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1.
Manfred Kutscher 《Geobios》2003,36(2):179-194
The Toarcian sediments exposed at Sainte-Verge (Deux-Sèvres, France) are especially rich in echinoderm remains. The present paper describes and illustrates the ophiuroids. On the basis of lateral arm plates, 13 species are distinguished, including two new ones: Sinosura fasciata sp. nov. and Sinosura extensa sp. nov. Most of the recognized species have been recorded previously from the Late Toarcian and Aalenian in Germany and, to a lesser extent, from the late Early Jurassic of England and Switzerland. High similarities between the faunas of northwest Europe suggest a boreal provincialism of ophiuroids. The recognition of 13 species is comparable to the diversity known from other stratigraphic levels (Jurassic and Cretaceous) or in the richest stations of recent oceans. The species association of the Toarcian of Sainte-Verge, with two Ophiolepididae, one Ophiacanthidae, four Ophioleucidae, two Ophiodermatidae, two Ophiuridae, and one Hemieuryalidae may be compared with species associations of recent shelf, offshore environments. Such persistence of components of diversity and ecological affinities of species suggests strong evolutionary conservatism of the ophiuroids, after a rapid radiation during the earliest Jurassic. © 2002 Éditions scientifiques et médicales Elsevier SAS. All rights reserved.  相似文献   

2.
Until the early 1980s, the composition and distribution of the asteroid (starfish), ophiuroid (brittle star) and holothurian (sea cucumber) bottom fauna of the southeastern Weddell Sea was virtually unknown. This southernmost part of the Atlantic sector of the Southern Ocean is a typical high-latitude Antarctic region located in the circumpolar permanent pack-ice zone. It became accessible for large-scale scientific surveys only through the availability of modern ice-breaking research vessels, such as the German RV “Polarstern”. Here, we describe a dataset of the faunal composition and abundance of starfish, brittle star and sea cucumber assemblages in this area, based on collections from trawl catches carried out during three “Polarstern” cruises in 1983, 1984 and 1985. The set comprises a total of 4,509 records of abundances of 35 asteroid species (with a total of 2,089 specimens) and 38 ophiuroid species (with a total of 18,484 specimens) from 34 stations, as well as of 66 holothurian species (with a total of 20,918 specimens) from 59 stations including zero-abundances (absences). A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. Overall, starfishes, brittle stars and sea cucumbers were present at all sites investigated in the study area but composition and abundance of asterozoan (asteroids and ophiuroids together) and holothurian fauna varied considerably. A synthesizing zoogeographical community analysis confirms the presence of three distinct assemblages of asteroids, ophiuroids, and holothurians with highest species richness on the eastern shelf. In the case of asterozoans, water depth and latitude seemed to be the most important drivers of assemblage distribution and composition. One of the holothurian assemblages was part of the rich macrozoobenthic community dominated by a diverse and abundant epifauna, mainly sponges and gorgonians. Another one was mainly composed of vagrant deposit-feeding species inhabiting a predominantly non-colonised substratum. In addition, a mixed holothurian assemblage was identified.  相似文献   

3.
The Upper Cretaceous rocks are widely distributed and well exposed in south Algeria and consist in beds rich in macrofauna. For the first time, twenty veneroid species (Bivalvia) are systematically described from the upper Cenomanian deposits of the Guir Basin. While three species were reported since long before [Granocardium desvauxi (Coquand), G. productum (J. de C. Sowerby) and Glossus aquilinus (Coquand)]; Lucina fallax Forbes, Crassatella (Rochella) tenuicostata (Seguenza), Protocardia hillana (J. Sowerby), G. productum (J. de C. Sowerby) var. byzacenica (Pervinquière), Arctica cordata (Sharpe), A. humei (Cox), A. inornata (d’Orbigny), A. picteti (Coquand), Tenea delettrei (Coquand), Paraesa faba (J. de C. Sowerby), Meretrix desvauxi (Coquand) were previously unknown from the Cretaceous of Algerian Sahara. Because of reduced degree of preservation, Sphaera cf. corrugata J. Sowerby, Maghrebella cf. forgemoli (Coquand), Maghrebella sp., Granocardium cf. carolinum (d’Orbigny), Protocardia sp. and Meretrix sp. are tentatively determined. The studied material, found in the lower part of the “Calcaires de Sidi Mohamed Ben Bouziane” Formation, evidences palaeobiogeographic affinities occurring over a wide geographical area: from North Africa, southern Europe to Middle East and India. The present study provides new information to the knowledge of the upper Cenomanian palaeobiology of the studied region.  相似文献   

4.
Changes in ostracod occurrence and assemblage composition from the Cenomanian of the Tarfaya Basin (Morocco) are investigated in order to evaluate their potential for palaeoenvironmental analyses of Cretaceous upwelling regions. Most frequent genera found at Tarfaya are Brachycythere, Veenia, Reticulocosta, Cytherelloidea, and Nigeroloxoconcha. Assemblages found at Tarfaya are characterised by low diversities. Successive appearance of assemblages dominated by these genera represents a depth gradient, corresponding to the results of the performed correspondence analysis. Ostracods are most abundant if associated either with moderate food supply and sufficient oxygenation or high food supply and high oxygenation. They disappear almost completely during permanent oxygen deficiency and are, contrary to benthic foraminifera, less frequent during periods of enhanced food supply. Species of the genus Brachycythere appear to be more sensitive to oxygen deficiency than other genera. Reticulocosta and Cytherelloidea avoid strong food pulses and are probably better adapted to oxygen depletion than other genera. Ostracods appear to be powerful environmental indicators for sea-level changes, oxygenation or food supply in Late Cretaceous upwelling settings, such as in the Cenomanian Tarfaya Basin.  相似文献   

5.
In Saxony (southeast Germany), the global early Late Cretaceous transgression is reflected by the onlap of shallow-marine siliciclastics of the lower Upper Cenomanian Oberhäslich Formation (Calycoceras naviculare Zone) onto the eastern Erzgebirge, the central part of the emergent Mid-European Island. Based on detailed logging of sections south of Dresden and the study of extensive collection material, the depositional environment and macroinvertebrate assemblages of the Oberhäslich Formation have been reconstructed. This unit, with a mean thickness of 10–15 m, usually shows a fining-upward trend that may become reversed towards the top, was laid down in a single 3rd-order sea-level cycle and is capped by an unconformity at the base of the overlying upper Upper Cenomanian Dölzschen Formation (sequence boundary Cenomanian 5; junction of the Calycoceras naviculare and Metoicoceras geslinianum zones). The macroinvertebrate assemblage of the Oberhäslich Formation, collected mainly from bioturbated, fine- or rarely medium-grained, quartz-rich sandstones, is fairly diverse, comprising nearly 50 taxa, predominantly bivalves (94.3%). Most conspicuous and abundant are relatively large forms such as Rhynchostreon (R.) suborbiculatum (25%) and Inoceramus pictus spp. (21%), eponymous taxa of the Rhynchostreon suborbiculatum/Inoceramus pictus assemblage. Non-bivalve benthic invertebrates are rare and represented by rather poorly preserved irregular and regular echinoids, siliceous sponges, a few gastropods, crustacean remains and a single starfish. Common Thalassinoides and Ophiomorpha burrows indicate that crustaceans were an important part of the infauna. Pervasive bioturbation resulted in a post-depositional homogenization of the sediments while all body fossils are preserved as (composite) internal moulds. The guild structure of the Rhynchostreon suborbiculatum/Inoceramus pictus assemblage shows a predominance of epifaunal and semi-infaunal suspension feeders (95.3%), suggesting eutrophic and unstable “green-water conditions” of an inner-shelf setting. Deposit-feeding biota are rare. The common occurrence of articulated bivalves and storm-induced shell beds indicate episodic rapid burial, most probably by tempestites. A current-influenced, well-oxygenated and nutrient-rich environment slightly below fair-weather base is inferred for the fine-grained sandy, fossiliferous sediments of the Oberhäslich Formation.  相似文献   

6.
A mannan-binding lectin activity was revealed in the coelomic fluid of the following echinoderm species inhabiting the coastal areas of the Sea of Japan, the holothurian Eupentacta fraudatrio, sea urchins Echinocardium cordatum, Strongylocentrotus nudus and S. intermedius, brittle star Amphipholis kochii, sea stars Asterina pectinifera, Lethasterias fusca, Lysastrosoma anthosticta, and Distolasterias nipon. It was shown that, concurrently with the general pattern of lectin interaction with branched bacterial mannans, there were also distinctions caused by the fine carbohydrate specificity of lectins. The obtained data preconditioned the further study of physical and chemical properties and structural features of the echinoderm MBL and the revelation of their role in the formation of the adaptive immune response and in other biological processes.  相似文献   

7.
The preservation of non-mineralized tissues in the fossil record is extremely rare. The Lower Devonian Hunsrück Slate of Germany has long been known for the preservation of non-mineralized tissues in pyrite but whether or not these remnants represent true soft tissues has been questioned. This is especially true for struetures visible only on radiographs that are too delicate for excavation by traditional methods. Here we report the discovery of well-preserved pyritized tube feet in six fully prepared specimens of the protasterid brittle starBundenbachia beneckei from the Hunsrück Slate. This discovery represents the first report of fossilized ophiuroid tube feet in the fossil record. The successful excavation of the delicate tube feet was made possible by improved airbrasive techniques developed by German fossil collectors. The relatively large size of the fossil tube feet inBunden-bachia beneckei is consistent with earlier inferences on size based on the presence of large podial basins. Protasterid ophiuroids lack the specialized arm musculature and articulations that provide increased flexibility and strength to the arms of modern ophiuroids with typically reduced tube feet. How-ever, tube foot form and perhaps function inBundenbachia might have been similar to those of living asteroids in which large tube feet are used primarily for locomotion and food-manipulation thus compensating for a lack of specialized arm musculature and articulation. Hence, feeding and life mode of protasterid ophiuroids was not necessarily limited to sedentary, infaunal microphagy as traditionally suggested. Two Hunsrück protasterid ophiuroids,Bundenbachia benecki andPalaeophiomyxa grandis are redescribed and compared.   相似文献   

8.
Well-preserved Cretaceous (Albian–Turonian) radiolarians were extracted from radiolarian-bearing chert olistoliths of the Monagroulli Member within the Moni Mélange (Campanian-Maastrichtian, Southern Cyprus). Four assemblages were distinguished: Middle Albian–Lower Cenomanian (Thanarla spoletoensis Zone), Upper Albian–Lower Cenomanian (Thanarla spoletoensis Zone, Dorypyle? anisa Subzone), lowermost Turonian (base of Alievium superbum Zone) and Lower Turonian (Alievium superbum Zone). The radiolarian assemblages are diverse and have taxonomic composition similar to coeval assemblages of Italy and Spain. The sediments of the Monagroulli Member differ from coeval rocks of the Mamonia Complex (western Cyprus) by the more common presence of radiolarian cherts and may have been formed in the distal part of a continental margin with less input of clastic material. A new spicular radiolarian genus Cyprothamnus with 2 new species (C. multifurcatus and C. moniensis) is described from the Lower Turonian strata.  相似文献   

9.
Coiffard, C. & Gomez, B. 2009: The rise to dominance of the angiosperm kingdom: dispersal, habitat widening and evolution during the Late Cretaceous of Europe. Lethaia, Vol. 43, pp. 164–169. The earliest fossil records of angiosperms in Europe occur in the Barremian and consist of freshwater wetland plants. From the Barremian onwards, angiosperms show a stepwise widening of their ecological range with the result that they inhabited most environments by the Cenomanian. Nevertheless, most angiosperms had still restricted habitats, while a few angiosperm trees were confined to disturbed environments, such as channel margins. A Wagner’s Parsimony Method analysis performed on a fossil plant and locality database from the Turonian to the Campanian of Europe indicates continued decrease in richness of ferns and gymnosperms compared with angiosperms, turnover between conifer and palm trees in freshwater‐related swamps at about the Cenomanian/Turonian boundary, and spreading of angiosperm trees through the floodplains. The ecological range of angiosperm trees was increased, being recorded in channel margins from the Cenomanian and spreading over floodplains (e.g. Platanaceae) and swamps (e.g. Arecaceae) by the Campanian. These new ecological ranges and successions went with innovative architectures, such as dicot trees and palm trees. Most living core angiosperm families had their earliest representatives in the Late Cretaceous, which should be considered as the dawn of modern angiosperm forests. □Core angiosperms, Europe, Late Cretaceous, palms, Wagner’s Parsimony Method.  相似文献   

10.
Composition and distribution of asteroid and ophiuroid assemblages were investigated by means of Agassiz trawl catches at 34 stations in 220- to 1,200-m depth in the Weddell Sea and at 17 stations in 90- and 830-m depth off Northeast Greenland. A total of 86 species (48 sea stars, 38 brittle stars) were identified in the Weddell Sea whereas off Northeast Greenland a total of 26 species (16 sea stars, 10 brittle stars) were recorded. In both study areas, brittle stars were numerically more important than sea stars, and abundances generally decreased with water depths. Multivariate analyses revealed a conspicuous depth zonation of sea and brittle stars off Greenland. Very high abundances of Ophiocten sericeum and Ophiura robusta characterized the assemblages on shallow shelf banks whereas in greater depths Ophiopleura borealis, Ophioscolex glacialis and Ophiacantha bidentata became dominant, albeit at significantly lower densities. Mass occurrences of brittle stars, such as those recorded on Greenlandic shelf banks, have not been discovered in the Weddell Sea, where distinct assemblages were discriminated in deep shelf trenches as well as on the eastern and southern shelf. Ophioplocus incipiens, Ophiurolepis martensi and Ophiurolepis brevirima were the most prominent species on the eastern shelf. Ophiacantha antarctica, Ophiurolepis gelida and Ophionotus victoriae on the southern shelf, and Ophiosparte gigas as well as the asteriod Hymenaster sp., in the shelf trenches. Overall, the Weddell Sea housed conspicuously more asterozoan species than the waters off Greenland. Higher species diversity was also evident at both a regional and local scale, especially for the eastern Weddell Sea shelf. However, because many species from the Weddell Sea are closely related, the Weddell Sea assemblages were not significantly different from the Greenland ones in terms of taxonomic diversity and distinctness. Received: 29 April 1996/Accepted: 10 June 1996  相似文献   

11.
《Annales de Paléontologie》2017,103(3):185-196
In the southwestern part of Algeria, the Cenomanian-Turonian marine deposits build up a prominent ledge in a perched syncline (Ksour Mountains, western Saharan Atlas) or at high radius of curvature (Guir Basin). The petrographical analysis of the Cenomanian-Turonian deposits of the Ksour Mountains and of the Guir Basin reveals unexpected assemblages of roveacrinoidal ossicles comparable with those formerly reported from the Tinrhert area. For the first time, isolated ossicles of genuine and undisputable Roveacrinidae are illustrated. Three sections, Djebel Rhoundjaia (western Saharan Atlas), Berridel and Kénadsa (Guir Basin), were scrutinized to recognize the microcrinoidal sections within the carbonate microfacies and to compile the successive occurrence of respective roveacrinid taxa (besides the classical search for standard index microfossils) in an attempt to pinpoint more precisely the position of the Cenomanian-Turonian boundary (C/T B). These assemblages are particularly morphologically and taxonomically diverse with three species of genus Roveacrinus and one of genus Orthogonocrinus. The presence of Saccocomidae (Applinocrinus) is especially unusual in such stratigraphic levels. The relative abundance and diversity of Roveacrinidae evidence a peak when approaching the C/T B. Such an event is recurring in the latest Cenomanian in various Tethyan and Atlantic areas. These fluctuations are consistent with a high surface-water productivity just before the C/T B.  相似文献   

12.
Peter M. Galton 《Geobios》1980,13(6):825-837
Hitherto the earliest positive record of ankylosaurs(armored dinosaurs) has been from beds well up in the Lower Cretaceous; in fact, however, specimens referable to the ankylosaurian family Nodosauridae are present in the Middle and Upper Jurassic of England: from the Middle Callovian [partial mandible Sarcolestes leedsiLydekker]], the Upper Oxfordian [femur Cryptodraco eumerus (Seeley)), maxilla Priodontognathus phillipsii (Seeley))], and the Upper Tithonian [caudal vertebra, tooth]. The Tithonian tooth and those of Priodontognathus are large and similar to those of the nodosaurids Priconodon and Sauropelta (Lower Cretaceous, U.S.A.). The incomplete mandible of Sarcolestes is similar to that of Sauropelta with a dermal scute fused to the lateral surface, and a tooth row extending to the anterior end of the jaw; an unusual feature is the caniniform first tooth. The quadrupedal ankylosaurs and stegosaurs probably represent separate evolutionary lines that extend back at least into the Lower Jurassic, and both lines probably evolved from ornithopod dinosaurs that were bipedal. Nodosaurid ankylosaurs occur in Europe from the Middle Jurassic to Late Cretaceous and probably reached North America via a filter route in the early Cretaceous.  相似文献   

13.
When comparing boreal radiolarian assemblages of the Triassic and Late Cretaceous, significant differences in their morphotypic composition are recognized. In particular, Triassic assemblages are dominated by spherical morphotypes, including pylomate forms of the genus Glomeropyle, while Late Cretaceous assemblages are dominated by prunoid morphotypes without polar spines (genera Prunobrachium and Amphibrachium). It is concluded that, in the course of evolution, high-latitude radiolarian assemblages considerably changed both taxonomically and morphologically. Therefore, it is impossible to determine the uniform morphological and taxonomic characters describing boreal assemblages of the entire Mesozoic. Features of boreal radiolarian assemblages are unique to each geological epoch.  相似文献   

14.
The only previously known Mesozoic fossils of the chilopod order Geophilomorpha are two species from the Late Jurassic and Late Cretaceous, both known from single specimens that cannot be assigned with precision to a family. Four specimens from the Late Cretaceous (earliest Cenomanian) amber of Burma include three that can be identified as conspecific, described here as Kachinophilus pereirai gen. nov. sp. nov. These specimens preserve greater morphological detail in comparison with other fossil geophilomorphs: the form and fine features of the head, the maxillary complex, the trunk sternites with associated glandular pores and the ultimate pair of legs defend the assignment of the species to the extant family Geophilidae, and most probably to a derived subgroup including well‐known extant genera such as Ribautia Brölemann, 1909. Confocal laser scanning microscopy supplements examination under incident and transmitted light to document details of high taxonomic relevance in the head and the forcipular segment. The modern appearance of this species and its membership among deeply nested extant clades are consistent with molecular estimates that most of the diversity of crown‐group Geophilomorpha originated before the Late Cretaceous.  相似文献   

15.
A large sample of more than 100 teeth of the titanosaurian sauropod Lirainosaurus astibiae from the Late Cretaceous Laño quarry (Northern Spain) has been studied. Most of the teeth are small (crown height less than 13 mm), cylindrical, with parallel edges and smooth enamel; a few larger teeth are tapered and have more ornamented enamel. These differences are regarded here as ontogenetic changes, the small teeth being interpreted as those of juveniles and the large ones as those of subadult or adult individuals. The juvenile teeth also present some differences in the apex of the crown: some of them have a tapered tip, and others have apical and/or mesial/distal facets. The first are probably unerupted or non-functional teeth, while the ones with wear facets are functional teeth. This is the first time a change in the microwear structures of the apical wear facets between juvenile and adult teeth is observed in a titanosaurian taxon. Moreover, this let us to hypothesize a switch in the diet and food processing between the juvenile and adult individuals of Lirainosaurus. Finally, the teeth of Lirainosaurus are different from those of the Late Cretaceous European titanosaurs described to date and also differ from the teeth of basal titanosauriforms from the Early Cretaceous of the Iberian Peninsula.  相似文献   

16.
Two isolated trunk vertebrae from the ?uppermost Albian–lower Cenomanian Kem Kem beds of Morocco are described and assigned to Lapparentophis, an early snake genus known from coeval deposits in Algeria. The Moroccan specimens represent a new species, Lapparentophis ragei, which can be distinguished from the type and only known species, Lapparentophis defrennei, by its smaller size, its more elongate vertebrae, the presence of parazygosphenal foramina, and paradiapophyses extending anteroventrally closer to the cotyle. The discovery of Lapparentophis in the Kem Kem beds adds to the relatively diverse snake assemblage previously reported from this formation and extends the geographical range of the genus. The distribution of Lapparentophis and lapparentophiid-grade (?lapparentophiid) snakes is discussed. This poorly known family of terrestrial snakes seems to be restricted to the latest Albian–early Cenomanian of North Africa, with the exception of Pouitella from the early–middle Cenomanian of France. As for many other vertebrate taxa of this period, this distribution is consistent with a dispersal event from Africa to the western part of the European archipelago.  相似文献   

17.
The early late Cretaceous (Cenomanian–early Turonian) is thought to have been one of the warmest periods of the Phanerozoic. This period was characterised by tropical sea surface temperatures of up to 36 °C and a pole-to-equator-gradient of less than 10 °C. The subsequent Turonian–Maastrichtian was characterised by a continuous climatic cooling, peaking in the Maastrichtian. This climatic cooling and the resulting palaeoceanographic changes had an impact on planktic primary producer communities including calcareous nannofossils. In order to gain a better understanding of these Cenomanian–Maastrichtian palaeoceanographic changes, calcareous nannofossils have been studied from the proto North Atlantic (Goban Spur, DSDP Sites 549, 551). In order to see potential differences between open oceanic and shelf dwelling nannofossils, the data from Goban Spur have been compared to findings from the European shelf (northern Germany).A total of 77 samples from Goban Spur were studied for calcareous nannofossils revealing abundant (mean 6.2 billion specimens/g sediment) and highly diverse (mean 63 species/sample) nannofossil assemblages. The dominant taxa are Watznaueria spp. (mean 30.7%), Prediscosphaera spp. (mean 18.3%), Zeugrhabdotus spp. (mean 8.3%), Retecapsa spp. (mean 7.2%) and Biscutum spp. (mean 6.6%). The Cenomanian assemblages of both Goban Spur (open ocean) and Wunstorf (shelf) are characterised by elevated abundances of high fertility taxa like Biscutum spp., Zeugrhabdotus spp. and Tranolithus orionatus. Early Turonian to Maastrichtian calcareous nannofossil assemblages of Goban Spur are, however, quite different to those described from European sections. Oceanic taxa like Watznaueria spp., Retecapsa spp. and Cribrosphearella ehrenbergii dominate in Goban Spur whereas the fertility indicators Biscutum spp. and T. orionatus are more abundant in the European shelf assemblages. This shift from a homogeneous distribution of calcareous nannofossils in the Cenomanian towards a heterogeneous one in the Turonian–Maastrichtian implies a change of the ocean circulation. The “eddy ocean” system of the Cenomanian was replaced by an oceanic circulation similar to the modern one in the Turonian–Maastrichtian, caused by the cooling. The increased pole-to-equator-gradients resulted in an oceanic circulation similar to the modern one.  相似文献   

18.
The French dinosaur record is one of the most extensive in Europe; it ranges stratigraphically from the Late Triassic to the Latest Cretaceous. All major clades of dinosaurs but marginocephalians are known. About 20 species are based on significant material; the theropods are the best represented. Most of these taxa have been described or revised in recent years. Important specimens have been discovered in the Late Triassic of eastern France, the Middle Jurassic of Normandy, and the Late Cretaceous of Provence and Languedoc. The ichnological record is good for the Late Triassic-Early Jurassic, and the Late Cretaceous egg sites are among the richest in the world. To cite this article: R. Allain, X.P. Suberbiola, Palevol 2 (2003) 27–44.  相似文献   

19.
《Annales de Paléontologie》2017,103(2):135-139
Gargantuavis philoinos is a large terrestrial bird, initially described from several bones (synsacrum, cervical vertebra, femora) discovered in the Late Cretaceous deposits of southern France. The synsacrum described here comes from the late Campanian (Late Cretaceous) site of Laño, in north-western Spain, and is similar in all respects to the other synsacra of Gargantuavis philoinos described from France. This is therefore the first specimen attributed to this species to be reported outside France. This find increases the diversity of the fossil assemblage from Laño and the geographical distribution of this bird, which existed on the Ibero-Armorican island, which included southern France and the Iberian Peninsula, during the Late Cretaceous.  相似文献   

20.
The classic leaf fossil floras from the Cretaceous of the Lusitanian Basin, Portugal, which were first described more than one hundred years ago, have played an important role in the development of ideas on the early evolution of angiosperms. Insights into the nature of vegetational change in the Lusitanian Basin through the Cretaceous have also come from studies of fossil pollen and spores, but the discovery of a series of mesofossil floras containing well-preserved angiosperm reproductive structures has provided a new basis for understanding the systematic relationships and biology of angiosperms at several stratigraphic levels through the Cretaceous. In the earliest mesofossil floras from the Torres Vedras locality, which are of probable Late Barremian-Early Aptian age, angiosperms are surprisingly diverse with about 50 different taxa. In slightly later mesofossil floras, which are of probable Late Aptian-Early Albian age, the diversity of angiosperms is still more substantial with more than hundred different kinds of angiosperm reproductive structures recognized from the Famalicão locality alone. However, this early diversity is largely among angiosperm lineages that produced monoaperturate pollen (e.g., Chloranthaceae, Nymphaeales) and early diverging monocots (Alismatales). Eudicots are rare in these Early Cretaceous mesofossil floras, but already by the Late Cenomanian the vegetation of the western Iberian Peninsula is dominated by angiosperms belonging to various groups of core eudicots. The Normapolles complex is a particularly conspicuous element in both mesofossil floras and in palynological assemblages. In the Late Cretaceous mesofossil floras from Esgueira and Mira, which are of Campanian-Maastrichtian age, core eudicots are also floristically dominant and flowers show great organisational similarity to fossil flowers from other Late Cretaceous floras described from other localities in Asia, Europe and North America.  相似文献   

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