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1.
We describe the earliest fossils of the enigmatic avian taxon Opisthocomiformes (hoatzins) from the Oligo-Miocene (22–24 mya)
of Brazil. The bones, a humerus, scapula and coracoid, closely resemble those of the extant hoatzin, Opisthocomus hoazin. The very similar osteology of the pectoral girdle in the new Brazilian fossil compared to the extant O. hoazin, in which it reflects peculiar feeding adaptations, may indicate that hoatzins had already evolved their highly specialized
feeding behavior by the mid-Cenozoic. We further show that Namibiavis senutae from the early Miocene of Namibia is another, previously misclassified representative of Opisthocomiformes, which documents
that the extant Neotropic distribution of hoatzins is relictual. Because of the weak flight capabilities of hoatzins, their
occurrence on both sides of the South Atlantic is of particular biogeographic interest. We detail that this distribution pattern
is best explained by dispersal from Africa to South America, and that Opisthocomiformes provide the first example of transatlantic
rafting among birds. 相似文献
2.
Mayr G 《Die Naturwissenschaften》2005,92(8):389-393
A skeleton of a chicken-sized crane precursor is described from the Lower Oligocene of the Lubéron in Southern France. Parvigrus pohli gen. et sp. nov. is the most substantial Paleogene fossil record of the Grues (Aramidae [limpkin] + Gruidae [cranes]), and
among its oldest representatives. The fossil species is classified in the new taxon Parvigruidae, which is shown to be the
sister group of extant Grues. It is the first fossil record of a stem lineage representative of the Grues and, among others,
differs from modern Grues in its smaller size, shorter beak, and rail-like limb proportions. Size increase in the stem lineage
of the Gruidae may be related to the spread of grasslands during the Oligocene and Miocene. Occurrence of stem lineage Grues
in the Lower Oligocene of Europe is in concordance with the fact that there is no evidence for the presence of crown group
members of modern avian “families” in pre-Oligocene fossil deposits.
Electronic Supplementary Material Supplementary material is available for this article at 相似文献
3.
Peigné S de Bonis L Likius A Mackaye HT Vignaud P Brunet M 《Die Naturwissenschaften》2005,92(6):287-292
We report on the earliest modern mongooses of Africa, from the late Miocene (ca. 7 Ma) of the hominid locality TM 266, Toros-Menalla, Chad. The material is based on fragmentary dentitions of three individuals. The main diagnostic feature of the Chadian species is the great development of the shear in the carnassials, which distinguishes the Chadian specimens from all extant herpestids except Herpestes and Galerella. In comparison with most extinct and extant Herpestes, the species from Toros-Menalla differs by a markedly smaller size and, depending on the species, relatively more elongated carnassials, more transversely elongated M1 and more reduced p4. On the basis of a great morphological similarity and the absence of significant differences, we assign our material to Galerella sanguinea; the Chadian finding therefore represents the earliest appearance of an extant species of Herpestidae. This record ties the first appearance of the genus to a minimum age of ca. 7 Ma, which is consistent with the estimated divergence date of 11.4 Ma known from the literature for the species of Galerella. 相似文献
4.
The recent identification of hoatzins (Opisthocomiformes) in the Miocene of Africa showed part of the evolution of these birds, which are now only found in South America, to have taken place outside the Neotropic region. Here, we describe a new fossil species from the late Eocene of France, which constitutes the earliest fossil record of hoatzins and the first one from the Northern Hemisphere. Protoazin parisiensis gen. et sp. nov. is more closely related to South American Opisthocomiformes than the African taxon Namibiavis and substantiates an Old World origin of hoatzins, as well as a relictual distribution of the single extant species. Although recognition of hoatzins in Europe may challenge their presumed transatlantic dispersal, there are still no North American fossils in support of an alternative, Northern Hemispheric, dispersal route. In addition to Opisthocomiformes, other avian taxa are known from the Cenozoic of Europe, the extant representatives of which are only found in South America. Recognition of hoatzins in the early Cenozoic of Europe is of particular significance because Opisthocomiformes have a fossil record in sub-Saharan Africa, which supports the hypothesis that extinction of at least some of these “South American” groups outside the Neotropic region was not primarily due to climatic factors. 相似文献
5.
Grohé C Chaimanee Y de Bonis L Yamee C Blondel C Jaeger JJ 《Die Naturwissenschaften》2010,97(11):1003-1015
We report new dental remains of Mustelidae from the late middle Miocene of Mae Moh Basin, northern Thailand, improving the
poor fossil record of the family in Southeast Asia. Siamogale thailandica is a poorly known mustelid, previously recorded from just a single tooth. Here we present over a hundred new specimens attributable
to this species. S. thailandica shows a combination of primitive and convergent features of the dentition that makes its original subfamilial assignment
to Lutrinae doubtful. Evidence from the dental morphology suggests that it belongs to a bunodont otter-like mustelid that
evolved in convergence with “true” otters (Lutrinae) toward a semi-aquatic way of life. Autapomorphic features such as the
height and the position of the m1 metaconid and the shape of the P4 lingual shelf make S. thailandica unique among Mustelidae. The morphology of this species is mostly similar to Mionictis species and Lartetictis dubia, reported in the Miocene of North America and Europe, respectively. These similarities could imply immigration events to
Thailand in the early or middle Miocene. Alternately, the lineage leading to Siamogale might have deeper origins from an endemic early Miocene Southeast Asian mustelid. 相似文献
6.
A giant termite is described and figured from the Late Miocene of the Styrian Basin in southeastern Austria. Gyatermes styriensis gen. n. et sp. n. is represented by a relatively complete forewing, with basal scale. The fossil approximates in size the largest of
all termites today and is the largest fossil termite on record. The presence of this species in the Late Miocene fauna of
Europe indicates that climatic conditions were appropriate for the persistence of species and colonies requiring relatively
stable, warm conditions. The genus is primitive in overall features but shares some similarity with the dampwood termites. 相似文献
7.
8.
Hans Pohl Benjamin Wipfler David Grimaldi Felix Beckmann Rolf G. Beutel 《Die Naturwissenschaften》2010,97(9):855-859
Fossilization in amber is unique in preserving specimens with microscopic fidelity; however, arthropod inclusions are rarely
examined beyond the exoskeleton as this requires destructive sampling when traditional techniques are used. We report the
first complete, digital 3D, non-destructive reconstruction of the anatomy of an insect fossil, a specimen of †Mengea tertiaria embedded in a 42-Ma Baltic amber. This was made possible using Synchrotron μ-CT. The species belongs to the stem group of
the phylogenetically enigmatic and extremely specialized Strepsiptera. Most internal structures of the fossil are preserved,
but small parts of the lumen had decayed due to incomplete infiltration of the resin. Data on internal organs provided additional
information for resolving phylogenetic relationships. A sister group relationship between †Mengea and all extant lineages of the group was confirmed with characters previously not accessible. The newly gained information
also yielded some insights in the biology of †Mengea and the early evolutionary history of Strepsiptera. The technique has a tremendous potential for a more accurate interpretation
of diverse fossil arthropods preserved in ambers from 130 Ma to the present. 相似文献
9.
Dietary characterization of the hominoid Khoratpithecus (Miocene of Thailand): evidence from dental topographic and microwear texture analyses 总被引:1,自引:0,他引:1
The genus Khoratpithecus, a hominoid thought to be related to the orangutan lineage, is represented by two known fossil species K. chiangmuanensis and K. piriyai. Both were discovered in Southeast Asia (Thailand) and are dated to the Middle and Late Miocene, respectively. In this study, dental topographic and microwear texture analyses were used to examine molars from both of these species, with the goal of understanding their dietary preferences. Although sample sizes are small for Khoratpithecus, available data are compared to that collected for extant apes. Environmental evidence, such as botanical remains and sedimentological data, is also considered for comparisons with dietary reconstruction. Results from dental topographic analysis suggest that the two fossil species were better adapted to a diet of fruits than to one of leaves, much like the living orangutan or chimpanzee. Results from microwear texture analysis further support this, suggesting that Khoratpithecus preferred soft fruits to hard fruits or seeds. And finally, the botanical and sedimentological evidence point to environments for Khoratpithecus that would have been compatible with a fruit-eating species. Given the small sample sizes available for analysis, however, definitive judgments are not yet possible at this time. 相似文献
10.
Kimura Y 《Die Naturwissenschaften》2011,98(1):87-95
The earliest species of birch mouse, Sicista primus sp. nov., was recovered from the 17-Ma-old (Early Miocene) Gashunyinadege locality, central Nei Mongol, China. It is ~9 Ma
older than the previous first appearance datum of Sicista in Eurasia. This study indicates that North American Macrognathomys is a synonym of Eurasian Sicista, having 12 shared dental characters. As a result, the biogeography of dipodids indicates that Asian Sicista dispersed to North America as opposed to the hypothesis that Sicista originated from the North American clade. Sicista is one of the few extant rodent genera that originated as early as the Early Miocene. 相似文献
11.
Palaeospinacids are a group of basal galeomorph sharks and are placed in the order Synechodontiformes (Chondrichthyes, Neoselachii) ranging from the Permian to the Eocene. Currently, there is a controversy concerning the identity of diagnostic characters for distinguishing palaeospinacid genera because of very similar dental morphologies and the scarcity of articulated skeletal material. The most notable character for distinguishing species within the Palaeospinacidae is, however, the dental morphology. The main dental character uniting all palaeospinacids is the very specialised pseudopolyaulacorhize root vascularisation. A re-examination of articulated neoselachian skeletons from the Lower Jurassic of Lyme Regis (England) and Holzmaden (S Germany), and recently discovered specimens from the Upper Jurassic of the Solnhofen area and Nusplingen (S Germany) has yielded several hitherto unrecognised complete skeletons of the palaeospinacids Synechodus and Paraorthacodus enabling a re-evaluation of characters. These specimens indicate that the number of dorsal fins and the presence or absence of dorsal fin spines represent important features for identifying palaeospinacids. Synechodus bears two dorsal fins without fin spines, whereas Paraorthacodus only has a single dorsal fin lacking a fin spine directly in front of the caudal fin. All palaeospinacids from the Early Jurassic have two spines supporting the dorsal fins and are consequently assigned to a new genus, Palidiplospinax nov. gen. Three species are placed into the new taxon: Synechodus enniskilleni, S. occultidens and S. smithwoodwardi. 相似文献
12.
The presence of salt-excreting glands in extinct marine sauropsids has been long suspected based on skull morphology. Previously,
we described for the first time the natural casts of salt-excreting glands in the head of the Jurassic metriorhynchid crocodyliform
Geosaurus araucanensis from the Tithonian of the Vaca Muerta Formation in the Neuquén Basin (Argentina). In the present study, salt-excreting glands
are identified in three new individuals (adult, a sub-adult and a juvenile) referable to the same species. New material provides
significant information on the salt glands form and function and permit integration of evolutionary scenarios proposed on
a physiological basis in extant taxa with evidence from the fossil record. G. araucanensis represents an advanced stage of the basic physiological model to marine adaptations in reptiles. G. araucanensis salt glands were hypertrophied. On this basis, it can be hypothesized that these glands had a high excretory capability.
This stage implies that G. araucanensis (like extant pelagic reptiles, e.g. cheloniids) could have maintained constant plasma osmolality even when seawater or osmoconforming
prey were ingested. A gradual model of marine adaptation in crocodyliforms based on physiology (freshwater to coastal/estuarine
to estuarine /marine to pelagic life) is congruent with the phylogeny of crocodyliforms based on skeletal morphology. The
fossil record suggests that the stage of marine pelagic adaptation was achieved by the Early Middle Jurassic. Salt gland size
in the juvenile suggests that juveniles were, like adults, pelagic. 相似文献
13.
Direct and indirect fossil records of megachilid bees from the Paleogene of Central Europe (Hymenoptera: Megachilidae) 总被引:1,自引:0,他引:1
Aside from pollen and nectar, bees of the subfamily Megachilinae are closely associated with plants as a source of materials
for nest construction. Megachilines use resins, masticated leaves, trichomes and other plant materials sometimes along with
mud to construct nests in cavities or in soil. Among these, the leafcutter bees (Megachile s.l.) are the most famous for their behaviour to line their brood cells with discs cut from various plants. We report on
fossil records of one body fossil of a new non-leafcutting megachiline and of 12 leafcuttings from three European sites—Eckfeld
and Messel, both in Germany (Eocene), and Menat, France (Paleocene). The excisions include the currently earliest record of
probable Megachile activity and suggest the presence of such bees in the Paleocene European fauna. Comparison with extant leafcuttings permits
the interpretation of a minimal number of species that produced these excisions. The wide range of size for the leafcuttings
indirectly might suggest at least two species of Megachile for the fauna of Messel in addition to the other megachiline bee described here. The presence of several cuttings on most
leaves from Eckfeld implies that the preferential foraging behaviour of extant Megachile arose early in megachiline evolution. These results demonstrate that combined investigation of body and trace fossils complement
each other in understanding past biodiversity, the latter permitting the detection of taxa not otherwise directly sampled
and inferences on behavioural evolution. 相似文献
14.
Venom delivery systems occur in a wide range of extant and fossil vertebrates and are primarily based on oral adaptations.
Teeth range from unmodified (Komodo dragons) to highly specialized fangs similar to hypodermic needles (protero- and solenoglyphous
snakes). Developmental biologists have documented evidence for an infolding pathway of fang evolution, where the groove folds
over to create the more derived condition. However, the oldest known members of venomous clades retain the same condition
as their extant relatives, resulting in no fossil evidence for the transition. Based on a comparison of previously known specimens
with newly discovered teeth from North Carolina, we describe a new species of the Late Triassic archosauriform Uatchitodon and provide detailed analyses that provide evidence for both venom conduction and document a complete structural series from
shallow grooves to fully enclosed tubular canals. While known only from teeth, Uatchitodon is highly diagnostic in possessing compound serrations and for having two venom canals on each tooth in the dentition. Further,
although not a snake, Uatchitodon sheds light on the evolutionary trajectory of venom delivery systems in amniotes and provide solid evidence for venom conduction
in archosaur-line diapsids. 相似文献
15.
Storch G 《Die Naturwissenschaften》2008,95(10):927-930
Most living mammal orders, including our own, started their career during the first 10 million years of the Cenozoic, the
Age of Mammals. The fossil record documents that early Paleogene adaptive radiations of various clades included tiny species
of the size of living shrews. Remains of particularly diminutive limb bones are described from the late Paleocene site of
Walbeck, Sachsen-Anhalt. Discovered in 1939, it has remained the only known Paleocene mammal-bearing locality from Germany.
The remains are referred to the family Adapisoriculidae, which is considered on the basis of the present postcranial evidence
to represent plesiadapiform primates rather than alleged lipotyphlan insectivores as previously proposed. The Walbeck fossils
compete with the Early Eocene species Toliapina vinealis from Europe and Picromomys petersonorum from North America for the status of the smallest known primate, fossil and living. Their estimated body weights are as small
as 10 g. The limb bones show features related to enhanced flexion at the elbow and hip joint, suggesting arboreal habits and
environments such as terminal branches. The diminutive size and tooth morphology suggest feeding on small insects and other
invertebrates. Postcranials are important to assess early radiations, such tiny specimens as the present ones are extremely
scarce in the fossil record, however. 相似文献
16.
Viviparity (giving birth to live young) in fossil reptiles has been known only in a few marine groups: ichthyosaurs, pachypleurosaurs,
and mosasaurs. Here, we report a pregnant specimen of the Early Cretaceous Hyphalosaurus baitaigouensis, a species of Choristodera, a diapsid group known from unequivocal fossil remains from the Middle Jurassic to the early Miocene
(about 165 to 20 million years ago). This specimen provides the first evidence of viviparity in choristoderan reptiles and
is also the sole record of viviparity in fossil reptiles which lived in freshwater ecosystems. This exquisitely preserved
specimen contains up to 18 embryos arranged in pairs. Size comparison with small free-living individuals and the straight
posture of the posterior-most pair suggest that those embryos were at term and had probably reached parturition. The posterior-most
embryo on the left side has the head positioned toward the rear, contrary to normal position, suggesting a complication that
may have contributed to the mother’s death. Viviparity would certainly have freed species of Hyphalosaurus from the need to return to land to deposit eggs; taking this advantage, they would have avoided intense competition with
contemporaneous terrestrial carnivores such as dinosaurs. 相似文献
17.
A new mammal family, Olseniidae, is proposed based on a complete foot skeleton of cf. Olsenia sp. from the Eocene Toru Ajgyr locality in Kyrgyzstan and an astragalus of Olsenia mira from the Eocene Shara Murun locality in northern China. The new form cf. Olsenia sp. is an early ungulate that combines characteristics of mesonychids, perissodactyls and artiodactyls: tetradactyl and paraxonic foot, terminal phalanges claw-like but not fissured, astragalus with shallow proximal caput and without distal trochlea. This unique character set fills a gap in the fossil record and gives insights into the ungulate phylogeny, which is still not completely understood. 相似文献
18.
Cane rats (Thryonomyidae) are represented today by two species inhabiting sub-Saharan Africa. Their fossil record is predominately African, but includes several Miocene species from Arabia and continental Asia that represent dispersal events from Africa. For example, Paraulacodus indicus, known from the Miocene of Pakistan, is closely related to living Thryonomys. Here we describe a new thryonomyid, Protohummus dango, gen. et sp. nov., from the late Miocene Baynunah Formation of the United Arab Emirates. The new thryonomyid is less derived than “Thryonomys” asakomae from the latest Miocene of Ethiopia and clarifies the origin of crown Thryonomys and the evolutionary transition from Paraulacodus. A phylogenetic analysis shows Protohummus dango to be morphologically intermediate between Paraulacodus spp. and extinct and living Thryonomys spp. The morphological grade and phylogenetic position of Protohummus dango further supports previous biochronological estimates of the age of the Baynunah Formation (ca. 6–8 Ma). 相似文献
19.
松属(Pinus L.)约113种,是松科现代属中最原始的类群。松属植物种类丰富且研究领域广泛,对其已经积累的资料数据进行系统梳理总结十分必要。本文通过总结国内外松属大化石资料,结合分子系统发育、地质背景和地理隔离事件讨论了其地史分布及植物地理学意义;该属化石在早白垩世至全新世地层中均有记录。化石证据表明松属很可能在早白垩世(之前)起源于西欧地区,从这一起源地通过北大西洋陆桥扩散到北美洲东部,而东亚的类群可能是从北美洲西部经过白令陆桥散布的。在晚白垩世分化出双维管束松亚属Subgenus Pinus L.及单维管束松亚属Subgenus Strobus (D. Don) Lemmon,前者更接近祖先类群。古新世由于全球显著增温以及白垩纪末期大灭绝等地质事件的影响使松属数量急剧减少,在晚始新世至中新世时期随着气温转凉转冷再次分化扩散,中新世达到其发展高峰且分布面貌与现代类群近似。松属多样性时空历史可能和新生代气候变迁及晚新生代构造运动塑造的山地隆升等环境变化紧密相关。 相似文献