The middle ear of the skull of birds: the ostrich, Struthio camelus L.

The morphology of the middle ear region including die basicranium and quadrate of Strulhxo is very simil.n to ilic same region in the orders Procellariiformes, Pelecaniformes, Ciconiiformes and Sphenisciformes. Struthio though, has some unique middle ear characters such as die lack of a chorda tympani nerve, the arrangement of die glossopharyngeal and vagus nerve foramina, die structure in the upper neck of die external ophthalmic vein and die position of die Eustachian tube. The articulatory surfaces for the quadrate bom on die zygomatic process of the squamosal and the mandible are unique in Struthio when compared to the several orders mentioned above.     

Phylogenetic analysis of pelecaniformes (aves) based on osteological data: implications for waterbird phylogeny and fossil calibration studies

Background

Debate regarding the monophyly and relationships of the avian order Pelecaniformes represents a classic example of discord between morphological and molecular estimates of phylogeny. This lack of consensus hampers interpretation of the group''s fossil record, which has major implications for understanding patterns of character evolution (e.g., the evolution of wing-propelled diving) and temporal diversification (e.g., the origins of modern families). Relationships of the Pelecaniformes were inferred through parsimony analyses of an osteological dataset encompassing 59 taxa and 464 characters. The relationships of the Plotopteridae, an extinct family of wing-propelled divers, and several other fossil pelecaniforms (Limnofregata, Prophaethon, Lithoptila, ?Borvocarbo stoeffelensis) were also assessed. The antiquity of these taxa and their purported status as stem members of extant families makes them valuable for studies of higher-level avian diversification.

Methodology/Principal Findings

Pelecaniform monophyly is not recovered, with Phaethontidae recovered as distantly related to all other pelecaniforms, which are supported as a monophyletic Steganopodes. Some anatomical partitions of the dataset possess different phylogenetic signals, and partitioned analyses reveal that these discrepancies are localized outside of Steganopodes, and primarily due to a few labile taxa. The Plotopteridae are recovered as the sister taxon to Phalacrocoracoidea, and the relationships of other fossil pelecaniforms representing key calibration points are well supported, including Limnofregata (sister taxon to Fregatidae), Prophaethon and Lithoptila (successive sister taxa to Phaethontidae), and ?Borvocarbo stoeffelensis (sister taxon to Phalacrocoracidae). These relationships are invariant when ‘backbone’ constraints based on recent avian phylogenies are imposed.

Conclusions/Significance

Relationships of extant pelecaniforms inferred from morphology are more congruent with molecular phylogenies than previously assumed, though notable conflicts remain. The phylogenetic position of the Plotopteridae implies that wing-propelled diving evolved independently in plotopterids and penguins, representing a remarkable case of convergent evolution. Despite robust support for the placement of fossil taxa representing key calibration points, the successive outgroup relationships of several “stem fossil + crown family” clades are variable and poorly supported across recent studies of avian phylogeny. Thus, the impact these fossils have on inferred patterns of temporal diversification depends heavily on the resolution of deep nodes in avian phylogeny.     

The mitochondrial genome of the Cinnamon Bittern, Ixobrychus cinnamomeus (Pelecaniformes: Ardeidae): sequence, structure and phylogenetic analysis

Ixobrychus cinnamomeus is a member of the large wading bird family, known as Ardeidae. In the present study, we determined the complete mitochondrial genome of I. cinnamomeus for use in future phylogenetic analysis. This circular mitochondrial genome is 17,180 bp in length and composed of 13 protein-coding genes, 22 tRNA genes, two rRNA genes and one putative control region. Three conserved domains and a minisatellite of 17 nucleotides with 22 tandem repeats were detected at the end of the control region. Phylogenetic relationships were reconstructed using the nucleotide and corresponding amino acid datasets of 12 concatenated protein-coding genes from the mitochondrial genome. Using maximum likelihood, maximum parsimony and Bayesian inference methods, the monophyly of Ciconiidae, Ardeidae and Threskiornithidae were confirmed; however, the monophyly of traditional Ciconiiformes and Pelecaniformes failed to be recovered. Although further studies are recommended to clarify relationships among and within the orders of Ciconiiformes, Pelecaniformes, Suliformes and Phaethontiformes, our results provide preliminary exploratory results that can be useful in the current understanding of avian phylogenetics.     

Intraordinal relationships of the Pelecaniformes and Cuculiformes: electrophoresis of feather keratins

Electrophoresis of soluble feather keratins was performed in Gradipore gels under two pH conditions. The taxa of two diverse orders, the Pelecaniformes and Cuculiformes, were compared. Dendograms based on identity indices and genetic distances were constructed by the Fitch-Margoliash and unweighed pair-group algorithms (UPGMA). Differences within taxa were influenced by both pH conditions and the algorithm used for analysis.
Values of identity indices at each pH were compared within and between taxa. Dendograms for the Pelecaniform consistently group species within genera and placed families within the traditional arrangements. One notable exception was Nannopterum. The Cuculiformes, with many monotypic genera, were more resistant to constant clustering.
The problems of relating genetic distance to phylogenies are discussed. The relationship of systematic, ecological and molecular diversity is still unresolved. Genetic distance of feather keratins consistently correlated with other estimates of divergence times. The values indicate the systematic equivalence of taxa within orders.     

The middle ear of the skull of birds The Procellariiformes

Much emphasis has been placed on the middle ear region of reptiles and mammals as a taxonomic character. However, the anatomy of the middle ear region of birds has yet to be described adequately. The literature on the middle ear of birds is reviewed briefly and then the osteology and soft anatomy of the middle ear region of the skull are described for the families of the avian order Procellariiformes. Particular emphasis is paid to the foramina and paths of the nerves and blood vessels. Also discussed is the morphology of the basicranium and the quadrate. Comparative analyses of the characters are used to assess taxonomic conclusions.     

Phylogenies of the Frigatebirds (Fregatidae) and Tropicbirds (Phaethonidae), two divergent groups of the traditional order Pelecaniformes, inferred from mitochondrial DNA sequences

The frigatebirds (Fregatidae) and Tropicbirds (Phaethonidae) represent the most morphologically and behaviorally distinct members of the traditional Order Pelecaniformes. Using 1756bp of mitochondrial DNA sequence consisting of the 12S, ATPase-6, ATPase-8, and COI genes obtained from all extant species, we derive a completely resolved phylogeny for both groups. The inferred relationships among these species are robust to the method of phylogenetic estimation used, and all branches are well supported, in spite of the relatively recent radiation within the frigatebirds. The two families are not closely related either to each other, or to any other putative relatives (e.g., pelicans; Pelecanidae).     

A study of the egg shells of the Gaviiformes, Procellariiformes, Podicipitiformes and Pelecaniformes

Egg shells of the Gaviiformes, Procellariiformes, Podicipitiformes and Pelecaniformes have been studied using general inspection, chemical analysis, histological and plastic embedding techniques.
In all four orders there is a true shell consisting of large crystals having their origin at the surface of the membrane. In the Gaviiformes and Procellariiformes, the true shell is then covered with a cuticle, while in the Podicipitiformes and Pelecaniformes (except for the Phaethontidae) there is a calcareous cover over the true shell. Histological studies showed no major difference in the organic matrix of the true shell as between the four orders.
Pore channels are all single and, in those egg shells which have a cover, these channels do not penetrate the cover. Considerable pigmentation is present in the Gaviiformes egg shells and also in the Phaethontidae, and pigment spots occur not only on the surface but also in the body of the shell. Studies of the apparent density of the true shells and the covers showed interesting differences.
The taxonomic aspect of the results is discussed.     

The anatomy of the middle ear of the tinamiformes (Aves: Tinamidae)

The morphology of the middle ear region including the basicranium and quadrate of tinamous is compared among ratites and flying birds belonging to the Procellariiformes, Sphenisciformes, Pelecaniformes, and Ciconiiforms. The middle ears of tinamous and ratites share a number of important characters including absence of a separate foramen for the glossopharyngeal nerve; eustachian tube, carotid artery, and stapedial artery encased in bone; and a metotic process with vascular canals or notches. Outgroup analysis confirms these characters as synapomorphies. These data support the position that the Tinami and Ratiti form a monophyletic assemblage.     

A new species of Syncuaria Gilbert, 1927 (Nematoda: Acuarioidea: Acuariidae) in the wood stork, Mycteria americana L. (Aves: Ciconiiformes: Ciconiidae) from the Area de Conservacion Guanacaste, Costa Rica

Syncuaria mycteriae n. sp. (Nematoda: Acuarioidea) was collected under the lining of the gizzard of a wood stork, Mycteria americana L., from the Area de Conservacion Guanacaste, Costa Rica. The new species can be distinguished from all known species of Syncuaria by having irregular dotted ornamentations on the caudal alae of males, a complex distal end of the left spicule comprising 3 protuberances, and a spicule ratio of 1:9.3. Preliminary phylogenetic analysis of 11 Syncuaria spp. based on 9 morphological characters produced 2 equally parsimonious cladograms with a consistency index of 85%, differing only in the placement of S. hargilae. The phylogenetic analysis suggests that the new species is the sister species of S. leptoptili, whose male members have a single protuberance on the left spicule. Furthermore, the analysis suggests that the plesiomorphic host group for the genus is Ciconiiformes, specifically Ciconiidae (host for 5 species), with 2 species occurring in Threskiornithidae (also Ciconiiformes), possibly as a result of cospeciation, and 2 species each occurring in Pelecaniformes and Podicipediformes, resulting from 4 episodes of speciation by host switching.     

Tertiary plotopterids (Aves, Plotopteridae) and a novel hypothesis on the phylogenetic relationships of penguins (Spheniscidae)

Plotopterids (Aves: Plotopteridae) are extinct wing-propelled diving birds which exhibit a strikingly similar wing morphology to penguins (Spheniscidae), but also share derived characters with 'pelecaniform' birds that are absent in penguins. The similarities between Plotopteridae and Spheniscidae have hitherto been attributed to convergence, and plotopterids were considered to be most closely related to the 'pelecaniform' Phalacrocoracidae (cormorants) and Anhingidae (anhingas). However, here I show that assignment of plotopterids to 'pelecaniform' birds does not necessarily preclude them from being the sister taxon of penguins. Cladistic analysis of 68 morphological characters resulted in sister group relationship between Plotopteridae and Spheniscidae, and the clade (Plotopteridae + Spheniscidae) was shown to be the sister taxon of the Suloidea, i.e. a clade including Sulidae (boobies and gannets), Phalacrocoracidae, and Anhingidae. Derived characters are discussed which support this novel hypothesis. Paedomorphosis probably accounts for the absence of derived characters in penguins that are shared by Plotopteridae and members of the Steganopodes. Plotopterids exemplify the importance of fossil birds for analyzing the phylogenetic relationships of modern taxa that exhibit a highly apomorphic morphology.     

Wood anatomy of Krameriaceae with comparisons with Zygophyllaceae: phylesis, ecology and systematics

Wood of nine species of Krameria (including all clades proposed within the genus) reveals a few characters related to infrageneric systematics; most relate primarily to ecology and habit. Wood of Krameria closely fits quantitative data reported for desert shrubs. Lack of vessel grouping correlates with the presence of densely pitted tracheids. Wood xeromorphy in Krameria may relate in part to hemiparasitism. Tracheid presence may also account for relatively low vessel density. Wood anatomy of six species of Zygophyllaceae (including both genera of Morkillioideae) is compared with that of Krameriaceae because recent phylogenies propose that these two families comprise the order Zygophyllales. Several wood characters appear to represent synapomorphies reflecting this relationship. Differences in wood anatomy between Krameriaceae and Zygophyllaceae are believed to represent autapomorphies. Notable among these include Paedomorphic Type II rays (Krameriaceae), storying (Zygophyllaceae), presence of vestured pits (Zygophyllaceae), and differentiation into vasicentric tracheids and fibre-tracheids (Zygophyllaceae). The latter feature is referable to the concept of fibre-tracheid dimorphism. Recognition of Krameriaceae as separate from Zygophyllaceae is supported by wood characters. Wood of Zygophyllales does not conflict with the idea that the order belongs to rosids, with Malpighiaceae as the outgroup of Zygophyllales.  © 2005 The Linnean Society of London, Botanical Journal of the Linnean Society , 2005, 149 , 257–270.     

The Impact of Molecular Methods on the Systematics of Angiosperms

A comparison is made between the systematics of selected orders and families based on morphology and other “classical” characters on the one hand, and the results of molecular methods on the other hand. It can be shown that taxa defined by a broad array of characters from morphology, anatomy, embryology and phytochemistry usually are confirmed by molecular results. On the other hand a family like the Saxifragaceae s.l. delimited solely on the basis of floral morphology has been shown to be grossly polyphyletic. Some quite surprising results of the molecular analyses usually agree with some embryological or phytochemical characters, and sometimes even with characters of vegetative morphology and anatomy. As a special case “unequal ancient splits” are discussed, where one clade contains few genera and species usually retaining many primitive characters, and the other shows great diversity and contains the more advanced members.     

Ontogenetic features of Luciocephalus (Perciformes, Anabantoidei) with a revised hypothesis of anabantoid intrarelationships

The anatomy of the anabantoid fish Luciocephalus is reinvestigated and the ontogeny of certain character complexes is described for the first time. Luciocephalus possesses the following previously unrecognized or equivocally interpreted anatomical characters: a clearly separate ectopterygoid bone, pharyngeal processes of the basioccipital, a toothless pharyngeal process of the parasphenoid, an infrapharyngobranchial I and an endoskeletal mental ossification. In addition, aspects of the ontogeny of the hyopalatine arch in the belontiids Belontia, Trichogaster and Ctenops are described. Species of these three genera all possess an ectopterygoid bone previously thought to be lacking in the family Belontiidae. The significance of the results for reconstructing interrelationships of the anabantoid families and the phylogenetic position of Luciocephalus is discussed. A revised hypothesis of anabantoid intrarelationships is presented. Four synapomorphic characters indicate that Luciocephalus is more closely related to the Belontiidae (including Osphronemus) rather than forming the sister group of all other anabantoids.     

PHYLOGENY AND FORELIMB DISPARITY IN WATERBIRDS

Previous work has shown that the relative proportions of wing components (i.e., humerus, ulna, carpometacarpus) in birds are related to function and ecology, but these have rarely been investigated in a phylogenetic context. Waterbirds including “Pelecaniformes,” Ciconiiformes, Procellariiformes, Sphenisciformes, and Gaviiformes form a highly supported clade and developed a great diversity of wing forms and foraging ecologies. In this study, forelimb disparity in the waterbird clade was assessed in a phylogenetic context. Phylogenetic signal was assessed via Pagel's lambda, Blomberg's K, and permutation tests. We find that different waterbird clades are clearly separated based on forelimb component proportions, which are significantly correlated with phylogeny but not with flight style. Most of the traditional contents of “Pelecaniformes” (e.g., pelicans, cormorants, and boobies) cluster with Ciconiiformes (herons and storks) and occupy a reduced morphospace. These taxa are closely related phylogenetically but exhibit a wide range of ecologies and flight styles. Procellariiformes (e.g., petrels, albatross, and shearwaters) occupy a wide range of morphospace, characterized primarily by variation in the relative length of carpometacarpus and ulna. Gaviiformes (loons) surprisingly occupy a wing morphospace closest to diving petrels and penguins. Whether this result may reflect wing proportions plesiomorphic for the waterbird clade or a functional signal is unclear. A Bayesian approach detecting significant rate shifts across phylogeny recovered two such shifts. At the base of the two sister clades Sphenisciformes + Procellariiformes, a shift to an increase evolutionary rate of change is inferred for the ulna and carpometacarpus. Thus, changes in wing shape begin prior to the loss of flight in the wing‐propelled diving clade. Several shifts to slower rate of change are recovered within stem penguins.     

THE DELIMITATION OF BIGNONIACEAE AND SCROPHULARIACEAE BASED ON FLORAL ANATOMY,AND THE PLACEMENT OF PROBLEM GENERA

The delimitation of Bignoniaceae and Scrophulariaceae has long been a taxonomic problem. Several genera, including Paulownia, Schlegelia, Gibsoniothamnus, and Synapsis, have been variously placed in one or the other family. Differences between these two families have been noted with regard to the presence of endosperm, embryo and seed morphology, and placentation; however, the lack of comprehensive data on the distribution of such characters within these two families left the delimitation problem unsolved. A comprehensive study of floral anatomy confirmed a basic difference in the placentation of these two families, as well as a basic difference in gynoecial vascularization. Paulownia has a floral anatomy, embryo morphology, and seed morphology consistent with placement in Scrophulariaceae. While reminiscent of Bignoniaceae, Paulownia is not an intermediate genus linking the two families. Schlegelia and Gibsoniothamnus have a floral anatomy consistent with placement in Scrophulariaceae. Schlegelia also has a scrophulariaceous seed morphology. Considered anomalous in the Bignoniaceae, the Schlegelieae similarly are distinct in the Scrophulariaceae.     

Floral structure and evolution in the Anacardiaceae

WANNAN, B. S. & QUINN, C. J, 1991. Floral structure and evolution in the Anacardiaceae. Carpel morphology and anatomy is investigated in 17 genera and carpellode morphology in 12 genera. There is an evolutionary sequence in the family from poorly differentiated, nearly apocarpous gynoecia towards syncarpous gynoecia with clearly defined stigmata, styles and ovaries. There has also been marked reduction culminating in pseudomonomery. The carpellodes of the male flowers appear more conservative, and provide evidence of affinities between genera with quite different fertile gynoecia. The characters have been polarized using Burseraceae as a sister group. Data from these sources, as well as from pericarp anatomy, wood anatomy and biflavonoid content indicate that the long standing intrafamilial classification into five tribes is artificial, and that the two small satellite families, Blepharocaryaceae and Julianiaceae should be included in the family. A large monophyletic group is recognized comprised of essentially four of the existing tribes (Anacardiëae, Dobineëae, Semecarpeae, Rhoëae), as well as the two satellite families. This group incorporates two subgroups of more closely allied genera. The remaining genera (mostly Spondiadeae) are very diverse, and for the present are placed in an artificial group characterised by a set of plesiomorphs. Relationships within this group must be resolved before a satisfactory taxonomy of the family can be achieved.     

Taxonomy of the Cupressaceae: Subfamilies,Tribes and Genera

Cupressaceae and Taxodiaceae have recently been merged under the earlier name Cupressaceae s.I. by many authors, as the two families are similar in a number of morpho logical characters. Sciadopitys S. et Z., which has often been treated as a morphologically isolated member of the Taxodiaceae, has recently been considered as a monotypic family, Sciadopityaceae. The Cupressaceae s.s. may be reorganized into two subfamilies. The Cu pressoideae is composed of genera with the uppermost cone-scales infertile and can be divided into four tribes: Cnpresseae, including Cupressus, X Cupressocyparis, Charnaecyparis and Fokeinia;Thujopsideae, including Thuja, Thujopsis and Platycladusl Junipereae, including Juniperus and Microbiota; and Tetraclineae, including Calocedrus and Tetraclinis. The Callitroideae is composed of genera with the uppermost cone-scales fertile and can be divided into three tribes: Actinostrobeae, including Actinostrobus, Callitris, Fitzroya and Neocallitropsis; Widdringtoneae, including Pilgerodendron, Diselma and Widdringtonia ; Libocedreae, including Libocedrus, Papuacedrus and Austrocedrus. Five geographical distribution patterns are recognized in the 21 genera of Cupressaceae. (a) One genus, X Cupressocyparis, is a natural hybrid derived from selections in England; (b) Two genera, Cupressus and Juniperus, are distributed in Africa, Europe, Asia and North America; (c) Three genera, Thuja, Chamaecyparis, and Calocedrus, are disjnnctly distributed in Eastem Asia and North America; (d) Five genera, Actinostrobus, Callitris, Libocedrus, Papuacedrus and Widdringtonia, have limited distribution; and (e) The other 10 genera, which are monotypic, are restricted to narrow areas except Plotycladus. Three centers of genera diversity are identified in the Cupressaceae, i. e Eastern Asia with nine genera, southwestern North America with five genera, and Australia and its adjacent islands in the east　with six genera, including New Zealand,. Tasmania, New Caledonia, and New Guinea. Other important areas are western Mediterranean with three genera and Chile and Argentinawith three genera.     

System of the class Holothuroidea

Various interpretations of the holothurian system and phylogeny are critically reviewed and the main characters that form the basis of the existing systematics of this group are analyzed. A system of holothurians based on thorough analysis of their morphology and anatomy is proposed. Four subclasses are recognized in the class Holothuroidea: Arthrochirotacea, Synaptacea, Elpidiacea, and Holothuriacea. The subclass Arthrochirotacea includes the extinct Paleozoic order Arthrochirotida. The subclass Synaptacea includes the order Synaptida with two suborders and three families. The subclass Elpidiacea includes the order Elasipodida with four families. The subclass Holothuriacea includes four orders: Aspidochirotida with five families; Dendrochirotida with 15 families (14 extant and one extinct); Molpadiida with three families; Gephyrothuriida with one family and two genera Gephyrothuria and Hadalothuria. The order Gephyrothuriida is re-established. The order Dactylochirotida Pawson et Fell, 1965 is synonymized under the order Dendrochirotida. A new suborder Cucumariina and new family Mesothuriidae are described. The family Vaneyellidae is synonymized under the family Cucumariidae. Four subfamilies are classified as families: Cladolabidae, Sclerothyonidae, Monilipsolidae, and Thyonidiidae.     

Comparative leaf anatomy of the Penaeaceae and its ecological Implications

The leaf anatomy of species representing all seven genera of the Penaeaceae was studied by light and scanning electron microscopy. Due to variability and inconsistency, leaf anatomical characters are not regarded as particularly useful for systematics within or among genera in this family. Across the family, a number of taxa exhibit a trend towards amphistomatous, isobilateral leaves, generally associated with increased leaf thickness and amount of palisade mesophyll. This trend is not apparent in closely related families, e.g. Alzateaceae, Cryp-teroniaceae, Oliniaceae and Rhynchocalycaceae. Most species are found in comparatively mesic habitats and it is difficult to postulate primary xeromorphic trends in leaf anatomy. The sclerophylly encountered across the family as a whole is likely to be related to paucity of soil nutrients rather than a response to water stress.     

Seed structure and the taxonomy of the Cruciferae

The external morphology and anatomy of the seeds of some 90 genera and some 200 species of the Cruciferae have been investigated. Emphasis has been laid on the relationships of seed structure to taxonomy. As regards seed anatomy, the testa is probably of greatest value in determining taxonomic relationships. Seed structure supports the Cruciferae as a natural taxon. In the present investigation, few genera and species show seed characters which are either exclusive or very distinct. Of the remainder, most genera are distinguishable from each other on a permutation of their macroscopic and microscopic seed characters. However it is difficult or impossible to distinguish between some genera on seed characters. The present investigation provides no support for tribal divisions within the Cruciferae.