2011
Ziegler, A., et al., 2011.
Application of magnetic resonance imaging in zoology.
Zoomorphology , 130 , pp. 227-254.
AbstractMagnetic resonance imaging (MRI) is a non- invasive imaging technique that today constitutes one of the main pillars of preclinical and clinical imaging. MRI’s capacity to depict soft tissue in whole specimens ex vivo as well as in vivo, achievable voxel resolutions well below (100 lm)3, and the absence of ionizing radiation have resulted in the broad application of this technique both in human diagnostics and studies involving small animal model organisms. Unfortunately, MRI systems are expen- sive devices and have so far only sporadically been used to resolve questions in zoology and in particular in zoomor- phology. However, the results from two recent studies involving systematic scanning of representative species from a vertebrate group (fishes) as well as an invertebrate taxon (sea urchins) suggest that MRI could in fact be used more widely in zoology. Using novel image data derived from representative species of numerous higher metazoan clades in combination with a comprehensive literature survey, we review and evaluate the potential of MRI for systematic taxon scanning. According to our results, numerous animal groups are suitable for systematic MRI scanning, among them various cnidarian and arthropod taxa, brachiopods, various molluscan taxa, echinoderms, as well as all vertebrate clades. However, various phyla in their entirety cannot be considered suitable for this approach mainly due to their small size (e.g., Kinorhyncha) or their unfavorable shape (e.g., Nematomorpha), while other taxa are prone to produce artifacts associated either with their biology (e.g., Echiura) or their anatomy (e.g., Polyplacophora). In order to initiate further uses of MRI in zoology, we outline the principles underlying various applications of this technique such as the use of contrast agents, in vivo MRI, functional MRI, as well as magnetic resonance spectroscopy. Finally, we discuss how future technical developments might shape the use of MRI for the study of zoological specimens.
Murienne, J., Edgecombe, G.D. & Giribet, G., 2011.
Comparative phylogeography of the centipedes Cryptops pictus and C. niuensis in New Caledonia, Fiji and Vanuatu.
Organisms Diversity & Evolution , 11 , pp. 61-74.
AbstractThe South Pacific is a biodiverse region of extreme evolutionary importance because it harbors ancient lineages and recent radiations. However, few population- level studies of genetic variation have been conducted in the land masses of this region. Likewise, the number of population-level studies using myriapods as models is extremely small. In this article, we compare the genetic structure of two species of centipedes in the genus Cryptops endemic to the South Pacific, one from a continental island, the other from oceanic islands. The level of genetic diversity and structure in C. pictus, a species endemic to New Caledonia, is much higher than in C. niuensis in Fiji and Vanuatu, despite the fact that C. niuensis is spread across two different archipelagos and several islands. The most likely explanation is the relatively young age of the remnants of the Vitiaz Arc (Fiji and Vanuatu) compared to New Caledonia. Using the emergence of Fiji-Vanuatu as a calibration point, C. pictus is estimated to have diverged by 23.4 Mya (upper 95% confidence interval) with a mean estimate of 11.7 Mya versus the 9.7 Mya of C. niuensis. Considering the absence of shared sequences between specimens from different sampling sites and the high genetic structuring within populations, C. pictus appears to be an ideal candidate to assess historical processes at a micro-evolutionary scale in New Caledonia.
Sharma, P.P. & Giribet, G., 2011.
The evolutionary and biogeographic history of the armoured harvestmen – Laniatores phylogeny based on ten molecular markers, with the description of two new families of Opiliones (Arachnida).
Invertebrate Systematics , 25 , pp. 106-142.
AbstractWe investigated the internal phylogeny of Laniatores, the most diverse suborder of Opiliones, using sequence data from 10 molecular loci: 12S rRNA, 16S rRNA, 18S rRNA, 28S rRNA, cytochrome c oxidase subunit I (COI), cytochrome b, elongation factor-1a, histones H3 and H4, and U2 snRNA. Exemplars of all previously described families of Laniatores were included, in addition to two families – Petrobunidae, fam. nov. and Tithaeidae, fam. nov. – that we erect herein. Data analyses were based on maximum likelihood and Bayesian approaches on static alignments, and included phylogenetic tree estimation, molecular dating, and biogeographic analysis of ancestral area reconstruction. The results obtained include the monophyly of Laniatores and the infraorder Grassatores – the focus of this study – as well as support for numerous interfamilial relationships. The two new families described cluster with other South-east Asian families (Podoctidae and Epedanidae). Diversification of Laniatores is estimated at ~348 Mya, and origin of most Grassatores superfamilies occurs in a ~25 million year span of time immediately after the end-Permian mass extinction (254 Mya). Ancestral range reconstruction of the clade (Samooidea + Zalmoxoidea) suggests that the ancestral range of Samooidea comprises West Tropical Gondwana (West Africa + Neotropics), whereas that of Zalmoxoidea is exclusively Neotropical. The following additional taxonomic changes are proposed: (1) Remyus is transferred to Phalangodidae, and (2) Escadabiidae and Kimulidae are transferred to Zalmoxoidea.
Sharma, P.P., Prieto, C.E. & Giribet, G., 2011.
A new family of Laniatores (Arachnida : Opiliones) from the Afrotropics.
Invertebrate Systematics , 25 , pp. 143-154.
AbstractAmong Opiliones, Afrotropical lineages constitute some of the least studied groups in comparison with those endemic to other biogeographic provinces. Based upon morphological evidence, we erect Pyramidopidae, fam. nov. to distinguish a group of Laniatores from the family Phalangodidae. We review evidence from recent molecular phylogenetic studies that corroborate the independence of Pyramidopidae, fam. nov. from previously described families and support its sister relationship to another largely Afrotropical group, the family Assamiidae. The monotypic genus Maiorerus Rambla, 1993 is transferred to Pyramidopidae, fam. nov. The new family comprises 12 genera geographically restricted to Africa and the adjacent Canary Islands. Interfamilial relationships of the derived Laniatores are discussed in the context of gross and genitalic morphology.
Novo, M., et al., 2011.
Understanding the biogeography of a group of earthworms in the Mediterranean basin—The phylogenetic puzzle of Hormogastridae (Clitellata: Oligochaeta).
Molecular Phylogenetics and Evolution , 61 , pp. 125-135.
AbstractTraditional earthworm taxonomy is hindered due to their anatomical simplicity and the plasticity of the characteristics often used for diagnosing species. Making phylogenetic inferences based on these charac- ters is more than difficult. In this study we use molecular tools to unravel the phylogeny of the clitellate family Hormogastridae. The family includes species of large to mid-sized earthworms distributed almost exclusively in the western Mediterranean region where they play an important ecological role. We analyzed individuals from 46 locations spanning the Iberian Peninsula to Corsica and Sardinia, represent- ing the four described genera in the family and 20 species. Molecular markers include mitochondrial regions of the cytochrome c oxidase subunit I gene (COI), 16S rRNA and tRNAs for Leu, Ala, and Ser, two nuclear ribosomal genes (nearly complete 18S rRNA and a fragment of 28S rRNA) and two nuclear protein-encoding genes (histones H3 and H4). Analyses of the data using different approaches corrobo- rates monophyly of Hormogastridae, but the genus Hormogaster is paraphyletic and Hormogaster pretiosa appears polyphyletic, stressing the need for taxonomic revisionary work in the family. The genus Vignysa could represent an early offshoot in the family, although the relationships with other genera are uncer- tain. The genus Hemigastrodrilus is related to the Hormogaster elisae complex and both are found in the Atlantic drainage of the Iberian Peninsula and France. From a biogeographic perspective Corsica and Sardinia include members of two separate hormogastrid lineages. The species located in Corsica and Northern Sardinia are related to Vignysa, whereas Hormogaster pretiosa pretiosa, from Southern Sardinia, is closely related to the Hormogaster species from the NE Iberian Peninsula. A molecular dating of the tree using the separation of the Sardinian microplate as a calibration point (at 33 MY) and assuming a model of vicariance indicates that the diversification of Hormogastridae may be ancient, ranging from 97 to 67 Ma.
Sharma, P.P., Kury, A.B. & Giribet, G., 2011.
Zalmoxidae (Arachnida: Opiliones: Laniatores) of the Paleotropics: a catalogue of Southeast Asian and Indo-Pacific species.
Zootaxa , 2972 , pp. 37-58.
AbstractA revised catalogue of the Paleotropical Zalmoxidae including images of selected available type specimens is presented. Distribution data are provided to the best of our knowledge. The genera Acrozalmoxis Roewer, 1915, Camanastus Roewer, 1949, Papuastus Roewer, 1949, Savoa Roewer, 1949, and Zalmoxomma Roewer, 1949 are newly synonymized with the type genus Zalmoxis Sørensen, 1886. The following new combinations are established: Zalmoxis australis, Zalmoxis bon- ka, Zalmoxis insularis, Zalmoxis maculosus, Zalmoxis occidentalis, and Zalmoxis ponapeus. Bogania Forster, 1955 and Bunofagea Lawrence, 1959 are removed from Zalmoxidae and transferred to Phalangodidae. Gjellerupia Roewer, 1913 and Spalicus Roewer, 1949 are considered Grassatores incertae sedis. The incidence of preoccupied taxon names is re- dressed by designation of new specific epithets as follows: Zalmoxis neoguinensis (Roewer, 1915) is renamed Zalmoxis thorelli; Zalmoxis neoguinensis (Müller, 1917) is renamed Zalmoxis muelleri; Zalmoxis neoguinensis (Roewer, 1949) is renamed Zalmoxis mutus; and Zalmoxis minima (Roewer, 1915) is restored to Gjellerupia minima. Zalmoxis pallicolor Strand, 1910 is synonymized with Zalmoxis armatipes Strand, 1910. Diagnoses of genera are provided. Species richness and familial level relationships of Zalmoxidae are discussed.
Garwood, R.J., et al., 2011.
Anatomically modern Carboniferous harvestmen demonstrate early cladogenesis and stasis in Opiliones.
Nature Communications , 2 , pp. 444.
AbstractHarvestmen or opiliones, the third most-diverse arachnid order, are an ancient group found on all continental landmasses, except Antarctica. However, a terrestrial mode of life and leathery, poorly mineralized exoskeleton makes preservation unlikely, and their fossil record is limited. The few Palaeozoic species discovered to date appear surprisingly modern, but are too poorly preserved to allow unequivocal taxonomic placement. Here we use high-resolution X-ray micro-tomography to describe two new harvestmen from the Carboniferous (~305myr) of France. The resulting computer models allow the first phylogenetic analysis of any Palaeozoic opiliones, explicitly resolving both specimens as members of different extant lineages, and providing corroboration for molecular estimates of an early Palaeozoic radiation within the order. Furthermore, remarkable similarities between these fossils and extant harvestmen implies extensive morphological stasis in the order. Compared with other arachnids—and terrestrial arthropods generally—harvestmen are amongst the first groups to evolve fully modern body plans.
Aktipis, S.H., Boehm, E. & Giribet, G., 2011.
Another step towards understanding the slit-limpets (Fissurellidae, Fissurelloidea, Vetigastropoda, Gastropoda): a combined five-gene molecular phylogeny.
Zoologica Scripta , 40 , pp. 238-259.
AbstractFissurellids, commonly known as slit or keyhole limpets, are limpet-shaped gastropods that typically possess a hole, slit or notch in their bilaterally symmetrical shells and usually occur on rocky marine substrates. Competing classifications for Fissurellidae have been circumscribed using various morphological characters such as radular, shell and mantle features; two to five different subfamilies have been recognized. Although fissurellid species are frequently included in larger vetigastropod phylogenies, relatively few phylogenetic studies of the group have been performed. This study presents a phylogenetic investigation of the relationships amongst slit-limpets in the vetigastropod superfamily Fissurelloidea, representing the first molecular phylogeny of this clade. In this study, the monophyly of Fissurelloidea and Fissurellidae varied depending on the analytical method used, but clades compatible with the subfamilies Diodorinae and Fissurellinae were recovered with high bootstrap support in all analyses. Species traditionally classified in Emarginulinae formed two groups identified in this study as Hemitominae (Puncturella, Cranopsis and Hemitoma) and Emarginulinae sensu stricto (Emarginula, Montfortula, Tugali, Scutus and Nannoscutum), but Hemitominae was only monophyletic in the maximum likelihood analysis. The results of this study contradict traditional fissurellid classifications as well as theories about the evolution of key fissurellid shell characters. The placement of Puncturella, Cranopsis and Hemitoma sister to all remaining fissurellids suggests that the presence of an anteriorly placed foramen or notch is plesiomorphic, and that an anterior notch or slit evolved multi- ple times in Fissurellidae.
Edgecombe, G.D., et al., 2011.
Higher-level metazoan relationships: recent progress and remaining questions.
Organisms, Diversity & Evolution , 11 , pp. 151-172.
Giribet, G., 2011.
Shearogovea, a new genus of Cyphophthalmi (Arachnida, Opiliones) of uncertain position from Oaxacan caves, Mexico.
Breviora , 528 , pp. 1-7.
AbstractShearogovea gen. nov. is erected for Neogovea mexasca Shear, 1977, a troglobitic cyphophthalmid species from a cave system in Oaxaca, Mexico. The new genus does not show affinity to Neogovea Hinton, 1938, as it lacks the characteristic toothed claw of leg II or the fusion of the coxae of legs II to those of legs III (which are in turn fused to coxae of legs IV). Shearogovea gen. nov. is probably not related to other Neotropical neogoveid genera, but its exact phylogenetic position remains unresolved.
giribet_2011.pdf Clouse, R.M., de Bivort, B.L. & Giribet, G., 2011.
Letter to the Editor: Phylogenetic signal in morphometric data.
Cladistics , 27 , pp. 337-340.
Clouse, R.M., et al., 2011.
An old lineage of Cyphophthalmi (Opiliones) discovered on Mindanao highlights the need for biogeographical research in the Philippines.
The Journal of Arachnology , 39 , pp. 147-153.
AbstractThe arachnid order Opiliones, and the suborder Cyphophthalmi in particular, have recently been used to test biogeographical patterns in Southeast Asia due to their ancient age and extremely low vagility. Here we report the first Cyphophthalmi—two juveniles—known from Mindanao in the southern Philippine Archipelago, and we place them in a molecular phylogeny to test biogeographical hypotheses for their colonization of that island. Five molecular markers were sequenced from one specimen, three from the other, and these sequences were added to a previously completed phylogenetic analysis. The specimens were recovered as members of a clade found almost exclusively on Borneo. Their deep placement within this clade suggests a very old origin and colonization that perhaps involved the mysterious landmass now underlying Mindanao’s Zamboanga Peninsula. This species prompts new questions about the abilities of Southeast Asian Cyphophthalmi (Stylocellidae) to disperse and colonize, and it emphasizes how much remains to be understood about the geological history of the Philippines.
