rates, c. 5 cm SCL year−1, are apparent. [ABSTRACT FROM AUTHOR]

A new eucryptodiran turtle,Xinjiangchelys qiguensissp. nov. from the Upper Jurassic (Oxfordian— ?Kimmeridgian) Qigu Formation of the southern Junggar Basin (north-west China) is described. The type material consists of a partial skeleton, including the complete carapace, plastron, nearly all cervical vertebrae, both scapulae, the pelvis and one ulna. It is clearly identifiable as a basal eucryptodire since it lacks the mesoplastron. It is distinguished from other species ofXinjiangchelysby several autapomorphies of the carapace and plastron, such as the first and fifth vertebrals extending on the peripherals, the plastron with three pairs of gulars, and an intergular which does not contact the hyoplastron. In the postcranium, the scapula with a long acromial and a small scapular process, the pelvis with a short ilial shaft and the elongated cervical vertebrae are characteristic. A new phylogenetic analysis of the in-group phylogeny of the Xinjiangchelyidae is proposed and discussed, resulting in a new classification of the family.Xinjiangchelys(Toxocheloides)narynensisis regarded as anomen dubium.Shartegemysis referred toXinjiangchelys, whereas the holotypes of‘ Plesiochelys’ chungkingensisand‘ P’.latimarginalisare excluded from the genusXinjiangchelysbut included in the Xinjiangchelyidae. [ABSTRACT FROM AUTHOR]

We describe the development of nine microsatellite loci from the gopher tortoise ( Gopherus polyphemus). Screening 270 individuals, we found these loci to be highly variable (from two to 15 alleles per locus) and thus likely to be applicable in parentage and population-level analyses for G. polyphemus. All nine loci amplified readily in the other three species of Gopherus as well. This observation, together with successful cross amplification of several loci in two additional families (Cheloniidae, Kinosternidae), underscores their potential utility among turtles in general. [ABSTRACT FROM AUTHOR]

Independent microsatellite development efforts at the University of Miami and Dalhousie University resulted in seven microsatellite loci for the Blanding's turtle ( Emydoidea blandingii). The level of polymorphism ranged from three to 15 alleles with observed heterozygosities ranging from 0.31 to 0.95. Cross species amplification suggests that these loci may have utility in other turtle species. [ABSTRACT FROM AUTHOR]