Evolutionary relationships and systematics of Atoposauridae (Crocodylomorpha: Neosuchia): implications for the rise of Eusuchia

Atoposaurids are a group of small‐bodied, extinct crocodyliforms, regarded as an important component of Jurassic and Cretaceous Laurasian semi‐aquatic ecosystems. Despite the group being known for over 150 years, the taxonomic composition of Atoposauridae and its position within Crocodyliformes are unresolved. Uncertainty revolves around their placement within Neosuchia, in which they have been found to occupy a range of positions from the most basal neosuchian clade to more crownward eusuchians. This problem stems from a lack of adequate taxonomic treatment of specimens assigned to Atoposauridae, and key taxa such as Theriosuchus have become taxonomic ‘waste baskets’. Here, we incorporate all putative atoposaurid species into a new phylogenetic data matrix comprising 24 taxa scored for 329 characters. Many of our characters are heavily revised or novel to this study, and several ingroup taxa have never previously been included in a phylogenetic analysis. Parsimony and Bayesian approaches both recover Atoposauridae as a basal clade within Neosuchia, more stemward than coelognathosuchians, bernissartiids, and paralligatorids. Atoposauridae is a much more exclusive clade than previously recognized, comprising just three genera (Alligatorellus, Alligatorium, and Atoposaurus) that were restricted to the Late Jurassic of western Europe, and went extinct at the Jurassic/Cretaceous boundary. A putative Gondwanan atoposaurid (Brillanceausuchus) is recovered as a paralligatorid. Our results exclude both Montsecosuchus and Theriosuchus from Atoposauridae. Theriosuchus is polyphyletic, forming two groupings of advanced neosuchians. Theriosuchus (restricted to Theriosuchus pusillus, Theriosuchus guimarotae, and Theriosuchus grandinaris) spanned the Middle Jurassic to early Late Cretaceous, and is known from Eurasia and North Africa. Two Cretaceous species previously assigned to Theriosuchus (‘Theriosuchus’ ibericus and ‘Theriosuchus’ sympiestodon) are shown to be nested within Paralligatoridae, and we assign them to the new genus Sabresuchus. The revised phylogenetic placement of Theriosuchus has several implications for our understanding of eusuchian evolution. Firstly, the presence of fully pterygoidean choanae, previously regarded as a defining characteristic of Eusuchia, is not found in some basal members of Eusuchia. However, eusuchians can be distinguished from Theriosuchus and other basal neosuchians in that their choanae are posteriorly positioned, with an anterior margin medial to the posterior edge of the suborbital fenestra. This feature distinguishes eusuchians from Theriosuchus and more basal neosuchians. Secondly, our refined understanding of Theriosuchus implies that this taxon possessed only amphicoelous presacral vertebrae, and therefore fully developed vertebral procoely is likely to have evolved only once in Crocodylomorpha, on the lineage leading to Eusuchia. These and other findings presented herein will provide an important framework for understanding the neosuchian–eusuchian transition.     

Permian–Triassic Osteichthyes (bony fishes): diversity dynamics and body size evolution

The Permian and Triassic were key time intervals in the history of life on Earth. Both periods are marked by a series of biotic crises including the most catastrophic of such events, the end‐Permian mass extinction, which eventually led to a major turnover from typical Palaeozoic faunas and floras to those that are emblematic for the Mesozoic and Cenozoic. Here we review patterns in Permian–Triassic bony fishes, a group whose evolutionary dynamics are understudied. Based on data from primary literature, we analyse changes in their taxonomic diversity and body size (as a proxy for trophic position) and explore their response to Permian–Triassic events. Diversity and body size are investigated separately for different groups of Osteichthyes (Dipnoi, Actinistia, ‘Palaeopterygii’, ‘Subholostei’, Holostei, Teleosteomorpha), within the marine and freshwater realms and on a global scale (total diversity) as well as across palaeolatitudinal belts. Diversity is also measured for different palaeogeographical provinces. Our results suggest a general trend from low osteichthyan diversity in the Permian to higher levels in the Triassic. Diversity dynamics in the Permian are marked by a decline in freshwater taxa during the Cisuralian. An extinction event during the end‐Guadalupian crisis is not evident from our data, but ‘palaeopterygians’ experienced a significant body size increase across the Guadalupian–Lopingian boundary and these fishes upheld their position as large, top predators from the Late Permian to the Late Triassic. Elevated turnover rates are documented at the Permian–Triassic boundary, and two distinct diversification events are noted in the wake of this biotic crisis, a first one during the Early Triassic (dipnoans, actinistians, ‘palaeopterygians’, ‘subholosteans’) and a second one during the Middle Triassic (‘subholosteans’, neopterygians). The origination of new, small taxa predominantly among these groups during the Middle Triassic event caused a significant reduction in osteichthyan body size. Neopterygii, the clade that encompasses the vast majority of extant fishes, underwent another diversification phase in the Late Triassic. The Triassic radiation of Osteichthyes, predominantly of Actinopterygii, which only occurred after severe extinctions among Chondrichthyes during the Middle–Late Permian, resulted in a profound change within global fish communities, from chondrichthyan‐rich faunas of the Permo‐Carboniferous to typical Mesozoic and Cenozoic associations dominated by actinopterygians. This turnover was not sudden but followed a stepwise pattern, with leaps during extinction events.     

Tales of dracula ants: the evolutionary history of the ant subfamily Amblyoponinae (Hymenoptera: Formicidae)

The ants in the subfamily Amblyoponinae are an old, relictual group with an unusual suite of morphological and behavioural features. Adult workers pierce the integument of their larvae to imbibe haemolymph, earning them the vernacular name ‘dracula ants’. We investigate the phylogeny of this group with a data set based on 54 ingroup taxa, 23 outgroups and 11 nuclear gene fragments (7.4 kb). We find that the genus Opamyrma has been misplaced in this subfamily: it is a member of the leptanilline clade and sister to all other extant Leptanillinae. Transfer of Opamyrma to Leptanillinae renders the Amblyoponinae monophyletic. The enigmatic Afrotropical genus Apomyrma is sister to all other amblyoponines, and the latter cleave into two distinct and well‐supported clades, here termed POA and XMMAS. The POA clade, containing Prionopelta, Onychomyrmex and Amblyopone, is well resolved internally, and its structure supports synonymy of the genus Concoctio under Prionopelta ( syn.n. ). The XMMAS clade comprises two well‐supported groups: (i) a predominantly Neotropical clade, for which we resurrect the genus name Fulakora ( stat.r., stat.n. ), with junior synonyms Paraprionopelta ( syn.n. ) and Ericapelta ( syn.n. ); and (ii) the remaining taxa, or ‘core XMMAS’, which are manifested in our study as a poorly resolved bush of about a dozen lineages, suggesting rapid radiation at the time of their origin. Most of these XMMAS lineages have been assigned to the catch‐all genus Stigmatomma, but the more distinctive elements have been treated as separate genera (Xymmer, Mystrium, Myopopone and Adetomyrma). Resolution of basal relationships in the core XMMAS clade and reconfiguration of ‘Stigmatomma’ to restore monophyly of all named genera will require more extensive genetic data and additional morphological analysis. However, the genus Bannapone can be synonymized under Stigmatomma ( syn.n. ) because it is embedded within a clade that contains S. denticulatum, the type species of Stigmatomma. Divergence dating analysis indicates that crown Amblyoponinae arose in the mid‐Cretaceous, about 107 Ma (95% highest probability density: 93–121 Ma). The POA and XMMAS clades have estimated crown ages of 47 and 73 Ma, respectively. The initial burst of diversification in the core XMMAS clade occurred in the Late Paleocene/Early Eocene (50–60 Ma). Ancestral range reconstruction suggests that amblyoponines originated in the Afrotropics, and dispersed to the Indo‐Malayan region and to the New World. During none of these dispersal events did the ants break out of their cryptobiotic lifestyle.     

Phylogenetic analysis of higher-level relationships of Odonata

Abstract. This is the most comprehensive analysis of higher‐level relationships in Odonata conducted thus far. The analysis was based on a detailed study of the skeletal morphology and wing venation of adults, complemented with a few larval characters, resulting in 122 phylogenetically informative characters. Eighty‐five genera from forty‐five currently recognized families and subfamilies were examined. In most cases, several species were chosen to serve as exemplars for a given genus. The seven fossil outgroup taxa included were exemplar genera from five successively more distant odonatoid orders and suborders: Tarsophlebiidae (the closest sister group of Odonata, previously placed as a family within ‘Anisozygoptera’), Archizygoptera, Protanisoptera, Protodonata and Geroptera. Parsimony analysis of the data, in which characters were treated both under equal weights and implied weighting, produced cladograms that were highly congruent, and in spite of considerable homoplasy in the odonate data, many groupings in the most parsimonious cladograms were well supported in all analyses, as indicated by Bremer support. The analyses supported the monophyly of both Anisoptera and Zygoptera, contrary to the well known hypothesis of zygopteran paraphyly. Within Zygoptera, two large sister clades were indicated, one comprised of the classical (Selysian) Calopterygoidea, except that Amphipterygidae, which have traditionally been placed as a calopterygoid family, nested within the other large zygopteran clade comprised of Fraser's ‘Lestinoidea’ plus ‘Coenagrionoidea’ (both of which were shown to be paraphyletic as currently defined). Philoganga alone appeared as the sister group to the rest of the Zygoptera in unweighted cladograms, whereas Philoganga + Diphlebia comprised the sister group to the remaining Zygoptera in all weighted cladograms. ‘Anisozygoptera’ was confirmed as a paraphyletic assemblage that forms a ‘grade’ towards the true Anisoptera, with Epiophlebia as the most basal taxon. Within Anisoptera, Petaluridae appeared as the sister group to other dragonflies.     

An assessment of the status of Polycirridae genera (Annelida: Terebelliformia) and evolutionary transformation series of characters within the family

A phylogenetic analysis was performed to determine the monophyly of non‐monotypic genera of the terebelliform family Polycirridae, i.e. Polycirrus, Amaeana, Lysilla, and Hauchiella, and the evolution of characters among members of this clade. The monotypic genera, Enoplobranchus and Biremis, were also included, together with members of both known species in Hauchiella. Representative species were included for remaining genera: 14 species of Polycirrus, six species of Amaeana, and six species of Lysilla. Out‐groups consisted of representatives of Spionidae, Cirratulidae, and Sabellariidae, as well as several species of Telothelepodidae. A total of 40 in‐ and out‐group species were coded for 50 subjects (‘characters’) and 117 subject–predicate relationships (‘states’). Although results are consistent with recent phylogenetic studies within Terebelliformia that suggest Polycirridae monophyly, only Hauchiella was found to be monophyletic, albeit part of the more inclusive clade comprising remaining polycirrid genera. Evolutionary transformation series are discussed for selected characters in relation to the non‐monophyly of Polycirrus, Lysilla, and Amaeana. Implications for the use of supraspecific taxa as ‘taxonomic surrogates’ are highlighted. The definition of Polycirridae is emended. © 2015 The Linnean Society of London     

Evidence for Carboniferous origin of the order Mantodea (Insecta: Dictyoptera) gained from forewing morphology

Homologies of the forewing venation pattern of the order Mantodea (Insecta: Dictyoptera) consistent with the accepted insect wing venation groundplan are proposed. A comparative morphological analysis was carried out based on a broad taxonomic sample of extant taxa. Besides macromorphological aspects, focus is given to the pattern of the tracheal system as a basis for establishing primary homologies. All extant praying mantids exhibit a composite stem composed of the posterior radius (RP) and the media (M) and most praying mantids exhibit a fusion of the anterior branch of RP + M with the anterior radius (RA). The wing venation of the species ?Mesoptilus dolloi, previously assigned to the polyphyletic fossil assemblage ‘Protorthoptera’, is re‐interpreted in the light of the new homology statement. Our interpretation suggests that it is a putative stem‐Mantodea, as are some other ‘protorthopterous’ taxa. This hypothesis implies that the total‐group Mantodea arose as soon as the Late Carboniferous, i.e. about 175 million years earlier than previously estimated. This analysis contributes to the view that most of the Late Carboniferous ‘Protorthoptera’ are stem‐representatives of the major polyneopteran clades (e.g. cockroaches, grasshoppers and crickets, rock‐crawlers), suggesting a survivorship of several main Pterygota lineages at the end‐Permian extinction event higher than previously expected. © 2009 The Linnean Society of London, Zoological Journal of the Linnean Society, 2009, 156 , 79–113.     

Molecular phylogeny of the mega‐diverse rove beetle tribe Staphylinini (Insecta,Coleoptera, Staphylinidae)

Chatzimanolis, S., Cohen, I. M., Schomann, A. & Solodovnikov, A. (2010). Molecular phylogeny of the mega‐diverse rove beetle tribe Staphylinini (Insecta, Coleoptera, Staphylinidae). —Zoologica Scripta, 39, 436–449. Phylogeny of the rove beetle tribe Staphylinini is explored by parsimony and Bayesian analyses of sequences of four genes (COI, wingless, Topoisomerase I, and 28S) for 43 ingroup (various genera of Staphylinini) and eight outgroup (two genera of Paederinae, six genera of other tribes of Staphylininae) taxa. Analyses were conducted for each gene independently and for the concatenated data set. Results of the most robust combined analyses were compared with the morphology‐based phylogenies of Staphylinini (‘test phylogeny’), and with the conventional classification of this tribe. Molecular results were congruent with the ‘test phylogeny’ in the following: ancestors of Staphylinini were ‘Quediina‐like’ lineages; formal subtribe Quediina mixes at least two relatively basal groups, ‘Quediina propria’ and ‘southern Quediina’; specialized subtribe Amblyopinina is an internal clade within ‘southern Quediina’; a relatively deeply nested ‘Staphylinini propria’ that unites current subtribes Staphylinina, Eucibdelina, Anisolinina, Xanthopygina and Philonthina is well supported as a monophyletic group. In strong contrast with morphology, molecular data place the tribes Othiini and Xantholinini nested within Staphylinini. Molecular results strongly conflict with morphology by uniting morphologically very different genera Holisus and Atanygnathus in one clade that has uncertain position within Staphylinini. Consistently with the most congruent areas of the morphology‐ and molecular‐based phylogenies, taxonomic changes are implemented for the formal subtribes Quediina and Amblyopinina.     

Morphology agrees with molecular data: phylogenetic affinities of Euptychiina butterflies (Nymphalidae: Satyrinae)

Euptychiina is the most species‐rich subtribe of Neotropical Satyrinae, with over 450 known species in 47 genera (14 monotypic). Here, we use morphological characters to examine the phylogenetic relationships within Euptychiina. Taxonomic sampling included 105 species representing the majority of the genera, as well as five outgroups. A total of 103 characters were obtained: 45 from wing pattern, 48 from genitalia and 10 from wing venation. The data matrix was analysed using maximum parsimony under both equal and extended implied weights. Euptychiina was recovered as monophyletic with ten monophyletic genera, contrasting previous DNA sequence‐based phylogenies that did not recover the monophyly of the group. In agreement with sequence‐based hypotheses, however, three main clades were recognized: the ‘Megisto clade’ with six monophyletic and three polyphyletic genera, the ‘Taygetis clade’ with nine genera of which three were monophyletic, and the ‘Pareuptyhia clade’ with four monophyletic and two polyphyletic genera. This is the first morphology‐based phylogenetic hypothesis for Euptychiina and the results will be used to complement molecular data in a combined analysis and to provide critical synapomorphies for clades and genera in this taxonomically confused group.     

Global interrelationships of Plesiosauria (Reptilia,Sauropterygia) and the pivotal role of taxon sampling in determining the outcome of phylogenetic analyses

Previous attempts to resolve plesiosaurian phylogeny are reviewed and a new phylogenetic data set of 66 taxa (67% of ingroup taxa examined directly) and 178 characters (eight new) is presented. We recover two key novel results: a monophyletic Plesiosauridae comprising Plesiosaurus dolichodeirus, Hydrorion brachypterygius, Microcleidus homalospondylus, Occitanosaurus tournemirensis and Seeleyosaurus guilelmiimperatoris; and five plesiosaurian taxa recovered outside the split between Plesiosauroidea and Pliosauroidea. These taxa are Attenborosaurus conybeari, ‘Plesiosaurus’macrocephalus and a clade comprising Archaeonectrus rostratus, Macroplata tenuiceps and BMNH 49202. Based on this result, a new name, Neoplesiosauria, is erected for the clade comprising Plesiosauroidea and Pliosauroidea. Taxon subsamples of the new dataset are used to simulate previous investigations of global plesiosaurian relationships. Based on these simulations, most major differences between previous global phylogenetic hypotheses can be attributed to differences in taxon sampling. These include the position of Leptocleididae and Polycotylidae and the monophyly or paraphyly of Rhomaleosauridae. On this basis we favour the results recovered by our, larger analysis. Leptocleididae and Polycotylidae are sister taxa, forming a monophyletic clade within Plesiosauroidea, indicating that the large‐headed, short‐necked ‘pliosauromorph’ body plan evolved twice within Plesiosauria. Rhomaleosauridae forms the monophyletic sister taxon of Pliosauridae within Pliosauroidea. Problems are identified with previous phylogenetic definitions of plesiosaurian clades and new, stem‐based definitions are presented that should maintain their integrity over a range of phylogenetic hypotheses. New, rank‐free clade names Cryptoclidia and Leptocleidia are erected to replace the superfamilies Cryptoclidoidea and Leptocleidoidea. These were problematic as they were nested within the superfamily Plesiosauroidea. The incongruence length difference test indicates no significant difference in levels of homoplasy between cranial and postcranial characters.     

Taxonomy,phylogeny, and diversity of the extinct Lesser Antillean rice rats (Sigmodontinae: Oryzomyini), with description of a new genus and species

Rice rats (Sigmodontinae: Oryzomyini) are abundant in the Late Quaternary fossil record and in Holocene pre‐Columbian archaeological middens across the Lesser Antilles. All of these rice rats are now extinct, and their regional diversity and systematics remain extremely poorly understood. We redescribe all of the region's rice rat taxa known from adequate diagnostic material (Megalomys desmarestii, Megalomys luciae, and Oligoryzomys victus), and describe a new genus and species, Pennatomys nivalis gen. et sp. nov. , from archaeological sites on St. Eustatius, St. Kitts, and Nevis, which formed a single larger island during Quaternary low sea‐level stands. Cladistic analysis supports the inclusion of O. victus within Oligoryzomys, and identifies Megalomys as a sister group of the large‐bodied genera Sigmodontomys or Sigmodontomys + Nectomys, suggesting that large body size in Megalomys represents phyletic gigantism rather than ‘island gigantism’. Megalomys and Pennatomys belong to an oryzomyine clade that has undergone remarkable radiation throughout the oceanic and continental‐shelf islands of the Neotropical region, but these genera do not represent a monophyletic group within the Nectomys subclade, indicating multiple over‐water colonization events of the Lesser Antillean island chain. Although Lesser Antillean rice rats were heavily exploited by prehistoric Amerindians, it is likely that most or all of these taxa survived until European arrival in the region. © 2010 The Linnean Society of London, Zoological Journal of the Linnean Society, 2010, 160 , 748–772.     

The early evolution of titanosauriform sauropod dinosaurs

Titanosauriformes was a globally distributed, long‐lived clade of dinosaurs that contains both the largest and smallest known sauropods. These common and diverse megaherbivores evolved a suite of cranial and locomotory specializations perhaps related to their near‐ubiquity in Mesozoic ecosystems. In an effort to understand the phylogenetic relationships of their early (Late Jurassic–Early Cretaceous) members, this paper presents a lower‐level cladistic analysis of basal titanosauriforms in which 25 ingroup and three outgroup taxa were scored for 119 characters. Analysis of these characters resulted in the recovery of three main clades: Brachiosauridae, a cosmopolitan mix of Late Jurassic and Early Cretaceous sauropods, Euhelopodidae, a clade of mid‐Cretaceous East Asian sauropods, and Titanosauria, a large Cretaceous clade made up of mostly Gondwanan genera. Several putative brachiosaurids were instead found to represent non‐titanosauriforms or more derived taxa, and no support for a Laurasia‐wide clade of titanosauriforms was found. This analysis establishes robust synapomorphies for many titanosauriform subclades. A re‐evaluation of the phylogenetic affinities of fragmentary taxa based on these synapomorphies found no body fossil evidence for titanosaurs before the middle Cretaceous (Aptian), in contrast to previous reports of Middle and Late Jurassic forms. Purported titanosaur track‐ways from the Middle Jurassic either indicate a substantial ghost lineage for the group or – more likely – represent non‐titanosaurs. Titanosauriform palaeobiogeographical history is the result of several factors including differential extinction and dispersal. This study provides a foundation for future study of basal titanosauriform phylogeny and the origins of Titanosauria. © 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 166 , 624–671.     

A molecular phylogeny of Planorboidea (Gastropoda, Pulmonata): insights from enhanced taxon sampling

Planorbid gastropods are the most diverse group of limnic pulmonates, with both discoidal and highspired taxa. Phylogenetic relationships among these genera are confused and controversial. In particular, the monophyly of the limpet‐like taxa (traditionally Ancylidae) is disputed. Even recent molecular studies have concluded that substantially more work is necessary to solve the remaining issues concerning intergeneric phylogenetic relationships and higher taxa systematics. Planorbid snails are of great significance for humans as several members of this group are intermediate hosts of blood flukes (schistosomes) causing a chronic disease, schistosomiasis. We used the two independent molecular markers COI and 18S (concatenated dataset of 2837 nucleotide bp) to infer phylogenetic relationships of 26 genera (27 species) of Planorboidea, represented mostly by type species from mainly topotypical populations. With the majority of the taxa discussed not having been studied previously, this study attempted to test several hypotheses on planorbid phylogenetic relationships using Bayesian inference techniques. The monophyly of Planorboidea (= ‘Ancyloplanorbidae’) is strongly suggested on the basis of our extensive molecular analysis. Besides a distinct Burnupia clade, two major clades were recovered that correspond to family level taxa (traditional Bulinidae and Planorbidae). Considerable rearrangements of suprageneric taxa are evident from the phylogeny inferred. Therefore, the only clades recognized by current classifications and supported by our analysis are Planorbini and Segmentinini. The present study found that Ancylidae as traditionally understood, i.e. covering most freshwater limpet gastropods, is paraphyletic, as the genera of Burnupia and Protancylus have been shown to lie phylogenetically outside the Ancylini. Chromosome numbers and levels of polyploidy are discussed in the light of the new phylogeny. An earlier theory of shell shape evolution, i.e. that of patelliform taxa being most advanced, was not supported by this study; a limpet‐shaped taxon is most basal within Planorboidea. Although many taxa still remain to be studied, our results will hopefully contribute towards a better understanding of this very important group of freshwater organisms. Some taxonomic implications are discussed.     

The first tunicate with a calcareous exoskeleton (Upper Triassic,northern Italy)

The first tunicates with a calcareous exoskeleton are reported from Late Triassic buildup‐slope deposits of the Dolomites. Although examples of this group have been known since the early 1900s from the middle–upper Permian of eastern Asia and Sicily as Khmeria, they were erroneously attributed to rugose corals. These early representatives are small, double‐valved, conical skeletons, which evolved into multi‐plated capsules with up to 35 opercula. The latter are joined along zigzag margins, which in life could probably be opened for the atrial and branchial siphons. The construction and shape of these skeletons distinguish them from plants or other invertebrate phyla, while they share several similarities with living tunicates, specifically to sessile ascidians. Apart from a soft‐bodied genus from the lower Cambrian of China, ascidians are known only from isolated spicules, which occur sporadically from the Lower Jurassic onwards. The calcareous skeleton of these Late Triassic tunicates consists of aragonitic fibres, which form spherulitic or clinogonal microstructures. It seems that the stellate aragonitic spicules of Jurassic to Recent ascidians are a vestige of Permian–Triassic ancestors, which after the Carnian lost the ability to construct compound solid skeletons but partly still retain a soft double‐valved or multi‐operculate cellulose‐like tunic. The following taxa are described as new: Order Khmeriamorpha with the genera Khmeria Mansuy and Zardinisoma gen. nov., and the following species: Khmeria stolonifera (late Permian), Khmeria minima (Late Triassic), Zardinisoma japonicum (late Permian), Z. cassianum, Z. pyriforme, Z. polyplacophorum and Z. pauciplacophorum (all Late Triassic).     

An investigation into the cladistic relationships and monophyly of therocephalian therapsids (Amniota: Synapsida)

A comprehensive phylogenetic investigation was performed to elucidate the cladistic relationships and possible monophyly of therocephalian therapsids (Amniota: Synapsida). The phylogenetic positions of 30 therapsid taxa were examined under maximum parsimony, including 23 therocephalian genera. The analysis incorporated 110 cranial and postcranial characters in order to assess the interrelationships of basal therocephalians and eutherocephalians and their relationships to Cynodontia, representing the most complete review of therocephalian phylogeny to date. The analysis supports the hypothesis that Therocephalia represents the monophyletic sister taxon to Cynodontia, with as many as 15 morphological synapomorphies, in contrast with other recent analyses of lesser taxon sampling. The results also support the hypothesis that Scylacosauridae is more closely related to Eutherocephalia than to the basal therocephalian family Lycosuchidae, supporting a ‘Scylacosauria’ clade. The taxa suggested here to be neotenic forms (e.g. Ictidosuchoides and Ictidosuchops) are positioned near the base of a monophyletic Baurioidea. Neotenic development of the therocephalian feeding apparatus and evolutionary parallelism with cynodonts are suggested to have been important trends in the early evolution of baurioid therocephalians into the Late Permian and Early Triassic.     

A second varanopseid skull from the Upper Permian of South Africa: implications for Late Permian 'pelycosaur' evolution

Late Permian terrestrial faunas of South Africa and Russia are dominated taxonomically and ecologically by therapsid synapsids. On the basis of a single specimen from the Upper Permian of South Africa, the varanopseid Elliotsmithia longiceps is the sole basal synapsid ('pelycosaur') known from Gondwana. Recent fieldwork in the Upper Permian of South Africa has produced a second varanopseid specimen that is referrable to Elliotsmithia . Data from both this specimen and the holotype suggest that Elliotsmithia forms a clade with Mycterosaurus from the Lower Permian of North America and Mesenosaurus from the Upper Permian of Eastern Europe. That postulate is supported by the three most parsimonious trees discovered in a new analysis of varanopseid phylogeny. However, the available data cannot resolve the interrelationships of these three genera. The new phylogenetic results contrast with earlier work identifying Elliotsmithia as the basal member of a clade that includes the North American taxa Aerosaurus , Varanops , and Varanodon . The new trees reduce the stratigraphic debt required by the latter scenario, and the one with the least stratigraphic debt identifies Elliotsmithia and Mesenosaurus as sister taxa. Two new taxa are erected, Mycterosaurinae and Varanodontinae, for the two varanopseid subclades.     

Two apparently unrelated groups of symbiotic annelids,Nautiliniellidae and Calamyzidae (Phyllodocida,Annelida), are a clade of derived chrysopetalid polychaetes

Nautiliniellidae Miura and Laubier, 1989 is a small family of marine polychaetes with 20 currently described species in 11 genera, most of which are known to live symbiotically in the mantle cavity of bivalves, mainly from cold seeps and hydrothermal vents, while Calamyzidae (Hartmann‐Schröder, 1971) including only one described species, Calamyzas amphictenicola Arwidsson 1932 lives as an ectoparasite on ampharetid polychaetes in Swedish waters. Nautiliniellidae and Calamyzidae have both been considered to belong to Phyllodocida, but the few phylogenetic studies including these taxa have found their positions unstable. The internal relationships within Nautiliniellidae are also poorly understood. Using molecular information from both nuclear and mitochondrial genes and morphological data we assessed the systematic placement of Nautiliniellidae (seven species; collected from Pacific hydrothermal vents and cold seeps and one from Atlantic waters) and Calamyzas amphictenicola. Our results show that C. amphictenicola and Nautiliniellidae formed a well‐supported clade that is nested within Chrysopetalidae, a free‐living group of polychaetes. The chrysopetalid genus Vigtorniella Kiseleva 1992; a bacterial mat grazer found at methane seeps, anoxic basins and whalefalls, formed a paraphyletic grade with respect to the Nautiliniellidae–Calamyzas clade. The internal relationships within the Nautiliniellidae–Calamyzas clade as well as the relationships with their hosts are also examined. As a result we synonymize Calamyzidae and Nautiliniellidae with Chrysopetalidae, with the last as the oldest available family‐group name. Within Chrysopetalidae we refer to the subfamilies Chrysopetalinae Ehlers 1864; Dysponetinae Aguado, Nygren & Rouse, herein; and Calamyzinae Hartmann‐Schröder, 1971. Calamyzinae contains C. amphictenicola, all taxa formerly in Nautiliniellidae, and the chrysopetalid genus Vigtorniella.     

The early Triassic rhynchosaur Mesosuchus browni and the interrelationships of basal archosauromorph reptiles

Restudy of the unique diapsid reptile Mesosuchus browni Watson, from the Cynognathus Assemblage Zone (late Early Triassic to early Middle Triassic) of the Burgersdorp Formation (Tarkastad Subgroup; Beaufort Group) of South Africa, confirms that it is the most plesiomorphic known member of the Rhynchosauria. A new phylogenetic analysis of basal taxa of Archosauromorpha indicates that Choristodera falls outside of the Sauria, Prolacertiformes is a paraphyletic taxon with Prolacerta sharing a more recent common ancestor with Archosauriformes than with any other clade, Megalancosaurus and Drepanosaurus are sister taxa in the clade Drepanosauridae within Archosauromorpha, and are the sister group to the clade Tanystropheidae composed of Tanystropheus, Macrocnemus, and Langobardisaurus. Combination of the phylogenetic relationships of basal archosauromorphs and their known stratigraphic ranges reveals significant gaps in the fossil records of Late Permian and Triassic diapsids. Extensions of the temporal ranges of several lineages of diapsids into the Late Permian suggests that more groups of terrestrial reptiles survived the end-Permian mass extinction than thought previously.     

The phylogeny of Sericini and their position within the Scarabaeidae based on morphological characters (Coleoptera: Scarabaeidae)

Abstract. To reconstruct the phylogeny of the Sericini and their systematic position among the scarabaeid beetles, cladistic analyses were performed using 107 morphological characters from the adults and larvae of forty‐nine extant scarabaeid genera. Taxa represent most ‘traditional’ subfamilies of coprophagous and phytophagous Scarabaeidae, with emphasis on the Sericini and other melolonthine lineages. Several poorly studied exoskeletal features have been examined, including the elytral base, posterior wing venation, mouth parts, endosternites, coxal articulation, and genitalia. The results of the analysis strongly support the monophyly of the ‘orphnine group’ + ‘melolonthine group’ including phytophagous scarabs such as Dynastinae, Hopliinae, Melolonthinae, Rutelinae, and Cetoniinae. This clade was identified as the sister group to the ‘dung beetle line’ represented by Aphodius + Copris. The ‘melolonthine group’ is comprised in the strict consensus tree by two major clades and two minor lineages, with the included taxa of Euchirinae, Rutelinae, and Dynastinae nested together in one of the major clades (‘melolonthine group I’). Melolonthini, Cetoniinae, and Rutelinae are strongly supported, whereas Melolonthinae and Pachydemini appear to be paraphyletic. Sericini + Ablaberini were identified to be sister taxa nested within the second major melolonthine clade (‘melolonthine group II’). As this clade is distributed primarily in the southern continents, one could assume that Sericini + Ablaberini are derived from a southern lineage. Plausibly, ancestors of Sericini + Ablaberini and Athlia were separated by a vicariance event, such as the separation of the African plate from the rest of Gondwana, whereas Sericini and Ablaberini probably diversified during the early Tertiary, with dispersal of some basal Sericini to South America.     

Antitropicality and convergent evolution: a case study of Permian neospiriferine brachiopods

Antitropical distribution is a biogeographical pattern characterized by natural occurrences of the same species or members of the same clade in the middle‐ or middle‐to‐high‐latitudinal habitats of both hemispheres, either on land or in marine environments, without appearing in the intervening tropical environments. For most of the noted examples of Permian antitropical distribution, particularly in marine invertebrates, the causes of disjunctions have been mainly linked to either dispersal or vicariance models. Little attention has been paid to other possible mechanisms. This study investigated the antitropicality of some Permian neospiriferine brachiopods through detailed taxonomic revision, comparison of palaeobiogeographical distribution, and a phylogenetic analysis. Several species, previously assigned to Kaninospirifer, are here reassigned to other genera, especially to Fasciculatia in the northern hemisphere and to Quadrospira in the southern hemisphere during the Permian. Both Kaninospirifer and Fasciculatia appear to have been restricted to north‐western Pangea and north‐eastern Asia during the Permian, but there is no robust evidence to suggest their presence in the southern hemisphere to which Imperiospira and Quadrospira were confined. In spite of the distributional separation between the two pairs of neospiriferine genera in the Permian palaeobiogeographical regime, they share considerable numbers of morphological characters, such as a large shell, subdued fasciculation, and reduction of ventral adminicula. Notwithstanding these morphological similarities, our phylogenetic reconstruction of the neospiriferines does not support a close relationship between these genera. This therefore must indicate that these similar morphological features were independently acquired, probably with these taxa living in spatially separate but ecologically compatible environmental conditions in the mid‐latitudinal area of each hemisphere during the Permian. We regard this as an example of convergent evolution.