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1.
A new exceptionally brevirostrine dyrosaurid is described from the middle Palaeocene (58–60 million years ago) Cerrejón Formation, northeastern Colombia, based on four partial skulls and associated postcrania. This taxon is unique among dyrosaurids not only in skull shape, but also in having orbital tuberosities, and osteoderms that are dorsoventrally thick and unpitted, a trait otherwise unknown in Crocodylomorpha. Results from a cladistic analysis of Dyrosauridae suggest that the new taxon, together with Cretaceous–Palaeocene Chenanisuchus lateroculi from Africa and Cerrejonisuchus improcerus also from the Cerrejón Formation, are the most basal members of the family. Results from a biogeographic analysis indicate at least three independent dispersals of dyrosaurids from Africa to the New World occurred in the Late Cretaceous or early Palaeocene. Widely set orbits in the new taxon indicate a deviation from surface-based predation, characteristic of other dyrosaurids, to sub-surface predation, as in modern Gavialis. Tooth impressions found on turtle shells recovered from the same locality match well with teeth of the new taxon indicating possible predation.http://www.zoobank.org/urn:lsid:zoobank.org:pub:AB2B24A5-27CC-4D3F-B580-F11F17851CE6  相似文献   

2.
The tropical Asian taxa of the species‐rich genus Solanum (Solanaceae) have been less well studied than their highly diverse New World relatives. Most of these tropical Asian species, including the cultivated brinjal eggplant/aubergine and its wild progenitor, are part of the largest monophyletic Solanum lineage, the ‘spiny solanums’ (subgenus Leptostemonum or the Leptostemonum clade). Here we present the first phylogenetic analysis of spiny solanums that includes broad sampling of the tropical Asian species, with 42 of the 56 currently recognized species represented. Two nuclear and three plastid regions [internal transcribed spacer (ITS), waxy, ndhF‐rpL32, trnS‐trnG and trnT‐trnF] were amplified and used to reconstruct phylogenetic relationships using maximum likelihood and Bayesian methods. Our analyses show that Old World spiny solanums do not resolve in a single clade, but are part of three unrelated lineages, suggesting at least three independent introductions from the New World. We identify and describe several monophyletic groups in Old World solanums that have not been previously recognized. Some of these lineages are coherent in terms of morphology and geography, whereas others show considerable morphological variation and enigmatic distribution patterns. Tropical Asia occupies a key position in the biogeography of Old World spiny solanums, with tropical Asian taxa resolved as the closest relatives of diverse groups of species from Australia and Africa.  相似文献   

3.
We studied anti‐predator strategies in nine species of tarantulas from Asia, Africa, and the Americas. Tarantulas in the New World possess urticating hairs which induce inflammation when in contact with vertebrate mucus membranes and skin. In contrast, tarantulas from the Old World lack this defense but are observed to exhibit a much greater willingness to escalate to an active defense when provoked. We had three goals: (1) describe the behaviors exhibited by each taxon in response to two levels of provocation, (2) look for the presence of alternative classes of anti‐predator strategy as predicted by the Old World–New World dichotomy in aggressive defense, and (3) examine the evolution of these behaviors in the context of the phylogeny of the group. We compared the response of nine different mygalomorph spider genera to two levels of aversive stimuli: puffs of air and prodding. We found that the overall structure of the defensive behavior was similar between the different taxa, consisting of fleeing, rearing, striking, and biting. Some genera did exhibit unique behaviors such as stridulating (Hysterocrates) or rocking (Haplopelma and Selenocosmia). We found that the genera from the New World exhibited low levels of escalation in their defense behaviors, while those from the Old World readily escalated to striking and biting. Our findings are consistent with the hypothesis that the possession of urticating hairs is associated with very low levels of active defense behaviors such as striking and biting. The phylogenetic analysis indicates that both the notable levels of aggression displayed by the African taxa tested and the relative passivity of the New World tarantulas each represents a synapomorphy.  相似文献   

4.
5.
Abstract:  New material of a long-snouted dyrosaurid has been discovered in the Paleocene of Morocco. It consists of a well-preserved skull with embedded mandible and four dorsal vertebrae. The particularly elongate snout, proportionally the longest of all known dyrosaurids, allows precise identification of this material as Atlantosuchus coupatezi Buffetaut, 1979 a , and presentation of an emended diagnosis for this species previously known only from a mandibular symphysis. A phylogenetic analysis of the dyrosaurids indicates a close relationship between A. coupatezi and Rhabdognathus . It also confirms a previous hypothesis that Congosaurus is distinct from Hyposaurus . It is more closely related to Atlantosuchus than Hyposaurus . The analysis also allows palaeobiogeographic interpretations to be made. Dyrosaurids ranged from North Africa to other areas. They were rare during the Maastrichtian and endemic to each continent at this time. Competition with large marine reptiles, such as mosasaurs, limited their dispersal during the Late Cretaceous. The disappearance of these rivals during the 'K-T crisis' enabled their diversification and widespread dispersal during the Paleocene, with the same genera present on several continents.  相似文献   

6.
Myriophora is the most species‐rich group of parasitoids that attack toxic, chemically defended millipedes in the superorder Juliformia and order Polydesmida—a resource that few insect predators and parasitoids are able to exploit. Worldwide, there are an estimated 200 species of Myriophora, with the majority of the diversity centred in the Neotropical region. The phylogeny of Myriophora is unknown, biogeographical patterns are not documented, and known host associations have not been assessed in a phylogenetic context. We provide the first phylogenetic study of the genus from a data set composed of 52 taxa primarily from the Neotropical region including 10 outgroups, 40 morphological characters, and molecular data from three mitochondrial (16S, COI and ND1) and one nuclear marker (AK). We find that Myriophora dispersed from the New World to the Old World in a single event before subsequently spreading to the Afrotropical region. The ancestral hosts reconstructed for Myriophora are the benzoquinone‐producing Juliformia, and this association has been retained in the Old World clade. In the Neotropical region, Myriophora that are associated with cyanide‐producing polydesmidan millipedes are confined to a single clade that shows remarkably little genetic variation between clearly morphologically diagnosable species.  相似文献   

7.
An investigation of intraspecific habitat‐related patterns of variation in oculoscapular lateral‐line superficial neuromasts (SN) identified a decrease in the ratio of total SNs to pores, and a trend towards decreased asymmetry in SNs in the habitat‐generalist common bully Gobiomorphus cotidianus from fluvial habitats compared to lacustrine habitats, suggesting habitat‐related phenotypic variability. A greater ratio of pores to SNs, as well as less variation in the total number and asymmetry of SNs observed in the fluvial habitat‐specialist redfin bully Gobiomorphus huttoni may provide further evidence of variations in the oculoscapular lateral‐line morphology of fluvial habitat G. cotidianus individuals serving as adaptations to more turbulent environments.  相似文献   

8.
Lithospermum (Boraginaceae) comprises approximately 40 species in both the Old and New Worlds, with a center of diversity in the southwestern United States and Mexico. Using ten cpDNA regions, a phylogeny of Lithospermum and related taxa was reconstructed. Lithospermum (including New World and Old World species) and related New World members of Lithospermeae form a monophyletic group, with Macromeria, Onosmodium, Nomosa, Lasiarrhenum, and Psilolaemus nested among species of Lithospermum. New World Lithospermeae also is a monophyletic group, with Eurasian species of Lithospermum sister to this group. Because Lithospermum is not monophyletic without the inclusion of the other New World genera, species from these genera are transferred to Lithospermum, and appropriate nomenclatural changes are made. New combinations are Lithospermum album, Lithospermum barbigerum, Lithospermum dodrantale, Lithospermum exsertum, Lithospermum helleri, Lithospemum leonotis, Lithospermum notatum, Lithospermum oaxacanum, Lithospermum pinetorum, Lithospermum rosei, Lithospermum trinverium, and Lithospermum unicum; new names are Lithospermum chiapense, Lithospermum johnstonii, Lithospermum macromeria, Lithospermum onosmodium, Lithospermum rzedowskii, and Lithospermum turneri.  相似文献   

9.
Upper Maastrichtian to lower Paleocene, coarse‐grained deposits of the Lefipán Formation in Chubut Province, (Patagonia, Argentina) provide an opportunity to study environmental changes across the Cretaceous–Palaeogene (K–Pg) boundary in a shallow marine depositional environment. Marine palynological and organic geochemical analyses were performed on the K–Pg boundary interval of the Lefipán Formation at the San Ramón section. The palynological and organic geochemical records from the San Ramón K–Pg boundary section are characteristic of a highly dynamic, nearshore setting. High abundances of terrestrial palynomorphs, high BIT‐index values and the occasional presence of plant fossils are indicative of a large input of terrestrial organic material. The organic‐walled dinoflagellate cyst (dinocyst) assemblage is generally dominated by Senegalinium and other peridinioid dinocyst taxa, indicative of high‐nutrient conditions and decreased salinities, probably associated with a large fluvial input. The reconstructed sea surface temperatures range from 25°C to 27°C, in accordance with the tropical climate inferred by palynological and megafloral studies. As in the Bajada del Jagüel section, ~500 km north‐north‐east of San Ramón, peaks of Senegalinium spp. were recorded below and above the K–Pg boundary, possibly related to enhanced runoff resulting from more humid climatic conditions. The lithological, palynological and organic geochemical records suggest the occurrence of a sea‐level regression across the K–Pg boundary, resulting in a hiatus directly at the boundary in both sections, followed by a transgression in the Danian.  相似文献   

10.
Phylogenetic analysis of the New World Ptininae (Coleoptera: Bostrichoidea)   总被引:2,自引:0,他引:2  
A phylogenetic analysis of the New World Ptininae (Anobiidae) was conducted with representatives of nine of ten New World genera, several Old World genera and seven more of the ten subfamilies of Anobiidae. One hundred and two characters (forty‐three multistate) from thirty‐four taxa were used. The single cladogram shows Ptininae as monophyletic and the sister group of the remaining Anobiidae, supporting their placement as subfamilies of a monophyletic Bostrichidae. Genus Niptus Boieldieu is polyphyletic supporting recognition of Pseudeurostus Heyden and the creation of a new genus to encompass the remaining New World species of Niptus. Flightlessness has evolved a minimum of three times within Ptininae and myrmecophily has probably evolved three times within just the New World taxa. The classifications of Ptininae and the remaining Anobiidae are examined and the evolution of feeding habits, myrmecophily and wing loss are discussed.  相似文献   

11.
Chloroplast DNA restriction site variation was examined for 35 taxa in theVernonieae and four outgroup tribes, using 17 restriction enzymes mapped for ca. 900 restriction sites per species; 139 mutations were found to be phylogenetically informative. Phylogenetic trees were constructed using Wagner and weighted parsimony, and evaluated by bootstrap and decay analyses. Relationships of Old and New World taxa indicate complex geographical relationships; there was no clear geographic separation by hemisphere. The relationships between Old and New World Vernonias found here support prior morphological analyses. The sister group to all New and most Old World taxa was composed of a small group of Old World species including yellow-flowered, trinervate-leaved species previously postulated to be basal in the tribe. The majority of both New and Old World taxa are derived from a lineage beginning with the monotypic genusStokesia, an endemic of the southeastern United States. The genusVernonia was also found to be paraphyletic within both the New and Old World. Available data do not support either the separation ofVernonia or the tribeVernonieae into geographically distinct lineages. The pattern of relationships within theVernonieae for taxa from North America, Asia, Africa, Central and South America is most similar to that of several other groups of both plants and animals with a boreotropical origin, rather than an origin in Gondwanaland. Such a pattern of distribution suggests more ancient vicariant events than are routinely postulated for theAsteraceae.  相似文献   

12.
A partial sequence of the cytb gene (382 bp) was amplified and sequenced from 35 individuals (mainly museum specimens) of the genus Pernis representing all valid taxa (10) and two taxa (P. p. gurneyi, P. p. japonicus) with questionable validity as well as representatives of the Old World Perninae, namely Henicopernis and Aviceda, to assess their relationships to the genus Pernis. Furthermore, Gypaetus barbatus, Neophron percnopterus, and Buteo buteo were included as outgroup taxa. In the trees derived from the sequence data, Aviceda represents the sister group of the genus Pernis. The genus Henicopernis and the Old World vultures Gypaetus andNeophron appear rather distantly related to Pernis. Within the genus Pernis, two of the described species (Pernis apivorus, Pernis ptilorhyncus) form monophyletic groups, whereas the relationships of the two clades representing three subspecies of Pernis celebensis are still uncertain. Although this study is based on comparatively short DNA‐sections, the trees deduced from these sequences can be considered as a first approach for inferring the phylogenetic relationships of the genus Pernis and related genera and for addressing questions concerning the evolutionary history, biogeography, and systematics of this group.  相似文献   

13.
The delimitation of the invasive moss species Campylopus introflexus from its closest relative, Campylopus pilifer, has been long debated based on morphology. Previous molecular phylogenetic reconstructions based on the nuclear ribosomal internal transcribed spacers (ITS) 1 and 2 showed that C. pilifer is split into an Old World and a New World lineage, but remained partly inconclusive concerning the relationships between these two clades and C. introflexus. Analyses of an extended ITS dataset displayed statistically supported incongruence between ITS1 and ITS2. ITS1 separates the New World clade of C. pilifer from a clade comprising C. introflexus and the Old World C. pilifer. Ancestral state reconstruction showed that this topology is morphologically supported by differences in the height of the dorsal costal lamellae in leaf cross‐section (despite some overlap). ITS2, in contrast, supports the current morphological species concept, i.e., separating C. introflexus from C. pilifer, which is morphologically supported by the orientation of the hyaline hair point at leaf apex as well as costal lamellae height. Re‐analysis of published and newly generated plastid atpB‐rbcL spacer sequences supported the three ITS lineages. Ecological niche modeling proved a useful approach and showed that all three molecular lineages occupy distinct environmental spaces that are similar, but undoubtedly not equivalent. In line with the ITS1 topology, the C. pilifer lineage from the New World occupies the most distinct environmental niche, whereas the niches of Old World C. pilifer and C. introflexus are very similar. Taking the inferences from ecological niche comparisons, phylogenetics, and morphology together, we conclude that all three molecular lineages represent different taxa that should be recognized as independent species, viz. C. introflexus, C. pilifer (Old World clade), and the reinstated C. lamellatus Mont. (New World clade).  相似文献   

14.
Capparis (Capparaceae) has been used as a medicinal plant since ancient time. Capparis species were divided into Old World and New World taxa as described by the sectional division of Capparis. However, plastid DNA sequence data of Indian Capparis species were not analyzed in previous phylogenetic studies. Here, we have added Indian Capparis data in previous phylogeny and analyzed the relationship of Indian Capparis with Old World and New World taxa. The plastid phylogeny presented here includes Capparis taxa from its major distribution areas, New World and African capparoids. The presented phylogeny is used for the determination of biogeographic history of Capparis and recently segregated genera. Phylogenetic analyses of the combined plastid data revealed that the Indian Capparis are more closely related to Old World taxa and have connections with African, Australian and Eastern Asian species. Sectional classification of Old World and Indian Capparis considered in this study is reflected from the presented plastid phylogeny. The ancestral area reconstruction using Bayesian Binary Markov Chain Monte Carlo method strongly supports for the Africa as the ancestral region for both Old World and New World Capparis. Molecular marker-based genetic diversity studies on Indian Capparis are scarce. This work also includes the genetic diversity study of Indian Capparis species. Utility and efficacy of ISSR markers to study inter- and intraspecies variation in Capparis is evident from the AMOVA results.  相似文献   

15.
Of all the genera of woody bamboos described from America, only three have pseudospikelets—Atractantha, Elytrostachys, and Guadua. The former two have pseudospikelets with an elongated rachilla internode that precedes the floret, making it pedicellate; they also share a type of leaf anatomy that separates them from the latter. The two new genera herein described, Criciuma and Eremocaulon, show most similarity to species of Guadua, both in spikelet morphology and in leaf anatomy. The study of these new taxa has helped to clarify the limits of New World genera with pseudospikelets and strengthened the case for maintaining Guadua as a genus distinct from its Old World counterpart, Bambusa. We are now able to discern a New World line of bamboos that includes Criciuma, Eremocaulon, and Guadua, separate from an Old World line that includes Bambusa, Dendrocalamus, and several other genera.  相似文献   

16.
Bordy, E.M., Sztanó, O., Rubidge, B.S. & Bumby, A. 2010: Early Triassic vertebrate burrows from the Katberg Formation of the south‐western Karoo Basin, South Africa. Lethaia, Vol. 44, pp. 33–45. Very large (~30–35 cm), uniform diameter cylindrical burrows were found at two localities, ~100–110 m above Permo‐Triassic boundary in the fluvial Katberg Formation (main Karoo Basin, South Africa). Analysis of their morphology and stratigraphical distribution allows us to improve both the understanding of the ethology of burrowing, and also the reconstruction of the earliest Triassic ecosystems. These burrows have a single opening that leads, via a large, uniform diameter, semi‐horizontal tunnel, to a rounded terminus. These 3‐m‐long structures descend at angles of ~30° to a maximum of 1.5 m depth. They are devoid of chambers, branching, cross‐cutting, coiling or spiralling. Filled with coarse sediments, some have a <5‐mm clay lining, and most have subtle indentations and various scratch marks. These burrows were possibly excavated as resting, hiding or aestivating shelters, and are tentatively attributed to dicynodonts (i.e. Lystrosaurus murrayi and L. declivis). Data suggest that burrowing was widespread after the P/Tr boundary event, when in this part of Gondwana, dryland fluvial systems had large fluctuations in flow with extended low‐flow periods or drought punctuated by high‐discharge periods. We hypothesize that these constructed refuges played a role in the biodiversity recovery and maintenance in the Early Triassic (Induan) ecosystem. □Early Triassic, Karoo Basin, Katberg Formation, South Africa, Tetrapod Burrows.  相似文献   

17.
Evidence for Gondwanan vicariance in an ancient clade of gecko lizards   总被引:2,自引:0,他引:2  
Aim Geckos (Reptilia: Squamata), due to their great age and global distribution, are excellent candidates to test hypotheses of Gondwanan vicariance against post‐Gondwanan dispersal. Our aims are: to generate a phylogeny of the sphaerodactyl geckos and their closest relatives; evaluate previous phylogenetic hypotheses of the sphaerodactyl geckos with regard to the other major gecko lineages; and to use divergence date estimates to inform a biogeographical scenario regarding Gondwanan relationships and assess the roles of vicariance and dispersal in shaping the current distributions of the New World sphaerodactyl geckos and their closest Old World relatives. Location Africa, Asia, Europe, South America, Atlantic Ocean. Methods We used parsimony and partitioned Bayesian methods to analyse data from five nuclear genes to generate a phylogeny for the New World sphaerodactyl geckos and their close Old World relatives. We used dispersal–vicariance analysis to determine ancestral area relationships among clades, and divergence times were estimated from the phylogeny using nonparametric rate smoothing. Results We recovered a monophyletic group containing the New World sphaerodactyl genera, Coleodactylus, Gonatodes, Lepidoblepharis, Pseudogonatodes and Sphaerodactylus, and the Old World Gekkotan genera Aristelliger, Euleptes, Quedenfeldtia, Pristurus, Saurodactylus and Teratoscincus. The dispersal–vicariance analysis indicated that the ancestral area for this clade was North Africa and surrounding regions. The divergence between the New World spaherodactyl geckos and their closest Old World relative was estimated to have occurred c. 96 Myr bp . Main conclusions Here we provide the first molecular genetic phylogenetic hypothesis of the New World sphaerodactyl geckos and their closest Old World relatives. A combination of divergence date estimates and dispersal–vicariance analysis informed a biogeographical scenario indicating that the split between the sphaerodactyl geckos and their African relatives coincided with the Africa/South America split and the opening of the Atlantic Ocean. We resurrect the family name Sphaerodactylidae to represent the expanded sphaerodactyl clade.  相似文献   

18.
Species of the braconid wasp genus Yelicones Cameron from North, Central and South America are revised and the first phylogenetic analysis of the world Yelicones fauna is presented. The results are considered from a biogeographical perspective and the effect of including and excluding colour characters is investigated. One hundred and twenty‐four species from throughout the world are recognised. Eighty‐five species are from the New World, 63 of which are new. A fully illustrated key to New World species is provided. A total of 116 characters were scored, of which 86 were morphological and 30 were based on the wasps’ colour pattern. All analyses show a near perfect diversion between New and Old World species. However, analyses excluding and including colour produced completely opposite results in terms of whether New or Old World species were basal. We found that in our data matrix colour characters performed at least as well as morphological characters in terms of their ensemble retention index, making it difficult to decide which phylogenetic hypotheses is correct. However, consideration of venom apparatus features leads us to prefer the hypotheses placing the New World taxa basally.  相似文献   

19.
Santiago R. Ron 《Biotropica》2005,37(2):209-221
One application of ecological niche modeling is predicting suitable areas for the establishment of invasive species. Herein, I model the fundamental niche of the chytrid fungus Batrachochytrium dendrobatidis, a pathogen linked to amphibian declines on several continents. Niche models were generated with the Genetic Algorithm of Rule‐Set Prediction using point distribution data of the pathogen and digital maps of environmental variables integrated in a GIS environment. The distribution of regions suitable for B. dendrobatidis in the New World is extensive and includes significant portions of: (1) Sierra Madre Occidental pine‐oak forest; (2) Sonoran and Sinaloan dry forest; (3) Veracruz moist forest; (4) Central America east from the Isthmus of Tehuantepec; (5) Caribbean Islands; (6) temperate forest in Chile and western Argentina south of latitude 30°S; (7) Andes above 1000 m of altitude in Venezuela, Colombia, and Ecuador; (8) eastern slopes of the Andes in Peru and Bolivia; (9) Brazilian Atlantic forest; (10) Uruguay, Paraguay, and northeastern Argentina; (11) southwestern and Madeira‐Tapajós Amazonian tropical rainforests. The regions with the highest suitability for B. dendrobatidis include habitats that contain the world's most diverse amphibian faunas. Models were built with New World localities, but also showed strong predictability for B. dendrobatidis localities in the Old World. Out of a total of 59 reported Old World localities for B. dendrobatidis, 56 occurred within regions with high predicted suitability. I also present analyses of the environmental envelope of B. dendrobatidis and discuss the implications of the results for the conservation of amphibians in the neotropics.  相似文献   

20.
Following our fieldwork in Paleogene deposits of Togo, we herein report cranial as well as postcranial elements belonging to the family Dyrosauridae. This assemblage is dated to the Late Paleocene (Thanetian) from two quarries in southern Togo. The specimens include a partial skull presenting two large supratemporal fossae and a massive occipital condyle; long and slender isolated teeth; amphicoelous vertebrae including several articulated ones; and two osteoderms devoid of carina. The morphology of the partial skull reveals similarities with some African longirostrine forms such as Rhabdognathus spp., although this attribution cannot be confirmed. Longirostrine forms, known in the late Paleocene and early Eocene of the Iullemmeden basin (Nigeria, Niger, Mali, Algeria) and in the phosphates of Morocco and Tunisia, is only represented in Thanetian levels in Togo. Different palaeoenvironmental settings seem to have characterized the various African basins during the lower Eocene, with consequences for the geographic distribution of dyrosaurids. These dyrosaurid remains confirm the presence of the family in Togo during the Paleocene and underline the fossiliferous potential of the coastal sedimentary basin in Togo and in the bay of Benin.  相似文献   

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