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1.
《Gondwana Research》2014,25(1):214-225
Jurodidae are thought to be some of the world's most mysterious beetles and display an intriguing mixture of characters occurring in three different suborders. Hitherto, all known fossil and extant Jurodidae were extremely rare and restricted to Russian Siberia and the Far East. Here we describe two new species, Jurodes daohugouensis sp. nov. and Jurodes pygmaeus sp. nov. from the Middle Jurassic of Daohugou, China. A key to all species of Jurodidae and their research history are given, and the detailed morphology of fossil Jurodidae is also presented. Our results confirm the presence of three ocelli in fossil Jurodidae, and reveal that hind wings of J. pygmaeus sp. nov. possess well developed radial and oblong cells, and are very similar to those of extant Jurodidae (Sikhotealinia zhiltzovae). Male genitalia of fossil Jurodidae were described herein for the first time, showing a basal trilobate structure. The presence of exposed propleuron, three pairs of external trochantins, metanepisterna with ridges, primitive characters of wing venation further support the probable placement of Jurodidae in the suborder Archostemata. J. daohugouensis and J. pygmaeus are very similar to S. zhiltzovae in having the big protruding eyes, elevated median portion of frons bearing three ocelli, pubescent body, contiguous procoxae, exposed trachantion of all coxae, elytra with rows of punctures, and wing venation. Our results show that these key characters of extant Jurodidae can be traced back to the Middle Jurassic, revealing that the family has been in a period of evolutionary stasis for at least 160 million years. Furthermore, our discoveries widen the paleogeographic distribution of fossil Jurodidae from Russian Siberia to northern China. 相似文献
2.
New specimens of the enigmatic Ediacara-type fossil Palaeopascichnus have been identified from the upper part of the Neoproterozoic Ranford Formation in the Kimberley region, northwest Australia. New material is morphologically similar to Palaeopascichnus and represents the largest species of this genus. They resemble the present-day xenophyophore protists in chamber morphology and growth patterns, supporting the interpretation that Palaeopascichnus is possibly a xenophyophore body fossil rather than a trace fossil. Stratigraphic correlation reveals that the new Palaeopascichnus specimens are preserved in the interglacial successions between the Landrigan/Marinoan and Egan/Ediacaran glaciations. If correlation with the early Ediacaran formations of South Australia is accepted, this represents the earliest known identifiable member of the Ediacara biota. New fossil record fills the evolutionary gap between the Cryogenian and Ediacaran animal assemblages and well-known Ediacaran biota. The new Palaeopascichnus specimens represent the first record of Ediacara-type fossils in Kimberley, and suggest the probability that additional Ediacaran fossils may be found in northwestern Australia. 相似文献
3.
Life cycle variations in the morphological and behavioral traits of modern pennate diatoms are known for a wide variety of genera and it is assumed that patterns of asexual and sexual reproduction (e.g. size reduction and auxosporulation) have remained essentially unchanged since their origin. We show here that many characteristics of modern pennate diatoms and the communities they inhabit can indeed be recognized in remarkably well-preserved, non-marine fossil material from the Cretaceous (∼70 Ma) Huepac Chert in NW Mexico. Besides the incremental size reduction of the siliceous frustules in species including Fragilaria tarahumara, we also demonstrate the spatial arrangement and distribution of these cells in in situ microalgal communities, and present evidence for local production of dense exopolymeric substances, cell division, and possibly auxospores. This is the first time that such life cycle stages are reported for non-marine fossil diatoms. 相似文献
4.
David R. Sussman 《Journal of South American Earth Sciences》2011,31(4):475-478
In 2007, Reguero et al. described a 2.5 Ma erethizontid dentary from the Uquía Formation in Argentina (MACN5376) and referred it to the genus Erethizon, a genus found at present only in North America. They based their generic identification on the presence in the fossil of a markedly inflected angular process. I argue in this commentary that this single trait (the angular process) in a single incomplete fossil is insufficient evidence for the Erethizon attribution, for the following reasons: 1. The trait (the inflected angular process) is variable in modern South and North American porcupines and observer bias and/or allometry may be responsible for observed differences; 2. Among fossil South American porcupines, the inflected angular process is not unique to the Uquían fossil; 3. The fossil possesses other traits (including one trait newly described in this paper) associated with modern South American (Coendou) porcupines and not modern Erethizon; and 4. The traits by which we recognize modern Erethizon, primarily related to the genus’s ability to survive severe winters, are most readily explained by evolution driven by the South American porcupine immigrants’ exposure in North America to that severe weather. The Uquían fossil is not Erethizon and should be attributed for the present to the genus Coendou. 相似文献
5.
《Gondwana Research》2013,23(3-4):761-771
The abundant and diverse assemblage of filamentous microbial fossils and associated organic matter permineralized in the ~ 3465 Ma Apex chert of northwestern Australia — widely regarded as among the oldest records of life — have been investigated intensively. First reported in 1987 and formally described in 1992 and 1993, the biogenicity of the Apex fossils was questioned in 2002 and in three subsequent reports. However, as is shown here by use of analytical techniques unavailable twenty years ago, the Apex filaments are now established to be bona fide fossil microbes composed of three-dimensionally cylindrical organic- (kerogenous-) walled cells. Backed by a large body of supporting evidence of similar age — other microfossils, stromatolites, and carbon isotopic data — it seems clear that microbial life was present and flourishing on the early Earth ~ 3500 Ma ago. 相似文献
6.
In the recent years, exceptional fossil sites have revealed astonishing details on the anatomy, lifestyles and behaviour of Cambrian animals but surprisingly, very little is known about one of their most vital features, reproduction. We describe here in situ eggs (clusters of 3 to 30 oocytes) in the tube-dwelling priapulid worm Paraselkirkia sinica from the Cambrian Stage 3 Xiaoshiba Lagerstätte (ca. 514 Ma, South China). These oocytes were accommodated within paired tubular ovaries located in the posterior half of the primary body cavity as in modern meiobenthic priapulid worms, thus indicating that the general organization of female tubular gonads in priapulid worms has remained virtually unchanged for half a billion years. Our findings provide for the first time, key information on the reproductive organs and strategies of early ecdysozoans, a huge animal clade that dominated Cambrian marine ecosystems and accounts for a large part of today's biodiversity (e.g. arthropods). Moreover, we also emphasize the critical role of ecology on the reproductive strategies and lifestyles of both modern and Cambrian worms. 相似文献
7.
Two new Early Cretaceous fossil rove beetle species, Paleosiagonium brevelytratum n. gen. n. sp. and Paleosiagonium adaequatum n. gen. n. sp. are described from the Lower Cretaceous Yixian Formation of Liaoning Province, China. They are clearly placed in the extant Piestinae according to the following characters: body elongate and flat; anterior coxae small and globose; abdomen long and parallel-sided, with six visible sterna and one pair of paratergites on segments III–VII. This is the first report on the occurrence of the coleopteran subfamily Piestinae in the fossil record. The new discoveries indicate that Piestinae have originated at least by the Early Cretaceous, at about 125–120 Ma. 相似文献
8.
Basal iguanodontians (“iguanodontids”) were a successful group of ornithopod dinosaurs that attained a near global distribution by the late Early Cretaceous. Despite their body fossils being known in abundance from the uppermost Jurassic and Lower Cretaceous of the western United States, their remains have never been found in western Canada. With its extensive, terrestrial sedimentary record for the whole of the Early Cretaceous, the expectation is that these dinosaurs would have been present in western Canada. This paper reports the finding of a fossil footprint from the Gladstone Formation in southwestern Alberta that is interpreted to have been made by an iguanodontid. This identification is based on the late Barremian age of the hosting rock, gross footprint details that match the skeletal foot structure of Iguanodon bernissartensis, and similarities to Early Cretaceous dinosaur footprints found elsewhere in the world that are attributed to iguanodontids. This finding fills a noticeable gap in the iguanodontian fossil record, and is consistent with the clade's attainment of global distribution during the Early Cretaceous. 相似文献
9.
Mesozoic whip-scorpions are very rare, with only two Cretaceous species known to date. Here we describe a new genus and species of Thelyphonidae, Mesothelyphonus parvus gen. & sp. nov., based on a very well-preserved male in Upper Cretaceous amber from Myanmar. Mesothelyphonus is firmly placed in the extant subfamily Thelyphoninae as supported by the abdominal tergites with a median longitudinal suture. Mesothelyphonus differs from other fossil and recent genera primarily by its very small body size, the absence of ommatoids on abdominal segment XII, and the elongate, slender and toothed patellar apophysis of the male pedipalp. The new discovery represents the oldest definitive fossil record for Thelyphoninae, highlighting the antiquity of the whip-scorpion group. 相似文献
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研究了云南西部龙陵县上新世的化石木。鉴定出两种木材类型。杜鹃花科杜鹃属的似腋花杜鹃Rhododendron cf. racemosum Franchet，其主要木材特征有散孔材，生长轮略明显，导管具多角形轮廓，螺纹加厚出现在整个导管壁上，梯状穿孔板，射线异形II型。松科华山松Pinus armandii Franchet的主要特征有交叉场纹孔窗格状，具正常轴向和纵向树脂道，且泌脂细胞壁薄，射线管胞内壁平滑或具稀疏的微锯齿。两种类型的化石木在我国均属首次报道。根据化石木结构和现代相应树种和植被的生境范围，当时植物生长于亚热带温凉湿润的山地环境，其海拔大约在1800米左右。 相似文献
13.
Som Nath Kundal 《Arabian Journal of Geosciences》2018,11(16):474
In this paper, two specimens of fossil Mus from the mudstone horizon underlying the geochronologically dated (2.48 Ma) volcanic ash bed/bentonitized tuff bands that straddle across Gauss-Matuyama transition exposed very near the village Barakhetar are described here. Based on molar morphological terminology, the specimens have been identified and tentatively referred to as Mus cf. Mus flynni. The specimens under the study are related to other fossil Mus from the Indian subcontinent in the present work. 相似文献
14.
Two new species, Cretohypna puncta sp. nov. and Cretohypna robusta sp. nov., of Glaphyridae are described and illustrated. These fossils were collected from the Jehol Biota, Lower Cretaceous Yixian Formation of Liutiaogou Village in Ningcheng, Inner Mongolia, China. Up to date, 18 fossil species in 6 genera of Glaphyridae have been reported, among which ten species are from China. Respective keys to the Mesozoic genera of Glaphyridae and to species of Cretohypna Yan, Nikolajev & Ren, 2012 are provided. This is the first report of spiracles in fossil Glaphyridae leading to a hypothesis that the character of the 7th abdominal spiracles present in pleural membrane is a plesiomorphy for Glaphyridae. 相似文献
15.
New fossil genus with a new species, Stellularis longirostris Chen, Yao and Ren, gen. et sp. nov., from the family Procercopidae, are described. New specimens were collected from the Lower Cretaceous non-marine sedimentary strata from the Yixian Formations of northeast China. The exceptionally well-preserved materials reveal fine details of the body structure and morphology including rostrum, legs, abdomen, anteclypeus and ovipositor. The genera Luanpingia Hong, 1983 and Cathaycixius Ren, Lu, and Guo, 1995 are discussed. 相似文献
16.
Cretaceous bryophyte fossils are known only from a few localities and only a few are known in ultrastructural fidelity. We describe a fossil moss gametophyte from Upper Cretaceous Taimyr amber and place it in the fossil genus Taimyrobryum martynoviorum gen. et sp. nov. (Bryopsida). Its unbranched, somewhat zig-zagged stems with distantly spaced, spreading, narrowly lanceolate leaves and the unbranched costa match the gross morphology of Dicranidae; however, the uniformly prosenchymatous leaf cells contradict an affiliation to this subclass. The Yantardakh in the Taimyr Peninsula is the fourth and northernmost Cretaceous amber locality yielding inclusions of bryophytes. 相似文献
17.
Amanjeet Panghal Ajay Kumar Suneel Kumar Joga Singh Parminder Singh B. S. Bajwa 《Journal of the Geological Society of India》2018,91(6):695-699
A fossil wood of Lagerstroemia L. from the Upper Siwalik sediments of Arunachal Pradesh is described. The genus is recorded for the first time from this state. The modern analog of the fossil species i.e. L. tomentosa C. Presl is not found in the fossil locality at present.. The most plausible reason for the disappearance of the species from the fossil locality is an increase in temperature seasonality caused by the upheaval of the Himalaya during the Pleistocene. 相似文献
18.
A study of the cheirolepidiaceous conifer Pseudofrenelopsis gansuensis from the Lower Cretaceous of Wangqing Jilin Province in China was conducted in detail using scanning and transmission electron microscopy techniques. In total, nine ultrastructural features were recognized for the cuticle of this fossil plant, which are helpful in the distinguishing between cuticles of ordinary epidermal cells, subsidiary cells, guard cells and hypodermal cells of the stomatal apparatus. A three dimensional reconstruction of the cuticle ultrastructure was obtained. Pseudofrenelopsis gansuensis is the second species of this genus for which the cuticle ultrastructure has been statistically examined with 30 measurements and estimated confidence interval values. The close comparison of the cuticle ultrastructure characters, including statistical data, among Cheirolepidiaceae and other fossil conifers provides potential evidence of the taxonomic significance of this genus: ten characters are potentially valuable for specific separation, eleven parameters for generic separation and three parameters seem also to be useful for Family determination. The differences in the chemical composition according to preliminary statistical element analyses of the cuticles based on three ratios in two species of Pseudofrenelopsis, P. dalatzensis and P. gansuensis, should also be examined in future studies. 相似文献
19.
Purnima Srivastava 《Arabian Journal of Geosciences》2012,5(6):1411-1422
Fossils of the Vindhyan Supergroup exhibit extensive diversity and variable biologic affinities represented by: bacteria, cyanobacteria, algae, fungi, acritarchs, metaphytes and metazoans (including members of the Ediacaran Fauna) and ranging from less than a micron to almost a metre in size. Besides identified fossils, a number of bizarre morphologies (due to deviation of morphology from conventional structures), present in various stratigraphic horizons, have been observed. It is very difficult to identify and decide their biologic affinities. In thin sections of Lower Vindhyan cherts, microfossils resembling lichen-like or fungal forms in which a sac encompassing a coiled filament may possibly indicate a symbiotic relationship, a Volvox colony-like structure and a vase-shaped body without an opening are unique. Among the carbonaceous fossils, very unusual and interesting fossil is a transparent disc comprising numerous appendages of an unidentified mesoscopic insect-like organism. Megascopic branching and associated Grypania-like structure is another form preserved as impression on micritic limestone. Petrographic thin sections of chert belonging to the Sirbu Shale Formation, exhibit presence of microscopic bizarre forms. The assemblage includes acritarchs and acanthomorphs of variable morphology and a dividing cell-like structure interpreted to be of rhodophycean affinity or a cleaving embryo of an animal affinity. Other peculiar morphologies among the carbonaceous fossils are: branched filaments that have attached sporangia-like vesicles, Chuaria-like body comprising cluster of very small-sized spheroids resemble scale-like structure, a chrysophycean alga or a multicellular tissue of a metaphyte. Another carbonaceous fossil represents a possible metazoan exhibiting an elongate body and a mid-gut-like structure or a Vaucheriacean alga. Although the biologic affinities of these bizarre forms can be a matter of debate, their biogenic nature is almost undoubted. The presence of such forms in the Vindhyans indicates advancement in morphology and a gradual evolution of life during the Palaeoproterozoic–Neoproterozoic period. In addition, presence of Ediacaran fossils in Bhander Group and large-sized acritarchs especially Trachyhystrichosphaera sp. in petrographic thin section of chert from the Sirbu Shale Formation, Bhander Group, Upper Vindhyans, suggests Ediacaran age as an upper age limit of the Vindhyan Supergroup. 相似文献
20.
Although five genera of procyonids are currently present in South America, only two of the extant genera, Procyon and Nasua are represented in the South American fossil record. A recent discovery of a procyonid lower second molar in Late Pleistocene deposits of Aurora do Tocantins, northern Brazil, offers potential to further our understanding of the stratigraphic and temporal range of South American fossil procyonids. We use geometric morphometric analysis of two-dimensional landmarks and semilandmarks to explore morphological variation in the lower second molars of extant Procyon lotor and Procyon cancrivorus and multivariate methods to support the identification of the Pleistocene specimen as P. cancrivorus. This material represents the second fossil record of P. cancrivorus in South America Procyonids entered South America in two phases: the first comprising by Cyonasua and Chapadmalania during the Late Miocene, and the other recent genera, beginning in the Late Pleistocene. These Late Miocene procyonids were more carnivorous than Late Pleistocene-Recent omnivorous taxa and possible went extinct due to competition with other placental carnivorans that entered South America and diversified during the latest Pliocene-Early Pleistocene. 相似文献