Turtle Bones Research Articles

Preserved collagen reveals species identity in archaeological marine turtle bones from Caribbean and Florida sites.

Advancements in molecular science are continually improving our knowledge of marine turtle biology and evolution. However, there are still considerable gaps in our understanding, such as past marine turtle distributions, which can benefit from advanced zooarchaeological analyses. Here, we apply collagen fingerprinting to 130 archaeological marine turtle bone samples up to approximately 2500 years old from the Caribbean and Florida's Gulf Coast for faunal identification, finding the vast majority of samples (88%) to contain preserved collagen despite deposition in the tropics. All samples can be identified to species-level with the exception of the Kemp's ridley (Lepidochelys kempii) and olive ridley (L. olivacea) turtles, which can be separated to genus level, having diverged from one another only approximately 5 Ma. Additionally, we identify a single homologous peptide that allows the separation of archaeological green turtle samples, Chelonia spp., into two distinct groups, which potentially signifies a difference in genetic stock. The majority of the archaeological samples are identified as green turtle (Chelonia spp.; 63%), with hawksbill (Eretmochelys imbricata; 17%) and ridley turtles (Lepidochelys spp.; 3%) making up smaller proportions of the assemblage. There were no molecular identifications of the loggerhead turtle (Caretta caretta) in the assemblage despite 9% of the samples being morphologically identified as such, highlighting the difficulties in relying on morphological identifications alone in archaeological remains. Finally, we present the first marine turtle molecular phylogeny using collagen (I) amino acid sequences and find our analyses match recent phylogenies based on nuclear and mitochondrial DNA. Our results highlight the advantage of using collagen fingerprinting to supplement morphological analyses of turtle bones and support the usefulness of this technique for assessing their past distributions across the Caribbean and Florida's Gulf Coast, especially in these tropical environments where DNA preservation may be poor.

New megaraptorid (Dinosauria: Theropoda) remains from the Lower Cretaceous Eumeralla Formation of Cape Otway, Victoria, Australia

ABSTRACTMegaraptorid theropods thrived in South America and Australia during the mid-Cretaceous. Their Australian record is currently limited to the upper Barremian–lower Aptian upper Strzelecki Group and the upper Aptian–lower Albian Eumeralla Formation of Victoria, the Cenomanian Griman Creek Formation of New South Wales, and the Cenomanian–lowermost Turonian Winton Formation of Queensland. The latter has produced Australovenator wintonensis, the stratigraphically youngest and most complete Australian megaraptorid. The Eric the Red West (ETRW) site on Cape Otway, Victoria (Eumeralla Formation; lower Albian), has yielded two teeth, two manual unguals, and a right astragalus that are almost identical to the corresponding elements in Australovenator. Herein, we classify these as Megaraptoridae cf. Australovenator wintonensis. We also reappraise the ‘spinosaurid’ cervical vertebra from ETRW and suggest that it pertains to Megaraptoridae. Three other theropod elements from ETRW—a cervical rib (preserving a bite mark), a caudal vertebra, and a non-ungual manual phalanx—are also described, although it is not possible to determine their phylogenetic position more precisely than Tetanurae (non-Maniraptoriformes). All elements were found in a fluvial deposit, associated with isolated bones of other theropods, ornithopods, and turtles, amongst others; consequently, no two can be unequivocally assigned to the same theropod individual. The new specimens from ETRW demonstrate that a megaraptorid theropod morphologically similar to Australovenator lived during the late Early Cretaceous in Victoria, at a higher paleolatitude than its northern counterpart. Moreover, they attest to the success of megaraptorids in late Barremian–early Turonian faunas throughout eastern Australia.

Plutonium and other radionuclides persist across marine-to-terrestrial ecotopes in the Montebello Islands sixty years after nuclear tests.

Since the 1956 completion of nuclear testing at the Montebello Islands, Western Australia, this remote uninhabited island group has been relatively undisturbed (no major remediations) and currently functions as high-value marine and terrestrial habitat within the Montebello/Barrow Islands Marine Conservation Reserves. The former weapons testing sites, therefore, provide a unique opportunity for assessing the fate and behaviour of Anthropocene radionuclides subjected to natural processes across a range of shallow-marine to island-terrestrial ecological units (ecotopes). We collected soil, sediment and biota samples and analysed their radionuclide content using gamma and alpha spectrometry, photostimulated luminescence autoradiography and accelerator mass spectrometry. We found the activity levels of the fission and neutron-activation products have decreased by ~hundred-fold near the ground zero locations. However, Pu concentrations remain elevated, some of which are high relative to most other Australian and international sites (up to 25,050 Bq kg-1 of 239+240+241Pu). Across ecotopes, Pu ranked from highest to lowest in the following order: island soils > dunes > foredunes > marine sediments > and beach intertidal zone. Low values of Pu and other radionuclides were detected in all local wildlife tested including endangered species. Activity concentrations ranked (highest to lowest) terrestrial arthropods > terrestrial mammal and reptile bones > algae > oyster flesh > whole crab > sea turtle bone > stingray and teleost fish livers > sea cucumber flesh > sea turtle skin > teleost fish muscle. The three detonations (one from within a ship and two from 30 m towers) resulted in differing contaminant forms, with the ship detonation producing the highest activity concentrations and finer more inhalable particulate forms. The three sites are distinct in their 240/239Pu and 241/239Pu atom ratios, including the Pu transported by natural process or within migratory living organisms.

Heterogeneous bioapatite carbonation in western painted turtles is unchanged after anoxia

Adsorbed and structurally incorporated carbonate in bioapatite, the primary mineral phase of bone, is observed across vertebrates, typically at 2–8 wt%, and supports critical physiological and biochemical functions. Several turtle species contain elevated bone-associated carbonate, a property linked to pH buffering and overwintering survival. Prior studies of turtle bone utilized bulk analyses, which do not provide spatial resolution of carbonate. Using Raman spectroscopy, the goals of this study were to: (1) quantify and spatially resolve carbonate heterogeneity within the turtle shell; (2) determine if cortical and trabecular bone contain distinct carbonate concentrations; and (3) assess if simulated overwintering conditions result in decreased bioapatite carbonation. Here, we demonstrate the potential for Raman spectroscopic analysis to spatially resolve bioapatite carbonation, using the western painted turtle as a model species. Carbonate concentration was highly variable within cortical and trabecular bone, based on calibrated Raman spot analyses and mapping, suggesting heterogeneous carbonate distribution among crystallites. Mean carbonate concentration did not significantly differ between cortical and trabecular bone, which indicates random distribution of crystallites with elevated and depleted carbonate. Carbonate concentrations (range: 5–22 wt%) were not significantly different in overwintering and control animals, deviating from previous bulk analyses. In reconciling bulk and Raman analyses, two hypotheses explain how overwintering turtles potentially access carbonate: (1) mobilization of mineral-associated, surface components of bone crystallites; and (2) selective, dispersed crystallite dissolution. Elevated bioapatite carbonate in the western painted turtle, averaging 11.8 wt%, represents the highest carbonation observed in vertebrates, and is one physiological trait that facilitates overwintering survival.

Archeological analysis of osteological material of Rakushechniy Yar settlement while studying the economy of the early Neolytic population

The paper contains the study results of the settlement Rakushechny Yar fauna from the excavations of 20132017. It is a reference site for this region, because it has a unique stratigraphy. It was possible to determine 201 bones of mammals, birds and turtles at the early Neolithic layers of Rakushechny Yar. The fish remains at the settlement are numerous, but have not been investigated. The large ungulates were of the greatest importance here for the hunting. The largest number of the bones belongs to the red deer. Cutting the carcasses of this animal occurred at the settlement. It should be noted that the horse is represented by a wild form here. An important event was the appearance of domestic cows, sheep and pigs in this region. As a result of the analysis of the available osteological material we can confidently state that the process of domestication of these species passed long before the arrival of the settlers on the Don River. The Early Neolithic population in the Northern Black Sea Region, from our point of view, was heterogeneous in terms of material culture and, probably, the origins of the formation. It is possible that this is the reason for the difference in economic activity of people in that territory.

Changes in the material properties of the shell during simulated aquatic hibernation in the anoxia-tolerant painted turtle.

Western painted turtles (Chrysemys picta bellii) tolerate anoxic submergence longer than any other tetrapod, surviving more than 170 days at 3°C. This ability is due, in part, to the shell and skeleton simultaneously releasing calcium and magnesium carbonates, and sequestering lactate and H+ to prevent lethal decreases in body fluid pH. We evaluated the effects of anoxic submergence at 3°C on various material properties of painted turtle bone after 60, 130 and 167-170 days, and compared them with those of normoxic turtles held at the same temperature for the same time periods. To assess changes in the mechanical properties, beams (4×25 mm) were milled from the plastron and broken in a three-point flexural test. Bone mineral density, CO2 concentration (a measure of total bone HCO3-/CO32-) and elemental composition were measured using microcomputed tomography, HCO3-/CO32- titration and inductively coupled plasma mass spectrometry (ICP-MS), respectively. Tissue mineral density of the sampled bone beams was not significantly altered by 167-170 days of aquatic overwintering in anoxic or normoxic water, but bone CO2 and Mg were depleted in anoxic compared with normoxic turtles. At this time point, the plastron beams from anoxic turtles yielded at stresses that were significantly smaller and strains that were significantly greater than the plastron beams of normoxic turtles. When data from anoxic and normoxic turtles were pooled, plastron beams had a diminished elastic modulus after 167-170 days compared with those of control turtles sampled on day1, indicating an effect of prolonged housing of the turtles in 3°C water without access to basking sites. There were no changes in the mechanical properties of the plastron beams at any of the earlier time points in either group. We conclude that anoxic hibernation can weaken the painted turtle's plastron, but likely only after durations that exceed what it might naturally experience. The duration of aquatic overwintering, regardless of oxygenation state, is likely to be an important factor determining the mechanical properties of the turtle shell during spring emergence.

Analysis of Archaeozoological Assemblage from Nebelivka Trypillian Settlement

The archaeological collection from Nebelivka settlement contains 2519 fragments of bones of mammals, birds, and turtles. 1616 bones were definable to the species they belonged to. The collection consists of «kitchen refuse». A peculiar feature of Nebelivka archaeozoological assemblage is the relatively low content of wild animal species (10,1 % of the total number of mammals). The inhabitants of the settlement bred cattle, small cattle, and pigs. Horse is represented by single bones. At present, there is no conclusive evidence for the refering of horse from Nebelivka to wild or to domestic form. The bones of dogs are also few. They are mainly represented by fragments of lower jaws that were used as tools. The population hunted tour, red deer, roe deer, and hare. The basic amount of animal food (90,3 %) was obtained from domestic animals breeding. The exploitation of domestic animal herds is described by the meat and dairy direction with usage of secondary products: cattle and small cattle’s milk and dairy products, as well as sheep and goats’ wool. The usage of cattle’s draft power is also possible. Pigs breeding was focused in obtaining meat: 77,3 % of animals were slaughtered before reaching sexual maturity. The bones of animals of various species were used to make tools. Domestic animals were pastured near the settlement and kept in stalls during the winter season. The domestic animals, obviously, were sufficiently provided with feed in winter. The structure of the hunting prey and a considerable number of pigs and small cattle indicate a forest-steppe landscape with the alternation of forest and meadow-steppe lands around the settlement.

Characterization of turtle demineralized bone matrix (DBM) and turtle bone in rat radial bone defects; radiological, histopathological, biomechanical and scanning electron microscopic evaluation

Characterization of turtle demineralized bone matrix (DBM) and turtle bone in rat radial bone defects; radiological, histopathological, biomechanical and scanning electron microscopic evaluation

Fishery in the eneolithic forest-steppe of the Volga Region (on excavation materials of Lebyazhinka VI settlement in 2013-2014 years)

The following paper contains information about fishers weapons and fish bones founded in Lebyazhinka VI eneolitic settlement in the forrest-steppe region of the Volga river. We analyse materials of the second half of the IV millennium BC. The filling of pits represents dwellings with the inner edge, stone and bone tools, animal bones of turtles, birds and fish. The importance of this studiing is in the possibility of a complex view. The purpose of this article is to analyze the fish catching, hunting and fish bones. Hunting tools are represented by bone harpoons with one, two or many teeth, arranged on one side. There are two types of fishbone hooks: whole and composite. We determined the typological features of catching tools, and moreover we determined quantitative, species, age and size characteristics of fish. The main fishes were pike and catfish, then luce, pike, perch, roach, sturgeon, sterlet. The fish sizes are medium and large, the age is about 8-10 years. We have an opinion of the way of fishing including hooks, harpoons, nets and stakes. The research will be completed with new materials.

A fossil sea turtle (Testudines: Pan-Cheloniidae) from the upper Oligocene Pomahaka Formation, New Zealand

Gard, H.J.L. & Fordyce, R.E., August 2016. A fossil sea turtle (Testudines: Pan-Cheloniidae) from the upper Oligocene Pomahaka Formation, New Zealand. Alcheringa 41, XX–XX. ISSN 0311-5518.An isolated turtle xiphiplastron similar to that of Puppigerus sp. is described from the upper Oligocene (27.3–25.2 Ma) Pomahaka Formation near Tapanui, Otago, New Zealand. The bone is unlike any previously described turtle from the Cenozoic of New Zealand and is from a newly recognized estuarine vertebrate locality. It represents the first Oligocene cheloniid turtle bone described from the southwest Pacific.Henry J. L. Gard [henrygard@hotmail.com] and R. Ewan Fordyce, [ewan.fordyce@otago.ac.nz], Department of Geology, University of Otago, PO Box 56, Dunedin, 9054, Otago, New Zealand.

The stomach content of a Mediterranean Monk Seal (Monachus monachus): finding of Green Turtle (Chelonia mydas) remains

The stomach contents of an adult Mediterranean Monk Seal (Monachus monachus) found stranded on the Turkish eastern Mediterranean coast near Antalya in May 2013 were analysed. In total, 69 individual food items were counted and nine taxa were identified to species or family level. Of the identified taxa, Sparidae was the most highly represented family of prey fish, and one cephalopod species, Octopus vulgaris, was found. Ariosoma balearicum and Argyrosomus regius were encountered for the first time in the diet of a Monk Seal in the Mediterranean. Several body parts (three heads, six forelimbs, neck bones and fractured upper forelimb bones) of Green Turtles (Chelonia mydas) were also identified, which is the first record of this species in the Monk Seal’s diet.

Bone as a buffer: Consequences for vertebrate design and anaerobic physiological performance

Conventional wisdom usually states that mineralized tissues are primarily used by vertebrates as sites for respiratory and locomotory muscle attachment or for physical protection from predators. Often ignored is the role these tissues play in maintaining ionic and acid‐base homeostasis and how this might have shaped vertebrate evolution. We have argued that this latter function may have been important in shaping vertebrate design in early tetrapods, particularly the maintenance of dermal armor in early tetrapods, and is still important for anaerobic physiological performance in many extant vertebrates, especially in reptiles and amphibians. We use physiological, biomechanical, and mineralogical approaches to understand how vertebrate bone, especially that of turtles, interacts with and is affected by extreme deviations in acid‐base homeostasis. Our work, and that of others, has shown that the mineral composition of turtle bone can predict tolerance to extreme acidosis, and that the most derived of these vertebrates, the anoxia‐tolerant painted turtle, is able to utilize calcium and magnesium carbonates within its bone to prevent lethal decreases in body fluid pH in the face of a 180 mM lactic acid load, with minimal effect on whole‐bone material properties.Support or Funding InformationThis work is funded by a CAREER Award from the National Science Foundation.

Post-Gondwana Africa and the vertebrate history of the Angolan Atlantic Coast

The separation of Africa from South America and the growth of the South Atlantic are recorded in rocks exposed along the coast of Angola. Tectonic processes that led to the formation of Africa as a continent also controlled sedimentary basins that preserve fossils. The vertebrate fossil record in Angola extends from the Triassic to the Holocene and includes crocodylomorph, dinosaur, and mammaliamorph footprints, but more extensively, bones of fishes, turtles, plesiosaurs, mosasaurs, crocodiles, and cetaceans. Pterosaurs, dinosaurs, and land mammals are rare in Angola. The northward drift of Africa through latitudinal climatic zones provides a method for comparing predicted paleoenvironmental conditions among localities in Angola, and also allows comparison among desert and upwelling areas in Africa, South America, and Australia. South America has shown the least northward drift and its Atacama Desert is the oldest coastal desert among the three continents. Africa’s northward drift caused the displacement of the coastal desert to the south as the continent moved north. Australia drifted from far southerly latitudes and entered the climatic arid zone in the Miocene, more recently than South America or Africa, but in addition, a combination of its drift, continental outline, a downwelling eastern boundary current, the Pacific Ocean to Indian Ocean throughflow, and monsoon influence, make Australia unique.

Effects of demineralization on the stable isotope analysis of bone samples.

The sampling of sequential, annually formed bone growth layers for stable carbon (δ(13)C values) and nitrogen (δ(15)N values) isotope analysis (SIA) can provide a time series of foraging ecology data. To date, no standard protocol exists for the pre-SIA treatment of cortical samples taken from fresh, modern, bones. Based on the SIA of historical bone, it is assumed that fresh bone samples must be pre-treated with acid prior to SIA. Using an elemental analyzer coupled to an isotope ratio mass spectrometer to measure stable carbon and nitrogen ratios, we tested the need to acidify cortical bone powder with 0.25 M HCl prior to SIA to isolate bone collagen for the determination of δ(13)C and δ(15)N values. We also examined the need for lipid extraction to remove potential biases related to δ(13)C analysis, based on a C:N ratio threshold of 3.5. It was found that acidification of micromilled cortical bone samples from marine turtles does not affect their δ(15)N values, and the small effect acidification has on δ(13)C values can be mathematically corrected for, thus eliminating the need for pre-SIA acidification of cortical bone. The lipid content of the cortical bone samples was low, as measured by their C:N ratios, indicating that lipid extracting cortical bone samples from modern marine turtles is unnecessary. We present a standard protocol for testing fresh, modern cortical bone samples prior to SIA, facilitating direct comparison of future studies. Based on the results obtained from marine turtle bones, pre-acidification and lipid removal of cortical bone are not recommended. This is especially useful as there is frequently not enough bone material removed via micromilling of sequential growth layers to accommodate both acid treatment and SIA.

European Pond Turtles from Obříství (Bohemia, Czech Republic)

AbstractThe paper describes and analyses recent finds of the European pond turtle (Emys orbicularis) from the archaeological sites at Obříství (Mělník District, at the confluence of the Elbe and Moldau rivers in the Bohemian Basin, Czech Republic). Turtle remains were found in three sunken features dated to the Late Bronze Age or to the Hallstatt period, and in one feature dated to the Neolithic. The high number of osteological finds, particularly the number of individuals found in one place, is unique within Bohemia and very rare for the Bronze Age to Iron Age in Europe. A large number of shell remains were identified, from at least 12 individuals in feature 1480, and from at least 5 individuals in feature 1483. The high numbers support the hypothesis that the European pond turtle was once a regular feature of the local fauna, even though the Bohemian basin is surrounded by mountains, which will have presented difficulties for the process of postglacial recolonization by semiaquatic thermophilous reptiles. The findings from Obříství show evidence of the exploitation of turtles for food. Signs of culinary procedures and the human consumption of turtles include anthropogenic chop marks, signs of burning and the apparently intentional segmentation of the turtle bodies. The quantity of turtle bones is still negligible, however, compared with those of mammals. Copyright © 2015 John Wiley & Sons, Ltd.

Bone-eating Osedax worms lived on Mesozoic marine reptile deadfalls.

We report fossil traces of Osedax, a genus of siboglinid annelids that consume the skeletons of sunken vertebrates on the ocean floor, from early-Late Cretaceous (approx. 100 Myr) plesiosaur and sea turtle bones. Although plesiosaurs went extinct at the end-Cretaceous mass extinction (66 Myr), chelonioids survived the event and diversified, and thus provided sustenance for Osedax in the 20 Myr gap preceding the radiation of cetaceans, their main modern food source. This finding shows that marine reptile carcasses, before whales, played a key role in the evolution and dispersal of Osedax and confirms that its generalist ability of colonizing different vertebrate substrates, like fishes and marine birds, besides whale bones, is an ancestral trait. A Cretaceous age for unequivocal Osedax trace fossils also dates back to the Mesozoic the origin of the entire siboglinid family, which includes chemosynthetic tubeworms living at hydrothermal vents and seeps, contrary to phylogenetic estimations of a Late Mesozoic-Cenozoic origin (approx. 50-100 Myr).

The J. M. Snow Site (41CE8) in the Neches River Basin, Cherokee County, Texas

The J. M. Snow site (41CE8) is an ancestral Caddo habitation site and probable small cemetery in the Pineywoods of East Texas. According to Jackson, the site had two habitation areas along the bank of an old channel of the Neches River, each some 300 m from an area where the landowner found 8-10 ceramic vessels from one or more burials that had eroded into a ravine. A Bullard Brushed jar was purchased from the landowner. One of the habitation areas had a well-preserved midden deposit about 4.6-7.6 m in diameter and ca. 46-76 cm in thickness. University of Texas (UT) excavations in September 1933 concentrated on this midden deposit. The work recovered burned clay, mussel shells, ash, bone awls (n=2), perforated mussel shells, bone beads (n=2), lithic scrapers, deer antler tools, and deer, dog, raccoon, turtle, turkey, fish, rabbit, and squirrel bone refuse, as well as ceramic pipe sherds and many ceramic vessel sherds.

Identification of giant softshell turtle species (Reptilia: Testudines: Trionychidae: Pelochelys, Rafetus) in Vietnam

The allocation of two giant softshell turtle species of the genus Pelochelys and Rafetus is reviewed and confirmed based on morphological features of skulls and carapace bones of giant sofshell turtles collected in North Vietnam. The examination results of these specimens are also compared with description of foreign authors in international herpetological journals. At present, two species of giant softshell turtles were recorded in Vietnam including Pelochelys cantorii Gray, 1864 and Rafetus swinhoei (Gray, 1873). The current status of giant softshell turtle species is considered to be facing an extremely high risk of extinction in the wild. Therefore, according to the IUCN Red List categories and criteria (2001), both species of giant softshell turtles are proposed to re-evaluate in new version of Red Data Book of Vietnam.

Empyema, acute respiratory failure, and septic shock after aspiration of a soft-shelled turtle (Pelodiscus sinensis) bone by an adult.

IntroductionThe common late complications of foreign body aspiration include granulation formation, obstructive pneumonia, and atelectasis. However, a foreign body-induced pleural infection is very rare, and especially when it is not iatrogenic.Case descriptionA 64-year-old Chinese man was admitted to our hospital with septic shock and acute respiratory failure requiring intubation and mechanical ventilation. Computed tomography revealed multiloculated pleural effusion on the whole right side and right lung atelectasis, with enhanced thickening and calcification of pleura and a foreign body in the right intermediate bronchus. The effusion appeared as a cloudy fluid consistent with pus. A bedside bronchoscopy revealed an irregular foreign body lodged in the right intermediate bronchus. The hard bone was removed and confirmed to be a soft-shelled turtle bone. A final diagnosis of foreign body-induced empyema, acute respiratory failure, and septic shock was confirmed. The patient showed good recovery after completing a course of broad-spectrum antibiotics and undergoing chest tube drainage.Discussion and evaluationAlthough empyema has been reported previously as a rare complication of long-term retention of an aspirated foreign body, no case has been observed that was as serious as our current patient. In addition, a foreign body aspiration by a soft-shelled turtle bone was never reported before.ConclusionsFor the first time, we describe the successful treatment of an adult patient presenting with empyema, accompanied by serious conditions of acute respiratory failure and septic shock induced by aspiration of a soft-shelled turtle bone. Clinicians should consider the possibility of non-iatrogenic foreign body-induced empyema with acute onset of respiratory failure, when a patient’s symptoms cannot be attributed to an alternative obvious cause.

An enormous Jurassic turtle bone bed from the Turpan Basin of Xinjiang, China

A spectacular new terrestrial Konzentratlagerstätte is introduced from the Turpan Basin of Xinjiang, China that probably belongs to the late Middle Jurassic Qigu Formation. It contains a mass accumulation of "xinjiangchelyid" turtles preliminarily identified as Annemys sp. In the zone with the highest turtle concentration, complete and articulated turtle skeletons are tightly packed at a density of up to 36 turtles per square meter. The fossiliferous layer is thickened here and shows an erosional base. This high concentration zone outcrops approximately 10m in length and shows no decrease in turtle density after exposing 2m of the layer into the hillside. Adjacent is a more expansive zone of at least 10m by 30m. In this region, the fossiliferous layer is evenly thick, and approximately five, fully disarticulated turtles are present per square meter. A conservatively estimated 1,800 turtles may, therefore, have been deposited at this site. It is likely that these aquatic turtles gathered in a retreating water hole in a riverine environment during a drought, much as some aquatic turtles will do today, but perished when the habitat dried up completely. A following catastrophic rainfall event caused a debris flow, possibly channelized in a dry river bed, which transported complete turtles, disarticulated turtles, and mudstone clasts and deposited them after a short distance. This taphonomic model is consistent with previous environmental reconstructions of the Turpan Basin during the late Middle Jurassic in predicting the episodic breakdown of regional monsoonal circulation resulting in a seasonally dry climate with severe episodic droughts.