Morphology of the quadrate in the Eocene anseriform Presbyornis and extant galloanserine birds

Despite the notoriety, phylogenetic significance, and large number of available specimens of Presbyornis, its cranial anatomy has never been studied in detail, and its quadrate has been partly misinterpreted. We studied five quadrates of Presbyornis that reveal features hitherto unknown in the anseriforms but otherwise present in galliforms. As a result, we analyzed the variable quadrate characters among all extant galloanserine families and identified synapomorphies and other morphological variation among the major galloanserine clades. In terms of quadrate morphology, Presbyornis is more plesiomorphic than any extant anseriform (including the Anhimidae) and shares ancestral galloanserine characters with the Megapodiidae, the earliest branch of extant galliforms. The quadrate's morphology is inconsistent with the currently accepted anseriform phylogeny that nests Presbyornis within the crown‐group as a close relative of the Anatidae. The presbyornithid quadrates exhibit an unusual variation in the presence of a caudomedial pneumatic foramen, which we interpret as a result of a discontinuous change in the growth path of the pneumatic diverticulum. Another episode of morphogenetic imbalance in the growth path of the pneumatic diverticulum may have accompanied the disappearance of the basiorbital pneumatic foramen (along with the pneumatization of the pterygoid) at the origin of the crown‐group anseriforms. This episode is marked by the striking individual variation in the presence and location of pneumatic foramina in the mandibular part of the quadrate in the Anhimidae. J. Morphol., 2010. © 2009 Wiley‐Liss, Inc.     

A fossil Dendrocygninae (Aves,Anatidae) from the Early Pliocene of the Argentine Pampas and its paleobiogeographical implications

In the present paper, the distal end of a humerus referable to a Dendrocygninae anseriform bird is reported. The specimen was collected at the Monte Hermoso Formation (early Pliocene) of the Farola Monte Hermoso locality (Buenos Aires Province, Argentina). This record constitutes one of the oldest for the group in South America and elsewhere. The overview of the anseriform record in South America indicates a similar pattern to that of other localities across the world. Paleogene localities are dominated by non-Anatinae taxa, whereas more recent faunas are dominated by anatines. Following this pattern, in South America the Anatinae appears in the fossil record as recently as in the Pleistocene, probably arriving from North America during the Great American Biotic Interchange. Pleistocene and Recent anseriform avifaunas are dominated by Anatinae taxa, and this dominance is probably due to some “key characters” regarding reproductive biology. In fact, the anatines exhibit a high reproductive success probably due to the capability of having two molts per year, and that the parental care of the downy young is only conducted by the female. The combination of characters may have allowed anatines to dominate most aquatic environments, surpassing in diversity more plesiomorphic taxa.     

Systematic relationships of the palaeogene family Presbyornithidae (Aves: Anseriformes)

The early Tertiary (Paleocene and Eocene) family Presbyornithidae is one of the most completely known group of fossil birds. Essentially all parts of the skeleton are represented in the fossil record, allowing a thorough analysis of the phylogenetic position of the family. Forty-two families of nonpasserine birds representing the orders Ciconiiformes, Anseriformes, Galliformes, Gruiformes and Charadriiformes, were included in a cladistic analysis of 71 skeletal characters. The previously suggested anseriform affinity of the Presbyornithidae was confirmed. Furthermore, the family proved to be closer to the Anatidae than to the Anhimidae or Anseranatidae. The many postcranial similarities with certain charadriiform birds as the Burhinidae, obviously are plesiomorphies. By this observation, a better undestanding of character evolution in nonpasserine skeletal morphology is gained. The often suggested close relationship of anseriform and galliform birds is not confirmed by osteology. Instead, the Anseriformes and the Phoenicopteridae form a monophyletic clade that is the sister to the remaining ciconiiform birds. This result renders the Ciconiiformes sensu Wetmore (1960) polyphyletic.     

Chulpasia and Thylacotinga, late Paleocene-earliest Eocene trans-Antarctic Gondwanan bunodont marsupials: New data from Australia

A new marsupial from the early Eocene Tingamarra Local Fauna of southeastern Queensland, Australia, is named and referred to ChulpasiaCrochet and Sigé, 1993, a genus otherwise known from early Tertiary deposits of Peru. This taxon, Chulpasia jimthorselli nov. sp., differs in upper molar morphology only in minor details from the Peruvian type species Chulpasia mattaueri and is almost identical in size. New materials referable to the Tingamarra marsupial Thylacotinga bartholomaii Archer, Godthelp and Hand are also described. Species of Chulpasia and Thylacotinga share many striking derived as well as plesiomorphic dental features that allow recognition of a new monophyletic subfamily, Chulpasiinae. Its familial relationships are in doubt, but members of the subfamily could have provided the ancestral stock for Rosendolops and other early Tertiary South American polydolopimorphian marsupials. This is the first evidence that a Gondwanan genus of therian land mammals spanned South America, Antarctica and Australia during the early Tertiary. The very close similarity between the Peruvian and Australian fossils (and suggested short time span between their stratigraphic occurrences) provides further paleontological support for a trans-Antarctic land connection between South America and Australia extending well into the early Paleogene.     

From Africa via Europe to South America: migrational route of a species‐rich genus of Neotropical lowland rain forest trees (Guatteria,Annonaceae)

Aim Several recent studies have suggested that a substantial portion of today’s plant diversity in the Neotropics has resulted from the dispersal of taxa into that region rather than by vicariance. In general, three routes have been documented for the dispersal of taxa onto the South American continent: (1) via the North Atlantic Land Bridge, (2) via the Bering Land Bridge, or (3) from Africa directly onto the continent. Here a species‐rich genus of Neotropical lowland rain forest trees (Guatteria, Annonaceae) is used as a model to investigate these three hypotheses. Location The Neotropics. Methods The phylogenetic relationships within the long‐branch clade of Annonaceae were reconstructed (using maximum parsimony, maximum likelihood and Bayesian inference) in order to gain insight in the phylogenetic position of Guatteria. Furthermore, Bayesian molecular dating and Bayesian dispersal–vicariance (Bayes‐DIVA) analyses were undertaken. Results Most of the relationships within the long‐branch clade of Annonaceae were reconstructed and had high support. However, the relationship between the Duguetia clade, the Xylopia–Artabotrys clade and Guatteria remained unclear. The stem node age estimate of Guatteria ranged between 49.2 and 51.3 Ma, whereas the crown node age estimate ranged between 11.4 and 17.8 Ma. For the ancestral area of Guatteria and its sister group, the area North America–Africa was reconstructed in 99% of 10,000 DIVA analyses, while South America–North America was found just 1% of the time. Main conclusions The estimated stem to crown node ages of Guatteria in combination with the Bayes‐DIVA analyses imply a scenario congruent with an African origin followed by dispersal across the North Atlantic Land Bridge in the early to middle Eocene and further dispersal into North and Central America (and ultimately South America) in the Miocene. The phylogenetically and morphologically isolated position of the genus is probably due to extinction of the North American and European stem lineages in the Tertiary.     

A phylogenetic analysis of basal Anseriformes, the fossil Presbyornis, and the interordinal relationships of waterfowl

A phylogenetic analysis of 123 morphological characters of basal waterfowl (Aves: Anseriformes) and other selected avian orders confirmed that the screamers (Anhimae: Anhitn-idae) are the sister-group of other waterfowl (Anseres), and that the magpie goose (Anseranatidae: Anseranas semipalmata) is the sister group of other modern waterfowl exclusive of screamers (Anatidae sensu stricto). The analysis also supports the traditional hypothesis of the gallinaceous birds (Galliformes) as the sister group of the Anseriformes. Presbyornis, a fossil from the early Eocene of Wyoming and averred by Olson & Feduccia as showing that the Anseriformes were derived from shorebirds (Charadriiformes), was found to represent the sister group of the Anatidae. Associated hypotheses by Olson & Feduccia concerning the implications of Presbyornis for the phylogenetic relationships of flamingos (Phoenicopteriformes), the position of the Anhimidae within the waterfowl, relationships among modern Anatidae, and a plausible evolutionary scenario for waterfowl also are rejected. Analyses revealed that cranial characters were critical to the establishment of the Galliformes as the sister group of the Anseriformes; exclusion of the Anhimidae, especially in combination with Anseranas, also undermined the support for this inference. Placement of Presbyornis as the sister group of the Anatidae casts doubt on the role suggested by Feduccia of ‘transitional shorebirds' in the origin of modern avian orders, and calls into question the concept of ‘fossil mosaics’. The phylogenetic hypothesis is used to reconstruct an evolutionary scenario for selected ecomorphological characters in the galliform-anseriform transition, to predict the most parsimonious states of these characters for Presbyornis, and to propose a phylogenetic classification of the higher-order taxa of waterfowl. This re-examination of Presbyornis also is used to exemplify the fundamental methodological shortcomings of the intuitive approach to the reconstruction of phylogenetic relationships.     

Pulmonary pneumaticity in the postcranial skeleton of extant aves: a case study examining Anseriformes

Anseriform birds were surveyed to examine how the degree of postcranial pneumaticity varies in a behaviorally and size-diverse clade of living birds. This study attempts to extricate the relative effects of phylogeny, body size, and behavioral specializations (e.g., diving, soaring) that have been postulated to influence the extent of postcranial skeletal pneumaticity. One hundred anseriform species were examined as the focal study group. Methods included latex injection of the pulmonary apparatus followed by gross dissection or direct examination of osteological specimens. The Pneumaticity Index (PI) is introduced as a means of quantifying and comparing postcranial pneumaticity in a number of species simultaneously. Phylogenetically independent contrasts (PICs) were used to examine the relationship between body size and the degree of postcranial pneumaticity throughout the clade. There is a high degree of similarity (i.e., clade-specificity) within most anseriform subgroups. As a whole, Anseriformes demonstrate no significant relationship between relative pneumaticity and body size, as indicated by regression analysis of body mass on PI. It is apparent, however, that many clades of diving ducks do exhibit lower PIs than their nondiving relatives. By exclusion of diving taxa from analyses, a significant positive slope is observed and the hypothesis of relatively higher pneumaticity in larger-bodied birds is only weakly supported. However, low correlations indicate that factors other than body size account for much of the variation observed in relative pneumaticity. Pneumaticity profiles were mapped onto existing phylogenetic hypotheses. A reduction in the degree of postcranial pneumaticity occurred independently in at least three anseriform subclades specialized for diving. Finally, enigmatic pneumatic features located in distal forelimb elements of screamers (Anhimidae) result from invasion of bone by a network of subcutaneous air sac diverticula spreading distally along the wings.     

Multivariate analysis of morphological and anatomical characters of Calophyllum (Calophyllaceae) in South America

Calophyllum (Calophyllaceae), previously placed in Clusiaceae, is easily recognizable by its opposite entire leaves with close parallel venation alternating with resin canals. However, distinction between species has been difficult, because of infraspecific variation in tepal and stamen number and resemblance among species that share similar habitats. Here, I report the results of multivariate analyses of morphological and anatomical characters for Calophyllum in South America, and provide a taxonomic treatment for the genus in South America, the first since that of Vesque in 1893. Thirteen preliminary morphogroups were identified. Thirty‐two morphological characters of the leaf, flower and fruit from 401 specimens, and 17 anatomical leaf characters from 45 specimens were measured and analysed using principal component analyses (PCAs) and discriminant analyses (DAs). PCAs were used to find groups and DAs were used to validate those PCAs that were potential groups. Two main subgroups were identified in the general analysis. Subgroup M1 has terete stems and smaller leaves and flowers than subgroup M2, which, instead, has quadrangular stems. Only subgroup M2 showed distinctive clusters in regional and local analyses. Distinctive clusters and morphological and anatomical characters helped us to recognize four species in South America, including a new species, Calophyllum pubescens sp. nov. . In addition, a new species, Calophyllum mesoamericanum sp. nov. , is described from Central America. © 2013 The Linnean Society of London,     

Cenozoic mystery birds – on the phylogenetic affinities of bony‐toothed birds (Pelagornithidae)

Mayr, G. (2011) Cenozoic mystery birds – on the phylogenetic affinities of bony‐toothed birds (Pelagornithidae). —Zoologica Scripta, 40, 448–467. The extinct Cenozoic bony‐toothed birds (Pelagornithidae) are characterized by the occurrence of unique spiky projections of the osseous jaws and are among the most distinctive neornithine taxa. Earlier authors considered these marine birds to be most closely related to ‘Pelecaniformes’ or Procellariiformes, but recent phylogenetic analyses resulted in a sister group relationship to Anseriformes. This latter hypothesis was, however, coupled with a non‐monophyly of galloanserine or even neognathous birds, which is not supported by all other current analyses. The character evidence for anseriform affinities of pelagornithids is thus reassessed, and it is detailed that the alleged apomorphies cannot be upheld. Pelagornithids lack some key apomorphies of galloanserine birds, and analysis of 107 anatomical characters did not support anseriform affinities, but resulted in a sister group relationship between Pelagornithidae and Galloanseres. By retaining a monophyletic Galloanseres, this result is in better accordance with widely acknowledged hypotheses on the higher‐level phylogeny of birds. The (Pelagornithidae + Galloanseres) clade received, however, only weak bootstrap support, and some characters, such as the presence of an open frontoparietal suture, may even support a position of Pelagornithidae outside crown‐group Neognathae.     

Molecular phylogeny and phylogeography ofLupinus (Leguminosae) inferred from nucleotide sequences of therbcL gene and ITS 1 + 2 regions of rDNA

Total DNA was extracted from 55 species of theLeguminosae (including 29 species ofLupinus). The chloroplast generbcL and the ITS 1 + 2 regions of nuclear RNA genes were amplified by polymerase chain reaction (PCR) and sequenced directly. The sequences obtained were evaluated with character state (Maximum Parsimony) and distance methods (Neighbour Joining). Phylogenetic trees obtained with both data sets and methods are mostly congruent.Genisteae andCrotalarieae are sister groups and share ancestry with theThermopsideae/Podalyrieae. The genusLupinus, which forms a monophyletic clade within theGenisteae, shows a distinct Old-New World disjunction and appears to be divided into several more or less distinct groups: (1) The species from the eastern part of South America. (2) The homogeneous rough-seeded group (Scabrispermae) of the Old World species which is well distinguished from the smooth-seeded group (Malacospermae). (3) Within the rather heterogeneous smooth-seeded lupins a smaller subgroup withL. angustifolius, L. hispanicus andL. luteus is recognized. (4) Also separated are North American lupins and South American species with a western distribution. Genetic distances imply that the genusLupinus evolved during the last 12–14 million years, ruling out the hypothesis that the present Old-New World disjunction can be interpreted as a result of the continental drift. The genetic data suggest an origin in the Old World and an independant colonisation of the Eastern parts of South America as opposed to North America and the Western parts of South America.     

Phylogenetic systematics and historical biogeography of the Neotropical electric fish Gymnotus (Teleostei: Gymnotidae)

Phylogenetic interrelationships of the Neotropical electric fish genus Gymnotus are documented from comparative study of phenotypic data. A data matrix was compiled of 113 phenotypic characters for 40 taxa, including 31 recognized Gymnotus species, six allopatric populations of G. carapo, two allopatric populations of G. coropinae, and three gymno‐tiform outgroups. MP analysis yielded 15 trees of equal length, the strict consensus of which is presented as a working hypothesis of Gymnotus interrelationships. Diagnoses are presented for 26 clades, including three species groups; the G. cylindricus group with two species restricted to Middle America, the G. pantherinus group with 12 species in South America, and the G. carapo group with 16 species in South America. The basal division of Gymnotus is between clades endemic to Middle and South America. Both the G. pantherinus and G. carapo groups include trans‐Andean sister‐taxon pairs, suggesting a minimum date for the origins of these groups in the late Middle Miocene (c. 12 Ma.). The geographically widespread species G. carapo is paraphyletic. Analysis of character state evolution shows characters of external morphology are more phylogenetically plastic and provide more phylogenetic information in recent branches than do characters of internal morphology, which themselves provide the more information in deeper branches. Nine regional species assemblages of Gymnotus are recognized, none of which is monophyletic. There are at least two independent origins of Gymnotus species in sediment rich, high conductivity, perennially hypoxic whitewater floodplains (varzea´) derived from an ancestral condition of being restricted to low conductivity non‐floodplain (terra firme) black and clearwater rivers and streams. These phylogenetic, biogeographic and ecological patterns suggest a lengthy and complex history involving numerous instances of speciation, extinction, migration and coexistence in sympatry. Evolution in Gymnotus has been a continent‐wide phenomenon; i.e. Amazonian species richness is not a consequence of strictly Amazonian processes. These patterns are similar to those of other highly diverse groups of Neotropical fishes and do not resemble those of monophyletic, rapidly generated species flocks.     

A New Marsupial from the Early Eocene Tingamarra Local Fauna of Murgon, Southeastern Queensland: A Prototypical Australian Marsupial?

Djarthia murgonensis, a new genus and species of marsupial from the early Eocene Tingamarra Local Fauna of Murgon in southeastern Queensland, is described on the basis of dental material. The combination of marsupial synapomorphies and symplesiomorphies present in D. murgonensis suggests phylogenetic placement within either Didelphidae or Australidelphia. Tarsal morphology, fundamental to the concepts of Ameridelphia and Australidelphia respectively, is not yet known for this taxon. Consequently, it cannot be assigned to either clade with confidence. If this taxon is australidelphian, it constitutes support for the hypothesis that the common ancestor of the Australian marsupial radiation was didelphoid-like in dental features. Some previous authors have contended that marsupial faunas of South America and Australia are manifestly distinct, excepting for the australidelphian affinity of South American microbiotheres. However, because tarsal anatomy is unknown in some generalized Australian fossil taxa, including D. murgonensis, and character analysis reveals that no synapomorphies of the dentition unequivocally define either Ameridelphia or Australidelphia to the exclusion of the other, we consider this interpretation to be premature. In short, available evidence neither supports nor refutes the argument of distinct South American and Australasian marsupial faunas. A further ramification is the need to reconsider the phylogenetic position of Ankotarinja tirarensis and Keeuna woodburnei. These central Australian fossil taxa might be referred to either Australidelphia or Ameridelphia, and it is recommended that both be treated as Marsupialia incertae sedis until further material comes to light.     

The biogeography of Gunnera L.: vicariance and dispersal

Aim The genus Gunnera is distributed in South America, Africa and the Australasian region, a few species reaching Hawaii and southern Mexico in the North. A cladogram was used to (1) discuss the biogeography of Gunnera and (2) subsequently compare this biogeographical pattern with the geological history of continents and the patterns reported for other Southern Hemisphere organisms. Location Africa, northern South America, southern South America, Tasmania, New Zealand, New Guinea/Malaya, Hawaii, North America, Antarctica. Methods A phylogenetic analysis of twenty‐six species of Gunnera combining morphological characters and new as well as published sequences of the ITS region, rbcL and the rps16 intron, was used to interpret the biogeographical patterns in Gunnera. Vicariance was applied in the first place and dispersal was only assumed as a second best explanation. Results The Uruguayan/Brazilian Gunnera herteri Osten (subgenus Ostenigunnera Mattfeld) is sister to the rest of the genus, followed sequentially upwards by the African G. perpensa L. (subgenus Gunnera), in turn sister to all other, American and Australasian, species. These are divided into two clades, one containing American/Hawaiian species, the other containing all Australasian species. Within the Australasian clade, G. macrophylla Blume (subgenus Pseudogunnera Schindler), occurring in New Guinea and Malaya, is sister to a clade including the species from New Zealand and Tasmania (subgenus Milligania Schindler). The southern South American subgenus Misandra Schindler is sister to a clade containing the remaining American, as well as the Hawaiian species (subgenus Panke Schindler). Within subgenus Panke, G. mexicana Brandegee, the only North American species in the genus, is sister to a clade wherein the Hawaiian species are basal to all south and central American taxa. Main conclusions According to the cladogram, South America appears in two places, suggesting an historical explanation for northern South America to be separate from southern South America. Following a well‐known biogeographical pattern of vicariance, Africa is the sister area to the combined southern South America/Australasian clade. Within the Australasian clade, New Zealand is more closely related to New Guinea/Malaya than to southern South America, a pattern found in other plant cladograms, contradictory to some of the patterns supported by animal clades and by the geological hypothesis, respectively. The position of the Tasmanian G. cordifolia, nested within the New Zealand clade indicates dispersal of this species to Tasmania. The position of G. mexicana, the only North American species, as sister to the remaining species of subgenus Panke together with the subsequent sister relation between Hawaii and southern South America, may reflect a North American origin of Panke and a recolonization of South America from the north. This is in agreement with the early North American fossil record of Gunnera and the apparent young age of the South American clade.     

Cretaceous roots of the amphisbaenian lizards

Amphisbaenians are highly specialized limbless burrowing lizards of controversial relationships. Among fossil lizards, the Eocene (47 Ma) Cryptolacerta is allegedly closest to the amphisbaenian ancestor, but this is put in doubt in this study. Similarities between Cryptolacerta and amphisbaenians, such as limb reduction and expansion of the skull roof, may be a result of parallel evolution. Instead, the Late Cretaceous lizard Slavoia with well‐developed limbs and several plesiomorphic skull characters is proposed to be the oldest known stem amphisbaenian. This is supported by two different phylogenetic analyses and observations on numerous specimens together representing almost the whole skeleton. Among the unique features, that Slavoia shares with amphisbaenians, the most significant are vomers strongly underlapping palatines and pterygoid quadrate ramus tightly wrapping around posteromedial surface of quadrate. The anatomy of Slavoia suggests that the reinforcement of the snout in amphisbaenian evolution preceded the elongation of the postorbital part of the skull, and that of the body, as well as modification of the limbs. Reduction of its hindlimbs was more advanced than that of the forelimbs. The ancient geological age of the central Asiatic Slavoia suggests that diversification of the main North American amphisbaenian groups may have resulted from a faunal dispersals from Asia after the Late Cretaceous.     

Osteology Supports a Stem-Galliform Affinity for the Giant Extinct Flightless Bird Sylviornis neocaledoniae (Sylviornithidae,Galloanseres)

The giant flightless bird Sylviornis neocaledoniae (Aves: Sylviornithidae) existed on La Grande Terre and Ile des Pins, New Caledonia, until the late Holocene when it went extinct shortly after human arrival on these islands. The species was generally considered to be a megapode (Megapodiidae) until the family Sylviornithidae was erected for it in 2005 to reflect multiple cranial autapomorphies. However, despite thousands of bones having been reported for this unique and enigmatic taxon, the postcranial anatomy has remained largely unknown. We rectify this deficiency and describe the postcranial skeleton of S. neocaledoniae based on ~600 fossils and use data from this and its cranial anatomy to make a comprehensive assessment of its phylogenetic affinities. Sylviornis neocaledoniae is found to be a stem galliform, distant from megapodiids, and the sister taxon to the extinct flightless Megavitiornis altirostris from Fiji, which we transfer to the family Sylviornithidae. These two species form the sister group to extant crown-group galliforms. Several other fossil galloanseres also included in the phylogenetic analysis reveal novel hypotheses of their relationships as follows: Dromornis planei (Dromornithidae) is recovered as a stem galliform rather than a stem anseriform; Presbyornis pervetus (Presbyornithidae) is the sister group to Anseranatidae, not to Anatidae; Vegavis iaai is a crown anseriform but remains unresolved relative to Presbyornis pervetus, Anseranatidae and Anatidae. Sylviornis neocaledoniae was reconstructed herein to be 0.8 m tall in a resting stance and weigh 27–34 kg. The postcranial anatomy of S. neocaledoniae shows no indication of the specialised adaptation to digging seen in megapodiids, with for example, its ungual morphology differing little from that of chicken Gallus gallus. These observations and its phylogenetic placement as stem galliforms makes it improbable that this species employed ectothermic incubation or was a mound-builder. Sylviornis neocaledoniae can therefore be excluded as the constructor of tumuli in New Caledonia.     

Phylogenetic position of a remarkable new fideliine bee from northern Chile (Hymenoptera: Megachilidae)

Fideliine bees are an archaic group with a disjunct distribution mostly restricted to deserts of South America and South Africa. This group was previously thought to be more diverse in Africa than in South America, where only one genus (Neofidelia) comprising five species is known. Here we describe a species belonging to a second South American genus: Xenofidelia colorada Packer gen. et sp.n. , from northern Chile. The species is illustrated and its phylogenetic position within Megachilidae is assessed using morphological, molecular and combined data. The 214 character morphological matrix includes 55 new characters with an additional 16 hitherto unexplored for megachilid phylogeny. The molecular dataset is based upon seven nuclear gene sequences, totalling 6439 bp, many of which are published for the first time for particular megachilid taxa. In all analyses, Xenofidelia was found as sister to Neofidelia (endemic to Chile and Peru). It differs from that genus most notably in its short mouthparts, absence of a glossal rod, unmodified female metabasitarsus and an elongate and horizontal dorsal surface of the metapostnotum. Morphological and combined data support a monophyletic Fideliinae (excluding Pararhophites), while molecular data alone failed to recover fideliine monophyly. Dating analyses suggest that Xenofidelia and Neofidelia diverged 34.3–40.6 Ma, indicating that New World fideliines were probably present in arid habitats of South America during the Eocene. This divergence time predates both the main orogenic events that resulted in the formation of the Andean mountains and the origin of hyperarid conditions in the Atacama Desert; it also corresponds to a period prior to the origin of the summer rainfall area in the far north of Chile where the new genus is found. These results support the view that arid habitats have been present continuously in South America since the Eocene. This published work has been registered in ZooBank, http://zoobank.org/urn:lsid:zoobank.org:pub:EA69BB4A‐6F59‐4A15‐AB44‐2A8949E3CF8F .     

The mouth apparatus of the Cambrian gilled lobopodian Pambdelurion whittingtoni

Omnidens is a large feeding apparatus composed of circlets of teeth, first documented from the early Cambrian of China. Originally interpreted as the oral cone of a radiodontan, it was later reinterpreted as the introvert of a priapulan. In both cases the Omnidens mouthparts underpinned estimates of gigantic (c. 2 m) body size. Recent evidence has been used to suggest that pharyngeal teeth and radially‐arranged oral plates in the stem‐group onychophoran Hallucigenia and the lower stem‐group euarthropod Jianshanopodia are homologous to structures of the introvert in priapulans and other scalidophorans, and are thus primitive characters for moulting animals (Ecdysozoa) as a whole. Here we show that the early Cambrian gilled lobopodian Pambdelurion whittingtoni from Sirius Passet, Greenland, possesses a mouth apparatus identical to Omnidens, being composed of the same three zones with detailed similarities of sclerites in each zone. An oral cone with rings of pharyngeal teeth, radial plates and outer scalid‐like plates are ecdysozoan characters retained in the euarthropod stem group. Omnidens from China probably belongs to an unrecognized Pambdelurion‐like animal rather than being part of a giant priapulan.     

Phylogeny of South American Bufo (Anura: Bufonidae) inferred from combined evidence

Despite the considerable research that has focused on the evolutionary relationships and biogeography of the genus Bufo, an evolutionary synthesis of the entire group has not yet emerged. In the present study, almost 4 kb of DNA sequence data from mitochondrial (12S, tRNA^Val, and 16S) and nuclear (POMC; Rag-1) genes, and 83 characters from morphology were analysed to infer a phylogeny of South American toads. Phylogenies were reconstructed with parsimony and maximum likelihood and Bayesian model-based methods. The results of the analysis of morphological data support the hypothesis that within Bufo , some skull characters (e.g. frontoparietal width), correlated with the amount of cranial ossification, are prone to homoplasy. Unique and unreversed morphological synapomorphies are presented that can be used to diagnose recognized species groups of South American toads. The results of all phylogenetic analyses support the monophyly of most species groups of South American Bufo . In most DNA-only and combined analyses, the South American (minus the B. guttatus and part of the ' B. spinulosus ' groups), North American, Central American, and African lineages form generally well-supported clades: ((((((((South America) (North America + Central America)) Eurasia) Africa) Eurasia) South America) West Indies) South America). This result confirms and extends prior studies recovering South American Bufo as polyphyletic. The biogeographical results indicate that: (1) The origin of Bufo predates the fragmentation of Gondwana; (2) Central and North American species compose the sister group to a large, 'derived' clade of South American Bufo ; and (3) Eurasian species form the sister group to the New World clade.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 146 , 407–452.     

Cypripedium subtropicum,a New Species Related to Selenipedilum

Cypripedium subtropicum S. C. Chen et K. Y. Lang is a phytogeographycally significant new species with its habit, inflorescence and column very similar to those of Selenipedilum of tropical America. It is found in Mêdog of southeastern Xizang, China. Its slender leafy stem bears at the summit a many-flowered raceme, amounting to 1.5 m in height. Although its ovary is unilocular—this is the reason why we place it in Cypripedium, the column characters resemble those of Selenipedilum. For example, the staminode is rather small and its long stalk is very similar in texture and color to the filament of the fertile stamens. Obviously, it is a primitive new species related to Selenipedilum based on the similarities mentioned above. In the subfamily Cypripedioideae, as generally recognized, Selenipedilum is the most primitive genus, from which or whose allies Cypripedium is derived. Of phytogeographical significance is the fact that Selenipedilum occurs in Central America and northern South America, while a cypripedium akin to it is discontinuously distributed in subtropical Asia. This suggests that Selenipedilum or Selenipedilum-like form be once continually distributed in North America and eastern Asia when the climate there was warmer, as it is in the subtropics today. The floristic relationship between Central America and subtropical Asia appears to be closer than expected, as shown by the distribution patterns of Tropidia, Erythrodes, etc. Based on the occurrence of all six sections and particularly the most primitive form in eastern Asia, Cypripedium seems to be of Asian, rather than Central American, origin. Selenipedilum possesses some very primitive characters, such as trilocular ovary, vanilla-scented fruit, seed with sclerotic testa, simple column and more or less suffrutescent habit. The latter is considered by Dahlgren & Clifford (1982) to be one of ancestral characters of monocotyledons, which is now very rare not only in Orchidaceae but also in all monocotyledons. It is indeed necessary to make further investigations on Selenipedilum and also the new species pub-lished here, as well as a detailed comparison between them.     

A taxometric analysis of seed proteins in the genusBriza s. l. (Poaceae)

The species ofBriza L. s. l. are disjunctly distributed between Eurasia and South America. A taxometric analysis has been carried out, using data from electrophoresis of seed polypeptides and published morphological characters. Evidence from a cluster analysis of seed polypeptide data strongly supports the recognition of two different natural groups, a S. American group and a Eurasian group, and is consistent with karyotype data, but does not support the generic groupings of South American taxa derived from the morphological data.