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1.
James I. Kirkland Luis Alcalá Mark A. Loewen Eduardo Espílez Luis Mampel Jelle P. Wiersma 《PloS one》2013,8(12)
Nodosaurids are poorly known from the Lower Cretaceous of Europe. Two associated ankylosaur skeletons excavated from the lower Albian carbonaceous member of the Escucha Formation near Ariño in northeastern Teruel, Spain reveal nearly all the diagnostic recognized character that define nodosaurid ankylosaurs. These new specimens comprise a new genus and species of nodosaurid ankylosaur and represent the single most complete taxon of ankylosaur from the Cretaceous of Europe. These two specimens were examined and compared to all other known ankylosaurs. Comparisons of these specimens document that Europelta carbonensis n. gen., n. sp. is a nodosaur and is the sister taxon to the Late Cretaceous nodosaurids Anoplosaurus, Hungarosaurus, and Struthiosaurus, defining a monophyletic clade of European nodosaurids– the Struthiosaurinae. 相似文献
2.
Peter M. Galton 《Geobios》1980,13(3):451-457
The holotype of the nodosaurid ankylosaur Dracopelta zbyszewskii n. gen. and n. sp. is described from the Kimmeridgian(Upper Jurassic) of Ribomar on the west coast of Portugal. This is the first Upper Jurassic ankylosaur to be described that is represented by articulated bones. The specimen consists of a partial rib cage with thirteen dorsal vertebrae and five different types of dermal armor, two of wich show a partial overlap between adjacent plates. 相似文献
3.
Ankylosaurian remains from the Transylvanian Basin, Romania, are extremely rare. More than 100 years after the discovery of the first and only better-known assemblage, namely the type material of Struthiosaurus transylvanicus, new ankylosaurian material has been discovered in the Maastrichtian of the Ha?eg Basin, as well as at another locality (Vurp?r), in the Transylvanian Basin, that is described here. The material consists of one tooth in a small jaw fragment (from the Ha?eg Basin) and at least two accummulations of associated, as well as several isolated, postcranial elements (from Vurp?r). No diagnostic elements are preserved that would overlap with the type of S. transylvanicus, so we cannot assign any of the new specimens to this species. The tooth shows marked differences compared to those of other anklyosaurs including S. austriacus and Hungarosaurus in having only six, more or less equally sized, apically pointed cusps separated by deep grooves. The postcranial material from Vurp?r represents at least three different individuals. The humerus is the most diagnostic element among the postcranial remains being most similar both in size and morphology to humeri referred to as Struthiosaurus from different European localities, thus here we refer the humerus and probably associated elements preserved in one assemblage to as cf. Struthiosaurus sp.; the remaining specimens from Vurp?r are retained as Nodosauridae indet. Histological studies have confirmed the adult nature of all sampled bones in the Vurp?r ankylosaur material suggesting that these fully grown animals were of similar size to Struthiosaurus, a small-bodied nodosaurid the ontogenetic status of which, however, has never been investigated histologically. The obviously diminished body size of the Transylvanian ankylosaurs compared to other members of the clade could be explained by insular dwarfism using the same histology-based argument as presented for Magyarosaurus. 相似文献
4.
Here we describe a complete skull and partial skeleton of a large cercopithecoid monkey (KNM-TH 46700) discovered in the Chemeron Formation of the Tugen Hills at BPRP Site #152 (2.63 Ma). Associated with the skeleton was a mandible of an infant cercopithecoid (KNM-TH 48364), also described here. KNM-TH 46700 represents an aged adult female of Theropithecus brumpti, a successful Pliocene papionin taxon better known from the Omo Shungura Formation in Ethiopia and sites east and west of Lake Turkana, Kenya. While the morphology of male T. brumpti is well-documented, including a partial skeleton with both cranial and postcranial material, the female T. brumpti morphotype is not well-known. This skeleton represents some of the first associated evidence of cranial and postcranial female T. brumpti remains. In addition to the complete skull, postcranial material includes elements of the axial skeleton and lower limb. While aspects of the skeleton conform to those of specimens previously assigned to T. brumpti, other features on the femur and tibia appear to differ from those previously described for this species. It is unclear whether these differences represent general variation within the T. brumpti population, variation between the sexes in T. brumpti, or the incorrect assignment of previous isolated hindlimb specimens. In total, the observable morphological features of the hindlimb suggest that KNM-TH 46700 was a terrestrial quadruped similar to modern savannah baboons (Papio). From the available evidence, it is difficult to assess whether or not KNM-TH 46700 frequently engaged in the specialized squatting and shuffling behavior observed in extant geladas (Theropithecus gelada). 相似文献
5.
BEN THUY 《Palaeontology》2011,54(1):215-233
Abstract: Two new genera and species of ophiuroid, Inexpectacantha acrobatica new gen. et sp. and Eirenura papillata new gen et sp., are described on the basis of 39 articulated specimens and several hundreds of arm fragments and isolated skeletal parts. The material was extracted from a lumachellic bed in a late early Pliensbachian succession of argillites at Sedan, French Ardennes. The material is unusually well preserved with even finest structures of the skeleton discernible. Despite the exceptionally detailed morphological data extractable from the material, the higher taxonomic classification in the system of recent ophiuroids could only be tentatively attained. Inexpectacantha acrobatica seems best placed within the Ophioplinthacinae inside the Ophiacanthidae whereas Eirenura papillata shares greatest similarities with the Ophioleucinae. The occurrence of articulated specimens of different sizes, with some of the most delicate skeletal structures left intact, together with completely disarticulated skeletons of the same species suggests that the ophiuroids were preserved as autochthonous faunule among an in situ population of Modiolus sp. during a period of more favourable bottom water conditions in an otherwise largely hostile near‐shore soft‐bottom environment. Based on its small size, the highly flexible arms and the presence of well‐developed hooks on distal arm segments, an epizoic way of life is inferred for I. acrobatica while E. papillata, with its rigid arm structure and the conspicuously large tentacle pores, is interpreted as mostly deposit‐feeding bottom surface dweller. 相似文献
6.
Fully adult partial skeletons attributed to Australopithecus afarensis (AL 288-1, “Lucy”) and to Homo habilis (OH 62, “Lucy's child”), respectively, both include remains from upper and lower limbs. Relationships between various limb bone dimensions of these skeletons are compared to those of modern African apes and humans. Surprisingly, it emerges that OH 62 displays closer similarities to African apes than does AL 288-1. Yet A. afarensis, whose skeleton is dated more than 1 million years earlier, is commonly supposed to be the ancestor of Homo habilis. If OH 62, classified as Homo habilis by its discoverers, does indeed represent a stage intermediate between A. afarensis and later Homo, a revised interpretation of the course of human evolution would be necessary. 相似文献
7.
Walter W. Ferguson 《Primates; journal of primatology》1987,28(3):377-391
The skull ofHomo antiquus
Ferguson, 1984, represented by cranial remains of a fossilized skeleton, A.L. 288-1, from the Plio/Pleistocene of Hadar in Ethiopia,
is reconstructed and the procedure described. Re-evaluation of the skull shows that it is apparently the smallest, normal,
unequivocal hominid skull known; and that its cranial morphology is not Australopithecine, but Hominine. 相似文献
8.
Cynthiacetus peruvianus nov. sp. is a new basilosaurid species, from Late Eocene to Early Oligocene Otuma Formation of Peru. It is the first described archaeocete in South-America and is represented by a sub-complete skeleton. C. peruvianus differs from C. maxwelli (middle to Late Eocene of Egypt and United States) principally in having one cuspid less on both mesial and distal sides of p3 and p4. Cynthiacetus is among the largest basilosaurids. Its more characteristic features are located on its postcranial skeleton: large vertebrarterial foramina on cervical vertebrae and absence of ventral expansion of the transverse process on C3-C5. Besides, C. peruvianus presents the greatest number of thoracic vertebrae (20) and ribs observed in Cetacea and the first thoracics have an almost vertical neural spine. A preliminary parsimony analysis establishes the monophyly of the Basilosauridae on the basis of three unambiguous cranial synapomorphies. However, within the Basilosauridae, the most diagnostic characters are observed on the postcranial skeleton. 相似文献
9.
Malena Lorente Javier N. Gelfo Guillermo M. Lpez 《Lethaia: An International Journal of Palaeontology and Stratigraphy》2019,52(2):244-259
Here, we describe the first skeletal remains of Notostylops recovered from middle Eocene levels of the Sarmiento Formation, Patagonia, Argentina. The remains include two teeth of Notostylops murinus, the axis, vertebral bodies, a rib, a left humerus, both radii, two metapodials, two phalanges, the pelvis, a right femur, a right calcaneus and several broken bones. Radial bones are not fused to ulnas, and are shorter than the humerus, very generalized, with an oval head, a marked neck and a radial tubercle. The humerus and the femur show pronounced insertion structures. Our analysis suggests that the appendicular skeleton of Notostylops is too generalized and shares several features with that of terrestrial rodents as Sciuridae. Unlike the appendicular skeletons of cursorial or saltatorial mammals, which restrict mobility, the skeleton of Notostylops indicates the ability to make a variety of different movements, as would be expected for terrestrial, fossorial or arboreal mammals. This skeleton gives new information about the locomotor behaviour of notoungulates, particularly in their basal forms. The results will also allow the identification of isolated notoungulate bones and raise questions about the previous taxonomic assignment of postcrania to Pleurostylodon. 相似文献
10.
ABSTRACT. Extraction of the ciliated protozoon Tetrahymena with nonionic detergents produces a surface-related cytoskeleton that consists of a basic lamina of whole-cell dimensions together with associated microtubule and microfilament systems, including all ciliary basal bodies. The organization of the isolated cytoskeleton has been studied using scanning electron microscopy, and several new features are described in the oral region. Here the ciliary basal bodies are arranged in a very stable and highly complex pattern. This pattern was found to be identical in the four species of Tetrahymena we examined. In addition, various microtubular bundles and two separate systems of filaments were observed in scanning electron micrographs of isolated oral skeletons. The appearance of the deep fiber bundle in preparations of this type suggests that it arises, at least in part, as an extension of the ribbed wall microtubules. On the basis of its distribution within the oral skeleton, one of the filament systems described is suggested to be a contractile system responsible for pinching off food vacuoles. 相似文献
11.
Jobst Wendt 《Palaeontology》2018,61(4):575-595
The first tunicates with a calcareous exoskeleton are reported from Late Triassic buildup‐slope deposits of the Dolomites. Although examples of this group have been known since the early 1900s from the middle–upper Permian of eastern Asia and Sicily as Khmeria, they were erroneously attributed to rugose corals. These early representatives are small, double‐valved, conical skeletons, which evolved into multi‐plated capsules with up to 35 opercula. The latter are joined along zigzag margins, which in life could probably be opened for the atrial and branchial siphons. The construction and shape of these skeletons distinguish them from plants or other invertebrate phyla, while they share several similarities with living tunicates, specifically to sessile ascidians. Apart from a soft‐bodied genus from the lower Cambrian of China, ascidians are known only from isolated spicules, which occur sporadically from the Lower Jurassic onwards. The calcareous skeleton of these Late Triassic tunicates consists of aragonitic fibres, which form spherulitic or clinogonal microstructures. It seems that the stellate aragonitic spicules of Jurassic to Recent ascidians are a vestige of Permian–Triassic ancestors, which after the Carnian lost the ability to construct compound solid skeletons but partly still retain a soft double‐valved or multi‐operculate cellulose‐like tunic. The following taxa are described as new: Order Khmeriamorpha with the genera Khmeria Mansuy and Zardinisoma gen. nov., and the following species: Khmeria stolonifera (late Permian), Khmeria minima (Late Triassic), Zardinisoma japonicum (late Permian), Z. cassianum, Z. pyriforme, Z. polyplacophorum and Z. pauciplacophorum (all Late Triassic). 相似文献
12.
13.
Chitin-based scaffolds are an integral part of the skeleton of the marine demosponge Ianthella basta
E. Brunner H. Ehrlich P. Schupp R. Hedrich S. Hunoldt M. Kammer S. Machill S. Paasch V.V. Bazhenov D.V. Kurek T. Arnold S. Brockmann M. Ruhnow R. Born 《Journal of structural biology》2009,168(3):539-547
The skeletons of demosponges, such as Ianthella basta, are known to be a composite material containing organic constituents. Here, we show that a filigree chitin-based scaffold is an integral component of the I. basta skeleton. These chitin-based scaffolds can be isolated from the sponge skeletons using an isolation and purification technique based on treatment with alkaline solutions. Solid-state 13C NMR, Raman, and FT-IR spectroscopies, as well as chitinase digestion, reveal that the isolated material indeed consists of chitin. The morphology of the scaffolds has been determined by light and electron microscopy. It consists of cross-linked chitin fibers approximately 40–100 nm in diameter forming a micro-structured network. The overall shape of this network closely resembles the shape of the integer sponge skeleton. Solid-state 13C NMR spectroscopy was used to characterize the sponge skeleton on a molecular level. The 13C NMR signals of the chitin-based scaffolds are relatively broad, indicating a high amount of disordered chitin, possibly in the form of surface-exposed molecules. X-ray diffraction confirms that the scaffolds isolated from I. basta consist of partially disordered and loosely packed chitin with large surfaces. The spectroscopic signature of these chitin-based scaffolds is closer to that of α-chitin than β-chitin. 相似文献
14.
Nehir Unver 《Phytochemistry Reviews》2007,6(1):125-135
The Amaryllidaceae alkaloids, represent a group of isoquinoline alkaloids, which are produced almost solely by members of
the Amaryllidaceae family. The alkaloids of this family have attracted considerable amount of interest due to some important
pharmacological activities they were shown to possess. In the last decade, our phytochemical studies on four Galanthus (Amaryllidaceae) species of Turkish origin have yielded quite a number of new alkaloids with diverse structures. Among these
alkaloids, gracilines and plicamines constitute two new subgroups for the Amaryllidaceae alkaloids. The gracilines contain
an incorporated 10b,4a-ethanoiminodibenzo[b,d]pyrane skeleton. The plicamines are dinitrogenous compounds, where the oxygen atom in position 7 of a tazettine skeleton
is replaced by a nitrogen atom substituted by a pendant 4-hydroxyphenethyl moiety. One of the new alkaloids, galanthindole,
which possesses a nonfused indole ring, unlike the already known subgroups of Amaryllidaceae alkaloids, may be considered
as the prototype of a third new subgroup of the Amaryllidaceae alkaloids. Additionally, two known isoquinoline alkaloids which
do not possess one of the established skeletons of the Amaryllidaceae alkaloids, namely ( − )-capnoidine and (+)-bulbocapnine,
have been isolated from a Turkish Galanthus species. Totally, 21 new, 20 known alkaloids and 2 known lignans have been characterized. In this review, the isolation and
structure elucidation of these compounds with interesting chemical structures are described. 相似文献
15.
The gravimetric density of humeri, radii, femora and tibiae from a series of 274 male and female skeletons of rhesus monkeys, Macaca mulatta, was determined for fetal, young and adult periods. The ages of 171 of the animals were known: they ranged from 57 days of gestation to 13.6 years; the ages of an additional 103 skeletons were estimated. The mean density of the fetal bones was found to increase linearly with age and was higher for males than females, and higher for the superior than for the inferior limb bones. During the young period the pattern of increase in density can be represented by a power-type curve, and the density is significantly higher in females than in males and in superior than in inferior limb bones. The densities of the long limb bones of the adult skeletons show a slight, but not significant, negative trend with increasing age. In this age group the mean densities are higher for males than females and higher for the superior than for the inferior limb bones. The percentage ash weight was determined for the total skeleton and for 21 subdivisions of 23 postnatal skeletons with estimated ages. The skull and long limb bones were found to have higher mean percentage ash weights than the vertebral segments and the sternum. Both the density and the percentage ash weight of the Macaca mulatta skeletons examined exceed those found in our earlier studies of the human skeleton. 相似文献
16.
Fabiano A. Fernandes Gislene L. Gonçalves Simone S. F. Ximenes Thales R. O. de Freitas 《Genetica》2009,136(3):449-459
The rodent genus Ctenomys (tuco-tucos) comprises more than 60 described species, and shows extraordinary inter- and intraspecific karyotypic variation.
The most widely distributed species of Ctenomys in Brazil is C. torquatus. Although several cytogenetic studies have been done, the karyotypic variability of this species is still poorly known. In
this paper we report two new diploid numbers for C. torquatus: 2n = 40 and 2n = 42, both showing AN = 72. The new distribution limits of C. torquatus here reported include localities in the southern, central and western parts of Rio Grande do Sul (RS) State in southern Brazil.
The phylogenetic relationship between C. torquatus from Alegrete, RS, and Ctenomys sp. from Corrientes, Argentina, is described by means of mtDNA cytochrome b analysis. Although both entities share similar karyotypes and sperm morphology, these two species are not phylogenetically
close. 相似文献
17.
Abstract: The new species Acynodon adriaticus is described on the basis of remains from the Santonian–Campanian of Villaggio del Pescatore (Trieste, NE Italy). This species differs in several cranial features from Acynodon iberoccitanus, the only other Acynodon species whose cranial osteology is known in detail. The absence of maxillary and dentary caniniform teeth coupled with the presence of enlarged molariform teeth suggests that Acynodon probably fed on slowly moving hard‐shelled prey. Moreover, the new materials reveal for the first time the morphology of some postcranial elements of Acynodon: in particular, medial‐most paravertebral osteoderms that are characterized by two keels. A new cladistic phylogenetic analysis resolves the previously reported polytomy among the basal Globidonta: Acynodon is recognized as the most primitive globidontan. This genus may represent the geologically oldest known globidontan. The fact that Acynodon has been found only in Europe and that the outgroup of Globidonta, the Diplocynodontinae, is mainly known from Europe, suggests that globidontans may have originated in Europe and not in North America as previously supposed. 相似文献
18.
The continued washing, sorting, and identification of middle Eocene (45 Mya) primates from the Shanghuang fissure-fillings (Jiangsu Province, China) have produced additional hind limb elements. All are isolated elements. The strepsirhine hind limb elements include a first metatarsal and a talus, which are appropriate in size and morphology to pertain to Adapoides troglodytes. Adapoides is interpreted as a quadrupedal-climbing (nonleaping) primate with similarities to living lorises and the fossil primate Adapis. The haplorhine hind limb elements are estimated to span a range of adult body sizes from tiny (17 g) to small (200 g). Included among the new sample of haplorhine hind limb specimens is the smallest primate talus reported thus far. These new postcranial specimens expand our understanding of early haplorhine hind limb anatomy and demonstrate additional similarities between Shanghuang eosimiids and other anthropoids. 相似文献
19.
The new calcisponges Regispongia fluegeli n. sp., and Iranospongia circulara n. gen. n. sp., are described from central Iran. These are the first heteractinid sponges reported from the Permian of the region. These wewokellid sponges are large, irregularly cylindrical forms with a distinct axial spongocoel. The calcareous spicular skeletons of both taxa have been overgrown and are recrystallized. However, the preserved skeleton of Regispongia fluegeli does include large polyactines in the main endosomal layer and small octactines and possibly other polyactine spicules in both the relatively massive dermal layer and the distinct, delicately spiculed, gastral layer. Iranospongia is characterized by a discontinuous ring of vertical exhalant canals interior to the dense dermal layer, and by an interior skeleton net that includes common coarse vertical fibers. Individual spicules in Iranospongia are commonly obscured, but locally some remnants of possible polyactines occur in outer parts of the skeleton. 相似文献