Morphology-based Phylogenetic Analyses Research Articles

An eosimiid primate of South Asian affinities in the Paleogene of Western Amazonia and the origin of New World monkeys

Recent fossil discoveries in Western Amazonia revealed that two distinct anthropoid primate clades of African origin colonized South America near the Eocene/Oligocene transition (ca. 34 Ma). Here, we describe a diminutive fossil primate from Brazilian Amazonia and suggest that, surprisingly, a third clade of anthropoids was involved in the Paleogene colonization of South America by primates. This new taxon, Ashaninkacebus simpsoni gen. et sp. nov., has strong dental affinities with Asian African stem anthropoids: the Eosimiiformes. Morphology-based phylogenetic analyses of early Old World anthropoids and extinct and extant New World monkeys (platyrrhines) support relationships of both Ashaninkacebus and Amamria (late middle Eocene, North Africa) to the South Asian Eosimiidae. Afro-Arabia, then a mega island, played the role of a biogeographic stopover between South Asia and South America for anthropoid primates and hystricognathous rodents. The earliest primates from South America bear little adaptive resemblance to later Oligocene-early Miocene platyrrhine monkeys, and the scarcity of available paleontological data precludes elucidating firmly their affinities with or within Platyrrhini. Nonetheless, these data shed light on some of their life history traits, revealing a particularly small body size and a diet consisting primarily of insects and possibly fruit, which would have increased their chances of survival on a natural floating island during this extraordinary over-water trip to South America from Africa. Divergence-time estimates between Old and New World taxa indicate that the transatlantic dispersal(s) could source in the intense flooding events associated with the late middle Eocene climatic optimum (ca. 40.5 Ma) in Western Africa.

An extraordinary case of elytra loss in Coleoptera (Elateroidea: Lycidae): discovery and placement of the first anelytrous adult male beetle

Abstract Insects are one of the few groups of animals that developed the ability of active flight. Such mobility allowed the group to successfully explore and thrive in nearly all kinds of ecological niches. At the same time, during the evolutionary history of insects, due to high costs of wing development, flight was lost independently in many groups. In beetles, the reduction or complete loss of hind wings has been reported in multiple lineages, especially in several extreme paedomorphic and larviform females, mainly in Elateroidea, in which not only the hind wings but also the elytra are lost. However, the complete absence of elytra in adult males was hitherto unknown, despite nearly half a million described species in Coleoptera. In this study, we report the discovery of Xenomorphon baranowskii gen. et sp. nov., the first completely anelytrous and wingless adult male beetle, belonging to the family Lycidae (Coleoptera: Elateroidea). Xenomorphon baranowskii is illustrated, described, and provisionally placed in Calopterini, based on our morphology-based phylogenetic analyses. We discuss the possible scenarios that could lead to such a rare event, when a beetle loses its elytra, and its evolutionary consequences.

New Cretaceous empidoids and the Mesozoic dance fly revolution (Diptera: Empidoidea).

Dance flies and relatives (Empidoidea) are a diverse and ecologically important group of Diptera in nearly all modern terrestrial ecosystems. Their fossil record, despite being scattered, attests to a long evolutionary history dating back to the early Mesozoic. Here, we describe seven new species of Empidoidea from Cretaceous Kachin amber inclusions, assigning them to the new genus Electrochoreutes gen.n. (type species: Electrochoreutes trisetigerus sp.n.) based on unique apomorphies among known Diptera. Like many extant dance flies, the males of Electrochoreutes are characterized by species-specific sexually dimorphic traits, which are likely to have played a role in courtship. The fine anatomy of the fossils was investigated through high-resolution X-ray phase-contrast microtomography to reconstruct their phylogenetic affinities within the empidoid clade, using cladistic reasoning. Morphology-based phylogenetic analyses including a selection of all extant family- and subfamily-ranked empidoid clades along with representatives of all extinct Mesozoic genera, were performed using a broad range of analytical methods (maximum parsimony, maximum-likelihood and Bayesian inference). These analyses converged in reconstructing Electrochoreutes as a stem-group representative of the Dolichopodidae, suggesting that complex mating rituals evolved in this lineage during the Cretaceous.

The importance of the appendicular skeleton for the phylogenetic reconstruction of lamniform sharks (Chondrichthyes: Elasmobranchii).

Lamniform sharks are one of the more conspicuous groups of elasmobranchs, including several emblematic taxa as the white shark. Although their monophyly is well supported, the interrelationships of taxa within Lamniformes remains controversial because of the conflict among various previous molecular-based and morphology-based phylogenetic hypotheses. In this study, we use 31 characters related to the appendicular skeleton of lamniforms and demonstrate their ability to resolve the systematic interrelationships within this shark order. In particular, the new additional skeletal characters resolve all polytomies that were present in previous morphology-based phylogenetic analyses of lamniforms. Our study demonstrates the strength of incorporating new morphological data for phylogenetic reconstructions.

First molecular phylogeny of the freshwater planarian genusGirardia(Platyhelminthes: Tricladida) unveils hidden taxonomic diversity and initiates resolution of its historical biogeography

AbstractThe genus Girardia (Platyhelminthes: Tricladida) comprises several species of which some have spread from their original areas of distribution in the Americas to other parts of the globe. Due to great anatomical similarity between species, morphology-based phylogenetic analyses have struggled to resolve the affinities between species and species-groups. This problem is exacerbated by the fact that populations of Girardia may show only asexual reproduction by fissiparity and, thus, do not exhibit a copulatory apparatus, which hampers taxonomic identification of phylogenetic characters. In the present work, this problem has been resolved by constructing a molecular phylogeny of the genus. Although our samples do not include representatives of all known species, they cover a large part of the original distributional range of the genus Girardia. Our phylogenetic results suggest the presence of two main clades, which are genetically and karyologically highly differentiated. North and South American populations of G. tigrina actually constitute two sibling species that are not even closely related. The South American form is here described as a new species. The phylogenetic tree brings to light that Girardia arose on the South American portion of Gondwanaland, from which it, subsequently, dispersed to the Nearctic Region, probably more than once.

Comparative cladistics: identifying the sources for differing phylogenetic results between competing morphology-based datasets

Competing morphology-based phylogenetic analyses are routinely compared and evaluated only by a posteriori phylogenetic topology and group support, with little or no analysis of a priori data sources responsible for differing results. Although discordant characters and character-state scores are usually key to differing results (more so than variation in terminal taxa), programs currently do not exist to facilitate even simple two-way comparisons of morphology-based datasets, despite the impracticality and imprecision of manual assessment for datasets involving hundreds of characters. This paper, a first step to remedy this circumstance, presents methods (within TNT) to identify, compile and evaluate differences in characters and character states between datasets that yield different trees and degrees of group support. These apparently simple and urgently needed computer-assisted routines involve conceptual and computational challenges, even when competing morphology-based datasets are grossly similar. Example two-way comparisons are presented using pairs of similar morphology-based datasets for hominin and basal dinosaur radiations.

Genetic variability, cryptic species and phylogenetic relationship of six cyathostomin species based on mitochondrial and nuclear sequences

Cyathostomins are important intestinal nematode parasites of equines and include 50 accepted species. Their taxonomy has been frequently revised and the presence of cryptic species suggested. Furthermore, usually molecular- and morphology-based phylogenetic analyses give divergent results. In this study, the nucleotide sequences of the nuclear second internal transcribed spacer (ITS-2) and the mitochondrial partial cytochrome c oxidase subunit I (COI) were determined for adults of six cyathostomin species (Coronocyclus coronatus, Coronocyclus labiatus, Cylicocyclus nassatus, Cylicostephanus calicatus, Cylicostephanus longibursatus, Cylicostephanus minutus) collected from different equine species within two geographic regions. Maximum likelihood trees were calculated for ITS-2, COI, and concatenated data. No obvious differentiation was observed between geographic regions or equine host species. As previously reported, Coronocyclus coronatus and Cylicostephanus calicatus revealed a close relationship. Cryptic species were detected in Cylicostephanus minutus and Cylicostephanus calicatus. Cylicocyclus nassatus and Coronocyclus labiatus showed diverse mitochondrial and nuclear haplotypes occurring in different combinations, while Cylicostephanus longibursatus was comparatively homogenous. In conclusion, a combined analysis of nuclear and mitochondrial haplotypes improved resolution of the phylogeny and should be applied to the remaining cyathostomin species and across additional equine host species and geographic regions.

Tachyporinae Revisited: Phylogeny, Evolution, and Higher Classification Based on Morphology, with Recognition of a New Rove Beetle Subfamily (Coleoptera: Staphylinidae).

Simple SummaryThe rove beetle subfamily Tachyporinae has been suggested to be polyphyletic for the last half century but there are no previous studies conducting phylogenetic analysis on this group specifically. Here, the most comprehensive tachyporine phylogeny is shown, which again rejects the monophyly of Tachyporinae and its largest tribe Tachyporini. A revised classification of Tachyporinae is proposed here based on observation of morphological characters and their phylogenetic analyses. This backbone phylogeny will be a framework for further evolutionary and ecological studies.Tachyporinae are one of the most phylogenetically problematic subfamilies in the mega-diverse rove beetle family Staphylinidae. Despite its high diversity and abundance in forest micro-environments, with over 1600 species worldwide, several previous studies had refuted the monophyly of this subfamily and its largest tribe, Tachyporini. Based on the results of morphology-based phylogenetic analyses and direct examination of specimens encompassing two extinct and all forty extant genera, a new suprageneric classification of Tachyporinae is proposed here, with the removal of the tribe Mycetoporini into a newly recognized subfamily Mycetoporinae stat. nov. Four tribes with two subtribes are arranged within Tachyporinae sensu nov.: Tachyporini sensu nov. (Tachyporina stat. nov., sensu nov. and Euconosomatina stat. rev., sensu nov.), Vatesini sensu nov., Deropini, and Tachinusini stat. rev., sensu nov. (= Megarthropsini syn. nov.). Urolitus syn. nov. is placed as a junior synonym of Sepedophilus. Additionally, Palporus stat. nov. is raised to a distinct genus from a subgenus of Tachyporus sensu. nov., and †Mesotachyporus syn. nov. is synonymized with the latter. Mycetoporine Bobitobus stat. rev. is resurrected from synonymy with Lordithon sensu nov., and considered as a valid genus. My revised classification provides a novel framework for taxonomic inventories and ecological studies of these groups.

New macrobenthic cycloneuralians from the Fortunian (lowermost Cambrian) of South China

Although morphology-based phylogenetic analyses and molecular data suggested that the cycloneuralians might have emerged in the Ediacaran Period, the oldest known fossil remains of cycloneuralians were first reported from the Cambrian Fortunian Stage of South China, and to date four genera and species as well as nine indeterminate forms have been described. Here, we report the latest discoveries of cycloneuralians from the Fortunian Kuanchuanpu Formation at Zhangjiagou Lagerstätte, Dahe Village, Xixiang County, southern Shaanxi Province, South China. A new genus and species Dahescolex kuanchuanpuensis n. gen. n. sp. is described, and a previously reported genus and species Eopriapulites sphinx is re-described. Dahescolex kuanchuanpuensis n. gen. n. sp. is suggested to be a stem-lineage derivative of Scalidophora, whereas E. sphinx may represent a stem-lineage derivative of Cycloneuralia. From the fragments discovered, the new specimens are suggested to have reached millimeters in dimension, and the original individuals are estimated to have dimensions in centimeter, hence falls within the size range of macrobenthos. Therefore, at least some of the Fortunian cycloneuralians can be considered macrobenthic, and it is suggested here that the Cycloneuralia may have originated in the Fortunian macrobenthos.

Nuclear and mitochondrial marker sequences reveal close relationship between Coronocyclus coronatus and a potential Cylicostephanus calicatus cryptic species complex

The Cyathostominae (Nematoda, Strongyloidea) parasitising equines represent a diverse group currently including 50 species. However, their taxonomy has been repeatedly revised and occasionally the presence of cryptic genospecies was suggested. Moreover, molecular- and morphology-based phylogenetic analyses give divergent results. For instance, molecular data have suggested close relationship between Coronocyclus coronatus and Cylicostephanus calicatus, although morphology-based taxonomy places them in different genera. Here, nuclear (internal transcribed spacer 2, ITS-2) and mitochondrial (cytochrome oxidase I, COI) sequences were obtained from the same individual, morphologically identified worms. In both morphospecies, two ITS-2 sequences types were observed: In Cor. coronatus, a small PCR product of 278 bp (nuclear haplotype group nHGBco) was always present but often in combination with a larger 369–370 bp fragment (nHGAco). In Cys. calicatus, either a large 370 bp product (nHGAca) or a short 281 bp amplicon (nHGBca) were found, but never both. Sequence identity between morphospecies was up to 100%. The smaller differed from the larger fragments by deletion of the region 110–198 in Cor. coronatus and 112–203 in Cys. calicatus. In COI, three and five mitochondrial haplotype groups (HGs), mtHG1co-mtHG3co and mtHG1ca-mtHG5ca were identified for Cor. coronatus and Cys. calicatus, respectively. In Cor. coronatus, there was no particular association of mtHG with nuclear genotypes (only nHGBco vs. both nHGBco plus nHGAco). In Cys. calicatus the nHGAca was always associated with the mtHG1ca, mtHG2ca or mtHG5ca whereas nHGBca was exclusively associated with mtHG3ca or mtHG4ca. Despite up to 100% identity in the nHGs, no mixing of mtHGs was observed between both species. Clear separation of certain nHGs with particular mtHGs in Cys. calicatus, despite the fact that the same host individuals were infected with both groups simultaneously, suggests presence of two non-interbreeding genospecies within Cys. calicatus, which needs further confirmation using additional samples from diverse geographical origins.

A new brittle star (Ophiuroidea: Ophiodermatina) from the Early Triassic Paris Biota (Bear Lake County, Idaho, USA)

Knowledge on the morphology of Early Triassic ophiuroids is very limited, in spite of the relatively high number of described species. This hampers attempts to use morphology-based phylogenetic analyses in order to explore the early diversification of the ophiuroid modern clades between the latest Paleozoic and the early Mesozoic. Here, a new ophiuroid from the Early Triassic of southern Idaho (USA) is described and assigned to the new taxon Shoshonura brayardi Thuy nov. gen., nov. sp. It is part of an exceptional Early Triassic faunal assemblage recently described as the Paris Biota. On account of the arm morphology and the shape of the arm spines and arm spine articulations, Shoshonura brayardi nov. gen., nov. sp. is considered a basal member of the suborder Ophiodermatina.

A new species of Hygrocybe from Kerala State, India

Hygrocybe indica sp. nov. is described based on specimens collected from Kerala State, India. Morphology-based methods and phylogenetic analyses of sequences of the internal transcribed spacer (nrITS) and nuclear large subunit (nrLSU) of the ribosomal RNA gene were employed to confirm the novelty of this species. The phylogenetic relationship inferred from independent nrLSU and nrITS sequence data matrices confirmed the difference of this new species from other species of Hygrocybe for which DNA sequences are available. The phylogenetic analyses clearly assigned H. indica to the subgenus Hygrocybe. A comprehensive description, photographs of the basidiocarps and the microstructures, and comparisons with morphologically similar and phylogenetically related species and phylograms to depict the placement of the new species are provided.

Incomplete sclerotization and phylogeny: The phylogenetic classification of Plastocerus (Coleoptera: Elateroidea).

The relationships of the monogeneric family Plastoceridae Crowson, 1972 (Coleoptera: Elateroidea) have remained contentious due to its modified morphology, incorrect information on incomplete metamorphosis of females and the absence of molecular data. We produced the sequences for P. angulosus (Germar, 1844) (the type-species of Plastocerus Schaum, 1852) and performed molecular phylogenetic analyses to estimate its position. The analyses of Elateroidea (186 spp.) and Elateridae (110 spp.) molecular datasets of two mitochondrial and two nuclear gene fragments repeatedly placed Plastocerus Schaum, 1852 in relationships with the elaterid genera Oxynopterus Hope, 1842 and Pectocera Hope, 1842. Alternative topologies were rejected by likelihood tests. Therefore, Plastoceridae Crowson, 1972 are down-ranked to the subfamily Plastocerinae in Elateridae Leach, 1815. We suggest that the morphology-based placement and high rank for some elateroid lineages were inferred from the presence of homoplasies which evolved due to incomplete sclerotization. Distantly related soft-bodied elateroids share freely movable and transverse coxae, a shortened prosternum, and a weakly sclerotized abdomen with free ventrites. Importantly, the apomorphic structures characteristic for their closest relatives, such as the prosternal process, mesoventral cavity, and intercoxal keel in the first abdominal ventrite are regularly absent. Consequently, morphology-based phylogenetic analyses suggest deeply rooted positions for lineages without expressed apomorphic character states. Molecular data represent an independent character system that is not affected by the convergent morphological evolution, and therefore molecular phylogenies can elucidate the relationships of incompletely sclerotized lineages.

When can clades be potentially resolved with morphology?

Morphology-based phylogenetic analyses are the only option for reconstructing relationships among extinct lineages, but often find support for conflicting hypotheses of relationships. The resulting lack of phylogenetic resolution is generally explained in terms of data quality and methodological issues, such as character selection. A previous suggestion is that sampling ancestral morphotaxa or sampling multiple taxa descended from a long-lived, unchanging lineage can also yield clades which have no opportunity to share synapomorphies. This lack of character information leads to a lack of ‘intrinsic’ resolution, an issue that cannot be solved with additional morphological data. It is unclear how often we should expect clades to be intrinsically resolvable in realistic circumstances, as intrinsic resolution must increase as taxonomic sampling decreases. Using branching simulations, I quantify intrinsic resolution across several models of morphological differentiation and taxonomic sampling. Intrinsically unresolvable clades are found to be relatively frequent in simulations of both extinct and living taxa under realistic sampling scenarios, implying that intrinsic resolution is an issue for morphology-based analyses of phylogeny. Simulations which vary the rates of sampling and differentiation were tested for their agreement to observed distributions of durations from well-sampled fossil records and also having high intrinsic resolution. This combination only occurs in those datasets when differentiation and sampling rates are both unrealistically high relative to branching and extinction rates. Thus, the poor phylogenetic resolution occasionally observed in morphological phylogenetics may result from a lack of intrinsic resolvability within groups.

Taxonomic classification of the reef coral family Mussidae (Cnidaria: Anthozoa: Scleractinia)

Molecular analyses are transforming our understanding of the evolution of scleractinian corals and conflict with traditional classification, which is based on skeletal morphology. A new classification system, which integrates molecular and morphological data, is essential for documenting patterns of biodiversity and establishing priorities for marine conservation, as well as providing the morphological characters needed for linking present-day corals with fossil species. The present monograph is the first in a series whose goal is to develop such an integrated system. It addresses the taxonomic relationships of 55 Recent zooxanthellate genera (one new) in seven families (one new), which were previously assigned to the suborder Faviina (eight genera are transferred to incertae sedis). The present monograph has two objectives. First, we introduce the higher-level classification system for the 46 genera whose relationships are clear. Second, we formally revise the taxonomy of those corals belonging to the newly discovered family-level clade (restricted today to the western Atlantic and Caribbean regions); this revised family Mussidae consists of ten genera (one of which is new) and 26 species that were previously assigned to the ‘traditional’ families Faviidae and Mussidae. To guide in discovering morphologic characters diagnostic of higher-level taxa, we mapped a total of 38 morphologic characters [19 macromorphology, eight micromorphology, 11 microstructure] onto a molecular tree consisting of 67 species [22 Indo-Pacific and seven Atlantic species in the traditional family Faviidae; 13 Indo-Pacific and ten Atlantic species in the traditional family Mussidae; 13 species in the traditional families Merulinidae (5), Pectiniidae (7), and Trachyphylliidae (1); two Atlantic species of traditional Montastraea], and trace character histories using parsimony. To evaluate the overall effectiveness of morphological data in phylogeny reconstruction, we performed morphology-based phylogenetic analyses using 27 (80 states) of the 38 characters, and compared morphological trees with molecular trees. The results of the ancestral state reconstructions revealed extensive homoplasy in almost all morphological characters. Family- and subfamily-level molecular clades [previously identified as XVII−XXI] are best distinguished on the basis of the shapes of septal teeth and corresponding microstructure. The newly revised family Mussidae (XXI) has septal teeth with regular pointed tips (a symplesiomorphy) and a stout blocky appearance. It has two subfamilies, Mussinae and Faviinae. The subfamily Mussinae is distinguished by spine-shaped teeth and widely spaced costoseptal clusters of calcification centres. The subfamily Faviinae is distinguished by blocky, pointed tricorne or paddle-shaped teeth with elliptical bases, transverse structures such as carinae that cross the septal plane, and well-developed aligned granules. Defining diagnostic characters for the broader data set is more challenging. In analyses of taxonomic subsets of the data set that were defined by clade, morphological phylogenetic analyses clearly distinguished the families Mussidae (XXI) and Lobophylliidae (XIX), as well as the two subfamilies of Mussidae (Mussinae, Faviinae), with one exception (Homophyllia australis). However, analyses of the entire 67-species data set distinguished the family Lobophylliidae (XIX), but not the Merulinidae (XVII) and not the newly defined Mussidae (XXI), although the subfamily Mussinae was recovered as monophyletic. Some lower-level relationships within the Merulinidae (XVII) agree with molecular results, but this particular family is especially problematic and requires additional molecular and morphological study. Future work including fossils will not only allow estimation of divergence times but also facilitate examination of the relationship between these divergences and changes in the environment and biogeography. Published 2012. This article is a U.S. Government work and is in the public domain in the USA. Zoological Journal of the Linnean Society, 2012, 166, 465–529.

“Regressed” Macrostomatan Snakes

On some morphology-based phylogenies of extant snakes the capacity to ingest prey of a diameter larger than the snake's head optimizes as a derived condition of macrostomatan snakes such as boas and pythons. The evolution of macrostomatan jaw mechanics can be traced in the more basal scolecophidian and anilioid snakes, such as blind snakes, thread snakes, pipe snakes, and shield tails. Several recent morphology-based phylogenetic analyses of snake interrelationships including fossil snakes have placed fossil taxa of large body size and/or with a macrostomatan skull structure basal to either all extant snakes, or basal to the Alethinophidia (Anilioidea plus Macrostomata, excluding Scolecophidia). This has led to the characterization of scolecophidians and/or anilioids as “regressed macrostomatans”. These snakes would have lost their macrostomatan feeding capacities in adaptation to a fossorial or secretive mode of life, correlated in some forms such as scolecophidians and uropeltines with miniaturization. However, the characterization of scolecophidians and/or anilioids as regressed macrostomatans is not only a matter of character optimization on a phylogeny, but is also incompatible with morphological and physiological aspects of feeding mechanics in snakes.

Phylogeny and evolution of corambid nudibranchs (Mollusca: Gastropoda)

Organismic diversity, as well as distributional and ecological patterns, can be fully understood in an evolutionary framework only. Reliable phylogenetic trees are required to ‘read history’, but are not yet available for most marine invertebrate groups. Molecular systematics offers an enormous potential, but still fails for ‘all-species approaches’ on groups with species that are rare or occur in remote areas only, simply because there is no easily collectable material available for sequence analyses. Exploring morphologically aberrant corambid nudibranch gastropods as a case study, we assess whether or not morphology-based phylogenetic analyses can fill this gap and produce a tree that allows a detailed view on evolutionary history. Morphology-based parsimony analysis of corambids and potential relatives resulted in a well-resolved and remarkably robust topology. As an offshoot of kelp-associated onchidoridid ancestors, and obviously driven by the heterochronic shortening of life cycles and morphological juvenilization in an ephemeral habitat, the ancestor of corambids originated in cool northern Pacific coastal waters. A basal clade (the genus Loy) diverged there, adapting to live on soft bottoms under successive reversals of paedomorphic traits. The more speciose Corambe lineage radiated preying upon short-lived encrusting bryozoa in a high-energy kelp environment. Selection favoured transformation of the mantle into a cuticle-covered shield, and successive paedomorphic translocations of dorid anal gills to the protected ventral side of the body, where compensatory, multiple gills evolved. Corambe species probably first colonized tropical American seas, and then radiated in worldwide temperate waters: this is explained by the excellent long-distance dispersal abilities afforded by rafting on kelp, with the subsequent divergence of colonizers in allopatry. The competitive coexistence of Corambe pacifica MacFarland & O'Donoghue, 1929 and Corambe steinbergae (Lance, 1962) off California is the result of independent colonization events. The closing of the Isthmus of Panama separated the latter species from a flock that have radiated within warm Atlantic waters since then. Our case study shows that morphological structures, if investigated in depth, bear the potential for an efficient phylogenetic analysis of groups that are still elusive to molecular analyses. Tracing character evolution and integrating a wide range of geographic, biological, and ecological background information allowed us to reconstruct an evolutionary scenario for corambids that is detailed and plausible, and can be tested by future molecular approaches. © 2011 The Linnean Society of London, Zoological Journal of the Linnean Society, 2011, 163, 585–604.

A methodological investigation of hominoid craniodental morphology and phylogenetics

The evolutionary relationships of extant great apes and humans have been largely resolved by molecular studies, yet morphology-based phylogenetic analyses continue to provide conflicting results. In order to further investigate this discrepancy we present bootstrap clade support of morphological data based on two quantitative datasets, one dataset consisting of linear measurements of the whole skull from 5 hominoid genera and the second dataset consisting of 3D landmark data from the temporal bone of 5 hominoid genera, including 11 sub-species. Using similar protocols for both datasets, we were able to 1) compare distance-based phylogenetic methods to cladistic parsimony of quantitative data converted into discrete character states, 2) vary outgroup choice to observe its effect on phylogenetic inference, and 3) analyse male and female data separately to observe the effect of sexual dimorphism on phylogenies. Phylogenetic analysis was sensitive to methodological decisions, particularly outgroup selection, where designation of Pongo as an outgroup and removal of Hylobates resulted in greater congruence with the proposed molecular phylogeny. The performance of distance-based methods also justifies their use in phylogenetic analysis of morphological data. It is clear from our analyses that hominoid phylogenetics ought not to be used as an example of conflict between the morphological and molecular, but as an example of how outgroup and methodological choices can affect the outcome of phylogenetic analysis.

Silvaphilus: A New Relict Forest-Endemic Canthonini Dung Beetle Genus from the Western Cape Province of South Africa (Coleoptera: Scarabaeidae: Scarabaeinae)

At a global scale, the ancient dung beetle tribe Canthonini (Scarabaeidae: Scarabaeinae) displays a mainly Gondwanan distribution, with most African genera having very restricted ranges (Davis et al. 2008; Deschodt & Scholtz 2008). As currently defined, the African Canthonini comprises 24 genera and about 100 described species (see Deschodt & Scholtz (2008) for a key to the African genera). However, preliminary molecular and morphology-based phylogenetic analyses of the Scarabaeinae indicate that the tribe consists of multiple paraphyletic lineages (Philips et al. 2004; Monaghan et al. 2007) and that generic inclusion should be reconsidered. Most of the 22 African genera currently placed in the Canthonini are species-poor and nine are currently monotypic. A large proportion of the African genera (14) are restricted to the isolated montane or coastal forest patches from Kenya to the Cape Peninsula of South Africa (Scholtz & Howden 1987; Deschodt & Scholtz 2008). The South African forest-associated Canthonini currently include the genera Bohepilissus Paulian, Endroedyolus Scholtz & Howden, Gyronotus Lansberge, Outenikwanus Scholtz & Howden, Peckolus Scholtz & Howden and the recently described Aliuscanthoniola Deschodt & Scholtz, Dwesasilvasedis Deschodt & Scholtz, Parvuhowdenius Deschodt & Scholtz and Nebulasilvius Deschodt & Scholtz (Scholtz & Howden 1987; Deschodt & Scholtz 2008). With the exception of Gyronotus (Davis et al. 2001), these are all endemic to South Africa.

Systematics of Podocoma (Asteraceae: Astereae): a generic reassessment

Podocoma is a southern South American genus of perennial herbs with short-radiate capitula with two- to four-seriate ray florets and a two- to three-seriate pappus of scabridulous setae. The ray florets have corollas with narrow limbs. The rostrate cypsela of Podocoma is one of the most distinct features of the genus. Podocoma, with many of the endemic southern South American genera of Astereae, is included in subtribe Podocominae. Podocoma traditionally contained seven mainly Brazilian species (P. asperrima, P. bellidifolia, P. blanchetiana, P. hieracifolia, P. hirsuta, P. regnellii and P. spegazzinii), and its expansion to include two species of Conyza (C. notobellidiastrum and C. rivularis) was, perhaps, the most significant recent change in the generic concept of Podocoma. However, recent molecular- and morphology-based phylogenetic analyses do not support the inclusion of these two species in Podocoma. Morphological and anatomical studies were carried out in order to clarify the taxonomy of Podocoma and to delimit the genus and its species. On the basis of the results of these morphological and anatomical studies, and those from molecular- and morphology-based phylogenetic analyses, P. notobellidiastrum and P. rivularis are excluded from Podocoma and transferred to a new genus that is currently under description. Moreover, P. regnellii and P. asperrima are placed in synonymy with P. hirsuta and P. spegazzinii, respectively. Three species, P. bellidifolia, P. blanchetiana and P. hieracifolia, are recognized here as a complex of closely related species from a morphological point of view; however, they are treated separately. © 2010 The Linnean Society of London, Botanical Journal of the Linnean Society, 2010, 163, 486–513.