共查询到20条相似文献,搜索用时 9 毫秒
1.
Nanda I Karl E Volobouev V Griffin DK Schartl M Schmid M 《Cytogenetic and genome research》2006,112(3-4):286-295
The karyotypes of most birds consist of a small number of macrochromosomes and numerous microchromosomes. Intriguingly, most accipitrids which include hawks, eagles, kites, and Old World vultures (Falconiformes) show a sharp contrast to this basic avian karyotype. They exhibit strikingly few microchromosomes and appear to have been drastically restructured during evolution. Chromosome paints specific to the chicken (GGA) macrochromosomes 1-10 were hybridized to metaphase spreads of three species of Old World vultures (Gyps rueppelli, Gyps fulvus, Gypaetus barbatus). Paints of GGA chromosomes 6-10 hybridize only to single chromosomes or large chromosome segments, illustrating the existence of high chromosome homology. In contrast, paints of the large macrochromosomes 1-5 show split hybridization signals on the chromosomes of the accipitrids, disclosing excessive chromosome rearrangements which is in clear contrast to the high degree of chromosome conservation substantiated from comparative chromosome painting in other birds. Furthermore, the GGA chromosome paint hybridization patterns reveal remarkable interchromosomal conservation among the two species of the genus Gyps. 相似文献
2.
Ningxiatherium euryrhinus sp. nov. is a relatively large elasmothere rhino from the Linxia Basin in northwestern China found in the early Bahean, which corresponds to the early Vallesian (MN 9), ca. 11.1 Ma. It is much larger than the extant Ceratotherium simum and has a single horn. Ningxiatherium is similar to the late Miocene Parelasmotherium from Gansu and Shanxi, but differs in having partially ossified nasal septum, terminal nasal horn boss, shallower nasal notch above the P3/P4 boundary, and much shorter premolars. N. euryrhinus sp. nov. differs from N. longirhinus from the late Miocene of Zhongning, Ningxia in northwestern China by its larger size, relatively wider nasals, shallower nasal notch, and sub-quadrangular occlusal surface of M3. In the Linxia Basin, the other early late Miocene (Bahean or Vallesian) elasmotheres are known from complete skulls or isolated teeth. They include two genera and three species: Parelasmotherium linxiaense, P. simplum, and Iranotherium morgani. They lack a nasal septum, but Ningxiatherium has one. The age of N. euryrhinus is early late Miocene based on direct association with biochronologic indicator taxa, such as Dinocrocuta gigantea, Hipparion dongxiangense, and Chilotherium primigenius. N. euryrhinus is more primitive than N. longirhinus sp. nov. in having a sub-quadrangular M3, a shallower nasal notch, and the presence of DP1 in adults. 相似文献
3.
A report of a louse sample identified as Colpocephalum cholibae Price & Beer by Oliveira et al. (2004), from the roadside hawk [Rupornis magnirostris (Gmelin)] in the state of S?o Paulo, Brazil, is regarded as a misidentification. A correction to the identity of the lice is given as Kurodaia (Kurodaia) fulvofasciata (Piaget). Key morphological differences between the genera Colpocephalum and Kurodaia are discussed, as well as possible reasons for the misidentification. 相似文献
4.
5.
6.
We report on the discovery of an Early Cretaceous bird from northwestern Gansu Province, in northwestern China. Represented by a nearly complete left wing and shoulder girdle the size of a rock dove, the new bird was quarried from laminated yellowish mudstones of the Xiagou Formation (Xinminpu Group) near Changma, in the Jiuquan area. These deposits have previously yielded the only known specimen of Gansus yumenensis, a basal ornithuromorph represented by the distal half of a hind limb with long and slender digits. Several derived characters of the new occurrence supports its allocation within Enantiornithes: (1) a convex lateral margin of the coracoid, (2) a minor metacarpal that projects distally more than the major metacarpal and (3) a proximal phalanx of the major digit longer than the intermediate (second) phalanx. The general proportions of the wing suggest it was a flier comparable to most other known enantiornithine birds. Although, direct comparisons between the new fossil and Gansus are not possible, phylogenetic based inferences supports their placement into two different clades. While the new fossil falls definitively within the enantiornithines, G. Yumenensis falls within the ornithuromorphs. The new occurrence thus adds to the taxonomic diversity of Early Cretaceous birds from Gansu Province in particular and central Asia in general. 相似文献
7.
The early middle Miocene biota from the Shanwang locality in eastern China is one of the most diverse and well preserved in the world. This overall richness contrasts with its low diversity of anuran amphibians. The most abundant anurans are representatives of the family Ranidae, which remains the dominant group in the extant anuran fauna of China. Besides Rana basaltica Young, some other ranids can be recognised at the locality, and are clearly distinguishable from R. basaltica based on their larger size and different proportions. Ranids are also represented by a developmental series of tadpoles, ranging from approximately Nieuwkoop-Faber (NF) stage 43 to a metamorphosing tadpole of NF stage 57. This is the first known developmental series of fossil non-pipoid Anura outside the Pelobatidae. In addition to the ranids, Bufo shandongensis nov. sp. (replacement name for B. linquensis), represented by one of the earliest known articulated bufonid skeletons, is described and illustrated. Another large toad, Macropelobates linquensis (Yang) nov. comb., is re-described; it can be assigned to the Pelobatoidea, with a possible relationship to the Scaphiopodidae, and can be considered, based on the presence of a large spade, a tibiofibula shorter than the femur, and a short astragalus and calcaneus, to be the earliest known anuran burrower. 相似文献
8.
Background
Old World vultures are likely polyphyletic, representing two subfamilies, the Aegypiinae and Gypaetinae, and some genera of the latter may be of independent origin. Evidence concerning the origin, as well as the timing of the divergence of each subfamily and even genera of the Gypaetinae has been elusive.Methodology/Principal Findings
Compared with the Old World, the New World has an unexpectedly diverse and rich fossil component of Old World vultures. Here we describe a new accipitriform bird, Anchigyps voorhiesi gen. et sp. nov., from the Ash Hollow Formation (Upper Clarendonian, Late Miocene) of Nebraska. It represents a form close in morphology to the Old World vultures. Characteristics of its wing bones suggest it was less specialized for soaring than modern vultures. It was likely an opportunistic predator or scavenger having a grasping foot and a mandible morphologically similar to modern carrion-feeding birds.Conclusions/Significance
The new fossil reported here is intermediate in morphology between the bulk of accipitrids and the Old World gypaetine vultures, representing a basal lineage of Accipitridae trending towards the vulturine habit, and of its Late Miocene age suggests the divergence of true gypaetine vultures, may have occurred during or slightly before the Miocene. 相似文献9.
10.
甘肃省早白垩世地层中,出土了大量恐龙骨骼以及恐龙足迹化石,但是至今未有蛋化石的报道。根据发现于兰州-民和盆地下白垩统河口组的蛋壳化石,建立一恐龙蛋新蛋属、蛋种,并将其归于一新蛋科:Polyclonoolithidae(多小枝蛋科)。新发现的蛋化石标本不同于所有已知的恐龙蛋类型,具有独特的显微特征组合:分叉的蛋壳单元向外延伸至蛋壳外表面,并未在靠近蛋壳外表面处融合成层;弦切面上具相互链接或独立的多角形的蛋壳单元;以及不规则的气孔道。中国的恐龙蛋化石大多出自晚白垩世地层,仅在辽宁有早白垩世恐龙蛋的报道。新发现扩展了中国恐龙蛋化石的地质和地理分布,也有可能为圆形蛋科蛋壳结构的起源提供新的认识。 相似文献
11.
In addition to the new fragments of the Omo I skeleton, renewed fieldwork in the Kibish Formation along the lower reaches of the Omo River in southwestern Ethiopia has yielded new hominin finds from the Kibish Formation. The new finds include four heavily mineralized specimens: a partial left tibia and a fragment of a distal fibular diaphysis from Awoke's Hominid Site (AHS), a parietal fragment, and a portion of a juvenile occipital bone. The AHS tibia and fibula derive from Member I and are contemporaneous with Omo I and II. The other specimens derive from Chad's Hominid Site (CHS), and derive from either Member III or IV, which constrains their age between approximately 8.6 and approximately 104ka. 相似文献
12.
A new freshwater goby,Rhinogobius xianshuiensis sp. nov. was collected from the upper Mulan River basin of Xianyou County, Fujian Province, eastern China. The species is
distinguished from related species in the region by 3–7 predorsal scales, 27 vertebrae, cephalic lateralis canals always always
with 2 derived post-orbital pores (ε1) in adults, a reddish-brown vertical line below the anterior margin of the eye, and
a red netlike pattern on the opercle. A key to species ofRhinogobius with higher vertebral numbers (27–29) from eastern China, Taiwan and Japan is provided. 相似文献
13.
Martínez J Criado-Fornelio A Lanzarot P Fernández-García M Rodríguez-Caabeiro F Merino S 《The Journal of parasitology》2004,90(5):1103-1105
This article describes a new pentastomid species from the abdominal air sacs of a black vulture (Aegypius monachus Linnaeus, 1766) from central Spain. The parasite's morphological characteristics (as shown by light and scanning electron microscopy) suggest that it should be classified in the new genus. It is the third pentastomid species described in birds and the first for the Accipitridae. The mouth is almost terminal, there are 2 pairs of hooks behind the mouth, and the genital pore is immediately posterior to these structures, placing the new species within the Cephalobaenida. The anterior and posterior hooks are similar in size and are flanked by parapodial lob. Cuticular tubercles are absent, false annulations can be seen, and the parasite's eggs have 2 layers. 相似文献
14.
记述了采自甘肃省蚱科一新种,即圆肩蚱(Tetrix tereeshumerus sp.nov.)。该新种近似于神农架蚱(Tetrix shenglonjiaensis Zheng,Li and Wei),主要区别为:(1)头顶宽为1眼宽的2倍;(2)头顶前缘圆弧形,明显突出于眼前;(3)侧面观,颜面隆起在侧单眼前直;(4)前胸背板后突到达后足股节2/3处;(5)沟前区侧隆线平行;(6)肩角圆弧形;(7)肩部之间不具一对短纵隆线;(8)后翅到达后足股节中部;(9)中足股节明显大于前翅宽;(10)雌性下生殖板长大于宽。新种的模式标本保存于陕西师范大学动物研究所。 相似文献
15.
A new species ofMadia sectionAnisocarpus from the serpentines of northwest California is described, illustrated and contrasted with its closest relatives. A key to the annual members of the section is presented. 相似文献
16.
18.
Greiner EC Fedynich AM Webb SL DeVault TL Rhodes OE 《The Journal of parasitology》2011,97(6):1137-1139
A survey of turkey vultures (Cathartes aura) in South Carolina revealed the presence of a novel haemoproteid. Haemoproteus catharti n. sp. is described from the slides developed from the blood of this vulture. The new species is a thick, halteridial form with complete margins, and is considered distinct from the other recognized haemoproteids from the diurnal raptors in shape, pigment number, parasite outline, and host-family specificity. While reviewing blood films, a series of unusual immature schizonts of Plasmodium sp. were also observed, and these are illustrated, along with another distinct haemoproteid from old slides of poor quality produced from turkey vulture blood. 相似文献
19.
George D. Koufos 《Pal?ontologische Zeitschrift》1984,58(3-4):307-317
A small hipparion from the Vallesian (early Late Miocene) of Northern Greece is studied. It is coming from the locality “Ravin de la Pluie” of the lower Axios valley, near Thessaloniki. Its characteristics as the small size, the short symphysis, the long snout, the high enamel plication, the well developed protostylid, the large m3 and the elongated m1-m3 series distinguish it from the other known eurasiatic small hipparions, allowed us to derive a new species,Hipparion macedonicum. It lived during Vallesian and can be used as a stratigraphic species for this period. 相似文献
