共查询到20条相似文献，搜索用时 31 毫秒
1.
The well-preserved trackway of a lacertiform, lizard-like trackmaker from the Haman Formation (Cretaceous) of Korea is described as Neosauroides koreaensis ichnogen. et ichnosp. nov. This is the only example of a Cretaceous lacertiform or lizard-like trackway currently known in the global track record. Although lacertiform trackways, mostly assigned to the ichnogenus Rhynchosauroides, are common in the global Triassic, they are almost entirely absent in the Jurassic and Cretaceous. Moreover, ichnological classification criteria allow that Neosauroides is morphologically distinct from Rhynchosauroides at the genus level, and more like the tracks of the extant lizard Sceloporus. The reasons for the conspicuous lack of post-Triassic occurrences are not certain, but not due to a post-Triassic lack of potential lizard trackmakers. Thus, the preservation biases are likely due to paleobiological factors such as trackmaker ecology and paleoenvironmental preference. 相似文献
2.
David W.E. Hone Kebai WangCorwin Sullivan Xijin ZhaoShuqing Chen Dunjin LiShuan Ji Qiang JiXing Xu 《Cretaceous Research》2011,32(4):495-503
Tyrannosaurids are primarily gigantic, predatory theropod dinosaurs of the Cretaceous. Here we report a new member of the tyrannosaurid clade Tyrannosaurinae from the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China, based on a maxilla and associated dentary. The discovery of this animal, here named Zhuchengtyrannus magnus gen. et sp. nov., adds to the known diversity of tyrannosaurids in Asia. Z. magnus can be identified by a horizontal shelf on the lateral surface of the base of the ascending process, and a rounded notch in the anterior margin of the maxillary fenestra. Several additional features contribute to a unique combination of character states that serves to further distinguish Z. magnus from other taxa. Comparisons with other tyrannosaurids suggest that Zhuchengtyrannus was a very large theropod, comparable in size to both Tarbosaurus and Tyrannosaurus. 相似文献
3.
The Cabullona Basin in the state of Sonora, Mexico is becoming recognized due to its diversity of southern Laramidian continental vertebrates, especially dinosaurs. In this study we describe and analyze three theropod teeth (ERNO specimens) that were found isolated and surface collected in the Corral de Enmedio Formation (Cabullona Group, Upper Cretaceous). The three specimens possess similar morphological characteristics that match the ones present in Late Cretaceous Laramidian tyrannosaurids, so they were referred to the Tyrannosauridae, probably belonging to a new unknown taxon. The implementation of statistical and cladistic analyses corroborated their taxonomical assignment. ERNO specimens correspond to the first record of tyrannosaurid dinosaurs in the basal Corral de Enmedio Formation, extending the stratigraphic distribution of these dinosaurs in the Cabullona Basin. Although tyrannosaurids have been previously described in the Cabullona Basin, the ERNO specimens of the Corral de Enmedio Formation seem to be different, because they possess more labiolingually compressed teeth. This new evidence could indicate a higher taxonomic diversity of the tyrannosaurid theropods that were present in the Cabullona Basin, adding more information to the Tyrannosauridae diversification on one of the most southern Laramidian regions during the Late Cretaceous. 相似文献
4.
Here we report a large dinosaur tracksite from an extensive fluvial sandstone surface in the Lower Cretaceous Jiaguan Formation of Sichuan Province, China. The site contains over 250 individual tracks comprising at least 18 recognizable trackways, including the longest theropod trackway (cf. Eubrontes) known from China. This exceptional theropod trackway consists of 81 successive footprints covering a distance of 69 m. The tracks are well-preserved and are expressed both as true tracks on the main “upper” surface and as transmitted undertracks on a locally exposed “lower” bed. Also recorded are six other theropod trackways, including small Grallator-like ichnites, eight sauropod trackways (cf. Brontopodus), and three small ornithopod (cf. Ornithopodichnus) trackways with a parallel orientation, which may indicate gregarious behavior. Several trackways of a larger theropod trackmaker show pes imprints with elongated traces of the metatarsals, suggesting extramorphological (substrate-controlled) variation and/or plantigrade posture, which is here interpreted as indicating a change in gait assumed in response to deep and soft sediment. The assemblage indicates a diverse dinosaur fauna in the Lower Cretaceous Sichuan Basin with variously sized theropods, sauropods, and ornithopods. The late occurrence of footprints of the Grallator-Eubrontes plexus in Lower Cretaceous strata is further evidence of the extended stratigraphic range of this morphotype and the distinct palaeobiogeographic distribution of these trackmakers in East Asia. 相似文献
5.
Christian Gaillard 《Swiss Journal of Geoscience》2011,104(1):57-72
A well-preserved large limulid trackway related to Kouphichnium lithographicum is described from the Upper Kimmeridgian Lithographic Limestones of Cerin (Ain, France). It is three meters long and exhibits ten successive sets of imprints characterized by a pair of well-preserved tetradactyl external imprints of legs VI (named pushers) and a variable number (mostly three pairs) of straight thin intermediate imprints (legs III–V). The trackway is unusually wide and was probably made by a very large adult approximately 38 cm wide and 80 cm long when related to the proportions of the modern Limulus polyphemus. The straightness of the trackway, the great repeat distance (stride), the length of series of leg imprints, their slight angle to the mid-line, the well-marked pusher (= leg VI) imprints and the absence of groove made by the telson all indicate fast progression of a vigorous animal on the sea-floor. This walking trackway can be easily differentiated from other limulid crawling, ploughing, and dying trackways usually found in lithographic limestones or other deposits of the geological record. Main characteristics of these different limulid trackways are evidenced. The occurrence of a living adult in the Cerin restricted lagoon is probably related to a brief period of connection with the open sea. This occurrence indicates either a passive introduction of the animal into the lagoon or a spawning behaviour. 相似文献
6.
Two pes imprints of a perissodactyl mammal constituting a single step of a trackway have recently been discovered in Oligocene Flysch deposits of the Barail Group in Manipur, India. The tridactyl, mesaxonic imprints (~7 cm in length) show strong similarities to footprints known from the Paleogene of China and can be attributed to a tapiroid, rhinocerotoid or equoid trackmaker. This is the first record of perissodactyl footprints from the Lower Oligocene of India and the first evidence of mammals in the Barail Group of the age. Remarkable is the occurrence in a marginal marine setting, whereas other known perissodactyl footprints from the Eocene–Oligocene in particular from North America, Europe and China come from fluvio-lacustrine strata. 相似文献
7.
Stephen P. Carey Aaron B. Camens Matthew L. Cupper Rainer Grün John C. Hellstrom Stafford W. McKnight Iain Mclennan David A. Pickering Peter Trusler Maxime Aubert 《Quaternary Science Reviews》2011,30(5-6):591-610
A diverse assemblage of late Pleistocene marsupial trackways on a lake bed in south-western Victoria provides the first information relating to the gaits and morphology of several megafaunal species, and represents the most speciose and best preserved megafaunal footprint site in Australia. The 60–110 ka volcaniclastic lacustrine sedimentary rocks preserve trackways of the diprotodontid Diprotodon optatum, a macropodid (probably Protemnodon sp.) and a large vombatid (perhaps Ramsayia magna or ‘Phascolomys’ medius) and possible prints of the marsupial lion, Thylacoleo carnifex. The footprints were imprinted within a short time period, demonstrating the association of the taxa present, rather than the time-averaged accumulations usually observed in skeletal fossil deposits. Individual manus and pes prints are distinguishable in some trackways, and in many cases some digital pad morphology is also present. Several parameters traditionally used to differentiate ichnotaxa, including trackway gauge and the degree of print in-turning relative to the midline, are shown to be subject to significant intraspecific variation in marsupials. Sexual dimorphism in the trackway proportions of Diprotodon, and its potential for occurrence in all large bodied, quadrupedal marsupials, is identified here for the first time. 相似文献
8.
Missing data, due to taphonomic deformation, inaccessibility of specimens, or human error in collecting, cataloguing and measuring features, is a formidable problem in current palaeontological studies. Missing values within a data set can undermine confidence in analyses, skew results in promoting analyses of small portions of a population, not necessarily representative of the entire data set, and drastically decrease sample sizes. Missing data estimation methods, however, may reduce the effects of these missing values and potentially boost sample sizes for palaeontological studies. Here, six missing data estimation models for the prediction of femoral circumferences in tyrannosaurids were statistically tested and their predictive success measured against true circumferences, and other models. The statistical analyses suggest that estimation models based on anteroposterior diameter values of tyrannosaurid femora were poor predictors of circumference, whereas those based on mediolateral diameters were much more successful. Three out of the six models, were presented as viable alternatives to missing measured circumferences and may be used to boost tyrannosaurid samples with significant levels of missing data. 相似文献
9.
藏东昌都地区阿涅塘化石点中侏罗世达布卡组滨湖相紫红色中-细砂岩中,发现以凸形迹完好地保存的4层恐龙足迹,包括Grallator类、大型兽脚类、小型兽脚类和小型蜥脚类等足迹类型,并构成两列完美的行迹. 组成行迹T1的4个Grallator类足迹被命名为Grallator anietangensis isp. nov.,对其进行了详细的形态学分析,并讨论了造迹恐龙的大小和运动状态,这是Grallator类足迹在西藏地区的首次发现. 组成行迹T2的9个大型兽脚类足迹被归为Theropoda igen. et isp. indet.,对该类足迹进行了形态描述和功能分析;这类足迹在中国是首次记录,其连续且清晰的尾迹表明造迹者并非处于正常运动状态,而是应对某种特殊境况的特别行为方式,即其正以昂起的前躯一边观察,一边以极低的速度前进,因前躯昂起,尾部相应下垂,从而留下尾迹. 两列行迹均显示出造迹者正沿古昌都湖岸前进. 中国迄今所发现的恐龙骨骼和Grallator类足迹化石主要表现为以西南地区为中心,再向四周不断发散的扩散模式,但Grallator类足迹化石综合提供的信息显示恐龙动物的扩散速度比骨骼化石反映的速度更快. 相似文献
10.
Speculation regarding Tyrannosaurus in West Texas has been largely based upon a sub-adult tyrannosaurid maxilla from the Javelina Formation (Late Cretaceous–Maastrichtian) of Big Bend National Park. However, a very large anterior caudal vertebra, recently collected from the Javelina Formation, exhibits a morphology that can confidently be assigned to Tyrannosauridae and, because of its size, likely pertains to an adult Tyrannosaurus. The stratigraphic position of the specimen is closely bracketed by titanosaurid remains and further supports coexistence of these taxa. The stratigraphic position of the specimen possibly records one of the earliest occurrences of Tyrannosaurus. If so, Tyrannosaurus likely existed during roughly equivalent temporal intervals in disparate paleobiomes in both northern and southern late Maastrichtian faunal realms of North America. 相似文献
11.
Newly discovered tracks of a large quadrupedal ornithopod and a theropod with trail trace, and a bird track from the Cretaceous Saniri Formation of Yeongdong area are described. One ornithopod trackway is very unusual in having large (length width ∼15 and >15 cm respectively) clover-leaf-like manus tracks situated anteromedial to the pes tracks with atypical negative, inward rotation of 45°. Ornithopod pes tracks are quadripartite with three separated, elongate-oval, nearly parallel sided, wide digit impressions and a separate suboval heel impression (mean length and width about 41 and 36 cm respectively: l/w ratio 1.13). Manus track morphotypes are a clover-leaf-shaped configuration of three digit impressions, representing digits II–IV, in triangular configuration and registered just in front of (anteromedial to) pes track digits II and III. The pes morphotype is typical of Caririchnium, but the manus morphotype is quite distinct from previously described ichnotaxa, thus justifying a new ichnotaxon: Caririchnium yeondongensis ichnosp. nov., probably representing a facultatively-quadrupedal Iguanodon-like trackmaker.Theropod tracks are composed of three tapered pes digit impressions with interdigital angles between digits II and IV 45°. Length and width about 22.8 cm and 15.5 cm, respectively. Pace, stride, and pace angles are about 51 cm, 101 cm, and 170°, respectively. Theropod tracks are characteristically associated with a nearly continuous tail trace, which is up to 360 cm in length, 4.5 to 6 cm in width, and broad “U” shaped in cross section. Expulsion rims and dragging striae occur intermittently. In addition, dinosaur skin impressions, poorly preserved large sauropod tracks, a bird track, invertebrate and plant fossils are found from the lake margin deposits also containing rain drop impressions and desiccation cracks. Dinosaur tracks of the Yeongdong area represent the oldest (Valanginian-Hauterivian) dinosaur tracks of Korea. 相似文献
12.
A partial trackway of a turtle from the Jinju Formation (Sindong Group) is the first report of Mesozoic turtle tracks from Korea and the first report of traces of an aquatic tetrapod from Korea. Six tracks show a partial trackway configuration inferred to represent a partially buoyant trackmaker, possibly engaged in “bottom walking” behavior. Although turtle tracks often co-occur with crocodylian tracks in Cretaceous coastal plain facies in other regions, especially North America, to date there are no such co-occurrences in east Asia. This suggests that in Asia paleoenvironments suitable for turtles were quite widespread, but paleoenvironments were not suitable for crocodylians. 相似文献
13.
Cretaceous dinosaur tracks from Hunan Province are historically significant as the basis for three ichnotaxa: Xiangxipus chenxiensis, Xiangxipus youngi, and Hunanpus jiuquwanensis all representing theropodan tracks, described from a single site in 1982. Although the type locality has since been destroyed, the type specimen and replicas remained available for restudy in 2006, when paratype Hunanpus tracks and sauropod footprints were described from a second, nearby locality. Material from both localities is here re-described in detail. It is proposed that while Xiangxipus chenxiensis can be regarded as a distinct ichnospecies, probably representing an ornithomimid trackmaker, Xiangxipus youngi cannot be accommodated in the same ichnogenus. We consider it similar to the ichnogenus Wupus from the Lower Cretaceous of Sichuan Province, and therefore of possible avian affinity. We also find no justification for regarding Hunanpus jiuquwanensis as generically distinct from the widespread ichnogenus Grallator, and therefore rename it Grallator jiuquwanensis comb. nov. The Hunan track record is generally consistent with the sparse record of theropod skeletal remains in the province, but adds evidence of sauropods that was previously lacking. 相似文献
14.
Trackways can provide unique insight to animals locomotion through quantitative analysis of variation in track morphology. Long trackways additionally permit the study of trackmaker foot anatomy, providing more insight on limb kinematics. In this paper we have restudied the extensive tracksite at Barranco de La Canal-1 (Lower Cretaceous, La Rioja, NW Spain) focussing on a 25-m-long dinosaur (ornithopod) trackway that was noted by an earlier study (Casanovas et al., 1995; Pérez-Lorente, 2003) to display an irregular pace pattern. This asymmetric gait has been quantified and photogrammetric models undertaken for each track, thus revealing distinct differences between the right and the left tracks, particularly in the relative position of the lateral digits II–IV with respect to the central digit III. Given that the substrate at this site is homogenous, the consistent repetition of the collected morphological data suggests that differences recorded between the right and the left tracks can be linked to the foot anatomy, but more interestingly, to an injury or pathology on left digit II. We suggest that the abnormal condition registered in digit II impression of the left pes can be linked to the statistically significant limping behaviour of the trackmaker. Furthermore, the abnormal condition registered did not affect the dinosaur's speed. 相似文献
15.
A sample of fallen blocks of fluvial sandstone from the Lower Cretaceous Jiaguan Formation of Sichuan Province yielded an assemblage of dinosaur and pterosaur tracks preserved as natural impressions and casts. Collectively the assemblage reveals 132 tracks representing at least 30 trackways of tridactyl and didactyl theropods, sauropods, ornithopods and pterosaurs. Ichnotaxonomically, the trackways of small tridactyl theropods (pes lengths 7–18 cm) are indeterminable, whereas the trackway of a small didactyl dromaeosaur (pes length up to 7.5 cm) is tentatively assigned to cf. Velociraptorichnus. The sauropod trackways are assigned to cf. Brontopodus based on the medium to nearly wide-gauge pattern. Other characteristics are the U-shaped manus and strong heteropody. One sauropod trackway shows a peculiar pattern with a lack of left manus imprints, and an unusual position and rotation of right manus imprints. Different scenarios and explanations for this phenomenon are discussed. Ornithopod trackways are the most abundant in the sample and characterized by pes imprints of a small biped that are assigned here to the new ichnospecies Caririchnium liucixini. It is characterized by an unusual broad shape and weak mesaxony. Bivariate analysis of different Caririchnium ichnospecies reveals increasing mesaxony toward the larger forms, a trend that is the reverse of typical theropod ichnotaxa, where large imprints have weak mesaxony. Three isolated, small pterosaur tracks (two manus, one pes) are visible on a single surface. They show strong similarities to the widespread ichnogenus Pteraichnus. This is the ninth report of tetrapod tracks from the Jiaguan Formation in recent years and represents one of the most diverse assemblages recorded to date. It is also rare evidence of typical didactyl dromaeosaur tracks and the co-occurrence of sauropod and ornithopod tracks in a fluvial depositional environment representing arid climate conditions. 相似文献
16.
The poor preservation and apparent monospecifity of Permian tetrapod footprints from eolian paleoenvironments have thus far hampered their reliable interpretation. This study clarifies how this is due to distinct and repeated ichnotaphonomic effects on trackway pattern and footprint morphology on originally inclined planes. Once these effects are excluded, the anatomy-consistent ichnotaxobases useful for ichnotaxonomy can be recognized. Several nomina dubia are identified, among these the ichnogenus Chelichnus, here considered a taphotaxon. The eolian ichnoassociations from the Lopingian of Scotland and Germany include six different ichnotaxa: cf. Capitosauroides isp. (?eutheriodont therapsid), Dicynodontipus geinitzi (cynodont therapsid), Dolomitipes isp. (dicynodont therapsid), Pachypes loxodactylus n. comb. (pareiasaurian parareptile), Procolophonichnium isp. (small parareptile) and Rhynchosauroides isp. (non-archosauriform neodiapsid). This is completely different from the interpretations of the last 20 years, which postulated that these paleoenvironments comprised monospecific associations of synapsid tracks. These ichnoassociations are instead moderately diverse, similar to low-latitude marginal marine to floodplain ichnoassociations and belong to the Lopingian Paradoxichnium footprint biochron. The Cornberg Formation of Germany, being constrained between the Illawarra reversal and the mid-Wuchiapingian Kupferschiefer at the Rotliegend/Zechstein transition, constitutes the earliest evidence of Lopingian tetrapod faunas at low paleolatitudes and the first evidence of low-paleolatitude faunal turnover related to the end-Guadalupian mass extinction from both the skeleton and the track record. This suggests a global extension of the dinocephalian extinction event, which occurred at high-mid (South Africa and Russia) and low (Western Europe) paleolatitudes of Pangea about 259–260 Ma and was probably triggered by the eruption of the Emeishan Large Igneous Province of SW China, which considerably changed global environmental conditions in both marine and continental settings. 相似文献
17.
Lida Xing Martin G.Lockley Yongzhong Tang Hendrik Klein W.Scott Persons IV Miaoyan Wang Xingwen Li Hao Wu 《地学前缘(英文版)》2021,12(2):737-745
Poorly preserved tracks have limited ichnotaxonomic or biotaxon utility,but may reveal useful information about the paleoenvironment,behavior and track taphonomy.Eight mostly parallel to sub parallel trackway segments(T1–T8)were registered on a truncation surface in the Lower Cretaceous Luohe Formation of Shaanxi Province.These attest to the passage of several bipeds,probably all theropods,in a paleo-contour-parallel,south-north direction in an arid setting.Quality of preservation in these trackways is poor,but notably superior in two additional trackways(T9–T10)on a foreset surface.Trackway T9 indicates a didactyl trackmaker,probably a deinonychosaurian,heading north to south.This is the 13th report of deinonychosaurian tracks from the Lower Cretaceous of China.If any or all the eight south-north oriented trackway segments represent continuations of other segments in the same trackways,the total number of individual trackmakers heading in this direction may have been as lowas three.Although the trackway pattern and sedimentological evidence could indicate a physically controlled pathway influencing the direction taken by these trackmakers,the possibility that the trackways also represented small social or gregarious group cannot be ruled out. 相似文献
18.
The North American fossil record of dinosaur eggshells for the Cretaceous is primarily restricted to formations of the middle (Albian–Cenomanian) and uppermost (Campanian–Maastrichtian) stages, with a large gap in the record for intermediate stages. Here we describe a dinosaur eggshell assemblage from a formation that represents an intermediate and poorly fossiliferous stage of the Upper Cretaceous, the Santonian Milk River Formation of southern Alberta, Canada. The Milk River eggshell assemblage contains five eggshell taxa: Continuoolithus, Porituberoolithus, Prismatoolithus, Spheroolithus, and Triprismatoolithus. These ootaxa are most similar to those reported from younger Campanian–Maastrichtian formations of the northern Western Interior than they are to ootaxa reported from older middle Cretaceous formations (i.e., predominantly Macroelongatoolithus). Characteristics of the Milk River ootaxa indicate that they are ascribable to at least one ornithopod and four small theropod species. The taxonomic affinity of the eggshell assemblage is consistent with the dinosaur fauna known based on isolated teeth and fragmentary skeletal remains from the formation, although most ornithischians and large theropods are not represented by eggshell. Relative to the Milk River Formation eggshell, similar oospecies occurring in younger Cretaceous deposits tend to be somewhat thicker, which may reflect an increase in body size of various dinosaur lineages during the Late Cretaceous. 相似文献
19.
Yuong-Nam Lee 《Cretaceous Research》1997,18(6):849-864
The ichnofauna of the Woodbine Formation (Cenomanian), Denton County, Texas includes bird and dinosaur tracks. A new bird trackway,Magnoavipes loweiichnogen. et ichnosp. nov., appears to represent the largest bird tracks known from the Mesozoic. A theropod trackway,Fuscinapedis woodbinensisichnogen. et ichnosp. nov., is characterized by long digits of uniform width and pointed small claws. Six hadrosaurid trackways,Caririchnium protohadrosaurichnosichnosp. nov., are the oldest hadrosaurid tracks associated with skeletal elements. They include one isolated small footprint, a medium sized quadrupedal, and five large bipedal hadrosaurid trackways. 相似文献
20.
《Quaternary Science Reviews》2007,26(11-12):1557-1609
High-resolution diatom analysis was carried out to assess the limnological and climatic changes that took place at Ribains maar (French Massif Central) during the Late Pleistocene (∼131–∼105 ka BP), with a focus on the Eemian interglacial in particular. Numerical analyses were used to show that most of the variability in the fossil diatom assemblages was due to climate independently from the changes in the lake catchment vegetation (as represented by pollen data). Diatom-based quantitative reconstructions of the past limnological conditions, as well as a comprehensive literature review on the auto-ecological requirements for the principal diatom taxa, were used to interpret the record. An absolute time-scale for the sequence was derived by matching the major pollen shifts with the radiometrically dated changes in oxygen isotopes observed in Italian stalagmites. This study shows that at Ribains maar, the transition from the Riss (=Saalian) Glacial to the Eemian interglacial was marked by a gradual increase in the contribution of spring-blooming diatom species, indicating a longer growing season and milder winter/spring conditions at that time. A short cooling event interrupts this trend and may correspond to a stadial. At the start of the Eemian a peak in benthic taxa and the suppression of spring-blooming flora probably reflects the effects of deglaciation on the catchment. During the Eemian interglacial itself three main phases were distinguished within the diatom record. The first phase (∼8000 years in duration) was dominated by Stephanodiscus minutulus, which suggests that intense mixing in the water-column took place during spring. The pollen record was simultaneously dominated by Quercus and Corylus that typify this phase as the climatic optimum of the Eemian. The second phase, almost equal in duration to the first phase (∼7000 years), is generally dominated by Cyclotella taxa and suggests a less productive lake and much reduced period of spring mixing compared with the first phase. In the pollen diagram this corresponds to an interval dominated by Carpinus–Picea–Abies that indicates a cooler and wetter climate. The third and last phase of the Eemian, ∼2000 year long, saw the return to Stephanodiscus-dominated assemblages, indicating a warming that may correspond to the Dansgaard–Oeschger event 25 identified in the Greenland ice-core record. In the early stage of the Würm Glacial (=Weichselian), assemblages in the Melisey I stadial (∼3000 year long) were dominated by either Aulacoseira subarctica or Asterionella formosa, which suggest colder spring conditions than during the late Eemian, but not as cold as the ones indicated by the pollen record. Stephanodiscus spp. again dominate during the Saint-Germain Ia interstadial (∼5000 year long) suggesting a return to the conditions that prevailed before the Melisey stadial, in agreement with the pollen record. The record ends with the Montaigu cold event, which is characterised by a Pinus peak in the pollen record, and corresponds to a large abundance of A. subarctica in the diatom sequence. Throughout the Eemian the abundance of Stephanodiscus spp., which is thought to be driven by winter conditions, show cyclic fluctuations that most likely match the cooling events identified in a pollen record from Germany. Variation in insolation throughout the Eemian may have been the driving factor behind the species succession observed in the diatom sequence. While this study demonstrates that diatom analysis of lake sediment can provide very detailed information on long-term climate change, a review of the few other diatom investigations published on European Eemian deposits shows that this technique has been so far seldom used to its full potential in this context in central and southern Europe. 相似文献