Search

The poorly known pleurodiran turtle 'Stereogenys' libyca (Podocnemididae, Erymnochelyinae) is studied in this paper. It was defined in lower Oligocene levels of the Fayum Depression (Egypt), its presence in the upper Eocene levels of the same area being confirmed here. Its holotype corresponds to an almost complete and well preserved shell, that was until recently considered to be lost. No photograph of material attributable to this species had hitherto been published. Thus, the current knowledge about it was exclusively based on the limited information published more than a century ago. The recently rediscovered holotype, and also more than fifteen additional historical but unpublished specimens recognized here as attributable to this species, are studied in this paper. This species is attributed to a new genus, Andrewsemys, and the new combination Andrewsemys libyca is proposed. http://www.zoobank.org/urn:lsid:zoobank.org:pub:6D87831A-4510-4A3E-A624-C40FD644F448 [ABSTRACT FROM AUTHOR]

Abstract Araripemydidae is a clade of freshwater pleurodiran turtles originally described in South America, where it is represented by the Brasilian Aptian–Albian Araripemys barretoi. Two potential members of this lineage were defined in an Aptian level of Africa, in Gadoufaoua (Niger): Taquetochelys decorata , described from several isolated plates, and Lagaremys tenerensis , known from an almost complete skeleton. The review of the Araripemydidae record, and the analysis of the intraspecific variability present in that and in other clades of Pleurodira, allow me to refute their attribution to two different forms. ' L. tenerensis ' is here recognized as a junior synonym of T. decorata. Therefore, the priority of T. decorata is demonstrated, as well as its attribution to Araripemydidae. The almost complete skeletal anatomy of the two currently recognized members of this Aptian–Albian clade (i.e. the African T. decorata and the South American A. barretoi) is well known, which is uncommon for the Cretaceous pleurodiran turtles. [ABSTRACT FROM AUTHOR]

The purpose of the present study was to identify the cardiac vagal nerve (CVN) of the turtle, to characterize its fiber composition, and to correlate this composition with cardioinhibitory functions. Turtles (Ocadia sinensis) were anesthetized with sodium pentobarbital. The CVN was identified anatomically as a thoracic vagal branch going to the heart. Transection or reversal block of this branch completely abolished the negative chronotropic and inotropic effects produced by ipsilateral cervical vagal stimulation. Electron microscopic examination of the CVN revealed that it is comprised of 500 to 1800 axon fibers. Among these, 86% were unmyelinated and 14% were myelinated fibers. Compound action potentials of the CVN consisted of A, B, and C groups. A decrease in the heart rate or a reduction of ventricular contractility was observed with electrical stimulation of the cervical vagus at an intensity which activates the B-fiber group. When the stimulus intensity increased to recruit both the B- and C-fiber groups, maximal cardioinhibitory effects were observed. The negative chronotropic effect of the right vagus was greater than that of the left vagus with low-frequency stimulation. In contrast, stimulation of the left vagus produced greater negative inotropic effect. These data indicate that the turtle heart is innervated by a single pair of CVN. The cardioinhibitory functions are subserved by small myelinated and large unmyelinated fibers. Functionally distinct vagal neurons may be distributed unevenly in the turtle brain, such that the right vagal nerve contains more chronotropic while the left more inotropic motor fibers. [ABSTRACT FROM AUTHOR]

Finite element (FE) models have become increasingly popular in comparative biomechanical studies, with researchers continually developing methods such as 'warping' preexisting models to facilitate analyses. However, few studies have investigated how well FE models can predict biologically crucial whole‐structure performance or whether 'warped' models can provide useful information about the mechanical behavior of actual specimens. This study addresses both of these issues through a validation of warped FE models of turtle shells. FE models for 40 turtle specimens were built using 3D landmark coordinates and thin‐plate spline interpolations to warp preexisting turtle shell models. Each actual turtle specimen was loaded to failure, and the load at failure and mode of fracture were then compared with the behavior predicted by the models. Overall, the models performed very well, despite the fact that many simplifying assumptions were made for analysis. Regressions of observed on predicted loads were significant for the dataset as a whole, as well as in separate analyses within two turtle species, and the direction of fracture was generally consistent with the patterns of stresses observed in the models. This was true even when size (an important factor in determining strength) was removed from analyses – the models were also able to predict which shells would be relatively stronger or weaker. Although some residual variation remains unexplained, this study supports the idea that warped FE models run with simplifying assumptions at least can provide useful information for comparative biomechanical studies. [ABSTRACT FROM AUTHOR]

Spatial and temporal scales are important for understanding habitat associations because organisms have neither unbounded mobility nor perfect knowledge of their environment, but still must make decisions on where to seek food, shelter, and mates. Semi-aquatic turtles exemplify the need to evaluate potential habitat characteristics at a range of scales, because their ectothermy makes these animals particularly sensitive to local environmental conditions, yet their limited mobility spatially constrains selection of microsites. Microsite choice may also be sensitive to larger geographic context. We explored site occupancy and abundance of western pond turtles (Actinemys [Emys] marmorata) as a function of environmental variables over a range of spatial scales up to that of the entire watershed. We modeled occupancy at ponds and abundance at river sites using data from surveys conducted at 50 ponds and 58 river locations throughout the South Umpqua, Umpqua, and North Umpqua watersheds in western Oregon, USA in 1999-2000. The South Umpqua supported the greatest abundance of western pond turtles in rivers and the highest rates of occupancy in ponds. No turtles were detected in rivers of the North Umpqua, and only low numbers were detected in ponds in that watershed. Increasing amount of potential relative solar radiation was associated with increased probability of pond occupancy, particularly in the North Umpqua watershed. Pond turtle abundance in rivers increased with increasing distance to nearest pond, decreasing area of nearby ponds, and increasing area of nearby wetland habitat of all types, particularly in the Klamath Mountain and Coast Range physiographic provinces, which dominate the South Umpqua and Umpqua watersheds, respectively. Western pond-turtle occupancy and abundance varied with both broadscale and fine-scale habitat features, not solely to the fine-scale features that are most often measured. [ABSTRACT FROM AUTHOR]

The use of plastral scute rings to age turtles is a widely practiced technique, but a lack of rigorous field testing of this method has led to critiques of its usefulness and accuracy. We tested the method's effectiveness for aging spotted turtles ( Clemmys guttata) by calculating an Age-Increase Ratio and by recording changes in the number of scutes within a year. We found no correlation between the change in the number of scute rings and the number of years between captures, which likely stems from the observer error associated with the difficulty of accurately counting scutes on older turtles; however, we did record a significant correlation between the number of scute rings and body size. [ABSTRACT FROM AUTHOR]

Plasticity of neural circuits takes many forms and plays a fundamental role in regulating behavior to changing demands while maintaining stability. For example, during spinal cord development neurotransmitter identity in neurons is dynamically adjusted in response to changes in the activity of spinal networks. It is reasonable to speculate that this type of plasticity might occur also in mature spinal circuits in response to injury. Because serotonergic signaling has a central role in spinal cord functions, we hypothesized that spinal cord injury (SCI) in the fresh water turtle Trachemys scripta elegans may trigger homeostatic changes in serotonergic innervation. To test this possibility we performed immunohistochemistry for serotonin (5-HT) and key molecules involved in the determination of the serotonergic phenotype before and after SCI. We found that as expected, in the acute phase after injury the dense serotonergic innervation was strongly reduced. However, 30 days after SCI the population of serotonergic cells (5-HT+) increased in segments caudal to the lesion site. These cells expressed the neuronal marker HuC/D and the transcription factor Nkx6.1. The new serotonergic neurons did not incorporate the thymidine analog 5-bromo-20-deoxyuridine (BrdU) and did not express the proliferating cell nuclear antigen (PCNA) indicating that novel serotonergic neurons were not newborn but post-mitotic cells that have changed their neurochemical identity. Switching towards a serotonergic neurotransmitter phenotype may be a spinal cord homeostatic mechanism to compensate for the loss of descending serotonergic neuromodulation, thereby helping the outstanding functional recovery displayed by turtles. The 5-HT1A receptor agonist (±)-8-Hydroxy-2-dipropylaminotetralin hydrobromide (8-OH-DPAT) blocked the increase in 5-HT+ cells suggesting 5-HT1A receptors may trigger the respecification process. [ABSTRACT FROM AUTHOR]

The article discusses the Claudius angustatus turtles, their eggs, their behavior and the breeding processes. It talks about the turtle population. It discusses the hatchling of eggs of turtles. It discusses the mating of the turtles and the pattern of shells of the turtles. It also focuses on the health of the turrtles.

The article discusses the breeding of the turtle species Kinosternon baurii in captivity. It talks about the appearance of the mud turtle species in Florida. It discusses its habitat and their behavior. It also discusses their physiology. It discusses the description of the neonates of the turtles and the hatchlings from their eggs.

OBJECTIVE To determine anatomic reference points for 4 turtle species and to evaluate data on relative anatomic dimensions, signal intensities (Sis), and position of selected organs within the coelomic cavity by use of MRI. ANIMALS 3 turtle cadavers (I red-eared slider [Trachemys scripta elegans], I yellow-bellied slider [Trachemys scripta scripta], and I Coastal plain cooter [Pseudemys concinna floridana]) and 63 live adult turtles (30 red-eared sliders, 20 yellow-bellied sliders, 5 Coastal plain cooters, and 8 hieroglyphic river cooters [Pseudemys concinna hieroglyphica]). PROCEDURES MRI and necropsy were performed on the 3 turtle cadavers. Physical examination, hematologic evaluation, and whole-body radiography were performed on the 63 live turtles. Turtles were sedated, and MRI in transverse, sagittal, and dorsal planes was used to measure organ dimensions, position within the coelomic cavity, and Sis. Body positioning after sedation was standardized with the head, neck, limbs, and tail positioned in maximum extension. RESULTS Measurements of the heart, liver, gallbladder, and kidneys in sagittal, transverse, and dorsal planes; relative position of those organs within the coelom; and SIs of the kidneys and liver were obtained with MRI and provided anatomic data for these 4 turtle species. CONCLUSIONS AND CLINICAL RELEVANCE MRI was a valuable tool for determining the position, dimensions, and Sis of selected organs. Measurement of organs in freshwater chelonians was achievable with MRI. Further studies are needed to establish reference values for anatomic structures in turtles. Results reported here may serve as guidelines and aid in clinical interpretation of MRI images for these 4 species. [ABSTRACT FROM AUTHOR]

Rionegrochelys caldieroi de la Fuente, Maniel, and Jannello gen. et sp. nov. is a Late Cretaceous turtle from Rio Negro Province, Argentina. The holotype and the referred specimens of this new species show an unusual shell morphology and microanatomy. The proportion between the carapace and plastron and the peculiar morphology of the shell such as the heart shaped carapace, a very deep nuchal notch, peripheral bones 2-11 with strongly gutter, the first vertebral scute twice as wide as long and subrectangular in shape, the posterior margin of vertebral scute 5 is three lobe shaped, and the unexpected osteohistology characterized by a massive structure, with higher compactness (80.6%) than other chelids, suggests beyond doubt that this turtle may be considered a new taxon. A semi-aquatic habitat with tendency towards terrestrial environments is inferred for Rionegrochelys caldieroi similar to that of the extant pelomedusid Pelomedusa subrufa among the extant pleurodires. Rionegrochelys caldieroi is recovered as a stem chelid. This new species seems to be closely related to Bonapartemys bajobarrealis and the clade formed by Lomalatachelys neuquina plus Mendozachelys wichmanni. [ABSTRACT FROM AUTHOR]

We studied nesting activities and measured afternoon nest-temperatures of the midland painted turtle (Chrysemyspicta marginata), common snapping turtle (Chelydra serpentina serpentina), and eastern box turtle (Terrapene Carolina Carolina) from a wetland matrix during May-November 2013 at the Powdermill Nature Reserve in western Pennsylvania, USA. Nesting turtles were encountered during a 36-day period (2 June-8 July). The aquatic turtle species nesting season spanned 17 days (2-18 June). In general, nests were located in areas lacking extensive vegetation and near wetlands. Across all species, successful nests constituted 15% (n = 5), abandoned nests 53% (n = 18), and depredated nests 32% (n = 11). Nest losses to predation were highest for C. s. serpentina at 75% (6/8 nests). Mean nest temperatures were lowest for C. p. marginata and T. c. Carolina. Nest successes were highest for C. s. serpentina at 42% (19/45 eggs) and hatchlings emerged from these nests by late August. By the first freeze in November, 40% (4/10 eggs) of T. c. Carolina eggs hatched and hatchlings remained in the nest to overwinter, whereas none of the eight C. p. marginata eggs had hatched by then. Our results from a single site are comparable to findings from other regions and for Pennsylvania generally. Our findings also provide the basis for examining responses in nesting phenology to environmental perturbations, most relevant being climate change. [ABSTRACT FROM AUTHOR]

Interest in the origin and evolution of the turtle shell has resulted in a most unlikely clade becoming an important research group for investigating morphological diversity in developmental biology. Many turtles generate a two-component shell that nearly surrounds the body in a bony exoskeleton. The ectoderm covering the shell produces epidermal scutes that form a phylogenetically stable pattern. In some lineages, the bones of the shell and their ectodermal covering become reduced or lost, and this is generally associated with different ecological habits. The similarity and diversity of turtles allows research into how changes in development create evolutionary novelty, interacting modules, and adaptive physiology and anatomy. [ABSTRACT FROM AUTHOR]

Adhesive toe pads of geckos house modified components of vascular and/or connective tissues that promote conformity of the setal fields with the locomotor substratum. Similar modifications have been claimed for the digits of Anolis, but evidence for them is not compelling. Angiographic and histological investigations of Anolis failed to identify any evidence of either an intralamellar vascular reticular network or a central sinus. Instead, their vascularity more closely resembles that of lizards in general than that of pad-bearing geckos. The loose connective tissue of the toe pads likely contributes to their general pliability and flexibility, promoting localized compliance with the substratum. Through the shedding cycle, the lamellae change shape as the replacing setae elongate. The outer epidermal generation lacunar cells on the inner lamellar faces simultaneously hypertrophy, providing for compatibility between overlapping lamellae, enabling reciprocity between them. This contributes to continuing compliance of the setal fields with the substratum. Overall, digital structure and attachment and release kinematics of the toe pads of Anolis are very similar to those of geckos exhibiting an incipient adhesive mechanism. Both lack major anatomical specializations for promoting conformity of the setae with the locomotor substratum beyond those of the seta-bearing portions of the epidermis. [ABSTRACT FROM AUTHOR]

Turtles (Testudinata) are a diverse group of reptiles that conquered a broad set of habitats and feeding ecologies over the course of their well-documented evolutionary history. We here investigate the cranial shape of 171 representatives of the turtle lineage and the relationship of shape to different habitat and diet preferences using two-dimensional geometric morphometrics. The skull shape of extant turtles correlates with both ecological proxies, but is more affected by habitat than diet. However, the application of these correlations to extinct turtles produces mostly flawed results, as least when compared to external data such as sedimentary environment, highlighting that the morphospace held by extant turtles is not necessarily the optimal location in tree space for a particular ecology. The inability of this study to correctly predict the ecology of extinct turtles is likely related to the fact that the shape of turtle skulls is dominated by the emarginations and jaw closure mechanisms, two shape features unrelated to habitat or feeding ecology. This indicates that various specializations that are apparent in the skull only contribute little to overall shape. [ABSTRACT FROM AUTHOR]

Detailed anatomical knowledge is a prerequisite for studying a variety of biological questions. This holds true particularly for the evolutionary realm, in which fossils play an important role. Putting paleontological data in perspective consequently requires a profound knowledge of the corresponding structures of the extant representatives of a given lineage as well. Numerous morphological studies have contributed to our understanding of chelonian anatomy over the past centuries, but one of the earliest ones-whose completion celebrated its bicentenary with this symposium-still stands out among all of them: Anatome Testudinis Europaeae, published by Ludwig Heinrich Bojanus (1776-1827) in two installments in 1819 and 1821. Numerous myths around this publication have evolved ever since. The intent of this article is to set the record straight for some of them, and, based on personal inspection of multiple copies, to discuss currently unrecognized aspects about the existence of exceptional colored variant editions. This ends in a proposal for how this work could be used even more effectively in its upcoming third century of existence. Last but not least and despite the controversies related to its bibliographical aspects, one fact remains an unchallenged reality: Anatome Testudinis Europaeae, even 200 years after its first publication, still ranks very high among the most detailed and accurate anatomical works on a single chelonian-and for that matter reptilian-species ever produced and has lost absolutely none of its value for modern-day science., (© 2022 The Author. The Anatomical Record published by Wiley Periodicals LLC on behalf of American Association for Anatomy.)

For decades, the genus Pelomedusa has been thought of as containing only a single species that is widely distributed in sub-Saharan Africa, the Arabian Peninsula, and Madagascar. However, ten species and up to five candidate species have been recognized recently. For these taxa, ecological information is scarce and distribution ranges are often only incompletely known. In this study, ecological niche spaces were estimated for eight Pelomedusa species, using a maximum entropy algorithm and geographical, climatic, and topographic information. Using the obtained models and Schoener's D and Hellinger's I indices, areas of sympatry between species were estimated and candidate areas for possibly overlooked taxa were identified. Furthermore, differences in niche spaces between species were assessed. The ecological niche models revealed geographical spaces that match the predicted niche of the eight examined species. However, for P. subrufa sensu stricto, the distribution range of the introduced populations in Madagascar was not predicted. Our models, together with statistical analyses, indicate that the studied Pelomedusa species occupy different geographical spaces. Areas of sympatry with significant niche overlap were identified between some species pairs. Yet, Pelomedusa species are generally allopatrically or parapatrically distributed. A minimum of five candidate regions possibly harbouring unknown taxa were identified. Our results provide a better understanding of the distribution ranges of Pelomedusa species and, thus, can serve as a basis for conservation planning. [ABSTRACT FROM AUTHOR]

Turtles (Testudinata) are a diverse group of amniotes that have a rich fossil record that extends back to the Late Triassic, but little is known about global patterns of disparity through time. We here investigate the cranial disparity of 172 representatives of the turtle lineage and their ancestors grouped into 20 time bins ranging fromthe Late Triassic until the Recent using two-dimensional geometric morphometrics. Three evolutionary phases are apparent in all three anatomical views investigated. In the first phase, disparity increases gradually from the Late Triassic to the Palaeogene with only a minor perturbation at the K/Textinct event. Although globalwarmingmay have influenced this increase, we find the Mesozoic fragmentation of Pangaea to be a more plausible factor. Following its maximum, disparity decreases strongly towards the Miocene, only to recover partially towards the Recent. The marked collapse in disparity is likely a result of habitat destruction caused by global drying, combined with the homogenization of global turtle faunas that resulted from increased transcontinental dispersal in the Tertiary. The disparity minimum in the Miocene is likely an artefact of poor sampling. [ABSTRACT FROM AUTHOR]

The dorsal and ventral aspects of the turtle shell, the carapace and the plastron, are developmentally different entities. The carapace contains axial endochondral skeletal elements and exoskeletal dermal bones. The exoskeletal plastron is found in all extant and extinct species of crown turtles found to date and is synaptomorphic of the order Testudines. However, paleontological reconstructed transition forms lack a fully developed carapace and show a progression of bony elements ancestral to the plastron. To understand the evolutionary development of the plastron, it is essential to know how it has formed. Here we studied the molecular development and patterning of plastron bones in a cryptodire turtle Trachemys scripta. We show that plastron development begins at developmental stage 15 when osteochondrogenic mesenchyme forms condensates for each plastron bone at the lateral edges of the ventral mesenchyme. These condensations commit to an osteogenic identity and suppress chondrogenesis. Their development overlaps with that of sternal cartilage development in chicks and mice. Thus, we suggest that in turtles, the sternal morphogenesis is prevented in the ventral mesenchyme by the concomitant induction of osteogenesis and the suppression of chondrogenesis. The osteogenic subroutines later direct the growth and patterning of plastron bones in an autonomous manner. The initiation of plastron bone development coincides with that of carapacial ridge formation, suggesting that the development of dorsal and ventral shells are coordinated from the start and that adopting an osteogenesis-inducing and chondrogenesis-suppressing cell fate in the ventral mesenchyme has permitted turtles to develop their order-specific ventral morphology. [ABSTRACT FROM AUTHOR]

Cell proliferation in forming shield scutes has been studied by immunofluorescence in embryos of turtle, alligator and snake after injection of 5-bromo-deoxy-uridine. Hinge regions of scutes in alligator and turtle carapace derive from an initial waving and invagination of the epidermis that contains 5-bromo-deoxy-uridine-labelled cells. This suggests that down growth of the epidermis into the dermis is driven by local proliferation in addition to dermal anchorage and stabilization of hinge regions. Few keratinocytes migrate into suprabasal layers 1 day after injection of 5-bromo-deoxy-uridine and keratinocytes reach the precorneous layer in about 5 days. Proliferating keratinocytes are randomly distributed in the outer scale surface of symmetric scutes but are more numerous in the outer scale surface of asymmetric or overlapped scutes indicating epidermal expansion. Higher localization of proliferating cells along hinge regions of embryonic turtle and alligator scutes is maintained in adult scutes where most growth occurs. In snake, skin proliferation becomes prevalent on the elongating outer side of the asymmetric scale. Comparison between proliferation sites in turtle–alligator–chick scales with lepidosaurian scales indicates that placodes are present only in turtle–alligator–chick scales. Conversely, scale primordia detected only using gene markers are found in most crocodilian and lepidosaurians embryonic skin. [ABSTRACT FROM AUTHOR]

Abnormalities and the postnatal development of the carapace were investigated in 106 captive tortoises (Testudini dae, Testudo hermanni boettgeri, Testudo graeca, Testudo marginata, Testudo horsfieldii) using computer tomography (CT) in live animals and/or dissection of preserved specimens. The carapace was reconstructed two-dimensionally through combining sectional images. The postnatal ossification was demonstrated in 3D CT images combined with dissection results. We found that abnormal numbers and arrangements of horny scutes and bony plates may occur independently at different locations and different ontogenetic stages. Abnormalities of the horny scutes are present at hatching when the bony plates are not yet fully formed. The temporal course of carapace ossification appears to be species-specific. We demonstrate that computer tomography is a non-invasive and convenient method suitable for studying abnormalities and the postnatal ossification process of the bony carapace, as well as for diagnostics in live chelonians. However, the resolution limit of the method will be reached in the case of very young or metabolically challenged subjects. [ABSTRACT FROM AUTHOR]

The long-necked chelid turtle Yaminuechelys aff. maior is described on the basis of post-cranial material of two specimens from the Lower–Middle Campanian Anacleto Formation, nortwestern Patagonia (Argentina). These post-cranial remains are described macroscopically (external morphology) and microscopically (histological sections of the shell). Although minor carapace and plastral differences are reported (e.g., extension of the axillary buttresses on visceral surfaces of the first costal bone, curled bridge peripheral bones, absence of a sub-rectangular fenestra retained in adults) the specimens exibit the shell morphology and surface ornamentation of specimens referred to Y . maior (Staesche, 1929) from Paleocene levels of the Salamanca Formation (Central Patagonia). This assignment is supported by a phylogenetic analysis, in which the new material is the most closely related to Y . maior . As Yaminuechelys is hypothesized to be the sister taxon of Hydromedusa , the capability of Hydromedusa tectifera to adapt to changing environments and the survivorship of Yaminuechelys genus in K/P boundary is discussed. [ABSTRACT FROM AUTHOR]

Extant turtles are characterized by diverse marginal reductions in their temporal skull region. Among other minor factors, their modes of neck retraction were hypothesized to have a key influence for shaping that region through evolution. A recent study on the mobility of the turtle neck highlighted the possibility that stem turtles, such as Proganochelys quenstedti were able to easily retract their necks by laterally tucking the skull under the anterior edge of the shell. A small emargination in the “cheek” of this species could be correlated to its mode of neck retraction. In the present study, by using a geometric morphometric approach, I correlated the curve shapes of retracted necks and other neck positions with the expansion of marginal reductions in turtle skulls. I hypothesize based on morphospace distributions that neck retraction evolved only once within turtle evolution and that pleurodiran and cryptodiran turtle retraction are directly and independently derived from ancestral neck tucking. Pleurodires evolved a middle kink in their elongated neck for lateral retraction. At the dawn of turtle evolution, associated to the ancestrally retracted (laterally rotated) neck, the cervicals were less specialized than in extant taxa. For cryptodires, that condition may have permitted a transitional, intervertebral rotation towards the vertical neck orientation found in that group during retraction. It retained the ancestral characteristically oriented curvature of the cervical column. I found that the cryptodiran mode of retraction and the ventral neck flexion in all turtles are strongly correlated to the expansion of the occiput emargination. Pleurodiran retraction, however, does not influence skull shape to such a degree. The “cheek” emargination is correlated with the expansion of the “occiput” emargination and appears to occur in correlation to the fixation of the palatoquadrate to the braincase in crown turtles. Neck related forces acting on the skull and ventral neck flexion are also hypothesized to be crucial factors for the reduction of a potential temporal fenestration inherited from a potentially fenestrated turtle ancestor. [ABSTRACT FROM AUTHOR]

Chelonian and crocodilian eggs and eggshells are relatively rare in the fossil record as compared to those of dinosaurs and avians. In India, prior to the present report, turtle eggshells have been reported from the supposed Late Cretaceous infratrappean beds of Duddukuru, Andhra Pradesh. Likewise, crocodilian eggshells were described from the intertrappean beds of Bombay whose assignment to Maastrichtian age is not based on any age diagnostic fossils. Here we report the first definitive Late Cretaceous turtle and crocodilian eggshells from the intertrappean beds of Kisalpuri, Dindori District, Madhya Pradesh (Central India). The testudoid eggshells from Kisalpuri, though broadly comparable to those of Duddukuru, particularly in radial structure, differ from each other in finer details such as external surface ornamentation and the organization of crystallites in the radial section. The crocodiloid eggshells from Central India are distinct from known fossil eggshells in having non-interlocking wedge-like crystallites and ringed craters on the basal plate groups. Keeping in view the limited fossil specimens available for the present study, the testudoid and crocodiloid eggshells from the Late Cretaceous of Central India are referred to the oofamilies Testudoolithidae and Krokolithidae, respectively. [ABSTRACT FROM AUTHOR]

The origin and early evolution of turtles have long been major contentious issues in vertebrate zoology. This is due to conflicting character evidence from molecules and morphology and a lack of transitional fossils from the critical time interval. The ∼220-million-year-old stem-turtle Odontochelys from China has a partly formed shell and many turtle-like features in its postcranial skeleton. Unlike the 214-million-year-old Proganochelys from Germany and Thailand, it retains marginal teeth and lacks a carapace. Odontochelys is separated by a large temporal gap from the ∼260-million-year-old Eunotosaurus from South Africa, which has been hypothesized as the earliest stem-turtle. Here we report a new reptile, Pappochelys, that is structurally and chronologically intermediate between Eunotosaurus and Odontochelys and dates from the Middle Triassic period (∼240 million years ago). The three taxa share anteroposteriorly broad trunk ribs that are T-shaped in cross-section and bear sculpturing, elongate dorsal vertebrae, and modified limb girdles. Pappochelys closely resembles Odontochelys in various features of the limb girdles. Unlike Odontochelys, it has a cuirass of robust paired gastralia in place of a plastron. Pappochelys provides new evidence that the plastron partly formed through serial fusion of gastralia. Its skull has small upper and ventrally open lower temporal fenestrae, supporting the hypothesis of diapsid affinities of turtles. [ABSTRACT FROM AUTHOR]

Western Pond Turtles ( Actinemys [ Emys] marmorata) occur in habitats ranging from large rivers and reservoirs to small streams and ponds, as well as from sea level to about 2000-m elevation. This range of environments can affect population parameters such as body size, growth rates, survivorship, and reproductive output. We marked 321 individuals in 287 trap-days in 2007 and 2010 at a high-elevation pond on the southern flank of the Tehachapi Mountains in Southern California, USA. The population was female-biased (92 F:78 M in 2007, 113 F:60 M in 2010), and estimated to contain 412 individuals. Growth rates were relatively high compared with other populations of A. marmorata. Monthly survivorship was 0.989-1.000 for adults and juveniles and sλ values denoted a stable population. Clutch size averaged 6.3 eggs, and we found 22 instances of intra-annual double-clutching, and possibly a third clutch for one female. Population traits of turtles at this high-elevation pond differed little from turtles at lower elevation sites at the same latitude. Despite conservation threats to this species, this population is indicative that A. marmorata can survive well in small habitats, many of which are human-created, and this has increased the amount of habitat for the species as other natural areas have been eliminated. [ABSTRACT FROM AUTHOR]

Understanding how and why biodiversity is structured across the globe has been central to ecology, evolution, and biogeography even before those disciplines took their modern forms. Three globalscale patterns in particular have been the focus of research and debate for decades: latitudinal gradients in species richness (richness decreases with increasing latitude), body size (body size increases with increasing latitude in endotherms; Bergmann's rule), and geographic range size (range size increases with increasing latitude; Rapoport's rule). Despite decades of study, the generality and robustness of these trends have been debated, as have their underlying causes. Here we investigate latitudinal gradients in species richness, body size, and range size in the world's turtles (Testudines), and add more evidence that these rules do not seem to apply across all taxa. We show that turtle diversity actually peaks at 25° north, a highly unusual global pattern. Turtles also fail to follow Bergmann's Rule, and may show the converse (larger at lower latitudes), though trends are weak. Turtles also show a complex relationship between latitude and range size that does not directly follow Rapoport's rule. Body size and geographic range size are significantly correlated, and multiple abiotic and biotic variables help explain the relationships between latitude and species diversity, body size, and range size. Although we show that turtles do not strictly follow some classic biogeographical rules, we also call for further in-depth research to investigate potential causal mechanisms for these atypical patterns. [ABSTRACT FROM AUTHOR]

Lately, solemydid turtles have been repeatedly recovered as stem Testudines, indicating that they belong to neither one of the two major branches of crown turtles, the Pancryptodira and Panpleurodira. Despite their wide temporal (Late Jurassic to Late Cretaceous) and spatial (North America and Europe) distributions, solemydid turtles are not particularly well known, as exemplified by the fact that only a single skull has been described for the whole group so far. Furthermore, the palaeoecology of solemydid turtles is still contested with hypotheses ranging from semi-aquatic to terrestrial lifestyles. However, the habitat preference of stem Testudines, such as solemydids, is important to understand the evolution and early radiation of the turtle crown, which is primitively aquatic. Here we describe the shell bone microanatomy and histological microstructures of solemydid turtles using a broad sample of taxa of different ages and localities, as well as review previous histological accounts, to elucidate the palaeoecology of the group independent of the geological setting and gross anatomy of the fossil finds. Our results indicate that Solemydidae share unique histological features pertaining to their strongly ornamented shell bones, which a) in cases allow taxonomic identification of even small shell fragments and b) unambiguously corroborate a terrestrial lifestyle of its members. The latter further supports a terrestrial lifestyle preference of most representatives of the turtle stem. [ABSTRACT FROM AUTHOR]

The unique ability of modern turtles to retract their head and neck into the shell through a side-necked (pleurodiran) or hidden-necked (cryptodiran) motion is thought to have evolved independently in crown turtles. The anatomical changes that led to the vertebral shapes of modern turtles, however, are still poorly understood. Here we present comprehensive geometric morphometric analyses that trace turtle vertebral evolution and reconstruct disparity across phylogeny. Disparity of vertebral shape was high at the dawn of turtle evolution and decreased after the modern groups evolved, reflecting a stabilization of morphotypes that correspond to the two retraction modes. Stem turtles, which had a very simple mode of retraction, the lateral head tuck, show increasing flexibility of the neck through evolution towards a pleurodiran-like morphotype. The latter was the precondition for evolving pleurodiran and cryptodiran vertebrae. There is no correlation between the construction of formed articulations in the cervical centra and neck mobility. An increasing mobility between vertebrae, associated with changes in vertebral shape, resulted in a more advanced ability to retract the neck. In this regard, we hypothesize that the lateral tucking retraction of stem turtles was not only the precondition for pleurodiran but also of cryptodiran retraction. For the former, a kink in the middle third of the neck needed to be acquired, whereas for the latter modification was necessary between the eighth cervical vertebra and first thoracic vertebra. Our paper highlights the utility of 3D shape data, analyzed in a phylogenetic framework, to examine the magnitude and mode of evolutionary modifications to vertebral morphology. By reconstructing and visualizing ancestral anatomical shapes, we provide insight into the anatomical features underlying neck retraction mode, which is a salient component of extant turtle classification. [ABSTRACT FROM PUBLISHER]

Western Painted Turtles ( Chrysemys picta bellii) are the most anoxia-tolerant tetrapods known, capable of surviving anaerobically at 3°C for nearly 5 mo. In the northernmost latitudes of their range, adult painted turtles can experience winters lasting 6-7 mo. During this time, the pond surface is covered with ice and snow, denying the turtles access to air and trapping them in water that can become severely hypoxic or anoxic. Previous studies have reported that turtles overwinter near the bottom of ponds, either buried in mud or on top of the substrate, where oxygen levels are hypoxic or anoxic. The oxygen is depleted by other respiring biomass within the mud, but why the turtles are found on or within it is not understood. To better understand the overwintering behavior of painted turtles, we conducted a series of laboratory experiments to determine how a turtle's buoyancy is affected by temperature, depth, and access to air. Acclimating turtles to 3°C resulted in a large variation in turtle buoyancy, but preventing access to air caused all turtles to become negatively buoyant. We suggest that painted turtles overwinter in the mud or on the pond bottom not necessarily because of any particular behavioral adaptation, but simply because they become negatively buoyant while overwintering without access to air. [ABSTRACT FROM AUTHOR]

The fossil record of solemydid turtles is primarily based on isolated fragments collected from Late Jurassic to Late Cretaceous sediments throughout North America and Europe and little is therefore known about the morphology and evolutionary history of the group. We here provide a detailed description of the only known near-complete solemydid skeleton, which was collected from the Lower Cretaceous (Aptian-Albian) Antlers Formation of Texas during the mid-twentieth century, but essentially remains undescribed to date. Though comparison is limited, the skeleton is referred to Naomichelys speciosa, which is based on an isolated entoplastron from the Lower Cretaceous (Aptian-Albian) Kootenai (Cloverly) Formation of Montana. The absence of temporal emarginations, contribution of the jugals to the orbits, and a clear subdivision of the middle and inner cavities, and the presence of elongate postorbitals, posteriorly expanded squamosals, a triangular fossa at the posterior margin of the squamosals, an additional pair of tubercula basioccipitale that is formed by the pterygoids, foramina pro ramo nervi vidiani (VII) that are visible in ventral view, shell sculpturing consisting of high tubercles, a large entoplastron with entoplastral scute, V-shaped anterior peripherals, and limb osteoderms with tubercular sculpture diagnose Naomichelys speciosa as a representative of Solemydidae. The full visibility of the parabasisphenoid complex in ventral view, the presence of an expanded symphyseal shelf, and the unusual ventromedial folding of the coronoid process are the primary characteristics that distinguish Naomichelys speciosa from the near-coeval European taxon Helochelydra nopcsai. [ABSTRACT FROM AUTHOR]

Behavioral responses to predation risk are critical for survival but as antipredator behavior is costly, prey animals should flexibly modulate their optimum defensive responses by considering both costs and benefits, which are partly influenced by the individual characteristics of the prey. Turtles have the shell as a morphological structure that may provide partial protection against predators, but hiding into the shell may entail some high costs, and turtles should decide when to switch to an active escape strategy to safe refuges. Here, we examined how gender, body size, and sexual coloration influence inter-individual variability of antipredatory hiding behavior into the shell of Spanish terrapins ( Mauremys leprosa). We simulated predatory attacks under different conditions and measured the time that the turtles spent hidden entirely inside the shell (i.e., appearance times) and from then until the turtle started to flee actively (i.e., waiting times). Our results showed that when risk increased, appearance times increased but waiting times decreased. When turtles were in a prone position, their hiding behavior was related with their body weight with heavier turtles having longer appearance times. Also, the conspicuousness of limb coloration was important for the appearance times of males, but not for females. Thus, males with brighter coloration of the limb stripes had longer appearance times than duller ones. In addition, when turtles were overturned, males appeared out of the shell earlier than females and heavier turtles started to right sooner, but only when risk was low. However, when turtles were overturned and risk was high, they should assume that they have already been detected, making inter-individual differences in size and coloration apparently unimportant for deciding hiding behavior. [ABSTRACT FROM AUTHOR]

Abstract: The differentiation of the corneous layers of reptilian epidermis has been analyzed by ultrastructural immunocytochemistry using specific antibodies against the conserved pre-core box region of their keratin-associated beta-proteins (KAbetaPs, formerly indicated as beta-keratins) and silver-intensification. The epitope analysis in the sequences of different reptilian KAbetaPs indicates that this antibody recognizes mainly glycine-rich beta-proteins in lizards and snakes. The immunoreactivity of the beta-layer of the tuatara to this antibody also suggests that a similar epitope is present in beta-proteins of this relict species. In crocodilians the antibody recognizes glycine-rich beta-proteins, so far representing all the known crocodilian KAbetaPs. In hard-shelled turtle the antibody labels mainly type 1 KAbetaPs that represent most types found in this turtle. The antibody does not label the corneous layer of the soft-shelled turtle that contains exclusively type 2 KAbetaPs, with a low identity to the epitope recognized by the antibody. The prevalent labeling of the beta-layers in lepidosaurian epidermis and of the corneous layer in turtle and crocodilian epidermis suggest that this antibody is mainly directed toward KAbetaPs rich in glycine. The latter are main constituents of the corneous layer in turtles and crocodilians and of the beta-layer in lizards, snakes and the tuatara. These proteins are largely responsible for the inflexibility, mechanical resistance, chromophobicity and relative hydrophobicity of the reptilian corneous layer. [Copyright &y& Elsevier]

The significant influence of thermal acclimation on physiological and behavioral performance has been documented in many ectothermic animals, but such studies are still limited in turtle species. We acclimated hatchling soft-shelled turtles Pelodiscus sinensis under three thermal conditions (10, 20 and 30°C) for 4 weeks, and then measured selected body temperature (Tsel), critical thermal minimum (CTMin) and maximum (CTMax), and locomotor performance at different body temperatures. Thermal acclimation significantly affected thermal preference and resistance of P. sinensis hatchlings. Hatchling turtles acclimated to 10°C selected relatively lower body temperatures and were less resistant to high temperatures than those acclimated to 20°C and 30°C. The turtles' resistance to low temperatures increased with a decreasing acclimation temperature. The thermal resistance range (i.e. the difference between CTMax and CTMin, TRR) was widest in turtles acclimated to 20°C, and narrowest in those acclimated to 10°C. The locomotor performance of turtles was affected by both body temperature and acclimation temperature. Hatchling turtles acclimated to relatively higher temperatures swam faster than did those acclimated to lower temperatures. Accordingly, hatchling turtles acclimated to a particular temperature may not enhance the performance at that temperature. Instead, hatchlings acclimated to relatively warm temperatures have a better performance, supporting the "hotter is better" hypothesis. [ABSTRACT FROM AUTHOR]

ABSTRACT The tough corneous layer in the carapace and plastron of hard-shelled turtles derives from the accumulation of keratin-associated beta-proteins (KAbetaPs, formerly called beta-keratins) while these proteins are believed to be absent in soft-shelled turtles. Our bioinformatics and molecular study has instead shown that the epidermis of the soft-shelled turtle Apalone spinifera expresses beta-proteins like or even in higher amount than in the hard-shelled turtle Pseudemys nelsoni. The analysis of a carapace cDNAs library has allowed the identification and characterization of three alpha-keratins of type I and of ten beta-proteins (beta-keratins). The acidic alpha-keratins probably combine with the basic beta-proteins but the high production of beta-proteins in A. spinifera is not prevalent over that of alpha-keratin so that their combination does not determine the formation of hard corneous material. Furthermore the presence of a proline and cisteine in the beta-sheet region of beta-proteins in A. spinifera may be unsuited to form hard masses of corneous material. The higher amount of beta-proteins over alpha-keratins instead occurs in keratinocytes of the hard and inflexible epidermis of P. nelsoni determining the deposition of hard corneous material. The study suggests that the hardness of the corneous layer derives not exclusively from the interactions between alpha-keratins with KAbetaPs but also from the different dynamic of accumulation and loss of corneocytes in the corneous layer of the hard shelled turtles where a prevalent accumulation and piling of corneocytes takes place versus the soft shelled turtle where a rapid turnover of the stratum corneum occurs. J. Exp. Zool. (Mol. Dev. Evol.) 320B: 428-441, 2013. © 2013 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Highlights: [•] Soft-shelled turtle contains scarce beta-proteins and prevalent alpha-keratin in corneous layer. [•] Hard-shelled turtle contains higher beta-protein levels relative to alpha-keratin. [•] Soft-shelled turtle has a rapid turnover of the corneous layer. [•] Hard-shelled turtle accumulate keratinocytes into a thick corneous layer. [•] Hardness of the corneous layer derives from the ratio beta-proteins to alpha-keratins. [ABSTRACT FROM AUTHOR]

Habitat preferences for juvenile loggerhead turtles in the North Pacific were investigated with data from two several-year long tagging programs, using 224 satellite transmitters deployed on wild and captive-reared turtles. Animals ranged between 23 and 81 cm in straight carapace length. Tracks were used to investigate changes in temperature preferences and speed of the animals with size. Average sea surface temperatures along the tracks ranged from 18 to 23 °C. Bigger turtles generally experienced larger temperature ranges and were encountered in warmer surface waters. Seasonal differences between small and big turtles suggest that the larger ones dive deeper than the mixed layer and subsequently target warmer surface waters to rewarm. Average swimming speeds were under 1 km/h and increased with size for turtles bigger than 30 cm. However, when expressed in body lengths per second (bl s−1), smaller turtles showed much higher swimming speeds (>1 bl s−1) than bigger ones (0.5 bl s−1). Temperature and speed values at size estimated from the tracks were used to parameterize a habitat-based Eulerian model to predict areas of highest probability of presence in the North Pacific. The model-generated habitat index generally matched the tracks closely, capturing the north-south movements of tracked animals, but the model failed to replicate observed east-west movements, suggesting temperature and foraging preferences are not the only factors driving large-scale loggerhead movements. Model outputs could inform potential bycatch reduction strategies. [ABSTRACT FROM AUTHOR]

The Chinese soft-shelled turtle Pelodiscus sinensis is the most common turtle species sold in China. In most turtle farms P. sinensis eggs are incubated at fluctuating temperatures. To examine if fluctuations in incubation temperature affect hatching success, incubation length and hatchling quality, we incubated P. sinensis eggs in five incubators: one set at 30°C, two ramp-programmed at 30±3°C and±5°C; the remaining two step-programmed at 30±3°C and±5°C. Temperatures changed at 12h (+) and 12h (−) in the ramp-programmed incubators, and at 6h intervals in an order of lowest–mean–highest–mean levels in the step-programmed incubators. Size-related (carapace length, carapace width and mass) rather than performance-related (swimming speed and early growth) hatchling phenotypes differed among the five treatments. Eggs in ramp-programmed incubators overall produced larger hatchlings than did those in step-programmed incubators, and eggs at 30°C produced larger hatchlings than did those incubated at fluctuating temperatures. However, temperature-induced variation in hatchling size was not a significant source of variation in post-hatching growth, and the pattern of fluctuations in incubation temperature was less important for turtles reared in the laboratory. We suggest that the most important thing that should be done by farmers is to avoid exposure of P. sinensis eggs to the temperatures potentially lethal to embryos rather than to incubate them at stable temperatures. [ABSTRACT FROM AUTHOR]

Turtle shells are a form of armor that provides varying degrees of protection against predation. Although this function of the shell as armor is widely appreciated, the mechanical limits of protection and the modes of failure when subjected to breaking stresses have not been well explored. We studied the mechanical properties of whole shells and of isolated bony tissues and sutures in four species of turtles ( Trachemys scripta, Malaclemys terrapin, Chrysemys picta, and Terrapene carolina) using a combination of structural and mechanical tests. Structural properties were evaluated by subjecting whole shells to compressive and point loads in order to quantify maximum load, work to failure, and relative shell deformations. The mechanical properties of bone and sutures from the plastral region of the shell were evaluated using three-point bending experiments. Analysis of whole shell structural properties suggests that small shells undergo relatively greater deformations before failure than do large shells and similar amounts of energy are required to induce failure under both point and compressive loads. Location of failures occurred far more often at sulci than at sutures (representing the margins of the epidermal scutes and the underlying bones, respectively), suggesting that the small grooves in the bone created by the sulci introduce zones of weakness in the shell. Values for bending strength, ultimate bending strain, Young's modulus, and energy absorption, calculated from the three-point bending data, indicate that sutures are relatively weaker than the surrounding bone, but are able to absorb similar amounts of energy due to higher ultimate strain values. J. Exp. Zool. 319A:86-98, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background Proterochersis robusta from the Late Triassic (Middle Norian) of Germany is the oldest known fossil turtle (i.e. amniote with a fully formed turtle shell), but little is known about its anatomy. A newly prepared, historic specimen provides novel insights into the morphology of the girdles and vertebral column of this taxon and the opportunity to reassess its phylogenetic position. Results The anatomy of the pectoral girdle of P. robusta is similar to that of other primitive turtles, including the Late Triassic (Carnian) Proganochelys quenstedti, in having a vertically oriented scapula, a large coracoid foramen, a short acromion process, and bony ridges that connect the acromion process with the dorsal process, glenoid, and coracoid, and by being able to rotate along a vertical axis. The pelvic elements are expanded distally and suturally attached to the shell, but in contrast to modern pleurodiran turtles the pelvis is associated with the sacral ribs. Conclusions The primary homology of the character "sutured pelvis" is unproblematic between P. robusta and extant pleurodires. However, integration of all new observations into the most complete phylogenetic analysis that support the pleurodiran nature of P. robusta reveals that this taxon is more parsimoniously placed along the phylogenetic stem of crown Testudines. All current phylogenetic hypotheses therefore support the basal placement of this taxon, imply that the sutured pelvis of this taxon developed independently from that of pleurodires, and conclude that the age of the turtle crown is Middle Jurassic. [ABSTRACT FROM AUTHOR]

Abstract: The discovery of abundant new material of the European turtle Dortoka vasconica at its type locality and a review of the previously analyzed material allow new interpretations of the anatomy and lifestyle of this Cretaceous taxon to be proposed. Both its carapace and plastron are highly varied and several characters are identified as subject to individual variability. Some characters previously considered in the diagnosis of this taxon were found to vary. Two morphotypes of the anterior lobe of the plastron are identified, both of which are characterized by a particular morphology and disposition of their bony elements and scute patterns. We also identified two morphotypes taking into account the morphology of the anal notch, which are potentially related to two sexual morphs. The curious shape of various elements of the carapace had been mentioned previously. We identify here the presence of a pair of autapomorphic fontanelles, which justify the development of these peculiar structures. The presence of these large fontanelles, which remain open throughout ontogeny, and a histological study examining various elements of the carapace and plastron corroborate our interpretation of Dortoka vasconica as having a more aquatic lifestyle than previously thought. [Copyright &y& Elsevier]

ABSTRACT The temporal region of turtles is characterized by significant anatomical diversity. Turtles show a pure anapsid morphotype that exhibits various different marginal reductions known as emarginations. As a result of this diversity, turtles can be taken as a model by which to understand the processes that may have resulted in the highly debated anatomy of the amniote temporal region in general. In this review on almost forgotten literature, I summarize ten potential factors that may act on the skull to shape the temporal region of turtles. These are: (1) phylogenetic constraints, (2) skull weights, (3) type of food, (4) skull dimensions, (5) muscle bulging, (6) ear anatomy and jaw muscle bending mechanisms, (7) extent and nature of muscle attachment sites, (8) internal forces within the jaw adductor chamber, (9) environmental pressure, and (10) neck bending mechanisms. Particular focus is laid on the interrelationship of the jaw musculature and the dermatocranial armour, which were assumed to influence each other to a certain degree. In the literature, cranial dimensions were assumed to influence temporal bone formation within major tetrapod groups. Among these, turtles seem to represent a kind of intermixture, a phenomenon that may be reflected in their specific anatomy. The references presented should be understood as product of the scientific environment in which they developed and the older literature does not always insist current empirical demands. However, the intuitive and creative ideas and the comprehensive anatomical considerations of these authors may inspire future studies in several fields related to this topic. J. Exp. Zool. (Mol. Dev. Evol.) 318:235-249, 2012. © 2012 Wiley Periodicals, Inc. [ABSTRACT FROM AUTHOR]

Background: Phenotypic anomalies are common in wild populations and multiple genetic, biotic and abiotic factors might contribute to their formation. Turtles are excellent models for the study of developmental instability because anomalies are easily detected in the form of malformations, additions, or reductions in the number of scutes or scales. Methodology/Principal Findings: In this study, we integrated field observations, manipulative experiments, and climatic and genetic approaches to investigate the origin of carapace scute anomalies across Iberian populations of the European pond turtle, Emys orbicularis. The proportion of anomalous individuals varied from 3% to 69% in local populations, with increasing frequency of anomalies in northern regions. We found no significant effect of climatic and soil moisture, or climatic temperature on the occurrence of anomalies. However, lower genetic diversity and inbreeding were good predictors of the prevalence of scute anomalies among populations. Both decreasing genetic diversity and increasing proportion of anomalous individuals in northern parts of the Iberian distribution may be linked to recolonization events from the Southern Pleistocene refugium. Conclusions/Significance: Overall, our results suggest that developmental instability in turtle carapace formation might be caused, at least in part, by genetic factors, although the influence of environmental factors affecting the developmental stability of turtle carapace cannot be ruled out. Further studies of the effects of environmental factors, pollutants and heritability of anomalies would be useful to better understand the complex origin of anomalies in natural populations. [ABSTRACT FROM AUTHOR]

An Adocus turtle collected from the Upper Cretaceous (late Campanian) Kaiparowits Formation in southern Utah contains partial eggs and numerous well-preserved bones beneath the carapace. The bones include the closely associated-articulated elements of the right pectoral girdle, skull and cervical vertebrae. The eggs are about 35 mm in diameter, and the rigid 250-280-μm thick eggshell exhibits needle-like aragonitic crystals that form the narrow, straight shell units. The eggs appear smaller than those within a gravid Adocus from Alberta, and the eggshell is thinner and lacks the feathered structure reported in the Alberta eggs. Differences in the Utah and Alberta Adocus eggs may result from differences in the stage of egg formation or the specimens may represent different Adocus species. [ABSTRACT FROM AUTHOR]

A new pleurosternid turtle from the Upper Jurassic of the Central West of Portugal is described. Pleurosternids are abundant in the European and American Upper Jurassic and Lower Cretaceous fossil record. Despite this, at present, there is no reference to any genus of pleurosternids before the upper Tithonian in Europe. Selenemys lusitanica, gen. et sp. nov., represented by several specimens from the upper Kimmeridgian of the Lusitanian Basin (Portugal), constitutes the most ancient generic attribution to a pleurosternid turtle in Europe. A cladistic analysis shows that Selenemys is more closely related to the European Lower Cretaceous pleurosternids than to the Jurassic North American representatives of this group. This is interpreted as a vicariant biogeographical distribution of the group on both sides of the North Atlantic during the Uppermost Jurassic, in contrast to that observed in other groups of reptiles. [ABSTRACT FROM AUTHOR]

Abstract: Recent studies have emphasized the importance of Indigenous producers and traders in the formation of ethnographic museum collections, but have found difficulty in finding concrete evidence for their active roles. A use-wear and residue study of turtle bone cleavers from Wuvulu Island, Papua New Guinea provides the opportunity to test whether objects that comprise a significant component of early collections were made specifically for sale, as hypothesized by contemporary observers in the late 19th century. Comparative studies of used and unused turtle bone artifacts from the Caroline Islands and Papua New Guinea identified differences between wear traces resulting from manufacture and use. Analyses of the Wuvulu turtle bone cleavers showed they had been heavily used prior to sale. Rather than produce artifacts to meet the high demand from German traders, the local people sold old, worn-out objects, many of which had been repaired. The study demonstrates that archaeological approaches to ethnographic museum collections can trace Indigenous agency within cross-cultural interaction. It also showcases the potential of use-wear and residue analytical techniques for the analysis of bone tools and the utility of digital, hand-held microscopes for the analysis of large artifacts. [ABSTRACT FROM AUTHOR]