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1.
Comparison of the ultrastructure of the hyaline tissue of conodont elements and the enamel of vertebrates provides little support for a close phylogenetic relationship between conodonts and vertebrates. Transmission and scanning electron microscopy shows that the mineralised component of the hyaline tissue of Panderodus and of Cordylodus elements consists of large, flat, oblong crystals, arranged in layers that run parallel to the long axis of the conodont. Enamel in the dentition of a living vertebrate, the lungfish Neoceratodus forsteri, has crystals of calcium hydroxyapatite, arranged in layers, and extending in groups from the dentine-enamel junction; the crystals are slender, elongate spicules perpendicular to the surface of the tooth plate. Similar crystal arrangements to those of lungfish are found in other vertebrates, but none resembles the organisation of the hyaline tissue of conodont elements. The crystals of hydroxyapatite in conodont hyaline tissue are exceptionally large, perpendicular or parallel to the surface of the element, with no trace of prisms, unlike the protoprismatic radial crystallite enamel of fish teeth and scales, or the highly organised prismatic enamel of mammals.  相似文献   

2.
Environmentally-related wear conditions and pathologies affecting the dentition of fossil lungfish from freshwater deposits in Australia have been analysed and compared with similar changes in the dentition of the living Australian lungfish, Neoceratodus forsten. Fossil populations from the Namba, Etadunna, Wipajiri and Katipiri formations in central Australia, and the Carl Creek Limestone and the Camfield beds in northern Australia were assessed.

Tooth plates from populations of living lungfish from the Brisbane River and Enoggera Reservoir in southeast Queensland were analysed for comparison. Tooth plates were measured to determine the numbers of different age groups in each population. They were assessed for abrasion, attrition, spur and step wear, erosion and caries, and for trauma and pathological conditions such as malocclusion, hyperplasia, abscesses, osteopenia and parasitic damage. AH of these conditions are related to the environment where the fish lived, are found in living members of the group, and can be compared directly with those of fossil relatives.

The results suggest that some of the fossil populations were at risk before climatic changes late in the Cainozoic destroyed their habitats. Some fossil lungfish populations, such as those of the Wipajiri Formation, exhibit active spawning and recruitment, good growth rates and a low incidence of disease and environmentally related damage to the tooth plates. Others, like those of the Katipiri and Namba Formations, include no young, and the adult fish were ageing and show environmentally-related damage to the dentition. Etadunna lungfish had active recruitment, but the tooth plates show a high incidence of attrition and caries. Riversleigh lungfish were actively spawning but did not grow large. Tooth plates from this latter deposit have a high incidence of pathological conditions. Fish from the Camfield Beds, where food was severely limiting, had little serious pathology but high levels of caries. Pathologies among living lungfish are common, but fossil fish were comparatively healthy, with few serious dental problems. Information from studies of fossil lungfish confirms that conservation of the few living species of lungfish depends on the maintenance of clean environments that provide adequate supplies of food and suitable sites for spawning and for the growth of young fish.  相似文献   

3.
Kemp, A., December 2017. Adaptations to life in freshwater for Mioceratodus gregoryi, a lungfish from Redbank Plains, an Eocene locality in southeast Queensland, Australia. Alcheringa 42, 306–311. ISSN 0311-5518

Few Cenozoic lungfish fossils consist of articulated, associated bones and tooth plates. Mioceratodus gregoryi from the Paleogene (Eocene) deposit of the Redbank Plains Formation in southeast Queensland is unusual in this respect because the fossil includes tooth plates and elements of the skull. An analysis of the material and reconstruction of the skull and associated skeletal material provides new insights into the fish and its environment. The fish has a mandible with a wide separation between the lower tooth-bearing bones, and a strong ceratohyal bone. This suggests that, like the extant Australian lungfish, Neoceratodus forsteri, the fossil fish had a moveable basihyal that could be inserted between the prearticular bones to seal the oral cavity. This would have allowed the fish to draw food, air and water into the mouth, and dig holes by sucking mud into the oral cavity and blowing it out again, all useful attributes for a fish that lived in a shallow freshwater lake. The living Australian lungfish has similar structures in the mandible and hyoid apparatus, and performs comparable actions. The occipital ribs, also preserved in the Redbank Plains fossil, are embedded in hypaxial muscles and not moveable. It is unlikely that these ribs have any influence on the suctorial process in these two species.

Anne Kemp [] Environmental Futures Centre, Griffith University, 170 Kessels Road, Nathan, Brisbane, Queensland 4111, Australia.  相似文献   


4.
A new species of Tertiary lungfish, Neoceratodus djelleh, is based on two well-preserved upper tooth plates, from Duaringa, Queensland. Both specimens are elongate and have curved mediolingual faces and poorly defined ridges, with little trace of crests or clefts on the flat occlusal surface. Each ridge is supported by a bony base which extends into a peak. Enameloid is present, showing growth lines without associated cusps on the labial surface. Another specimen from Billeroo Creek, South Australia, is referred to Neoceratodus cf. N. djelleh.  相似文献   

5.
A new genus and species of lungfish with toothplates, Adelargo schultzei, is described from the Hunter Siltstone (Devonian, Late Famennian) near Grenfell, New South Wales. Materials assigned to Adelargo schultzei gen. et sp. nov., include a portion of the left side of the skull comprising B, I (postparietal) and J (parietal) bones, pterygoid and prearticular toothplates, a parasphenoid with a long posterior stalk, vertebrae, ribs, anal fin supports and scales. Toothplates are similar to Dipterus, although morphology of the skull, parasphenoid and postcranial elements is more derived. Biogeographic relationships of the Grenfell fauna were based on the presence of the antiarch group Sinolepidoidei, also present on Asian terranes during the Late Devonian. A small number of lungfish scales have been described from Asian sinolepid localities of this age, but differ from those of Adelargo schultzei, and other faunal similarities between these areas appear limited. Paucity of eastern Australian Devonian taxa on the North and South China blocks implies that strong biogeographic relationships between eastern Australia and Euramerican localities during the Late Devonian were not the result of Asian migration routes, but the closer proximity of these areas.  相似文献   

6.
Abstract

The second (1988–1989) and third (1990) seasons of excavation and survey at the 2nd-millennium B.C. urban site of Tell Abu Duwari (ancient Mashkan-shapir), Iraq, have yielded important new evidence on the organization of ancient Mesopotamian cities. A combination of aerial and surface survey has provided a broad overview of the differing functional areas, and of the role played by canals, streets, and walls to divide the city. Excavations consisted of both small soundings and one broad horizontal exposure. The soundings were designed to test the relationship between surface traces and the remains beneath the ground, and the larger excavation generated an artifactual, faunal, and floral inventory from an administrative district which will be compared with similar collections excavated in other parts of the city in future seasons.  相似文献   

7.
The excavation of a number of Early Bronze Age sites in the Aegean has recovered perforated ceramic fragments. Archaeometallurgical analysis of slag adhering to these fragments indicates that they are the remains of copper‐smelting furnaces. Despite compelling analytical data supporting this identification, no attempt has been made, thus far, to establish how these unusual furnaces may have operated. The use of perforations is poorly understood and can be considered a counter‐intuitive solution for the reduction of oxidic copper ores. The experiments reported here explore the possible technological choices made by the ancient metalworkers of Chrysokamino to ensure the effective reduction of copper minerals. Temperature data and slag samples were obtained to ascertain the technical performance of the furnace structure with, and without, perforations. Possible reasons are given for the use of a perforated design, and the implications of such technological choices are considered.  相似文献   

8.
9.
Infective lesions of bone in leprosy are of two types. In the rhinomaxillary syndrome, superficial infective changes in the bones of the maxilla are due to the presence of Mycobacterium leprae. Lytic foci in the medulla or the outer cortical surface may be due to Mycobacterium leprae at the site as granulomatous lesions. The most frequent infective bone changes in leprosy are, however, sequelae of regional anaesthesia and soft tissue ulceration. The bone lesions are due to pyogenic bacteria and the nature of these infective lesions is similar to that in non-leprous conditions. The pyogenic lesions in leprosy are restricted to the bones of the hands, feet and lower legs.  相似文献   

10.
An example of ante‐mortem cranial perforations in the skull of a European wisent (Bison bonasus) from Armenia is presented. The implications for reinterpreting the possible causes of this condition in ancient domestic cattle (outlined in a previous paper) are briefly discussed. Copyright © 1999 John Wiley & Sons, Ltd.  相似文献   

11.
Qiao, T. & Zhu, M., 13.4.2015. A new Early Devonian lungfish from Guangxi, China, and its palaeogeographic significance. Alcheringa 39, xxx–xxx. ISSN 0311-5518

A new species of Cathlorhynchus (Dipnorhynchidae, Dipnoi) is described based on a mandible from the marine Yukiang Formation (early Emsian, Early Devonian) of Guangxi, southern China. It resembles the type species of Cathlorhynchus, C. trismodipterus, in that the anterior portion of the internal median septum terminates abruptly and does not contact dermal bones ventrally. The new Chinese form, together with Erikia jarviki from the Emsian of Yunnan, southern China, confirms the occurrence of the Dipnorhynchus lineage outside Australia. Coupled with the distribution of Westollrhynchus, Ichnomylax and Jessenia, we propose that the Dipnorhynchus lineage was dispersed widely during the early Emsian, corroborating the trans-Panthalassic distribution of early sarcopterygians.

Tuo Qiao [] and Min Zhu [], Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, PO Box 643, Beijing 100044, PR China.  相似文献   

12.
Whale bone was used by Māori throughout New Zealand prehistory as an industrial resource for the manufacture of a range of artefacts. However, the selection of bone and the methods used to process it are poorly understood. This paper details the analysis of a southern right whale (Eubalaena australis) bone working floor that was excavated from a fifteenth‐century coastal fishing camp at Kahukura, on the southeast coast of New Zealand. The whale bone working floor assemblage, comprising a large quantity of debitage fragments, was used to reconstruct reduction methods and to determine the products being made at the site. Rib bones were the main element being worked, and were reduced longitudinally using a chipping technique. The intensive bone working assemblage at Kahukura represents the by‐products from primary processing. This stage focused on reducing the bones into workable portions so that they could be easily transported to another location, where they were likely further reduced into artefacts. Copyright © 2015 John Wiley & Sons, Ltd.  相似文献   

13.
The Homo erectus cranium found at Gongwangling, near Lantian, China, and dated to ≈1.2 ma BP has been analyzed with respect to its evolutionary position. However, the remains, and especially the internal and external surfaces of the neurocranium, present a series of marked abnormalities. These irregularities consist principally of a pronounced cresting and scalloping of the external surface of the frontal bone and anterior parietal bone and a similar alteration of the internal surface of a mid transverse section of parietal bone that connects with the fossilization break across the anterior parietal bone. There is no obvious exposure of diploë on the surfaces. Woo (Vertebrata PalAsiatica 10:1–16, 1966) briefly ascribed these abnormalities to postmortem erosion, and Caspari (Am. J. Phys. Anthropol. 102:565–568, 1997) has attributed the irregularities of the right supraorbital torus to antemortem trauma. It has been suggested that the pervasive neurocranial alterations might be pathological. Computerized tomography (CT) analysis of the frontal and parietal bones revealed complete radiopacity of the anterior half of the fossil; it is possible to distinguish large frontal sinuses but other details, including in the area of the purported traumatic lesion, are invisible. However, in the posterior frontal bone and preserved portions of the parietal bone the diploë and tables are discernible. Externally on the frontoparietal section and internally on the transverse parietal piece, there are clear erosional lacunae in the associated table, combined with a thin layer of matrix which obscures the eroded diploë externally. The superficial irregularities are therefore due to postmortem taphonomic alterations of the bone and not pathological processes. In addition, it is apparent that the two pieces were embedded in the matrix at different angles, resulting in their differential erosion.  相似文献   

14.
Cavanosteus, a new genus of homostiid arthrodire, with C. australis (McCoy) as type species, is erected for new material from the Early Devonian (Emsian) of the Burrinjuck area, NSW. This new material compares closely with the holotype from Buchan, Victoria, identified as the central plates from the skull; it includes lower jawbones (infragnathals) lacking denticulation also closely similar to those of Homostius from the Middle Devonian of the Baltic Province and Scotland. The only bone from the dermal trunk armour referred to the new genus is an anterior dorsolateral plate. Relationships of other large Early Devonian arthrodires assigned to the family Homostiidae are discussed. Cavanosteus gen. nov. is probably the closest relative to the type genus known from the Early Devonian.  相似文献   

15.
Microradiographs of femur midshaft thin sections were examined in a mortuary sample (n = 119) from the lower Illinois Valley to evaluate variation in histological preservation. Twenty-three per cent of the sections displayed varying degrees of microfocal destruction due to fungal/and or bacterial invasion. Histological preservation did not vary with whole bone preservation. The activity of micro-organisms resulted in both extensive resorption of tissue and redeposition of mineral on bone surfaces. Based on the observed patterns of invasive activity, it is suggested that initial invasion and spread of organisms depend on several intrinsic properties of the tissue, including the degree of mineralization and the availability of vascular spaces to provide surfaces for tunneling. The findings indicate that histological evaluation of diagenesis should be a necessary prerequisite to dietary reconstructions which utilize invasive and non-invasive methods of analysis  相似文献   

16.
A complex lesion, on a skull of a female cave bear (Ursus spelaeus) associated with perforations of the frontal sinus is described. Paleopathological analysis suggests that the lesion is attributable to complex cranial trauma, probably complicated by an infection which appears to have occurred following a fight, most likely with another bear or, possibly, a cave lion (Panthera leo spelaea); at least one of the perforations observed on the skull may have been produced by the canine of a large carnivore. This hypothesis is supported by the frequent intraspecific aggressiveness documented in modern bears, and by evidence suggesting interspecific fights between cave bears and cave lions. The case is discussed in the light of other evidence reported in the literature. © 1998 John Wiley & Sons, Ltd.  相似文献   

17.
An example of ante‐mortem occipital perforations in the cranium of a probable aurochs (Bos primigenius) cow from a late Neolithic archaeological site at Letchworth, Hertfordshire is presented. This is the second reported occurrence thus far of cranial perforations in a wild bovid and lends support to a congenital cause of the condition in archaeological domestic cattle skulls. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献   

18.
Stable nitrogen isotopes have been used to reconstruct infant feeding practices as nursing infants have elevated δ15N ratios compared with their mothers. However, infancy is also a time of rapid growth, which may alter nitrogen isotope diet‐to‐tissue spacing. Several studies have documented a decrease in δ15N during growth in tissues with relatively fast accretion rates. This study investigates the effect that the growth of long bones, via collagen accretion, has on δ15N ratios. Long bones from individuals aged seven to nineteen years were obtained from a protohistoric ossuary in Ontario, Canada. Analysis of juveniles and adolescents permitted the examination of growth in a group who were not also nursing. It is concluded that a nitrogen isotope growth effect is not detectable in bone collagen from juveniles and adolescents, because: (1) δ15N ratios are not significantly different among the epiphyses, metaphyses and diaphysis of a growing long bone; (2) δ15N ratios are not significantly different between faster‐growing versus slower‐growing metaphyses; and (3) δ15N ratios are not significantly different between bones (or areas of a bone) that are still undergoing growth, versus bones that have ceased growing. The relatively slow speed of collagen accretion may explain why a growth effect is not manifested. Ultimately this research lends support to the use of nitrogen isotopes from bone collagen for infant feeding reconstructions. Copyright © 2009 John Wiley & Sons, Ltd.  相似文献   

19.
20.
A large network of exceptionally well-engineered prehistoric canals has been discovered near Safford, Arizona. Within an area of roughly 450 km2, 12 distinct canal systems, comprised of 41 canals, have been identified originating in the bajada of the Pinaleño Mountains. Conveying water from runoff and springs, the longest canal is about 13?km, and the total length of all systems exceeds 125?km. While a few canals may date to ca. a.d. 1100, the vast majority date to between ca. a.d. 1250 and 1450 and appear to be constructed by migrants from northeastern Arizona. These features represent the second largest network of canal systems in the American Southwest, and, while smaller in size and total length than the canal systems of the Phoenix Basin, they exhibit engineering sophistication not found in those systems. These canals have expanded the knowledge of prehistoric water management engineering and agricultural intensification in the American Southwest.  相似文献   

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