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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]

The diverse climatic and geological history of Southeast Asia has been a driving force behind significant Pleistocene and Holocene range dynamics and the consequent biological diversification in the region. Among the species exhibiting wide distributions, extending across several well-known zoogeographic barriers, the Elongated Tortoise (Indotestudo elongata) is noted for its extensive variability in size, shape, and colouration. To examine phylogeographic differentiation within I. elongata, we analysed three mitochondrial gene fragments (ND4, cyt b, and COI) for 52 individuals including fourteen historic specimens and 25 sequences obtained from Gen- Bank. Phylogenetic analyses of the concatenated alignment revealed genetic homogeneity across the range, supported by a shallow mean uncorrected p distance of 1.2% in cyt b. This corresponds to a surprising lack of biogeographic structuring. Concordantly, multivariate statistical analyses of morphometric and colouration-related characters of 166 adult tortoises (79 males and 87 females) from Myanmar, Thailand, Cambodia, and Vietnam showed no statistically significant differences between biogeographic units. The lack of any phylogeographic signal and morphological differentiation despite the presence of significant biogeographic barriers is unusual for a terrestrial vertebrate from this region. Archaeological evidence suggests that Elongated Tortoises have been used as a food item for millennia. It could be that their current wide distribution and the absence of genetic differentiation are the result of a significant range expansion caused by extensive human-mediated dispersal over the prehistoric and historic tortoise trade. The observed lack of phylogeographic structure considerably simplifies conservation measures such as conservation breeding, reintroduction, and population reinforcement. [ABSTRACT FROM AUTHOR]

The European pond turtle (Emys orbicularis) is an endangered Old World species. The phylogeographic history of E. orbicularis has been extensively studied throughout its range. While local genetic variation holds valuable information for conservation efforts, specific regional details have yet to be thoroughly examined everywhere. The Valencian region on the Iberian Peninsula is one such area. Here, different evolutionary lineages of E. orbicularis meet, forming a part of the western Mediterranean hybrid zone. In this study, we comprehensively sampled all Valencian localities where E. orbicularis occurs. Using mitochondrial DNA and nuclear microsatellites, we determined the genetic structure of E. orbicularis populations. Our data reveals that the mitochondrial haplotype originating from the glacial refugium in the Apennine Peninsula is primarily restricted to the northern part of the Valencian region. Additionally, human-mediated dispersal processes may have contributed to the complex relationships between the evolutionary lineages of E. orbicularis in the natural hybrid zone. On a finer scale, E. orbicularis in the Valencian region can be classified into five distinct genetic populations. Morphometric analyses revealed sexual dimorphism in the plastron shape and slight variation among genetic populations. Notably, female, but not male, plastron shape correlates with individual heterozygosity. Given the ongoing threat posed by exotic turtles, we propose implementing targeted management strategies to mitigate the presence of alien turtles. These strategies should be directed towards localities that represent each genetic population within the region, reflecting the extensive population structure observed in our study. [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]

Simple Summary: This case report offers a comprehensive analysis of the clinical symptoms, radiological findings, and postmortem examinations of three green sea turtles (Chelonia mydas) investigated for spirorchiidiasis. These findings highlight the complexity and severity of the disease, emphasizing the presence of systemic, granulomatous inflammation, and its impact on the overall health of sea turtles. This study advocates for continuous research and conservation efforts to mitigate the impact of spirorchiidiasis on marine turtles. Despite the precarious state of marine turtles as a highly endangered species, our understanding of their diseases remains limited. This case report presents a detailed pathological investigation of spirorchiidiasis, a blood fluke infection that poses a substantial threat to marine turtles. This retrospective study examined three cases of spirorchiid-infected sea turtles, specifically, green sea turtles stranded on Jeju Island, South Korea. Premortem examination of the three spirorchiid-infected green sea turtles demonstrated nonspecific clinical symptoms; blood analysis revealed dehydration, malnutrition, and anemia. Computed tomography scans provided insights into severe pulmonary and extrapulmonary manifestations, including the mass present in the joint region. Post-mortem examinations consistently indicated severe lung lesions and systemic manifestations, with histopathological examination confirming the presence of spirorchiid ova across various organs. Despite the global prevalence of spirorchiidiasis in sea turtles, disease severity varies regionally. This report provides a detailed demonstration of the pathology of spirorchiidiasis in sea turtles from Northeast Asia. [ABSTRACT FROM AUTHOR]

Context: GPS tags have revolutionised the field of wildlife spatial ecology by providing a large number of animal location datapoints at a very fine spatial scale. Although GPS tags have been used on large animals for several decades, it is only recently that technological advances have allowed lightweight GPS tags to be deployed on small animals with limited travel distances. Importantly, factors such as canopy cover, topography, and tag orientation can affect the ability of GPS tags to obtain satellite fixes, which can subsequently affect the accuracy of recorded locations. Aims: If not corrected for, biases in location data obtained from GPS tags could lead to erroneous inferences regarding animals' habitat use, home-range sizes, and movement paths, which could reduce the effectiveness of conservation efforts based on such inferences. Methods: Here, we used a double-sampling method (i.e. GPS tags and ground-truthing with radio-telemetry) and quantified the effects of habitat characteristics and data screening on the accuracy of location data obtained from GPS tags deployed both in stationary tests and on wild eastern box turtles and spotted turtles, which co-occur at our study sites but use different habitat types. Key results: We found that canopy cover reduced both the number and accuracy of locations obtained from GPS tags, that dense ground vegetation decreased the fix success rate of GPS tags, and that GPS tags were ineffective when submerged underwater. We further showed that using a simple method to screen data and exclude low-accuracy locations is essential if locations obtained from GPS tags are used to make inferences about a species' habitat use or spatial ecology. Conclusions: Screening data to reduce location error is particularly important for animals with small home-range sizes and short travel distances because a small number of erroneous locations can introduce substantial bias in inferences regarding a species' space use. Implications: We encourage researchers to report measures of error (i.e. location error, horizontal dilution of precision, number of satellites received) for GPS location data and to employ data-screening methods to exclude low-accuracy locations and improve the reliability of published animal location data, and the inference drawn there from. GPS tags are used to study animal spatial ecology because they can remotely obtain huge numbers of locations without disturbance to animals. We assessed how variation in accuracy of locations from GPS tags affected estimated home-range sizes and inferred macrohabitat use in co-occurring turtles. Canopy cover, ground cover, and submersion underwater reduced the number and accuracy of locations from GPS tags, and data screening increased accuracy of estimates regarding habitat use and home-range size from GPS tag data. Photograph by A. C. Hulbert. [ABSTRACT FROM AUTHOR]

Although the fossil record of turtles in the Cretaceous of Patagonia is diverse and abundant, the record from the Austral-Magallanes Basin (Santa Cruz Province, Argentina, and Magallanes Region, Chile) is scarce and fragmentary. This contribution presents a new record of a turtle from the Piedra Clavada Formation (early Cenomanian) found near Tres Lagos Village, Santa Cruz Province, Argentina. This new fossil is characterized by a unique combination of character states: medium-sized carapace (length circa 50 cm), shell with a smooth surface, having narrow vertebral scutes, regular neural bones longer than wide, the tips of thoracic ribs seen in dorsal view, posterior marginals reaching costal bones, and not having costo-peripheral fontanelles. Furthermore, based on paleolatitudinal reconstructions, the new turtle from the Piedra Clavada Formation lived in the circumpolar region (54º S), representing the oldest southernmost record of turtles in the Late Cretaceous of South America. Considering this unique combination of characters and the comparison with other Early--early Late Cretaceous turtles from Gondwana, we can suggest that MSV103 does not only belong to a new species but a new, previously unrecognized lineage of turtles in southern Patagonia [ABSTRACT FROM AUTHOR]

O jabuti-piranga (Chelonoidis carbonaria), espécie de quelônio, apresenta particularidades anatômicas e fisiológicas que tornam a anestesia um procedimento desafiador. Somado a isso, existem poucos relatos de casos e de protocolos anestésicos seguros a serem seguidos para esses pacientes. O presente artigo teve como objetivo relatar as técnicas e procedimentos anestésicos empregados em um exemplar de jabuti-piranga, pesando 1,71 kg, submetido a celiotomia para retirada de corpo estranho. O paciente apresentava inquieto e com sinais de dor, como vocalização e exposição de pênis há 6 meses. Na anamnese foi observado presença de secreção nasal e ruído respiratório, casco disforme e lesões superficiais. Pelo exame radiográfico foi evidenciada uma estrutura afilada radiopaca, medindo 3,3 cm de comprimento de permeio, condizente com formato de um prego. Diante do quadro, optou-se por tratamento cirúrgico. Como medicação pré-anestésica, fez-se o uso de metadona (0,2 mg/kg; IM) e midazolam (0,5 mg/kg; IM) e administração de propofol (7 mg/kg IV). Após relaxamento muscular, o animal foi intubado com tubo endotraqueal número 2,0 (sem cuff) e infusão contínua de propofol (0,05-0,6 mg/kg/minuto). Para analgesia foi realizado o bloqueio local com a técnica splash block em cavidade abdominal com bupivacaina 0,5% sem vasocontritor (0,7 mL) após incisão cirúrgica. Os parâmetros fisiológicos monitorados, como frequência cardíaca e respiratória, temperatura cloacal, oximetria e capnografia se mantiveram estáveis durante todo o procedimento anestésico. Ao final da anestesia foi administrado flumazenil (0,05 mL IV) doxapram (0,5mL IV) e adrenalina (0,05mL IM). O procedimento anestésico escolhido foi seguro, obteve sucesso e não houve intercorrências.

Bothremydidae was one of the most diverse and widespread group of side-necked turtles (pleurodirans) during the Cretaceous and part of the Paleogene. In South America, the Paleogene record of bothremydids is restricted to Puentemys mushaisaensis from the middle–late Paleocene Cerrejón Formation of Colombia, Inaechelys pernambucensis from the Paleocene of Brazil, and Motelomama olssoni from the early Eocene of Perú. Here, we describe two shells of P. mushaisaensis and several other isolated bones conferred to this taxon from the upper Paleocene and lower Eocene Arcillolitas de Socha Formation found in the Socha Region, Boyacá Department of Colombia. U-Pb dating of detrital zircon from two levels from this formation indicates maximum depositional ages of 56.83±0.04 Ma and 57.2±0.5 Ma for the areniscas guía interval of the formation. The new occurrence of P. mushaisaensis in the Socha region, at least 500 km south from Cerrejón, indicates a wider biogeographical distribution of northern South America Paleocene herpetofauna, possibly helped by low topography and ecosystems connectivity via a faunistic corridor.

Blood cell counts are valuable diagnostic tools for assessing the health status of chelonians, however, reference standards for healthy blood parameters in various turtle species are lacking. In this study, forty wild female Malayemys subtrijuga were captured from ponds in Kasetsart University, and transported to laboratory for recuperating in captivity. All turtles were infected with a single leech species, Placobdelloides siamensis, with a mean of 513.7 ± 164.9 individuals per turtle, and exhibited penetrating and lesion wounds from leech infestations on both their skin and shell. Subsequently, they were cleaned and treated to eliminate ecto- and endoparasites before the recuperation period began. The turtles did not exhibit significantly differences in weight, carapace length (CL), red blood cell count (RCC), and white blood cell count (WCC) with a mean of 654.2 ± 199.9 g, 15.0 ± 2.5 cm, 327,080 ± 70,156 cells/mm3, and 73,340 ± 15,859 cells/mm3, respectively, during the initial records (week 0). However, after being maintained for 17 weeks, their health significantly improved in term of their blood parameters (RCC and WCC) and weight, except CL which remained unchanged, with a mean of 491,470 ± 16,169 cells/mm3, 18,790 ± 1496 cells/mm3, and 738.9 ± 191.5 g, respectively. Therefore, the health status obtained in this study can be used as a reference for blood parameters, weight, and recuperation period for the treatment of ill wild M. subtrijuga in captivity or as part of conservation management programs for turtles.

Sea turtles have been considered the least vocal of living reptiles, but recent studies are changing this perception. Here, we aimed to investigate the acoustics of hatchlings of, Eretmochelys imbricata and Caretta caretta in Northeast Brazil, to describe their acoustic signals and compare sound structure within and between species. We monitored 13 km in Ipojuca, southern coast of Pernambuco State. We recorded five nests of each species and the hatchlings' walk to the sea in 2020/2021. We recorded 12 sonotypes in C. caretta and 5 in E. imbricata, increasing the number of described signals. Nevertheless, not all sonotypes were produced by all or in the different developmental stages. Some of the sounds for both species reached ultrasonic frequencies. The sound structure varied between C. caretta nests, suggesting a potential vocal signature, but the sound structure had no variation between E. imbricata nests. The sound structure varied between species. Despite their reputation for being silent, this study shows a diverse acoustic repertoire in the target species, further supporting speculations of acoustic signals mediating the potential synchronisation of hatchlings' departure to the sea. Our signal descriptions could be used for future passive acoustic monitoring of the target species. Future studies should focus on understanding the functionality of acoustic signals in the different life stages. [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]

The study aims to describe the development of the heart in Podocnemis expansa during the incubation period and immediately after hatching. A total of 108 embryonic hearts and five hearts from freshly hatched individuals (1st day post-hatching) were fixed and processed for light and ultrastructural microscopy analysis, respectively. The primitive heart was observed on the 5th day of incubation, featuring only a sinus venosus, an atrial chamber, and a ventricle containing small trabeculae, while atria were observed only from the 10th day onwards. On the 13th day, the ventricular cavity was visualized, differentiating into the venosum, arteriosum, and pulmonale cavums. The atrioventricular valve, pulmonary trunk, and aortic arches were formed on the 18th day. Additionally, the atria were transversely separated by the first atrial septum. On the 39th day, the separation of the cavum venosum from the cavum pulmonale by the horizontal septum and the separation of the cavum venosum from the cavum arteriosum by the vertical septum were observed. In the post-hatched specimens, the myocardium remained spongy, with close proximity to erythrocytes, also forming evident partial septa and exhibiting the presence of nervous tissue, indicative of subepicardial plexus formation. It is concluded that by the 25th day, the fundamental events in the formation of the heart of P. expansa, such as the bending of the cardiac tube, the formation of the first atrial septum, atrioventricular valve formation, and partial ventricular septa, had already been completed. After hatching, the internal cardiac structures already resembled those observed in adults. [ABSTRACT FROM AUTHOR]

Blood cell counts are valuable diagnostic tools for assessing the health status of chelonians, however, reference standards for healthy blood parameters in various turtle species are lacking. In this study, forty wild female Malayemys subtrijuga were captured from ponds in Kasetsart University, and transported to laboratory for recuperating in captivity. All turtles were infected with a single leech species, Placobdelloides siamensis , with a mean of 513.7 ± 164.9 individuals per turtle, and exhibited penetrating and lesion wounds from leech infestations on both their skin and shell. Subsequently, they were cleaned and treated to eliminate ecto- and endoparasites before the recuperation period began. The turtles did not exhibit significantly differences in weight, carapace length (CL), red blood cell count (RCC), and white blood cell count (WCC) with a mean of 654.2 ± 199.9 g, 15.0 ± 2.5 cm, 327,080 ± 70,156 cells/mm3, and 73,340 ± 15,859 cells/mm3, respectively, during the initial records (week 0). However, after being maintained for 17 weeks, their health significantly improved in term of their blood parameters (RCC and WCC) and weight, except CL which remained unchanged, with a mean of 491,470 ± 16,169 cells/mm3, 18,790 ± 1496 cells/mm3, and 738.9 ± 191.5 g, respectively. Therefore, the health status obtained in this study can be used as a reference for blood parameters, weight, and recuperation period for the treatment of ill wild M. subtrijuga in captivity or as part of conservation management programs for turtles. • Wild female Mekong snail-eating turtles displayed distinct size-related traits. • Blood counts in recuperating Mekong turtles aid health assessment. • Siamese shield leeches cause damage and symptoms in Mekong turtles. [ABSTRACT FROM AUTHOR]

Matamata turtles (Chelus Duméril, 1806) are composed of two extant species, Chelus fimbriata Schneider, 1783 and Chelus orinocensis Vargas-Ramírez, Caballero, Morales-Betancourt, Lasso, Amaya, Martínez, Silva-Viana, Vogt, Farias, Hrbek, Campbell & Fritz, 2020, inhabitants of the main freshwater drainages of northern South America. The systematics and palaeobiogeography of Chelus is still unresolved. Here, we describe several new fossil specimens from the Late Miocene of Urumaco (Venezuela) and Tatacoa (Colombia). The fossils are mostly complete, articulated shells that allow reestablishing validity of two extinct taxa, Chelus colombiana Wood, 1976 and Chelus lewisi Wood, 1976. One of the specimens of C. lewisi from Urumaco represents the first record within the genus for which autopodial bones (a left manus) and additional limb bones are preserved together with ashell, demonstrating evolutionary conservatism in limb anatomy for the genus. The specimen comes from the Socorro Formation, representing the earliest so far known record of Chelus for the Urumaco sequence. Additionally, one specimen from Tatacoa is the first fossil for which cervical and pectoral girdle elements are preserved. Phylogenetic analysis supports the existence of two separate clades inside of Chelus, one formed by the extinct species and the other by the extant ones. [ABSTRACT FROM AUTHOR]

The Asian box turtles of the Cuora galbinifrons complex (C. galbinifrons, C. bourreti, and C. picturata) rank among the most endangered chelonian species in the world. Despite several previous studies, the phylogenetic relationships and species boundaries of this complex remain a matter for dispute due to a shortage of field-collected samples for genetic validation, observed discordance between mitochondrial and nuclear markers, and reported intergradation zones combined with a strong tendency of hybridization in the genus. Here, we re-investigate the relationships and potential hybridization between the species of the C. galbinifrons complex based on the most comprehensive dataset to date consisting of 394 morphologically identified specimens (136 C. galbinifrons, 200 C. bourreti, 49 C. picturata, and nine individuals allegedly from Hainan). The turtles mainly came from assurance colonies as well as from zoological and private collections across the USA and Europe. Bayesian and Maximum Likelihood analyses of a concatenated mitochondrial dataset (COI and ND4 plus adjacent tRNA genes) yielded almost identical topologies, supporting three major clades corresponding to C. galbinifrons, C. bourreti, and C. picturata, respectively. In accordance with previous studies, C. bourreti represented the sister clade to C. galbinifrons and these two clades together were sister to C. picturata. Haplotype networks revealed pronounced mitochondrial divergences between the taxa. STRUCTURE and PCA analyses using 12 microsatellite loci also confirmed three distinct clusters that are in agreement with the recognized species. Only a few specimens with admixed ancestry (hybrids) or mismatched mitochondrial identity were revealed, suggesting extremely limited gene flow among the three species. However, this pattern could also reflect the separate captive management of the individual taxa and an underrepresentation of geographic contact zones in our sampling. [ABSTRACT FROM AUTHOR]

Background: The growing contact between men and wild animals, caused by the increase in the population in urban centers and the destruction of the habitat of these animals, has been leading to a greater circulation of pathogens between humans and wildlife. Chelonoidis carbonaria, a tortoise found throughout South America, is one of the animals most rescued from animal trafficking and illegal breeding. Considering this situation, this study aimed to verify the occurrence of hemoparasites in C. carbonaria. Materials and Methods: Blood samples from 73 C. carbonaria were collected from animals located in (1) a rural commercial breeding unit, (2) an urban zoo, and (3) a center of rescued animal screening. Genomic DNA was extracted from these animals and used in PCRs to detect specific genomic fragments of haemogregarines (i.e., Hepatozoon and Hemolivia), and members of the Anaplasmataceae Family (i.e., Ehrlichia sp. and Anaplasma sp.). Blood samples were screened for hemopathogens by direct microscopy and were used for hematological assays, and serum samples were analyzed to determine the concentration of serum components. Results: It was found that 34.2% of the tortoises presented Sauroplasma sp. in their blood samples; these animals showed clinical biochemistry changes that indicate altered liver function. Two zoo animals were positive for Ehrlichia sp. in PCR, and also presented clinical biochemistry and hematological changes. Conclusion: The present project is pioneer in the detection of Ehrlichia sp. in C. carbonaria, and was able to identify changes in clinical biochemistry that can be a result of the infection by hemopathogens in this species. [ABSTRACT FROM AUTHOR]

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Tortoises and freshwater turtles are among the most threatened taxa of vertebrates in the world due to consumption, urban development, agriculture, and land and water pollution. About 50% of the currently recognised chelonian species are considered threatened with extinction according to the IUCN Red List. Asia is an epicentre for the turtle and tortoise extinction crisis, containing the highest diversity of threatened species. In this study, we used species distribution models (SDMs) to assess the effectiveness of existing protected areas across Southeast and South Asia for the conservation of three large critically endangered freshwater turtles (Batagur borneoensis, B. affinis, and Pelochelys cantorii). We derived the models based on selected bioclimatic variables at the sites of known species records. Our SDMs showed that Indonesia is of particular importance in prioritising conservation for these three species, containing the largest areas of suitable habitat within protected areas. However, when considering water surface coverage, Thailand has the highest proportion of suitable areas under protection. Our results suggest that the present cover of protected network reserves seems inadequate in terms of size and should be expanded to sustain populations of the three target species. Therefore, we identified priority areas and reserves critical for further field surveys to guide the potential discovery of novel populations. To investigate the effect of climate change, we also projected potential distributions onto ensembles of four IPCC story lines. As a result, we found larger extralimital areas of suitable environment for all three species, particularly northwards and inland. However, high degrees of uncertainty in climate conditions indicate few reserves may provide long term protection. Lastly, we review the threats and propose recommendations for conservation of these poorly known freshwater turtles.

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]

We review in detail the published fossil record of turtles from Sardinia and, in addition, we document previously undescribed specimens for the first time. Among these undescribed specimens, is the oldest occurrence of Testudo hermanni on the island, from the Early Pleistocene of Monte Tuttavista. The turtle fossil record in Sardinia goes back to the Eocene and comprises 18 different taxa, pertaining to 6 lineages: Podocnemididae, Cheloniidae, Emydidae, Geoemydidae, Testudinidae, and Trionychidae. Remarkable is the occurrence of Eocene pleurodires, whose presence is in agreement with the Oligo-Miocene rifting of the Corso-Sardinian block. Interestingly, the fossil record provides evidence for the presence in the island of both Testudo hermanni and Emys orbicularis during the Pleistocene although according to molecular data the extant populations of these two taxa were introduced in recent times. Finally, a large ungual phalanx from the Middle–Late Pleistocene Monte San Giovanni bone breccia testifies the occurrence of a giant tortoise in the Quaternary terrestrial ecosystem of Sardinia. [ABSTRACT FROM AUTHOR]

Animal morphological structure can influence behaviour and interaction with the environment. Owing to their wide range of habitats, from aquatic to terrestrial, and their variation in shell shapes, turtles are highly suitable for ecomorphological studies. However, previous studied have encountered several limitations, including small sample sizes, simplified habitat classification, and no consideration of sexual dimorphism, that may prevent the identification of the ecological mechanisms responsible for divergent morphologies of turtles on a global scale. In this study, we collected the carapace length (CL), carapace width (CW), and carapace height (CH), as an indicators of body size, from 6664 adult individuals of 115 species, 61 genera, and 11 families and calculated the ratio between the CH and CW to delineate shell shape. These turtle species were divided into four habitat types (marine, freshwater, mainland, and island) and eight subtypes (freshwater: large lentic, large lotic, small lentic, small lotic, all water bodies; mainland: desert, flatland, highland) to better understand the ecomorphological alteration of their shell shape. The results of the linear regression showed that shell shape became flat with increasing body size in aquatic turtles, whereas the opposite trend was observed for male mainland tortoises. According to the results of the general linear model, there was a gradual increase in the domed shape of turtle shells from sea to freshwater habitats, from freshwater to mainland terrestrial habitats, and from mainland to island terrestrial habitats. There were no significant differences between the shell shape and habitat subtype for freshwater turtles and mainland tortoises. To the best of our knowledge, this study represents the first investigation into the variation pattern of shell shape in turtles living in habitats ranging from marine to island and its relationship to body size. The study results suggest that conservation strategies for turtles should consider both their shell shape and habitat characteristics.

The study aims to provide anatomical and histological information about the liver in female Iraqi green freshwater turtles. Ten female green freshwater turtles (Chelonia mydas) were collected from Shatt Al-Hilla and used in this study. They were anesthetized by chloroform in closed chambers. The anatomical information was recorded and the histological sections of the liver were stained by using hematoxylin and Eosin stains. The result showed that the liver of a female green freshwater turtle (Chelonia mydas) is a large elongated organ. The mean weight of turtles is 735±0.04 gm, and the mean weight of the liver is 28±0.02 gm. The ratio between the weight of the liver to the weight of the body was 3.809 %. The liver of (Chelonia mydas) is formed from three lobes right, left and middle (central) lobes. The right lobe is the large one with an average weight of 13 ±0.022 gm. It looks like a square and has two surfaces ventral and dorsal (visceral) surface. The left lobe is smaller than the right with an average weight of 9±0.05gm, and its shape is rectangular. The middle lobe is rounded and small. Its mean weight is 7±0.01gm. Histologically, the liver is covered by mesothelium under its connective tissue layer as a hepatic capsule which divided the liver into lobules in the shape of hexagons with portal spaces, from the central to the walls of the hepatocyte. [ABSTRACT FROM AUTHOR]

The paper describes a series of turtle remains from the Early Late Miocene of Grytsiv (Khmelnytskyi Oblast, Ukraine). This fossil assemblage was quite diverse and included representatives of four families (Emydidae, Geoemydidae, Testudinidae, and Trionychidae), most of which are described only to the family level due to incompleteness. The discovery of shell fragments, identified here as Testudo chernovi, is the earliest record of this species on the territory of Ukraine. Scratches on the nuchal of T. chernovi are interpreted as traces of gnawing or rasping and are described as a new ichnospecies, Machichnus inrosus isp. n. These traces are identified as gnawing marks of the rodent Anomalomys grytsivensis, as evidenced by the width of the lower incisors and the presence of two characteristic longitudinal ridges on their labial surface. [ABSTRACT FROM AUTHOR]

Tortoises and freshwater turtles are among the most threatened taxa of vertebrates in the world due to consumption, urban development, agriculture, and land and water pollution. About 50% of the currently recognised chelonian species are considered threatened with extinction according to the IUCN Red List. Asia is an epicentre for the turtle and tortoise extinction crisis, containing the highest diversity of threatened species. In this study, we used species distribution models (SDMs) to assess the effectiveness of existing protected areas across Southeast and South Asia for the conservation of three large critically endangered freshwater turtles (Batagur borneoensis, B. affinis, and Pelochelys cantorii). We derived the models based on selected bioclimatic variables at the sites of known species records. Our SDMs showed that Indonesia is of particular importance in prioritising conservation for these three species, containing the largest areas of suitable habitat within protected areas. However, when considering water surface coverage, Thailand has the highest proportion of suitable areas under protection. Our results suggest that the present cover of protected network reserves seems inadequate in terms of size and should be expanded to sustain populations of the three target species. Therefore, we identified priority areas and reserves critical for further field surveys to guide the potential discovery of novel populations. To investigate the effect of climate change, we also projected potential distributions onto ensembles of four IPCC story lines. As a result, we found larger extralimital areas of suitable environment for all three species, particularly northwards and inland. However, high degrees of uncertainty in climate conditions indicate few reserves may provide long term protection. Lastly, we review the threats and propose recommendations for conservation of these poorly known freshwater turtles.

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]

Chersina angulata females ovulate sequentially and oviposit multiple, mostly single egg clutches from early autumn (March) throughout winter and spring until early summer (December). No matter when eggs are laid, they usually hatch in autumn (March/April). Evidence based on circumstantial observations also demonstrates that wild and captive females occasionally retain the last clutch of the season until completion of embryonic development in autumn, conforming to the accepted definition of viviparity in reptiles. However, developmental progress throughout the year and embryonic stages of freshly deposited last clutches has not yet been reported. We candled all eggs laid from April to December in a captive colony of C. angulata in an outdoor enclosure in Cape Town, South Africa, to estimate developmental progress and embryonic stages. In all eggs laid during autumn, winter, and early spring (March to mid-October), vitelline blood vessels, indicating development had progressed to somite formation, only started to become visible at approximately the same time in late November. Until mid-spring, embryonic development of those eggs had been arrested prior to somite formation; the embryos underwent diapause until, presumably, increasing temperatures reinitiated development. Development then progressed throughout summer until the hatching stage was reached in early autumn. However, eggs laid in late spring (mid-October to November) skipped diapause, and embryonic development progressed without interruption, demonstrating that, depending on the season of oviposition, diapause in C. angulata is facultative. Candling of an egg laid in late December showed that, prior to oviposition, embryonic development inside the female had already advanced to an embryonic stage with well-developed vitelline circulation corresponding to Yntema stage 12. Contrary to the generally accepted wisdom that intrauterine embryonic development in the order Testudines is always arrested at the gastrula stage, embryonic development inside the female had already reached the stage of somite formation. This phenotypic plasticity in the expression or abolishment of preovipositional developmental arrest represents a transitional stage in the evolution towards viviparity. [ABSTRACT FROM AUTHOR]

Haemogregarines are blood parasites with a life-cycle involving a vertebrate as the intermediate host and an invertebrate as the definitive host and vector. Extensive phylogenetic investigations based on 18S-rRNA gene sequences have shown that Haemogregarina stepanowi (Apicomplexa: Haemogregarinidae) is able to infest a large diversity of freshwater turtle species, including the European pond turtle Emys orbicularis, the Sicilian pond turtle Emys trinacris, the Caspian turtle Mauremys caspica, the Mediterranean pond turtle Mauremys leprosa, and the Western Caspian turtle Mauremys rivulata, among others. From the same molecular markers, H. stepanowi is further considered to be a complex of cryptic species predisposed to infect the same host species. While Placobdella costata is known to be the unique vector of H. stepanowi, it is only recently that independent lineages within P. costata have been illustrated—suggesting the presence of at least five unique leech species across Western Europe. The aims of our study were therefore to investigate from mitochondrial markers (COI) the genetic diversity within haemogregarines and leeches infecting freshwater turtles of the Maghreb, in order to identify processes of parasite speciation. We showed that H. stepanowi consists of at least five cryptic species in the Maghreb, while two Placobella species were identified in the same area. Although an Eastern–Western speciation pattern was apparent for both leeches and haemogregarines, we cannot make definitive conclusions regarding co-speciation patterns between parasites and vectors. However, we cannot reject the hypothesis of a very strict host–parasite specificity within leeches. [ABSTRACT FROM AUTHOR]

ABSTRACT We analyzed the influence of the season, the environment, and the sex, as well as the relation of body mass (BM) in the serum albumin (ALB), aspartate aminotransferase (AST), creatinine (C), creatine kinase (CK), phosphorus (P), total calcium (tCa), total protein (TP), urea (U), uric acid (UA), calcium:phosphorus ratio (Ca:P), and the globulin value (GV) of thirty individuals of Phrynops geoffroanus of the urban area of Cuiabá, Mato Grosso, Brazil. The modeling of biochemical parameters was performed using the Generalized Additive Models for Location, Scale and Shape (GAMLSS) to verify the influence of variables considered in this study on each of the biochemical parameters analyzed. The season influenced AST, CK, C, tCa, Ca:P and UA. The environment influenced tCa, Ca:P, U and UA. On the other hand, CK, tCa, P, Ca:P and U differed significantly between males and females. Regarding the BM, a relationship of this variable was observed with CK, C, tCa, P, U, UA and Ca:P. We concluded that the season, environment, sex, and body mass can influence the biochemical parameters of P. geoffroanus, and these factors should be routinely considered in the interpretation of laboratory results.

Abstract Proganochelys quenstedtii represents the best-known stem turtle from the Late Triassic, with gross anatomical and internal descriptions of the shell, postcranial bones and skull based on several well-preserved specimens from Central European fossil locations. We here report on the first specimen of P. quenstedtii from the Late Triassic (Klettgau Formation) Frickberg near the town of Frick, Canton Aargau, Switzerland. Similar to other Late Triassic ‘Plateosaurus-bearing bonebeds’, Proganochelys is considered to be a rare faunal element in the Swiss locality of Frick as well. The specimen, which is largely complete but was found only partially articulated and mixed with large Plateosaurus bones, overall resembles the morphology of the classical specimens from Germany. Despite being disarticulated, most skull bones could be identified and micro-computed tomography (CT) scanning of the posterior skull region reveals new insights into the braincase and neurovascular anatomy, as well as the inner ear region. These include the presence of a fenestra perilymphatica, potentially elongated cochlear ducts, and intense vascularization of small tubercles on the posterior end of the skull roof, which we interpret as horn cores. Other aspects of the skull in the braincase region, such as the presence or absence of a supratemporal remain ambiguous due to the fusion of individual bones and thus lack of visible sutures (externally and internally). Based on the size of the shell and fusion of individual elements, the specimen is interpreted as a skeletally mature animal.

Albinism is a genetic disorder in which there is a defect in melanin production, a pigment which gives color to the skin, hair and eyes. This congenital malformation can also occur in sea turtles, although it is not fatal, but it reduces their chances of survival in the natural environment. Even so, there are still no reports of its occurrence in Eretmochelys imbricata, a species known as the hawksbill turtle or legitimate turtle, with wide distribution in tropical seas. The present study describes the case of an individual with partial albinism in the E. imbricata species, found on the northern coast of Rio Grande do Norte, Brazil. The animals were collected at Cabo de Sí£o Roque beach in January 2020 during the reproductive season of the species. After analyzing the animal, it can be classified as having partial piebald albinism, since it still has lighter spots both on the skin and in the carapace and plastron regions.

Turtle shells frequently exhibit anomalous osseous modifications on their surface which can sometimes compromise the survival of the organism. Nowadays, despite the large number of anomalies identified in both extant and extinct turtle shells, the etiology, as well as the pathogenesis, of the various osseous modifications remains unknown in most documented extinct representatives. In fact, the interpretation of these anomalies in most fossil turtles is often speculative, the great majority of anomalous osseous modifications being attributed to vertebrate feeding traces, without considering other potential causative agents. In this context, we herein re-analyzed the shell anomalies recognized in an individual determined as Neochelys sp. (Pleurodira, Podocnemididae) from the middle Eocene (Lutetian) of the El Tejar fossil site (Corrales del Vino, Zamora, Spain), previously proposed as traumatic injuries resulting from a crocodile attack. The re-evaluation of these osseous alterations through detailed physical examination, comparison through direct observation and from the literature on extant turtles, and the use of the files obtained from a computerized axial tomography scan, allows the proposal of diverse causal agents, none of them supporting the previous interpretation. In addition, information regarding the pathogenesis and stages of the healing of the shell anomalies studied herein is provided. [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]

Simple Summary: Genetic diversity and habitat suitability of the star tortoise, Geochelone elegans is poorly understood throughout its range in South Asian countries. The mitochondrial gene sequence and distribution modeling analyses demonstrated lower intraspecific genetic diversity and more highly fragmented habitats in India than in Sri Lanka. The present study recommends the intensive genetic screening of wild and trade/captive individuals before translocation, effective enforcement to prohibit wildlife trafficking, and habitat restoration urgently demanded to conserve this highly-threatened species in the wild. The Indian star tortoise (Geochelone elegans) is a massively traded animal in South Asia. To mitigate this risk, the conservation agencies recommended guidelines to safeguard this charismatic species in nature. We adopted mitochondrial DNA-based investigation and performed species distribution modeling of G. elegans throughout its distribution range in the Indian subcontinent. The genetic analyses revealed weak genetic landscape shape interpolations, low intraspecific distances (0% to 1.5%) with mixed haplotype diversity, and a single molecular operational taxonomic unit (MOTU) in the cytochrome b gene dataset. The star tortoise, G. elegans, and its sister species Geochelone platynota showed a monophyletic clustering in the Bayesian (BA) phylogeny. We also attempt to understand the habitat suitability and quality of G. elegans in its distribution range. Our results suggest that, out of the extant area, only 56,495 km2 (9.90%) is suitable for this species, with regions of highest suitability in Sri Lanka. Comparative habitat quality estimation suggests the patch shape complexity and habitat fragmentation are greater in the western and southern ranges of India, which have been greatly influenced by an increased level of urbanization and agriculture practices. We have also provided a retrospect on the potential threat to G. elegans related to the wildlife trade on the regional and international spectrum. Our results detected multiple trading hubs and junctions overlying within the suitable ranges which need special attention in the vicinity. The present study calls for a proper conservation strategy to combat the fragmented distribution and explicitly recommends intensive genetic screening of founder individuals or isolated adult colonies, implementing scientific breeding, and subsequent wild release to restore the lost genetic diversity of star tortoises. [ABSTRACT FROM AUTHOR]

The first skull of Solemys (Testudines: Helochlydridae) is reported from the Late Cretaceous (Rognacian) Bastide Neuve locality, Fox Amphoux, Var, France. It is assigned to Solemys gaudryi (Matheron, 1869) on the basis of associated shell elements. Our study provides new insights regarding the skull morphology of the family Helochelydridae and suggests that Helochelydra from England and Naomichelys from North America appear to be closer to each other than to Solemys. [ABSTRACT FROM AUTHOR]

The paper describes a series of turtle remains from the Early Late Miocene of Grytsiv (Khmelnytskyi Oblast, Ukraine). This fossil assemblage was quite diverse and included representatives of four families (Emydidae, Geoemydidae, Testudinidae, and Trionychidae), most of which are described only to the family level due to incompleteness. The discovery of shell fragments, identified here as Testudo chernovi, is the earliest record of this species on the territory of Ukraine. Scratches on the nuchal of T. chernovi are interpreted as traces of gnawing or rasping and are described as a new ichnospecies, Machichnus inrosus isp. n. These traces are identified as gnawing marks of the rodent Anomalomys grytsivensis, as evidenced by the width of the lower incisors and the presence of two characteristic longitudinal ridges on their labial surface.

ABSTRACT: Spirorchidiasis is one of the most common diseases in green turtles. Eggs and the adult form of trematodes are mainly found in the heart, liver, lung, spleen, and gastrointestinal tract. The present study aimed to describe the pathological aspects of Spirorchiidae trematode infection in green turtles (Chelonia mydas) in the Campos Basin, Rio de Janeiro. The current study was based on the necropsy of 99 green turtles (Chelonia mydas, Chelonidae) from April to December 2021. Epidemiological data were obtained from the Aquatic Biota Monitoring Information System (SIMBA). A histopathological examination was performed at the “Setor de Anatomia Patológica” (SAP) from “Universidade Federal Rural do Rio de Janeiro” (UFRuralRJ). Tissue fragments (buccal papilla, esophagus, trachea, lung, heart, kidney, bladder, stomach, liver, spleen, intestines, gonads, adrenal, thyroid, pancreas, salt glands, muscle, and skin) were sampled for histological examination. The green turtles had lesions compatible with parasitic infection in 89% (88/99) cases. Out of 88 turtles, 87 were juveniles (99%), 75% (66/88) were females, and 25% (22/88) were males. Adult parasites and their eggs were found to cause granulomatous tissue reactions in 14% (12/88) of turtles. Egg-associated granulomatous inflammation was found in 86% (76/88) of the turtles. The organs with the highest number of egg-associated granulomas in order of occurrence were: the spleen, small intestine, adrenal gland, pancreas, and lungs. The adult trematodes were observed in histological lesions in order of occurrence, mainly in the esophagus, stomach, and small intestine. Out of the total number of turtles parasitized, 33% (29/88) of deaths occurred due to multiple causes such as fractures, interaction with fishing, predation, and fibropapillomas. The other 67% (59/88) presented multisystemic granulomatous disease caused by Spirorchiidae infection as a cause of death. Evidence is presented that spirorchidiasis is highly prevalent in young green turtles, is responsible for extensive chronic lesions, and responsible for significant debilitation and mortality.

The leatherback sea turtle family Dermochelyidae has an extensive evolutionary history, though it is represented by only one living species today, Dermochelys coriacea. Dermochelyid fossils occur worldwide from upper Cretaceous to Pliocene marine strata. Herein described is the first occurrence of a sea turtle from the lowermost Pliocene Purisima Formation of northern California, a single carapacial non-ridge ossicle. The ossicle exhibits external morphological and internal structural characteristics (ossicle thickness, internal layering, serrate margins) that are comparable to both the extinct genus Psephophorus and to the extant genus Dermochelys. Identification of the ossicle as cf. Psephophorus is based on examination of its thickness, internal structure, surface textures and geochronological age. This paper reports the third occurrence of leatherback sea turtle fossils from the western coast of the United States.

Testudines, also known as living fossils, have evolved diversely and comprise many species that occupy a variety of ecological niches. However, the immune adaptation of testudines to the different ecological niches remains poorly understood. This study compared the composition, function, and differentiation trajectories of peripheral immune cells in testudines (Chelonia mydas, Trachemys scripta elegans, Chelonoidis carbonaria, and Pelodiscus sinensis) from different habitats using the single-cell RNA sequencing (scRNA-seq) technique. The results showed that T. scripta elegans, which inhabits freshwater and brackish environments, had the most complex composition of peripheral immune cells, with 11 distinct immune cell subsets identified in total. The sea turtle C. mydas, had the simplest composition of peripheral immune cells, with only 5 distinct immune cell clusters. Surprisingly, neither basophils were found in C. mydas nor T cells in C. carbonaria. Basophil subsets in peripheral blood were identified for the first time; two basophil subtypes (GATA2-high-basophils and GATA2-low-basophils) were observed in the peripheral blood of T. scripta elegans. In addition, ACKR4 cells, CD4 T cells, CD7 T cells, serotriflin cells, and ficolin cells were specifically identified in the peripheral blood of T. scripta elegans. Furthermore, LY6G6C cells, SPC24 cells, and NKT cells were specifically observed in C. carbonaria. Moreover, there were differences in the functional status and developmental trajectory of peripheral immune cells among the testudine species. The identification of specific features of peripheral immune cells in testudines from different habitats may enable elucidation of the adaptation mechanism of testudines to various ecological niches. [ABSTRACT FROM AUTHOR]

This paper is devoted to the description of a new species of xinjiangchelyid turtle – Annemys variabilis sp. nov. – represented by thousands of isolated bones and several more complete specimens from the Middle Jurassic (Bathonian) Itat Formation of the Berezovsk coal mine, Krasnoyarsk Territory, western Siberia, Russia. The description is based on a sample of the best-preserved specimens. The new species differs from other Annemys spp. by a combination of cranial and shell characters. The basisphenoids (about 200 specimens) of A. variabilis demonstrate variation in 12 characters, some of which are reported in turtles for the first time. About 20 shell characters of A. variabilis are subject to ontogenetic or interindividual variation. Some of these characters are variable in other Annemys spp. and other xinjiangchelyids. The formula of the cervical vertebrae [(2(3()4()5()6()7()8) or (2(3()4()5()6()7()8(] with two opisthocoelous vertebrae (2 and 3), four or five amphicoelous vertebrae (4–7 or 4–8), and one procoelous vertebra is unique for this species among xinjiangchelyids, which were previously known to have only amphicoelous cervicals. Other characters of the non-shell postcranium correspond to those of other xinjiangchelyids. Of the three phylogenetic analyses performed in this study, Analysis 1 does not support the monophyly of either Xinjiangchelyidae or Annemys, Analysis 2 shows paraphyly of Xinjiangchelyidae and monophyly of the Annemys clade (A. latiens, A. levensis, A. variabilis and A. wusu), and Analysis 3 supports monophyly of the Annemys clade with A. latiens, A. levensis and A. variabilis, only in the majority rule consensus tree. The diversity of the turtle assemblage of the Itat Formation is re-assessed as containing 2–3 taxa (A. variabilis [=Testudines indet. 2], Testudines indet. 1 and 3), which is in agreement with similar diversities seen in some other Middle Jurassic Asian turtle assemblages. The known record of Annemys spp. is restricted to the northern part of Asia. [ABSTRACT FROM AUTHOR]

Pelomedusoides and Chelidae are groups of pleurodiran turtles that have evolved from the Cretaceous period to the present. In this study, we carried out thin sections in shell elements (including costal, neural, peripheral and xiphiplastron bones) from Bauruemys elegans , an undetermined Podocnemididae taxon, and shell fragments of other pelomedusoids from Upper Cretaceous and Paleogene sedimentary deposits. We explored and discussed shell microstructures and microanatomy data of these extinct pelomedusoids alongside two extant pleurodires, Podocnemis unifilis and Phrynops sp. Our study of costo-neural bones reinforces the hypothesis that the turtle carapace originated endoskeletally from ribs and vertebral arches. Our osteohistological examination of these shell bones suggests an aquatic to semi-aquatic lifestyle for the studied extinct Pelomedusoides. Notably, all examined bones show high bone compactness, a feature often associated with terrestrial life, although it is not exclusive to such a lifestyle. Additionally, our comparative analysis reveals greater shell compactness in Podocnemididae compared to the other specimens sampled. These findings contribute to our understanding of the environmental interactions of these pleurodires. • The turtle carapace originated endoskeletally from ribs and vertebral arches. • Comparative analysis reveals greater shell compactness in Podocnemididae than in Chelidae. • The first record of Testudines from the Late Cretaceous graben of Mato Grosso State. [ABSTRACT FROM AUTHOR]

Micronucleus (MN) cell counting emerged in 1973–1975 as a valid alternative for characterizing chromosomal damage caused by different agents. It was first described in mammals, but its application was rapidly extended to other vertebrates, mainly fish. However, it was not until 28 years later that this test was implemented in studies on reptiles. Nowadays, reptiles are found to be excellent non-target species from environmental contamination exposure and MN test has become a fundamental tool for analyzing genotoxic effects induced by various xenobiotics. In this article we provide an updated review of the application of the MN test in reptile species, from an ecotoxicological perspective. Therefore, we present (I) a bibliometric analysis of the available research on genotoxic-induced MN formation in reptile species; (II) the use of reptiles as sentinel organisms in ecotoxicological studies; and (III) the strength and weakness of the application of the MN test in this group. With this review, we aim to provide a comprehensive view on the use of the MN test in ecotoxicology and to encourage further studies involving reptile species. • Environmental contaminants induce MN and NA formation in reptiles. • reptiles are excellent non-target species for environmental contamination. • MN test applied to 32 out of the 12.060 reptile species worldwide. • Crocodilians are the reptile group most studied (11.11 % of total). • The main pollutants reported are pesticides, followed by heavy metals. [ABSTRACT FROM AUTHOR]

Abstract 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.

In this paper we report the trauma suffered by a green turtle (Chelonia mydas), caused by a collision with a motorboat, and describe the case ante and post-mortem. An adult female green turtle was rescued alive on December 2, 2016 at Ponta Negra beach, municipality of Natal, Rio Grande do Norte, Brazil. The rescued animal was sent to the Marine Fauna Rehabilitation Center (PCCB-UERN), municipality of Areia Branca (RN), in Brazil. Physical examination revealed an excellent body score, noisy breathing, moderate dehydration, absence of hind limb and cloacal reflexes when stimulated by pressure, and two traumatic injuries characteristic of a collision with a motorboat. After three days of supportive treatment, the animal died and was immediately sent for necropsy. The animal had a complete fracture of the vertebral bodies (dorsal elements D9 and D10) and spinal cord section. The entire gastrointestinal tract had food content, in addition to sharp injuries in the colon caused by the bone fragments of the fractured carapace. The lungs were congested, hemorrhagic with frothy and bloody secretion, and interstitial bronchiole fibrosis. There was also present some fibrin and a large number of leukocyte cells, consisting mainly of macrophages. The liver was enlarged, with rounded edges and thickening of the capsule, multifocal areas of hepatocellular necrosis, and dissociation of the hepatocyte cords. The collision resulted in the exposure of the coelomic cavity and spinal cord, causing the animal intense pain, paralysis of the hind limbs and cloaca, septicemia, and consequently, death.

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]

Simple Summary: Marketed globally, freshwater turtles are popular pets. However, the introduction of non-native species can pose a serious threat to biodiversity as well as to human health as carriers of potentially zoonotic pathogens. This update reports the distribution of two species of the Chelydridae family, i.e., the snapping turtle (Chelydra serpentina) and the alligator snapping turtle (Macrochelys temminckii). Their potential impact on human health and biodiversity is also discussed. Marketed globally, freshwater turtles are popular pets. Two species of the Chelydridae family are increasingly reported in Italy: the snapping turtle (Chelydra serpentina) and the alligator snapping turtle (Macrochelys temminckii). Both pose potential threats to public safety and habitat biodiversity. This update reports on their distribution and impact on biodiversity and human health. The recent increase in the number of C. serpentina in urban and rural areas suggests illegal importation into the country. Findings are reported for the north (35% and 100% for C. serpentina and M. temminckii, respectively) and the central-northern regions (60% for C. serpentina), predominantly Umbria and Latium, and the Tiber River catchment area in particular. Because omnivorous, Chelydridae species can affect native biodiversity; because they are carriers of pathogens, they endanger public health. Monitoring plans need to take account of this neglected threat. [ABSTRACT FROM AUTHOR]

Albinism is a genetic disorder in which there is a defect in melanin production, a pigment which gives color to the skin, hair and eyes. This congenital malformation can also occur in sea turtles, although it is not fatal, but it reduces their chances of survival in the natural environment. Even so, there are still no reports of its occurrence in Eretmochelys imbricata, a species known as the hawksbill turtle or legitimate turtle, with wide distribution in tropical seas. The present study describes the case of an individual with partial albinism in the E. imbricata species, found on the northern coast of Rio Grande do Norte, Brazil. The animals were collected at Cabo de São Roque beach in January 2020 during the reproductive season of the species. After analyzing the animal, it can be classified as having partial piebald albinism, since it still has lighter spots both on the skin and in the carapace and plastron regions. [ABSTRACT FROM AUTHOR]

Despite only comprising seven species, extant sea turtles (Cheloniidae and Dermochelyidae) display great ecological diversity, with most species inhabiting a unique dietary niche as adults. This adult diversity is remarkable given that all species share the same dietary niche as juveniles. These ontogenetic shifts in diet, as well as a dramatic increase in body size, make sea turtles an excellent group to examine how morphological diversity arises by allometric processes and life habit specialisation. Using three-dimensional geometric morphometrics, we characterise ontogenetic allometry in the skulls of all seven species and evaluate variation in the context of phylogenetic history and diet. Among the sample, the olive ridley (Lepidochelys olivacea) has a seemingly average sea turtle skull shape and generalised diet, whereas the green (Chelonia mydas) and hawksbill (Eretmochelys imbricata) show different extremes of snout shape associated with their modes of food gathering (grazing vs. grasping, respectively). Our ontogenetic findings corroborate previous suggestions that the skull of the leatherback (Dermochelys coriacea) is paedomorphic, having similar skull proportions to hatchlings of other sea turtle species and retaining a hatchling-like diet of relatively soft bodied organisms. The flatback sea turtle (Natator depressus) shows a similar but less extreme pattern. By contrast, the loggerhead sea turtle (Caretta caretta) shows a peramorphic signal associated with increased jaw muscle volumes that allow predation on hard shelled prey. The Kemp's ridley (Lepidochelys kempii) has a peramorphic skull shape compared to its sister species the olive ridley, and a diet that includes harder prey items such as crabs. We suggest that diet may be a significant factor in driving skull shape differences among species. Although the small number of species limits statistical power, differences among skull shape, size, and diet are consistent with the hypothesis that shifts in allometric trajectory facilitated diversification in skull shape as observed in an increasing number of vertebrate groups. [ABSTRACT FROM AUTHOR]