RESUMO
This synoptic review aims to bring some general information on fossil scorpions, namely those trapped in amber - fossilized resin - ranging from Lower Cretaceous through the Palaeocene and up to the Miocene. The question to be addressed is how the study of these fossils can be connected with possible present scorpionism problems. A precise knowledge of these ancient lineages provides information about the evolution of extant lineages, including the buthoids, which contain most known noxious species. Among the Arthropods found trapped in amber, scorpions are considered rare. A limited number of elements have been described from the Late Tertiary Dominican and Mexican amber, while the most ancient Tertiary amber from the Baltic region produced more consistent results in the last 30 years, primarily focusing on a single limited lineage. Contrarily, the Cretaceous amber from Myanmar, also called Burmite, has yielded and continues to yield a significant number of results represented by several distinct lineages, which attest to the considerable degree of diversity that existed in the Burmese amber-producing forests. As in my previous similar contributions to this journal, the content of this note is primarily addressed to non-specialists whose research embraces scorpions in various fields such as venom toxins and public health. An overview knowledge of at least some fossil lineages can eventually help to clarify why some extant elements associated with the buthoids represent dangerous species while others are not noxious.(AU)
Assuntos
Animais , Escorpiões/anatomia & histologia , Fósseis , Âmbar/análiseRESUMO
SUMMARY: Sri Lanka, an island off the tip of the Southeast of the Indian subcontinent processes the earliest skeletal evidence of anatomically modern Homo sapiens (37,000 B.P.) and the best human skeletal record sequence in the South Asian region. Adding another to the list, the skeletal remains, which belong to Mesolithic culture were found at Pallemalala shell midden in Southern Sri Lanka during scientific archaeological exploration by Postgraduate Institute of Archaeology, University of Kelaniya. Sri Lanka. The aim of the study was to determine the minimum number of human individuals, age, sex, and pathological conditions related to the ancient Pallemalala commiunity. For the primary analysis, 426 bone fragments were available. Out of those, 233 bones were identified as human bones which represent 7 minimum number of individuals. The rest of the collection comprises some animal bones and shell species. The community was predominated by the female population. The identified age categories were around 20 years, between 35-45 years, and over 45 years. The encountered pathological lesions were bone thickening, alveolar resorption, dental abscesses, dental caries, antemorterm tooth loss, calculus deposits and brown colour stains on teeth. Regarding the dietary pattern, it was evident that their diet may have consisted of coarse foodstuffs with an extremely basic dietary chemistry.
RESUMEN: Sri Lanka es una isla en la punta del sureste del subcontinente indio que procesa la evidencia esquelética más antigua del Homo sapiens anatómicamente moderno (37.000 AP) y la mejor secuencia de registros esqueléticos humanos en la región del sur de Asia. Agregando otro elemento a la lista, los restos óseos, que pertenecen a la cultura mesolítica, se encontraron en el vertedero de conchas de Pallemalala en el sur de Sri Lanka durante la exploración arqueológica científica realizada por el Instituto de Postgrado de Arqueología de la Universidad de Kelaniya, Sri Lanka. El objetivo del estudio fue determinar el número mínimo de individuos humanos, edad, sexo y condiciones patológicas relacionadas con la antigua comunidad Pallemalala. Para el análisis se dispuso de 426 fragmentos óseos. De esos, 233 huesos fueron identificados como huesos humanos que representan un número mínimo de 7 individuos. El resto de la colección se componía de algunos huesos de animales y especies de conchas. La comunidad estaba dominada por la población femenina. Las categorías de edad identificadas fueron alrededor de 20 años, entre 35-45 años y mayores de 45 años. Las lesiones patológicas encontradas fueron engrosamiento óseo, reabsorción alveolar, abscesos dentales, caries dental, pérdida de dientes antemortem, depósitos de cálculo y manchas de color marrón en los dientes. En cuanto al patrón dietético, era evidente que su dieta pudo haber consistido en alimentos toscos con una química dietética extremadamente básica.
Assuntos
Humanos , Masculino , Feminino , Adulto , Esqueleto/anatomia & histologia , Restos Mortais/anatomia & histologia , Arqueologia , Esqueleto/patologia , Sri Lanka , Vertedores , Restos Mortais/patologia , FósseisRESUMO
Introduction: The taphonomic attributes of a faunal assemblage provide information about which agents affect the distribution and preservation of ancient or newly formed biogenic materials during depositional and post-depositional processes. Actuotaphonomy thus is a valuable tool for reconstructing fossil communities because it establishes analogies between observable processes in the present and those that happened in the past. Objective: The taphonomic attributes of a marginal marine environment were analyzed to assess the origin of fragmentation, bioerosion, and encrustation processes and the role of these characteristics in the deterioration of current sediment accumulations of mollusks (gastropods and bivalves). Methods: The material studied was collected from a shell-remain accumulation called "El Conchal" in the Laguna de Mandinga, Veracruz, a lagoonal complex located in the Gulf of México. Taphonomic analysis included fragmentation, bioerosion, and encrustation features on recent gastropods and bivalve's shells. The categories of each attribute were classified in three degrees: poor, regular and good. The analysis was performed only in complete shells. Results: A bulk sample of 1 697.9 g was processed, recovering 1 165 complete specimens, of which 5 genera of bivalves and 4 genera of gastropods were identified. The fragmentation and bioerosion were classified as regular (grade 1), this may be the results of the water energy in the environment, that permits a constant rework, and exhumation of the remains at the lagoon's water-sediment interface; meanwhile, three eroders were identified to ichnogenus level: Entobia, Oichnus, and Caulostrepsis, being Caulostrepsis the least abundant. The encrustation was classified as poor (grade 2); the result can be interpreted based on the ecosystem intrinsic conditions that do not allow many encrusting organisms to develop properly. The encrusters are represented by calcareous organisms including bryozoans, serpulids tubes, and barnacles. The results yielded an actuotaphonomic model that could be applicable to analogous ecosystems in Laguna de Mandinga (Mandinga Lagoon), in Veracruz, Mexico. Conclusions: In marine marginal environments as in lagoon areas the encrustation does not have an important role in the preservation or destruction of shelly assemblages, being taphonomically more important than fragmentation and bioerosion as potentially destructive agents that can be a source of loss of fidelity in the fossil record.
Introducción: Los atributos tafonómicos de los conchales proveen información acerca de cuáles agentes afectan la distribución y preservación de la acumulación de materiales biogénicos recientes o fósiles, especialmente durante las etapas deposiconales y postdeposicionales. La actuotafonomía es una herramienta valiosa para la reconstrucción de las comunidades fósiles, para establecer analogías entre los procesos observables en el presente con los que ocurrieron en el pasado. Objetivos: Evaluar el impacto de los rasgos tafonómicos y su papel en la formación de los conchales en ambientes de lagunas costeras. Métodos: El material estudiado fue recolectado en una acumulación de restos de conchas llamado "El Conchal" en la Laguna de Mandinga, Veracruz, un complejo lagunar ubicado en el Golfo de México. El análisis tafonómico incluye las características tafonómicas de fragmentación, bioerosión e incrustación en conchas de gasterópodos y bivalvos recientes. Las categorías de cada atributo se clasificaron en tres grados: pobre, medio y alto. El análisis fue realizado solo en conchas completas. Resultados: Se procesaron 1 697.9 g de sedimentos, recuperando 1 165 ejemplares completos, de los cuales se identificaron 5 géneros de bivalvos y 4 géneros de gasterópodos. La fragmentación y bioerosión se clasificaron como un "grado regular", esto puede ser el resultado de la energía del agua en el ambiente, que permite el constante retrabajo y la exhumación de los restos en la interfase agua-sedimento en la laguna; en tanto que, se identificaron tres erosionadores a nivel de género, estos corresponden a los icnogéneros: Entobia, Oichnus y Caulostrepsis, siendo Caulostrepsis el menos abundante. La incrustación mostró un "grado pobre"; el resultado puede interpretarse basado en las condiciones intrínsecas del ecosistema que no permiten que muchos incrustantes se desarrollen de la manera adecuada. Los incrustantes están representados por organismos calcáreos incluyendo briozoarios, tubos de serpúlidos y balanos. Se analizaron los atributos tafonómicos para generar un modelo actuotafonómico que pueda ser aplicable a ecosistemas análogos en el registro fósil. Conclusiones: En ambientes marino marginales como son las áreas lagunares la incrustación no tiene un papel importante en la preservación o destrucción de los conchales, siendo tafonómicamente más importante la fragmentación y bioerosión como agentes potencialmente destructivos que pueden ser un recurso de pérdida de la fidelidad en el registro fósil.
Assuntos
Exoesqueleto/crescimento & desenvolvimento , Fósseis/anatomia & histologia , Moluscos/anatomia & histologia , MéxicoRESUMO
The phylogenetic paradigm of eukaryotic evolution has changed dramatically over the past two decades, with profound reflections on the understanding of life on earth. Arcellinida testate (shelled) amoebae lineages represent some of the oldest fossils of eukaryotes, and the elucidation of their phylogenetic relationships opened a window to the distant past, with important implications for understanding the evolution of life on earth. This four-part essay summarises advances made in the past 20 years regarding: (i) the phylogenetic relationships among amoebae with shells evolving in concert with the advances made in the phylogeny of eukaryotes; (ii) paleobiological studies unraveling the biological affinities of Neoproterozoic vase-shaped microfossils (VSMs); (iii) the interwoven interpretation of these different sets of data concluding that the Neoproterozoic contains a surprising diversity of organisms, in turn demanding a reinterpretation of the most profound events we know in the history of eukaryotes, and; (iv) a synthesis of the current knowledge about the evolution of Arcellinida, together with the possibilities and pitfalls of their interpretation.
Assuntos
Paleontologia , Amoeba , Filogenia , Evolução Biológica , FósseisRESUMO
La especie extinta de tiburón Carcharocles megalodon (Clase: Chondrichthyes; Orden: Lamniformes) es considerado uno de los depredadores más grandes y más poderosos que ha poblado los mares templados de todo el mundo entre el Mioceno medio y el Plioceno (15,9-2,6 Ma). La reconstrucción de su historia evolutiva y ecología se basa principalmente en el estudio morfológico y métrico de los dientes, que representan la abrumadora mayoría de los restos fósiles de esta especie con esqueleto cartilaginoso hallados hasta hoy. En el presente artículo presentamos las características morfológicas y métricas de los dientes de Carcharocles megalodon que se conservan en el Museo Universitario de Chieti (Italia). La colección se compone de nueve dientes de la arcada superior, que pertenecerían a diferentes ejemplares de tamaño variable entre los 6,27-14,50 m y los 2.510-35.918 kg. de peso. Los dientes implementan el registro fósil existente de Carcharocles megalodon, de modo que los datos morfométricos recabados contribuirán a mejorar el conocimiento de los estudios filogenéticos y ecológicos de esta especie.
The extinct species of shark Carcharocles megalodon (Class: Chondrichthyes; Order: Lamniformes) is considered one of the largest and most powerful predators that populated the temperate seas around the world between the middle Miocene and the Pliocene periods (15.9-2.6 My). The reconstruction of its evolutionary history and ecology is based mainly on the morphological and metric studies of the teeth, which represent the overwhelming majority of the fossil remains of this cartilaginous skeleton species. In this article we present the morphological and metric characteristics of the teeth of Carcharocles megalodon that are housed in the University Museum of Chieti (Italy). In particular, the collection is composed of nine teeth of the upper arch, which belonged to different specimens of variable size and weight (total length range: 6.27-14.50 m; weight range: 2,510-35,918 kg). The teeth implement the existing fossil record of Carcharocles megalodon, so that the morphometric data collected will contribute to improve knowledge of the phylogenetic and ecological studies of this species.
Assuntos
Animais , Tubarões/anatomia & histologia , Dente/anatomia & histologia , Fósseis , PaleontologiaRESUMO
La paleopatología es la ciencia que estudia el origen y la evolución de las enfermedades del pasado. El interés por esta disciplina deriva del hecho de que la frecuencia y la distribución de las patologías que han afectado a las especies extintas se correlacionan con su ecología y etología. Esta suposición también es válida en el caso de Carcharocles megalodon, el tiburón más grande jamás existido, situado en lo alto de la cadena alimenticia y que vivió en los mares templados desde el Mioceno medio hasta el Plioceno (15,9-2,6 Ma). En el presente artículo presentamos las alteraciones patológicas de los dientes de Carcharocles megalodon que se conservan en el Museo Universitario de Chieti (Italia). La colección se compone de nueve dientes de la arcada superior, todos ellos con presencia de alteraciones patológicas correspondientes a defectos del desarrollo y traumas de la corona. Un diente en particular (espécimen #165), presenta una aposición anómala del esmalte sobre la superficie labial, que corresponde a una condición no descrita en la literatura. La colección del Museo Universitario de Chieti enriquece el registro paleopatológico relativamente pobre existente, contribuyendo a completar el conocimiento sobre la paleobiología de Carcharocles megalodon.
Paleopathology is the science that studies the origin and evolution of diseases. The interest in this discipline derives from the fact that the frequency and distribution of the pathologies that have affected the extinct species, correlate with their ecology and ethology. This assumption is also valid in the case of Carcharocles megalodon, the largest shark that ever existed, located at the top of the food chain and that lived in temperate seas from the middle Miocene to the Pliocene periods (15.9-2.6 My). In the present article we present the pathological alterations of the teeth of Carcharocles megalodon housed in the University Museum of Chieti (Italy). The collection consists of nine teeth of the upper arch, all of them with pathological alterations corresponding to developmental defects and crown trauma. A particular tooth (specimen #165) presents an anomalous apposition of the enamel on the labial surface, a condition not yet described in the literature. The collection of the University Museum of Chieti enriches the existing relatively poor paleopathological record, and could improve the knowledge of the paleobiology of Carcharocles megalodon.
Assuntos
Animais , Tubarões/anatomia & histologia , Dente/patologia , Anormalidades Dentárias , Paleopatologia , FósseisRESUMO
Fossil gonorynchiform fishes range from the Lower Cretaceous to the early Miocene, and are represented by a few dozen living species. The order is currently divided into two major clades: Gonorynchoidei, which includes the families Gonorynchidae and Kneriidae, and Chanoidei, encompassing a single family, Chanidae, with a single recent species, the Indo-Pacific Chanos chanos, and several fossil taxa. Chanidae includes some poorly known taxa, such as Dastilbe moraesi, described from the Aptian (Lower Cretaceous) of the Areado Formation, Sanfranciscana basin, Brazil. This species is currently considered to be a junior synonym of the type species of its genus, Dastilbe crandalli, from Santana Formation, Aptian, northeastern Brazil. The analysis of abundant D. moraesi specimens revealed several new morphological features, many of which had previously been misinterpreted. Dastilbe moraesi was incorporated into a gonorynchiform character matrix as revised and modified for the Chanidae. We obtained a single most parsimonious tree in which D. moraesi is distinct and phylogenetically apart from D. crandalli. According our analysis, D. moraesi forms a sister pair with Chanos, a clade which is closely related to Tharrhias, all composing the tribe Chanini.(AU)
Gonorynchiformes fósseis ocorrem desde do Cretáceo inferior ao Mioceno inferior, e são representados por alguns representantes viventes. A ordem está dividida atualmente em dois clados principais: Gonorynchoidei, que inclui as famílias Gonorynchidae e Kneriidae, e Chanoidei, compreendendo uma única família, Chanidae, com uma única espécie vivente, Chanos chanos, do Indo-Pacífico, além de vários representantes fósseis. Chanidae inclui alguns táxons problemáticos, tais como Dastilbe moraesi, descrito do Aptiano (Cretáceo Inferior) da Formação Areado, bacia Sanfranciscana, Brasil. Esta espécie é atualmente considerada um sinônimo júnior da espécie-tipo de seu gênero, Dastilbe crandalli, da Formação Santana, Aptiano do nordeste do Brasil. A análise de abundante material de D. moraesi revelou várias novas características anatômicas, muitas das quais haviam sido previamente mal interpretadas. Dastilbe moraesi foi incorporado em uma matriz revisada de caracteres da família Chanidae. Nós obtivemos uma única árvore mais parcimoniosa na qual D. moraesi é distinto e filogeneticamente distante de D. crandalli. De acordo com nossa análise, D. moraesi é o grupo-irmão de Chanos, um clado intimamente relacionado a Tharrhias, com todos compondo a tribo Chanini.(AU)
Assuntos
Animais , Filogenia , Peixes/genética , FósseisRESUMO
A morphological revision is presented here on the cohort Otomorpha, a clade currently interpreted as the most primitive among the large supercohort Clupeocephala. Otomorpha is a morphologically heterogeneous group represented by clupei forms , alepocephaliforms, and ostariophysans (gonorynchiforms, cypriniforms, characiforms, siluriforms, and gymnoti forms) that inhabit various marine and freshwater environments worldwide. Otomorphs have a long (ca. 145 Ma) and diverse fossil record. They are the largest fish teleostean clade worldwide, as well as the largest of the Neotropical Region. While molecular studies strongly confirm the monophyly of Otomorpha, most potential morphological synapomorphies of the group become homoplastic largely due to the peculiar morphological character states (either losses or transformations) present in alepocephaliforms. The fusion of haemal arches with their respective vertebral centra anterior to preural centrum 2 stands as an unambiguous synapomorphy of the clade. The ankylosis or fusion of the extrascapular and parietal bones, and silvery areas associated with the gas bladder are also interpreted as synapomorphies, although they are homoplastic characters mainly due to secondary losses or further transformations of the morphological features in the alepocephaliforms.(AU)
Se realizó una revisión morfológica de la cohorte Otomorpha la que se interpreta como el grupo más primitivo dentro de la gran supercohorte Clupeocephala. Otomorpha incluye peces con una gran diversidad corporal la que está representada por clupeiformes, alopocefáliformes y ostariofisos (gonorinchiformes, cipriniformes, caraciformes, siluriformes y gimnotiformes), los que habitan diversos ambientes marinos y de aguas continentales del planeta. Otomorfos son el grupo de peces más grande a nivel mundial y al mismo tiempo, el más grande de la Región Neotropical. Mientras estudios moleculares confirman la monofilia de Otomorfa, la mayoría de las sinapomorfías morfológicas del grupo se interpretan como homoplásticas debido fundamentalmente a la naturaleza peculiar de ciertos caracteres morfológicos (ya sea pérdidas o transformación de estados de caracteres) de alepocefaliformes. La fusión de los arcos hemales con sus respectivos centros vertebrales anterior al centro preural 2 es una sinapomorfía de la cohorte. La anquilosis o fusión de los huesos extrascapular y parietal y la presencia de áreas plateadas asociadas con la vejiga natatoria son interpretados como sinapomorfías, independientemente de que son caracteres homoplásticos debido a pérdidas o transformaciones de tales caracteres en los alepocefáliformes.(AU)
Assuntos
Peixes/anatomia & histologia , Peixes/genética , FósseisRESUMO
BACKGROUND: With 29 Km2, the Fildes Peninsula is the largest ice free area in King George Island and probably in Antarctica. The region is house of six permanent bases including the only airport in the South Shetlands, which led to impacts on its original landscape and vegetation. In recognition for the need to protect natural values, an Antarctic Specially Protected Area (ASPA 125) was established in the region. Focused mostly on protecting the fossils, the ASPA also plays a role in protecting the vegetation but so far, the management plan for the area does not contain a list of moss species present there. RESULTS: We provided an updated study and checklist of mosses present in ASPA 125. A key to species identification and photographs of main morphological features are also available in this paper. Also, six new occurrences are reported for Fildes Peninsula. CONCLUSION: Considering the scarce knowledge about specific local floras in Antarctica associated with highly impacted area, of which only a fraction is protected, it is suggested the necessity to invest in detailed sampling studies, as well as in a better understanding of the local floras interactions in Antarctica.
Assuntos
Monitoramento Ambiental/métodos , Briófitas/classificação , Fósseis , Briófitas/anatomia & histologia , Ilhas , Regiões AntárticasRESUMO
BACKGROUND Paleoparasitology reveals the status of parasitic infections in humans and animals in ancient times based on parasitic particles found in biological remains from archaeological excavations. This line of research emerged in Iran in 2013. OBJECTIVE The identification of parasites from Neolithic times is an attractive subject that shows the oldest origins of parasitic infections in a given geographical region. From an archaeological point of view, this archaeological site is well-known for animal domestication and agriculture in ancient Iran. METHODS In this study, soil deposited on the surface and in the pores of a dog pelvic bone was carefully collected and rehydrated using trisodium phosphate solution. FINDINGS The results showed ascarid and taeniid eggs retrieved from the biological remains of a dog excavated at the East Chia Sabz archaeological site, which dates back to the Neolithic period (8100 BC). MAIN CONCLUSION The current findings clearly illustrate the natural circulation of nematode and cestode parasites among dogs at that time. These ancient helminth eggs can also be used to track the oldest parasitic infections in the Iranian plateau and contribute to the paleoparasitological documentation of the Fertile Crescent.
Assuntos
Animais , Cães , Paleopatologia , Ascaridia/isolamento & purificação , Solo/parasitologia , Taenia/isolamento & purificação , Cães/parasitologia , Fósseis , Óvulo , História Antiga , Irã (Geográfico)RESUMO
ABSTRACT Paleocene ostracods and planktonic foraminifera from the Maria Farinha Formation, Paraíba Basin, are herein presented. Eleven ostracod species were identified in the genera Cytherella Jones, Cytherelloidea Alexander, Eocytheropteron Alexander, Semicytherura Wagner, Paracosta Siddiqui, Buntonia Howe, Soudanella Apostolescu, Leguminocythereis Howe and, probably, Pataviella Liebau. The planktonic foraminifera are represented by the genera Guembelitria Cushman, Parvularugoglobigerina Hofker, Woodringina Loeblich and Tappan, Heterohelix Ehrenberg, Zeauvigerina Finlay, Muricohedbergella Huber and Leckie, and Praemurica Olsson, Hemleben, Berggren and Liu. The ostracods and foraminifera analyzed indicate an inner shelf paleoenvironment for the studied section. Blooms of Guembelitria spp., which indicate either shallow environments or upwelling zones, were also recorded reinforcing previous paleoenvironmental interpretations based on other fossil groups for this basin.
Assuntos
Animais , Crustáceos/classificação , Foraminíferos/classificação , Brasil , Microscopia Eletrônica de Varredura , Crustáceos/ultraestrutura , Foraminíferos/ultraestrutura , Fósseis/ultraestruturaRESUMO
ABSTRACT The non-avian dinosaurs died out at the end of the Cretaceous, ~66 million years ago, after an asteroid impact. The prevailing hypothesis is that the effects of the impact suddenly killed the dinosaurs, but the poor fossil record of latest Cretaceous (Campanian-Maastrichtian) dinosaurs from outside Laurasia (and even more particularly, North America) makes it difficult to test specific extinction scenarios. Over the past few decades, a wealth of new discoveries from the Bauru Group of Brazil has revealed a unique window into the evolution of terminal Cretaceous dinosaurs from the southern continents. We review this record and demonstrate that there was a diversity of dinosaurs, of varying body sizes, diets, and ecological roles, that survived to the very end of the Cretaceous (Maastrichtian: 72-66 million years ago) in Brazil, including a core fauna of titanosaurian sauropods and abelisaurid and carcharodontosaurid theropods, along with a variety of small-to-mid-sized theropods. We argue that this pattern best fits the hypothesis that southern dinosaurs, like their northern counterparts, were still diversifying and occupying prominent roles in their ecosystems before the asteroid suddenly caused their extinction. However, this hypothesis remains to be tested with more refined paleontological and geochronological data, and we give suggestions for future work.
Assuntos
Animais , Dinossauros/classificação , Fósseis/anatomia & histologia , Paleontologia , Brasil , Dinossauros/anatomia & histologia , Extinção BiológicaRESUMO
ABSTRACT Clupeomorphs are found in many assemblages of the northeastern Brazil, whose ages range from the Neocomian to Paleogene. Ten species were described. Among them †Scutatuspinosus itapagipensis, a torpedo-like fish found in shales of the Marfim Formation from Bahia, remains poorly known. At first it was positioned within †Scutatuspinosinae and indicated as closely related to †Diplomystus. Diagnoses for the subfamily and genus were based on certain characters masking relationships. Recently it was placed in †Ellimmichthyiformes, but its systematic position remains controversial. We furnish additional data and restorations together with a parsimony analysis with TNT program, using 60 unordered and unweighted characters from selected species of 13 genera. Our analysis produced 12 trees with 158 steps, a consistency index (CI) of 0.44 and retention index (RI) of 0.52. Low support indices still indicate insufficient data for many taxa and uncertain status for clades. According to the majority rule consensus, †Scutatuspinosus itapagipensis is placed within a "†paraclupeine" group with †Ezkutuberezi carmenae, †Ellimma branneri, †Ellimmichthys longicostatus, and †Paraclupea chetunguensis. Its minimum age and position among †paraclupeids indicate an early history of the group older than it was thought to be, supporting a biogeographical hypothesis based on generalized track from China to northeastern Brazil during the Lower Cretaceous.
Assuntos
Animais , Torpedo/anatomia & histologia , Filogenia , Osso e Ossos/anatomia & histologia , Brasil , Torpedo/classificação , Tamanho Corporal , Filogeografia , Fósseis/anatomia & histologiaRESUMO
ABSTRACT The lagerpetid Dromomeron romeri and the theropod Tawa hallae are two dinosauromorphs from the Norian (Upper Triassic) of the Chinle Formation, situated in New Mexico, USA. However, a recent study suggests the inclusion of the holotype of D. romeri (GR 218) and paratype (GR 155) and referred (GR 235) specimens of T. hallae in an ontogenetic series of a single species. The specimens GR 218 and GR 155 include just an isolated femur, while GR235 includes femora, pelvis and tail. The inclusion of the specimens in an unique ontogenetic series relies on the putative immature condition and plastic deformation of the specimen GR 218. However, as observed here, the disparity between the femora of D. romeri and T. hallae is considerably higher than those expected from the ontogenetic variance in dinosauromorphs. In addition, D. romeri shares an unique suite of traits with Dromomeron gigas, a species known from a mature specimen. Therefore, the high disparity between D. romeri and T. hallae, lack of traits shared solely between the three femora, and a suite of traits shared between D. romeri and D. gigas, precludes the inclusion of the three femora from Hayden Quarry in a growth series of a single taxon.
Assuntos
Animais , Dinossauros/anatomia & histologia , Dinossauros/classificação , Fêmur/anatomia & histologia , Fósseis/anatomia & histologia , Filogenia , Especificidade da Espécie , New MexicoRESUMO
ABSTRACT The origin and dispersion of the first Americans have been extensively investigated from morphological and genetic perspectives, but few studies have focused on their health and lifestyle. The archaeological site of Lapa do Santo, central-eastern Brazil, has exceptionally preserved Early Holocene human skeletons, providing 19 individuals with 327 permanent and 122 deciduous teeth dated to 9,250 to 7,500 years BP. In this study, we test whether the inhabitants of Lapa do Santo had high prevalence of dental caries as previous studies of Lagoa Santa collection have indicated, using individual and tooth as units of analyses. The results show a high prevalence of dental caries in the permanent dentition (5.50%, n=327 teeth; 69.23%, n=13 individuals) compared to other samples of hunter-gatherers worldwide. In addition, dental caries in deciduous teeth start occurring as early as 3 to 4 years old, suggesting an early start to caries. Compared with other samples from Lagoa Santa, Lapa do Santo shows statistically similar prevalence of overall caries but different caries location pattern. We believe that a subsistence adaptation to a tropical environment rich in sources of carbohydrates, such as fruits, is the best explanation for the overall caries prevalence.
Assuntos
Humanos , Masculino , Feminino , Adulto , Pessoa de Meia-Idade , Cárie Dentária/epidemiologia , Fósseis , Arqueologia , Brasil/epidemiologia , Prevalência , Fatores Etários , Distribuição por SexoRESUMO
ABSTRACT We report on the pioneering discovery of Devonian fish remains in the Paraná Basin, which represents the southernmost record of fishes from that period in mainland South America. The material comes from an outcrop at the lower portion of the São Domingos Formation, within Sequence C of the Paraná-Apucarana sub-basin in Tibagi, State of Paraná. Marine invertebrates are abundant in the same strata. The dark colored fish remains were collected in situ and represent natural moulds of partially articulated shark fin rays (radials). No elements such as teeth or prismatic cartilage have been preserved with the fins rays. This can be attributed to the dissolution of calcium-phosphatic minerals at the early stages of fossilization due to diagenetic processes possibly linked to strong negative taphonomic bias. This may have contributed to the fact that fishes remained elusive in the Devonian strata of this basin, despite substantial geological work done in the Paraná State in recent decades. In addition, the scarcity of fish fossils may be explained by the fact that the Devonian rock deposits in this basin originated in a vertebrate impoverished, cold marine environment of the Malvinokaffric Realm, as previously suspected.
Assuntos
Animais , Tubarões/anatomia & histologia , Sedimentos Geológicos , Nadadeiras de Animais/anatomia & histologia , Fósseis/anatomia & histologia , Paleontologia , Brasil , Mapeamento GeográficoRESUMO
ABSTRACT Cranial crests show considerable variation within the Pterosauria, a group of flying reptiles that developed powered flight. This includes the Wukongopteridae, a clade of non-pterodactyloids, where the presence or absence of such head structures, allied with variation in the pelvic canal, have been regarded as evidence for sexual dimorphism. Here we discuss the cranial crest variation within wukongopterids and briefly report on a new specimen (IVPP V 17957). We also show that there is no significant variation in the anatomy of the pelvis of crested and crestless specimens. We further revisit the discussion regarding the function of cranial structures in pterosaurs and argue that they cannot be dismissed a priori as a valuable tool for species recognition.
Assuntos
Animais , Répteis/anatomia & histologia , Crânio/anatomia & histologia , Fósseis/anatomia & histologia , Maxila/anatomia & histologia , Valores de Referência , Répteis/classificação , China , Fatores Sexuais , Voo AnimalRESUMO
ABSTRACT Recent fossil material found in Dinaledi Chamber, South Africa, was initially described as a new species of genus Homo, namely Homo naledi. The original study of this new material has pointed to a close proximity with Homo erectus. More recent investigations have, to some extent, confirmed this assignment. Here we present a phenetic analysis based on dentocranial metric variables through Principal Components Analysis and Cluster Analysis based on these fossils and other Plio-Pleistocene hominins. Our results concur that the Dinaledi fossil hominins pertain to genus Homo. However, in our case, their nearest neighbors are Homo habilis and Australopithecus sediba. We suggest that Homo naledi is in fact a South African version of Homo habilis, and not a new species. This can also be applied to Australopithecus sediba.
Assuntos
Animais , Crânio/anatomia & histologia , Hominidae/anatomia & histologia , Hominidae/genética , Fósseis/anatomia & histologia , África do Sul , Evolução BiológicaRESUMO
ABSTRACT A new azhdarchoid pterosaur from the Upper Cretaceous of Patagonia is described. The material consists of an incomplete edentulous lower jaw that was collected from the upper portion of the Portezuelo Formation (Turonian-Early Coniacian) at the Futalognko site, northwest of Neuquén city, Argentina. The overall morphology of Argentinadraco barrealensis gen. et sp. nov. indicates that it belongs to the Azhdarchoidea and probable represents an azhdarchid species. The occlusal surface of the anterior portion is laterally compressed and shows blunt lateral margins with a medial sulcus that are followed by two well-developed mandibular ridges, which in turn are bordered laterally by a sulcus. The posterior end of the symphysis is deeper than in any other azhdarchoid. This unique construction of the lower jaw suggests the existence of an elaborate interlocking mechanism with the upper jaw. Furthermore, although speculative, it is advocated here that Argentinadraco barrealensis might have used the lower jaw to obtain its prey by cutting or ploughing through unconsolidated sediment in shallow waters, a feeding behavior not previously proposed for pterosaurs.
Assuntos
Animais , Dinossauros/anatomia & histologia , Fósseis , Mandíbula/anatomia & histologia , Filogenia , Argentina , Dinossauros/classificaçãoRESUMO
Esta entrevista a Pascale Molinier se realizó en Buenos Aires, en octubre del 2014, en el contexto de las actividades organizadas por el Programa de Salud y Trabajo del Departamento de Salud Comunitaria de la Universidad Nacional de Lanús, Argentina. La entrevista aborda la relación entre trabajo y subjetivación, examinando el rol del trabajo tanto en la estructuración psíquica, como en la dinámica placer-sufrimiento y en la construcción de las identidades de género. Se examina el trabajo del cuidado "feminizado" -enfermeras, cuidadoras, mucamas, etc.- desde la perspectiva del "care", analizando su invisibilidad intrínseca y la imposibilidad de ser cuantificado y medido, lo que constituye un importante desafío para las lógicas de gestión y de management.
This interview with Pascale Molinier was carried out in Buenos Aires in October 2014, in the context of activities organized by the Health and Work Program at the Department of Community Health of the Universidad Nacional de Lanús, Argentina. The interview explores the relationship between work and subjectivation, examining the role of work in the structuring of the psyche, in the dynamics of pleasure and suffering, and in the construction of gender identities. "Feminized" work - that of nurses, caregivers and maids, among others - is examined from a "care" perspective, analyzing its intrinsic invisibility and impossibility of being quantified and measured, which makes it a challenge to management-based logic.