Hygrophorus aurantiosquamosus (Hygrophoraceae, Agaricales), a new species of Hygrophorus section Chrysodontes from western China

In China, the European species, Hygrophorus chrysodon, is widely reported in western and northeastern provinces. After carefully comparing H. chrysodon from China and Europe, we found that the European and Chinese materials were different lineages in molecular trees, and there were also obvious differences in morphology between the two lineages. The evidence from morphology and phylogeny indicated that the presence of H. chrysodon in China is doubtful and that the Chinese material represents an undescribed species. Thus, H. aurantiosquamosus is proposed as a new species. This new taxon is characterized by its yellowish white pileus covered with golden yellow squamules, a stipe concolorous with the pileus and covered with yellow floccules, a distinct pileipellis composed of narrow hyphae with inflated terminal elements of various shapes (clavate, cylindrical, lacrymoid to subglobose), and elongate to subcylindrical basidiospores measuring 9.5–12 × 4–5.5 μm. The new species occurs in Picea forests at high elevations of western China, such as Qinghai, Sichuan, and Tibet provinces.

Molecular Phylogenies Map to Biogeography Better than Morphological Ones

Phylogenetic relationships are inferred principally from two classes of data: morphological and molecular. Most current phylogenies of extant taxa are inferred from molecules, and when morphological and molecular trees conflict the latter are often preferred. Although supported by simulations, the superiority of molecular trees has never been assessed empirically. Here we test phylogenetic accuracy using two independent data sources: biogeographical distributions and fossil first occurrences. For 48 pairs of morphological and molecular trees, we show that molecular trees are, on average, significantly more biogeographically congruent than their morphological counterparts. We also report an increase in the biogeographical congruence of phylogenies over research time. We find no significant differences in stratigraphical congruence between morphological and molecular trees. These findings have implications for understanding homoplasy in morphological data sets, the utility of morphology as a test of molecular hypotheses, and the difficulty of analysing fossil groups for which molecular data are unavailable.

Phylogenetic revision of the shrimp genera Ephyrina, Meningodora and Notostomus (Acanthephyridae: Caridea)

The shrimp genera Ephyrina, Meningodora and Notostomus have an unusual carapace strengthened with carinae and a half-serrated mandible, which may suggest a possible monophyly of this group. Here we test this hypothesis and present the first phylogenetic study of these genera based on 95 morphological characters (all valid species coded) and six molecular markers (71% of valid species sequenced). Representatives of all genera of Oplophoridae (sister to Acanthephyridae) were outgroups, 32 species belonging to all genera and potentially different clades of Acanthephyridae were ingroups. Both morphological and molecular analyses retrieve trees with similar topology. Our results reject the hypothesis of a clade formed by Ephyrina + Meningodora + Notostomus. We show that Ephyrina and Notostomus are monophyletic, both on morphological and on molecular trees, Meningodora gains support only on morphological trees. Evolutionary traits in the Ephyrina and Meningodora + Notostomus clades are different. Synapomorphies are mostly linked to adaptations to forward motion in Ephyrina (oar-like meri and ischia of pereopods, stempost-like rostrum) and to progressive strengthening of the carapace and pleon in Meningodora and Notostomus (net of sharp carinae). Unusual mandibles evolved in the clades independently and represent convergent adaptations to feeding on gelatinous organisms.

The phylogenetic significance of the morphology of the syrinx, hyoid and larynx, of the southern cassowary, Casuarius casuarius (Aves, Palaeognathae)

Background Palaeognathae is a basal clade within Aves and include the large and flightless ratites and the smaller, volant tinamous. Although much research has been conducted on various aspects of palaeognath morphology, ecology, and evolutionary history, there are still areas which require investigation. This study aimed to fill gaps in our knowledge of the Southern Cassowary, Casuarius casuarius, for which information on the skeletal systems of the syrinx, hyoid and larynx is lacking - despite these structures having been recognised as performing key functional roles associated with vocalisation, respiration and feeding. Previous research into the syrinx and hyoid have also indicated these structures to be valuable for determining evolutionary relationships among neognath taxa, and thus suggest they would also be informative for palaeognath phylogenetic analyses, which still exhibits strong conflict between morphological and molecular trees. Results The morphology of the syrinx, hyoid and larynx of C. casuarius is described from CT scans. The syrinx is of the simple tracheo-bronchial syrinx type, lacking specialised elements such as the pessulus; the hyoid is relatively short with longer ceratobranchials compared to epibranchials; and the larynx is comprised of entirely cartilaginous, standard avian anatomical elements including a concave, basin-like cricoid and fused cricoid wings. As in the larynx, both the syrinx and hyoid lack ossification and all three structures were most similar to Dromaius. We documented substantial variation across palaeognaths in the skeletal character states of the syrinx, hyoid, and larynx, using both the literature and novel observations (e.g. of C. casuarius). Notably, new synapomorphies linking Dinornithiformes and Tinamidae are identified, consistent with the molecular evidence for this clade. These shared morphological character traits include the ossification of the cricoid and arytenoid cartilages, and an additional cranial character, the articulation between the maxillary process of the nasal and the maxilla. Conclusion Syrinx, hyoid and larynx characters of palaeognaths display greater concordance with molecular trees than do other morphological traits. These structures might therefore be less prone to homoplasy related to flightlessness and gigantism, compared to typical morphological traits emphasised in previous phylogenetic studies.

The phylogenetic significance of the morphology of the syrinx, hyoid and larynx, of the Southern Cassowary, Casuarius casuarius (Aves, Palaeognathae)

Background: The Palaeognathae are a basal clade within Aves and include the large and flightless ratites and the smaller, volant tinamous. Although much research has been conducted on various aspects of palaeognath morphology, ecology, and evolutionary history, there are still areas which require investigation. This study aimed to fill gaps in our knowledge of the Southern Cassowary, Casuarius casuarius, for which information on the skeletal systems of the syrinx, hyoid and larynx is lacking - despite these structures having been recognised as performing key functional roles associated with vocalisation, respiration and feeding. Previous research into the syrinx and hyoid have also indicated these structures to be valuable for determining evolutionary relationships among neognath taxa, and thus suggest they would also be informative for palaeognath phylogenetic analyses, which still exhibits strong conflict between morphological and molecular trees. Results: The morphology of the syrinx, hyoid and larynx of C. casuarius is described from CT scans. The syrinx is of the simple tracheo-bronchial syrinx type, lacking specialised elements such as the pessulus; the hyoid is relatively short with longer ceratobranchials compared to epibranchials; and the larynx is comprised of entirely cartilaginous, standard avian anatomical elements including a concave, basin-like cricoid and fused cricoid wings. As in the larynx, both the syrinx and hyoid lack ossification and all three structures were most similar to Dromaius. We documented substantial variation across palaeognaths in the skeletal character states of the syrinx, hyoid, and larynx, using both the literature and novel observations (e.g. of C. casuarius). Notably, new synapomorphies linking Dinornithiformes and Tinamidae are identified, consistent with the molecular evidence for this clade. These shared morphological character traits include the ossification of the cricoid and arytenoid cartilages, and an additional cranial character, the articulation between the maxillary process of the nasal and the maxilla. Conclusion: Syrinx, hyoid and larynx characters of palaeognaths display greater concordance with molecular trees than do other morphological traits. These structures might therefore be less prone to homoplasy related to flightlessness and gigantism, compared to typical morphological traits emphasised in previous phylogenetic studies. Key Words: Palaeognathae, Cassowary, Syrinx, Hyoid, Larynx, Morphology, Phylogenetics, Optimisation

The phylogenetic significance of the morphology of the syrinx, hyoid and larynx, of the Southern Cassowary, Casuarius casuarius (Aves, Palaeognathae)

The Palaeognathae are a basal clade within Aves and include the large and flightless ratites and the smaller, volant tinamous. Although much research has been conducted on various aspects of palaeognath morphology, ecology, and evolutionary history, there are still areas which require investigation. This study aimed to fill gaps in our knowledge of the Southern cassowary, Casuarius casuarius , for which information on the skeletal systems of the syrinx, hyoid and larynx is lacking despite these structures having been recognised as performing key functional roles associated with vocalisation, respiration and feeding. Previous research into the syrinx and hyoid have also indicated these structures to be valuable for determining evolutionary relationships among neognath taxa, and thus be informative for palaeognath phylogenetic analyses, which still exhibits strong conflict between morphological and molecular trees. We documented variation across palaeognaths in the skeletal character states of the syrinx, hyoid, and larynx, using both the literature and novel observations (e.g. of cassowary). Notably the molecular moa-tinamou clade was found to share morphological character traits including the ossification of the cricoid and arytenoid cartilages, and an additional cranial character, the articulation between the maxillary process of the nasal and the maxilla. These findings contributed to optimisation of syrinx, hyoid and larynx characters showing increased phylogenetic support for palaeognath relationships derived from a molecular and morphological combined-data topology.

The phylogenetic significance of the morphology of the syrinx, hyoid and larynx, of the Southern Cassowary, Casuarius casuarius (Aves, Palaeognathae)

The Palaeognathae are a basal clade within Aves and include the large and flightless ratites and the smaller, volant tinamous. Although much research has been conducted on various aspects of palaeognath morphology, ecology, and evolutionary history, there are still areas which require investigation. This study aimed to fill gaps in our knowledge of the Southern cassowary, Casuarius casuarius, for which information on the syrinx, hyoid and larynx is lacking despite these structures having been recognised as performing key functional roles associated with vocalisation, respiration and feeding. Previous research into the syrinx and hyoid have also indicated these structures to be valuable for determining evolutionary relationships among neognath taxa, and thus may also shed light on palaeognath phylogeny, which still exhibits strong conflict between morphological and molecular trees. We thus documented variation across palaeognaths in syringeal, hyoidal, and laryngeal character states, using both the literature and novel new observations (e.g. of cassowary). Notably the molecular moa-tinamou clade was found to share derived morphological traits including the ossification of the cricoid and arytenoid cartilages, and an additional cranial character, the articulation between the maxillary process of the nasal and the maxilla. Syringeal, hyoidal and laryngeal characters better optimised onto the topology resulting from phylogenetic analyses of a combined molecular and morphology analysis, than molecular-only or morphological-only trees. One primary factor for this support was the aforementioned shared character states between the moa and tinamou, also present in Lithornis and outgroup taxa.

Spines and homologues in ‘araphid’ diatoms

Background and aims – Many diatoms have spines on the surface of their valves. These structures differ from one taxon to another. Are all these spines the same? Are they homologues of one another? This paper sets out to explore some of the issues surrounding the determination of homologues with reference to members of Fragilariaceae. Methods – A variety of spines from species in Fragilariaceae are examined (in the SEM) and position on the valve documented relative to those already recorded in the literature. Key results – Spines that occur on the valves of some ‘araphid’ diatoms in Fragilariaceae can be interpreted in the light of where they are found. Spines that occur on the virgae can be thought of as modifications of that structure; spines that occur on the vimines can be thought of as modifications of that structure – the two kinds of spines are not homologues of each other. The term ‘spine’, on its own, is not useful for understanding taxon relationships; the term ‘spine’ is not even a character in the comparative biology sense but a descriptive catch-all for something that simply ‘sticks out from a surface’. Conclusions – Systematic characters, those applicable to comparative biology, are modifications of other characters and so are, in one sense, like taxonomies: hierarchical. A consequence of this is that plotting morphological characters on molecular trees of relationships is a futile endeavour – treating characters and their modifications, as if they are static (unit) features of a non-changing entity, is book-keeping not science.