A taxonomic revision of Paradoris sea slugs (Mollusca, Gastropoda, Nudibranchia, Doridina)

Paradoris , traditionally a generic taxon of discodorid sea slugs, is revised for the first time. One hundred and thirty specimens were examined, including all types and most of the nontype specimens available. New records for Paradoris are provided: South Africa, Tanzania, Seychelles, Western Australia, Thailand, Philippines, shallow waters of New Caledonia, southern Japan, and Hawaii. The individual variation of all taxonomic characters is thoroughly evaluated. Prior to the present study, Paradoris included 15 nominal species: 12 valid names and three synonyms. Three additional names, Discodoris erythraeensis , D. lora , and D. cavernae , are re-allocated to Paradoris , based on phylogenetic analysis. A phylogenetic diagnosis is provided for Paradoris : in particular, two new synapomorphies are described. Eight species names are regarded as valid: P. araneosa , P. dubia , P. erythraeensis , P. indecora , P. liturata , P. lopezi , P. mulciber , and P. tsurugensis . However, most of these species are poorly known, i.e. from very few specimens, and their taxonomic status might change when more individuals are available. P. lora is regarded as a nomen dubium . Six new synonymies are proposed, and explained by the fact that: (1) species names were created for one or a few specimens, without considering individual variation; (2) authors have not worked within a phylogenetic framework and have created new species names without considering all the existing species names already available within Paradoris . Three new morphospecies are described, but not formally named because their taxonomic status is still uncertain for several reasons (e.g. lack of knowledge of individual variation for some critical features).  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 147 , 125–238.     

Phyllanthus section Choretropsis (Euphorbiaceae) in Brazil

Section Choretropsis genus Phyllanthus (Euphorbiaceae) is formed by plants whose branches are modified into phylloclades. Despite the suitable characteristics of phylloclades within the Phyllanthus genus, the systematics of these species are poorly understood. Morphological data are presented here to allow future revision of this taxonomic group. The section is represented by nine species distributed in South America, eight of them endemic to Brazil. Our taxonomic studies distinguish the species and propose the synonymization of nine varieties of P. klotzschianus and two varieties of P. flagelliformis based on vegetative and reproductive characters. The diversity of branching and the morphology of phylloclades are discussed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 131–164.     

Morphological perspective on the classification and evolution of Recent Pterioidea (Mollusca: Bivalvia)

The evolutionary relationships of the Recent Pterioidea are inferred from a phylogenetic analysis of representatives of all pterioidean genera based on original observations of anatomy and shell morphology, and an extensive survey of bivalve literature. The well-resolved cladogram supports monophyly for the superfamily, but renders all but one family (the monotypic Pulvinitidae) polyphyletic. In addition, these results reveal a considerable level of convergence and parallelisms through the Pterioidea. The branching order of pterioid genera in the morphological analysis is largely corroborated by the sequence of their appearance in the fossil record. The palaeontological evidence provides important information on dating lineage splitting events and transitional taxa. The proposed phylogeny integrates the cladistic analysis of the Recent Pterioidea with the fossil record and suggests that the crown-group pterioideans probably originated in the Triassic from the Bakevelliidae, an extinct paraphyletic stem group from which the Ostreoidea are also ultimately derived.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 253–312.     

A new polypterid fish: Polypterus faraou sp. nov. (Cladistia, Polypteridae) from the Late Miocene, Toros-Menalla, Chad

Polypterus faraou sp. nov. (Cladistia, Polypteridae) from the Late Miocene of Toros-Menalla (western Djourab, Chad) is described on the basis of a subcomplete articulated skeleton preserved in three dimensions. This is the first time such a complete fossil polypterid skeleton has been described. It is the only verifiable fossil record for the genus Polypterus . P. faraou closely resembles P. bichir and P. endlicheri , extant fish found in the Chad–Chari system. Intrarelationships among the polypterids are not yet resolved: however, P. faraou shows a primitive shape of the body and a primitive shape of the opening of the lateral line on the scales, similar to that of three living species ( P. bichir , P. endlicheri and P. ansorgii ).  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 146 , 227–237.     

A new species of Arctotis (Compositae, Arctotideae) from kommetjie grassland in Eastern Cape Province, South Africa

Arctotis debensis R.J.McKenzie, a new species from the Albany Centre of Floristic Endemism, South Africa, is described and illustrated. It grows almost exclusively in grassland on kommetjies, a distinctive landform of depressions and mounds associated with giant earthworms, in a restricted area west of King William's Town, Eastern Cape Province. It is the first plant taxon reported to be endemic or near-endemic to this unusual habitat. The new species appears to have been collected rarely and previous collections examined have remained undetermined to species level. The new species is distinguished from closely allied species by the combination of its usually larger dimensions in all parts, prostrate habit, coriaceous leaves that are green, scabrous, and eglandular on the adaxial surface and densely lanate on the abaxial surface, and involucral-bract morphology.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 581–588.     

Reconstructing the Anomalodesmata (Mollusca: Bivalvia): morphology and molecules

The extant anomalodesmatan bivalves have always proved rather enigmatic and difficult to interpret, both in terms of their relationships to other bivalve taxa and the interrelationships of the constituent families. These difficulties stem from their diverse and often highly specialized life habits which have resulted in a wide array of disparate morphologies, and also from the fact that many are extremely rare. Classifications based on morphological characters have been dogged by fears that convergent and parallel evolution has masked phylogenetic signals. Molecular surveys of members of 12 of the 15 constituent families, using the 18S rRNA gene, have revealed that anomalodesmatans are robustly monophyletic and lie within the basal heterodonts. The Anomalodesmata should no longer be regarded as a subclass, but as a part of the Heterodonta. Here we present an enhanced analysis of 32 anomalodesmatan species (representatives of 12 families). Our results, subjected to Maximum Parsimony, Maximum Likelihood and Bayesian analyses, challenge our understanding of the internal relationships within the Anomalodesmata. In particular they indicate the need for a re-distribution of the families traditionally placed in the Thracioidea and Pandoroidea into a 'thraciid' lineage (Thraciidae + Cleidothaeridae + Myochamidae) and a 'lyonsiid' lineage (polyphyletic Lyonsiidae + Clavagellidae + Laternulidae + Pandoridae). The endolithic Clavagella and endobenthic Brechites and Penicillus form a robust clade. The hypothesis that the carnivorous septibranchs are monophyletic can, thus far, be neither supported nor rejected. Mapping critical morphological characters onto our molecular results provides evidence of multiple loss of some characters (e.g. prismato-nacreous shell microstructure and shell spicules) and also multiple gain of others (e.g. chondrophores).  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 148 , 395–420.     

A new Mantalania species (Rubiaceae) from Madagascar

Mantalania longipedunculata De Block & A.P. Davis, a new species of Rubiaceae (Gardenieae) from Île Sainte Marie, Madagascar, is described, illustrated, and compared with the three other species in the genus. An extinction risk assessment is given, using the categories and criteria of the World Conservation Union (IUCN).  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 421–424.     

Morphological character evolution and molecular trees in sepiids (Mollusca: Cephalopoda): is the cuttlebone a robust phylogenetic marker?

The sepiids are characterized by their cuttlebone or sepion, an internal shell resulting from secondary mineralization of a chitinous 'gladius'. The various species are identified using a combination of shell criteria and 'soft-part' characters. Using mitochondrial genes, we established phylogenetic relationships of sepiids including the three accepted genera ( Sepia , Sepiella , Metasepia ) and a species complex of uncertain status ( Doratosepion ). We showed the Sepia genus to be paraphyletic and found no direct correlation between geographical distribution and systematics. We mapped, on the molecular tree, shell characteristics commonly used as reliable diagnostic criteria for taxonomy. Due to the plasticity of the shell, these characters did not appear phylogenetically informative. In an attempt to define systematic categories related to phylogenetic relationships, new clear synapomorphies need to be established for each genus, necessitating a revision of the genus Sepia .  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 139–150.     

A mass recruitment event in the land crab Gecarcinus ruricola (Linnaeus, 1758) (Brachyura: Grapsoidea: Gecarcinidae), and a description of the megalop

A mass return to land of the megalop of the land crab Gecarcinus ruricola is reported. The return occurred in June 2004 on the island of Providencia in the western Caribbean: this is the first detailed report of larval return in this species, and the most detailed report for any gecarcinid. Crabs emerged from the sea as megalops over 2 to 3 days, and moved rapidly landwards. Vast numbers migrated > 50 m across land before moulting to the first crab – the megalop is clearly the invasive stage. The megalop is described for the first time, and criteria are identified to discriminate it from other Caribbean gecarcinids.  © 2006 The Linnean Society of London, Zoological Journal of the Linnean Society , 2006, 146 , 149–164.     

On the confusion surrounding Pareledone charcoti (Joubin, 1905) (Cephalopoda: Octopodidae): endemic radiation in the Southern Ocean

Until recently, all papillated specimens of Pareledone were ascribed to the species Pareledone charcoti (Joubin, 1905), of which P. aurorae (Berry, 1917) was considered a junior synonym. Re-examination of the papillated type material of Pareledone, coupled with extensive fishing over several years off the Antarctic Peninsula, has led to a revision of this position. Seven new species of papillated Pareledone are identified from the Antarctic Peninsula region. They are identified by subtle taxonomic characters, such as the morphology and placement of their papillae, although traditional indices often fail to separate the species. Whilst apparently sympatric, there is some evidence of niche separation of these species with respect to depth. A key is provided for their identification.  © 2005 The Linnean Society of London, Zoological Journal of the Linnean Society , 2005, 143 , 75−108.     

Canarian land snail diversity: conflict between anatomical and molecular data on the phylogenetic placement of five new species of Napaeus (Gastropoda, Pulmonata, Enidae)

Five new species of land snail (family Enidae) are described from La Gomera (Canary Islands) of which the majority, on the basis of anatomy alone, could be incorporated within a new supraspecific taxon. In addition to the morphological study of these new species, a region of the 16S mitochondrial gene is sequenced from three of the new species and a range of species of Napaeus from within its two subgenera ( Napaeinus and Napaeus ) . There is a disparity between the morphological and preliminary molecular phylogenetic data. Possible explanations for this conflict are discussed, as well as the evolutionary relationships among these different taxa, and it is suggested that this group may be an excellent model for further studies of adaptation and diversification.  © 2006 The Linnean Society of London, Biological Journal of the Linnean Society , 2006, 89 , 169–187.     

Adaptive modifications of carapace outlines in the Cytheroidea (Ostracoda: Crustacea)

Shell outlines of 202 extant cytheroidean ostracods were analysed in dorsal, lateral, and posterior views by elliptic Fourier analysis. The results obtained confirm that the exterior morphology is related to ecological factors as well as phylogenetic constraints. Phytal species living on tall seagrass and benthic species burrowing in sediments are characterized and differentiated from the species crawling on sediments by the presence of slender shells with tapered venters. With reference to reconstruction of ancestral state of outline traits on the molecular phylogeny, the hypothetical ancestor of cytheroidean ostracods is presumed to have had an average-shaped shell. Morphological plasticity of the shell outline was observed in many families. The phytal species living on tall seagrass appear to have evolved convergently with species from other habitats, acquiring slim shell outlines during the Cenozoic period. The present analysis also reveals the phylogenetic constraints on the morphological evolution of the Trachyleberididae in their adaptation to a burrowing habit.  © 2009 The Linnean Society of London, Biological Journal of the Linnean Society , 2009, 97 , 810–821.     

Chromosome study of the fern genus Cyrtomium (Dryopteridaceae)

Cyrtomium (Dryopteridaceae) is an Asiatic genus comprising about 40 species characterized by having anastomosing veins that form areolae with included veinlets. Twelve chromosome counts representing 11 taxa were made in the present study. The chromosome numbers of six species endemic to China are reported for the first time: C. uniseriale , 2 n  = 164; C. guizhouense , 2 n  = 82; C. shingianum , n  = 82, 2 n  =  c .164; C. chingianum , 2 n  = 164; C. urophyllum , 2 n  = 82 and C. aequibasis , 2 n  = 123. The results were used to show that (1) C. uniseriale should be reduced to varietal status under C. balansae ; (2) subseries Balansana is not closely related to any other Cyrtomium species and should be separated from Cyrtomium ; and (3) C. guizhouense and C. lonchitoides are basal groups when subseries Balansana is not considered. These results were also supported by morphology. A high level of differentiation is a distinct characteristic in Cyrtomium . The genus has two reproductive types: sexual and apogamous. Sexual species are distributed mostly in China. Southwestern China is a modern diversity centre of Cyrtomium , with 80.6% of known species occurring there. Many species are endemic, most of which are sexual tetraploids or apogamous triploids. Both the apogamous reproductive type and polyploid species are adaptions to limestone habitats.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 221–228.     

A new species of Noccaea (Brassicaceae) from South Anatolia, Turkey

Noccaea camlikensis sp. nov. (Brassicaceae) is described and illustrated from a localized serpentine range in southern Turkey. Its close relationship to N. cariensis , from which it differs in leaf and carpological characters, is discussed. The protologue of this fairly unknown species can now be amended to cover better the morphological variability of this taxon. A comparative study of seed-coat anatomy advocates its move from Thlaspi to Noccaea ; the relevant combination N. cariensis (Carlström) Parolly, Nordt & Aytaç is made. The ecology of both vicarious species is discussed and their distribution mapped.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 409–416.     

The pollen morphology of Phyllanthus (Euphorbiaceae) section Choretropsis

The pollen grain morphology of the eight South American species of the genus Phyllanthus , subgenus Phyllanthus , section Choretropsis , endemic to Brazil, was investigated using light and scanning electron microscopy. The high homogeneity in pollen shape, as well as aperture number and configuration, allowed the definition of a basic pollen type for this section, viz. prolate spheroidal or subprolate, zonocolporate with 4–5 invaginated colpi, sexine reticulate. Two subtypes have been observed, based on pollen grain apertures and exine sculpture. The first subtype is characterized by straight and narrow colpi provided with costae, lalongate endoapertures and a reticulum of rectilineous muri as in P. choretroides and P. spartioides . The second subtype has wider colpi without costae, circular endoapertures and a reticulum with curvilineous muri as in P. flagelliformis , P. goianensis and P. scoparius , or curvilineous-rectilineous muri as in P. angustissimus , P. gladiatus and P. klotzschianus . It was demonstrated that the pollen shape and the number of colpi varied within and between some of the species. The results suggest that pollen grain morphology, in association with plant architecture and the presence of phylloclades, constitute additional evidence to delimit the species of the section Choretropsis and to further understand their evolutionary origin within the genus Phyllanthus.  © 2004 The Linnean Society of London, Botanical Journal of the Linnean Society , 2004, 144 , 243–250.     

Evidence for ecological speciation in the sister species Candidula unifasciata (Poiret, 1801) and C. rugosiuscula (Michaud, 1831) (Helicellinae, Gastropoda)

This paper studies the speciation of two land snail species in south-east France. By using two mitochondrial and one nuclear gene, the species are shown to be sister species within the larger clade of western European Candidula species. The species never occurred syntopically, but a narrow contact zone population was identified. Recent range expansions inferred from phylogeographical methods indicated that the present day distributions are not limited by the colonization capacity of the species. Analysis of environmental variables suggested distribution along an ecotone. The gastropod community is also correlated to this gradient. Morphometric shell analysis showed that the divergence between the sister species is a result of desiccation-resistant shell characters. We therefore conclude that the cause for the ecological speciation is most probably the establishment of the Mediterranean climate ≈ 3.2 mya. A model of ecological speciation with a moving ecotone is put forward.  © 2003 The Linnean Society of London, Biological Journal of the Linnean Society , 2003, 79, 611–628.     

Polyploidy in Aconitum subgenus Lycoctonum (Ranunculaceae)

Chromosome numbers and morphology in 22 populations belonging to 11 taxa of Aconitum subgenus Lycoctonum (Ranunculaceae) from China were studied. Some taxa were diploid, with 2 n  = 16, but four species and two varieties were found to be tetraploid, with 2 n  = 32. They are concentrated in the Hengduan Mountains region in south-west China, indicating that polyploidy could have played an important role in the speciation of the subgenus in this region, one of the areas of the world with a high concentration of endemic species. The relationships of some of the species are discussed.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 150 , 343–353.     

A new dwarf Coffea (Rubiaceae) from southern Cameroon

A distinctive new species of dwarf monocaulous Coffea (Rubiaceae) from Cameroon is described and illustrated. Coffea mapiana is the second dwarf monocaulous known from Cameroon. Its diagnostic characters are elucidated and its taxonomic affinities are discussed; a conservation assessment is provided.  © 2006 The Linnean Society of London, Botanical Journal of the Linnean Society , 2006, 151 , 425–430.