No full-text available
To read the full-text of this research,
you can request a copy directly from the authors.
A molecular phylogeny of the temperate Gondwanan family Pettalidae (Arachnida, Opiliones, Cyphophthalmi) and the limits of taxonomic sampling
Abstract
We evaluate the phylogenetic and biogeographical relationships of the members of the family Pettalidae (Opiliones, Cyphophthalmi), a textbook example of an ancient temperate Gondwanan taxon, by means of DNA sequence data from four markers. Taxon sampling is optimized to cover more than 70% of the described species in the family, with 117 ingroup specimens included in the analyses. The data were submitted to diverse analytical treatments, including static and dynamic homology, untrimmed and trimmed alignments, and a variety of optimality criteria including parsimony and maximum-likelihood (traditional search and Bayesian). All analyses found strong support for the monophyly of the family Pettalidae and of all its genera, with the exception of Speleosiro, which is nested within Purcellia. However, the relationships among genera are poorly resolved, with the exceptions of a first split between the South African genus Parapurcellia and the remaining species, and, less supported, a possible relationship between Chileogovea and the other South African genus Purcellia. The diversification of most genera is Mesozoic, and of the three New Zealand genera, two show evidence of constant diversification through time, contradicting scenarios of total submersion of New Zealand during the Oligocene drowning episode. The genera Karripurcellia from Western Australia and Neopurcellia from the Australian plate of New Zealand show a pattern typical of relicts, with ancient origin, depauperate extant diversity and recent diversification. The following taxonomic actions are taken: Milipurcellia Karaman, 2012 is synonymized with Karripurcellia Giribet, 2003 syn. nov.; Speleosiro Lawrence, 1931 is synonymised with Purcellia Hansen & Sørensen, 1904 syn. nov. The following new combinations are proposed: Parapurcellia transvaalica (Lawrence, 1963) comb. nov.; Purcellia argasiformis (Lawrence, 1931) comb. nov.
... These analyses were followed by a series of phylogenetic studies for the whole suborder using a selection of nuclear and mitochondrial markers sometimes combined with morphology (e.g., Giribet et al., 2012;Oberski et al., 2018). Despite the dense molecular sampling existing now for all families of Cyphophthalmi (e.g., Giribet et al., 2016a;Giribet et al., 2017;Benavides et al., 2019;Schmidt et al., 2020;Giribet et al., 2021;Karaman et al., 2022), all these studies are limited in the amount of genetic data available per sample, and this has resulted in inaccurate resolution of genus-level relationships for some families or even questioned the monophyly of Sironidae and Neogoveidae. It is for this reason that more recently phylotranscriptomics was applied to resolve the interrelationships of Pettalidae (Baker et al., 2020). ...
... Among Cyphophthalmi, the phylogeny of the family Pettalidae has received unparalleled attention from a molecular point of view, including Sanger data (e.g., Giribet, 2007,2009;Giribet et al., 2016a;Oberski et al., 2018;Baker et al., 2020;Boyer et al., 2022;Giribet et al., 2022), transcriptomes (Baker et al., 2020), and UCEs (Giribet et al., 2022;Heine et al., 2024). Here, all genera represented by multiple terminals are monophyletic and the relationships among these genera are identical to those in the study of Giribet et al. (2022) using the same 840 UCEs. ...
... It is also worth noting that Karaman (2012) erected the genus Milipurcellia Karaman, 2012 for Karripurcellia sierwaldae as he stated that "it is clear that this genus is not closely related to the genus Karripurcellia" (Karaman, 2012: 92). Our molecular data however show a sister group relationship between Karripurcellia peckorum Giribet, 2003 and sequences extracted from a paratype of K. sierwaldae, showing that these two species are closely related, and thus supporting the synonymy of Milipurcellia with Karripurcellia proposed by Giribet et al., (2016a)-but not acknowledged by Karaman (2022). Within the East Gondwanan clade, all analyses support Karripurcellia as sister group to Aoraki, these as sister group to Neopurcellia, and the three genera as sister group to Austropurcellia. ...
... compare Fig. 3b, e with Fig. 3c, f). Phylogenetic analysis of molecular data has previously called into question the species status of A. granulosa and A. tumidata; A. tumidata appears as paraphyletic grade sister to A. granulosa in one analysis and A. granulosa appears as a paraphyletic grade sister to A. tumidata in another analysis by Giribet et al. (2016). Our most recent phylogenetic analysis, presented later in this paper, supports the proposed synonymy. ...
... The relationships recovered among species are concordant with results from previous studies Boyer andGiribet 2007, 2009;Giribet et al. 2012Giribet et al. , 2016Fernández and Giribet 2014;Baker et al. 2020). As in all previous phylogenetic analyses of this group, we find a wellsupported sister group relationship between the two species with heavily granulose fourth male tarsi and anal plates that lack scopulae but bear a distinctive central cuticular protuberance (A. ...
... and A. longitarsa were found nested within the subspecies (Fig. 12). This is not surprising, as A. denticulata denticulata has been recovered as paraphyletic in past studies, with A. denticulata major and A. longitarsa nested within Boyer and Giribet 2009;Giribet et al. 2016). At this time, we refrain from revising either of the A. denticulata subspecies. ...
New Zealand is home to 30 recognised endemic mite harvestman species and subspecies, 26 of which were described by Ray Forster in 1948 and 1952. These species comprise three genera: RakaiaHirst, 1926, NeopurcelliaForster, 1948, and AorakiBoyer & Giribet, 2007. Here, we focus on the diversity and distribution of Aoraki: we describe A. grandis Boyer, Tuffield & Dohr, sp. nov. and A. meridialis Boyer, Hahn & Ward, sp. nov. and we synonymise A. granulosa (Forster, 1952) with A. tumidata (Forster, 1948), bringing the total of named species and subspecies to twelve, and extending the southern range of the genus by over 100 km. Our phylogenetic analysis revealed three major lineages within the genus characterised by differing levels of granulation of the male fourth tarsus. We report striking variation in the range size and level of genetic structuring present within currently recognised species and subspecies of Aoraki, and propose future studies to address evolutionary, biogeographic and taxonomic questions in the group.
urn:lsid:zoobank.org:pub:BDD4D61C-B099–44D5–949C-34AD217A016F.
... Chousou-Polydouri et al., 2019;Murienne, Daniels, Buckley, Mayer, & Giribet, 2014). One notable example is the mite harvestman family Pettalidae (Arachnida, Opiliones, Cyphophthalmi; Giribet et al., 2016;Shear, 1980). Mite harvestmen are small (1-to 4-mm-long) arachnids that live in damp, dark environments such as leaf litter, caves and rotting logs. ...
... Pettalidae has a classic temperate Gondwanan distribution, with representatives in Chile, South Africa, Madagascar, 1 Sri Lanka, Australia and New Zealand (Figure 1). After more than a decade of taxonomic study of the family, using both morphology and traditional molecular markers, systematists have settled on 10 accepted monophyletic genera in the family, each of which is restricted to one geographically cohesive landmass of former Gondwana Giribet et al., 2012Giribet et al., , 2016. However, while the monophyly of each genus has been well established using traditional Sanger sequencing markers, the relationships between genera remain largely unresolved, with the exception of the South African genus Parapurcellia being the sister group to all other genera. ...
... We found the South African genus Parapurcellia to be the sister group to all other genera, consistent with results from previously published Sanger-based phylogenies Giribet et al., 2016). Furthermore, in all our analyses, we recovered a clear split between a clade of taxa from former Eastern Gondwana Zealand) with high support (Figure 2d). ...
Aim
We explored the extent to which Gondwanan vicariance contributed to the circum‐Antarctic distribution of the mite harvestman family Pettalidae, a group of small, dispersal‐limited arachnids whose phylogeny has been poorly resolved, precluding rigorous biogeographic hypothesis testing.
Location
Continental landmasses of former temperate Gondwana (Chile, South Africa, Sri Lanka, Australia and New Zealand).
Taxon
Pettalidae, Opiliones.
Methods
We generated transcriptomes for a phylogeny of 16 pettalids, spanning 9 genera. Data were analysed using maximum likelihood, Bayesian inference and coalescence methods. The phylogenetic position of the Sri Lankan genus Pettalus was further explored using quartet likelihood mapping and changes in gene likelihood scores. We also estimated divergence times and looked for signatures of extinction across Antarctica and central Australia using previously published phylogenies with near‐complete species sampling constrained to match our transcriptomic results. Finally, we estimated ancestral ranges and inferred instances of vicariance.
Results
We recovered a well‐supported topology with a division between taxa from landmasses that made up East Gondwana, and a grade of taxa from West Gondwana. Pettalus was resolved either as the sister group of the Queensland‐endemic Austropurcellia , or as the sister group to a larger clade from East Gondwana, though favouring Pettalus + Austropurcellia . Divergence times for multiple vicariance events coincided with Gondwana's breakup. Speciation–extinction analysis found one diversification process for the family: an initial burst of cladogenesis that slowed down through time.
Main Conclusions
Given that the order of cladogenesis corresponds to the order in which Gondwana fragmented, and the concurrent timing of vicariance and rifting, Gondwanan breakup explains major biogeographic patterns in Pettalidae. Some divergences predate initial rifting, but there is no evidence of trans ‐oceanic dispersal. The Sri Lanka–eastern Australia relationship makes sense in the light of large‐scale extinction across Antarctica and central Australia; however, we find no clear signatures of mass extinction.
... Pettalidae is an old lineage of mite harvestmen (Arachnida, Opiliones, Cyphophthalmi) confined to the circum-Antarctic terranes, persisting on what are nowadays the former landmasses of southern Gondwana (i.e., southern South America, South Africa, Madagascar, Sri Lanka, Australia and New Zealand) (Shear 1980;Giribet 2003;Giribet et al. 2016). Karripurcellia Giribet, 2003 was erected for three species of Pettalidae from Western Australia due to their unique morphology and isolation from other Australian species, with which they may not form a clade (Giribet et al. 2016). ...
... Pettalidae is an old lineage of mite harvestmen (Arachnida, Opiliones, Cyphophthalmi) confined to the circum-Antarctic terranes, persisting on what are nowadays the former landmasses of southern Gondwana (i.e., southern South America, South Africa, Madagascar, Sri Lanka, Australia and New Zealand) (Shear 1980;Giribet 2003;Giribet et al. 2016). Karripurcellia Giribet, 2003 was erected for three species of Pettalidae from Western Australia due to their unique morphology and isolation from other Australian species, with which they may not form a clade (Giribet et al. 2016). The genus is endemic to the Southwest Australian Floristic Region (SWA-FR) or south-western Western Australian biodiversity hotspot (SWWA), a relatively small region on a temper-Due to their low vagility, restriction to moist habitats, and usually isolated ranges, pettalids follow a typical distribution of short-range endemics (Jay et al. 2016), species which inhabit a relatively small area of less than 10,000 km 2 (Harvey 2002), as observed in many SWWA terrestrial arthropods (Rix et al. 2015;Harms 2018). ...
... The genus is endemic to the Southwest Australian Floristic Region (SWA-FR) or south-western Western Australian biodiversity hotspot (SWWA), a relatively small region on a temper-Due to their low vagility, restriction to moist habitats, and usually isolated ranges, pettalids follow a typical distribution of short-range endemics (Jay et al. 2016), species which inhabit a relatively small area of less than 10,000 km 2 (Harvey 2002), as observed in many SWWA terrestrial arthropods (Rix et al. 2015;Harms 2018). The monophyly and validity of Karripurcellia and of one of its species have, however, been questioned by Karaman (2012), who erected the genus Milipurcellia Karaman, 2012 for K. sierwaldae Giribet, 2003, and synonymized K. harveyi Giribet, 2003with K. peckorum Giribet, 2003 Milipurcellia was later synonymized with Karripurcellia in a paper that included sequence data from multiple Karripurcellia specimens from different localities (Giribet et al. 2016). Unfortunately, little information is available about the broader population structure of the species of Karripurcellia, as the type localities of all three named species come from near the town of Pemberton. ...
The mite harvestmen of the genus Karripurcellia Giribet, 2003 are endemic to the tall, wet eucalypt forests of south-western Western Australia, a region known as a hotspot for biodiversity. Currently, there are two accepted species, K.peckorum Giribet, 2003 and K.sierwaldae Giribet, 2003, both with type localities within the Warren National Park. We obtained 65 COI mtDNA sequences from across the entire distributional range of the genus. These sequences, falling into two to three geographically separate groups, probably correspond to two species. Morphologically, all of the studied specimens correspond to K.peckorum , suggesting cryptic speciation within that species. A few common haplotypes occur in more than one population, but most haplotypes are confined to a single population. As a result, populations are genetically differentiated and gene flow after initial colonization appears to be very limited or completely lacking. Our study provides another example of short-range endemism in an invertebrate from the south-western mesic biome.
... Additional collections were received from collaborators at the Queensland Museum and the Naturkundemuseum -Karlsruhe. Specimen information is summarized in Supplementary Table 1 for new specimens and in the following places for previously published data: Table 1 in Boyer et al., 2015; Table 2 in Giribet et al., 2012; Table 1 in Giribet et al., 2016. The software OpenJUMP v.1.9.1 was used to visualize GPS coordinates. ...
... Before performing statistical analyses, we fused new data with previously published Cyphophthalmi datasets, including data for the mitochondrial locus 16S and the nuclear protein-coding gene for histone H3 for some taxa (Boyer et al., 2015 [GenBank accession numbers in Table 1]; Giribet et al., 2012 [GenBank accession numbers in Table 2], Giribet et al., 2016 [GenBank accession numbers in Table 1]). Outgroup taxa consisted of two Dyspnoi (Hesperonemastoma modestum and Acropsopilio chilensis), four Eupnoi (Caddo agilis, Forsteropsalis turneri, Marthana sp., and Rhampsinitus sp.), three Laniatores (Equitius doriae, Sandokan malayanus, and Conomma oedipus), and the horseshoe crab Limulus polyphemus (Giribet et al., 2012;Groh and Giribet, 2015;Sharma and Giribet, 2011). ...
... The older ages recovered by Giribet et al. (2016) may be artefactual. As the molecular markers used by most of these studies are identical, we focused on the difference in sampling of outgroup lineages. ...
Austropurcellia, a genus of dispersal-limited arachnids endemic to isolated patches of coastal rainforest in Queensland, Australia, has a remarkable biogeographic history. The genus is a member of the family Pettalidae, which has a classical temperate Gondwanan distribution; previous work has suggested that Austropurcellia is an ancient lineage, with an origin that predates Gondwanan rifting. Subsequently, this lineage has persisted through major climatic fluctuations, such as major aridification during the Miocene and contraction and fragmentation of forest habitats during the Last Glacial Maximum (LGM). In order to understand Austropurcellia's evolutionary and biogeographic history, we generated DNA sequences from both mitochondrial and nuclear loci and combined this information with previously published datasets for the globally-distributed suborder Cyphophthalmi (i.e., all mite harvestmen). We generated phylogenetic trees using maximum likelihood and Bayesian approaches to date divergences using a relaxed molecular clock. According to our estimates, the family Pettalidae diversified in the late Jurassic, in accordance with Gondwanan vicariance. Within Pettalidae, Austropurcellia split from its sister group in the early Cretaceous and began to diversify some 15 Ma later. Therefore, its presence in Australia predates continental rifting-making it one of very few hypothesized examples of Gondwanan vicariance that have withstood rigorous testing. We found a steady rate of diversification within the genus, with no evidence for a shift in rate associated with Miocene aridification. Ages of splits between species predate the Pleistocene, consistent with a "museum" model in which forest refugia acted to preserve existing lineages rather than drive speciation within the group.
... The large HPD intervals on these estimates span the Late Jurassic. Furthermore, both age of origin and diversification of the family are approximately contemporaneous with two other well-characterized temperate Gondwanan panarthropod groups, the harvestman family Pettalidae Giribet, 2007, 2009;Giribet et al., 2012; but see Giribet et al., 2016 for an alternative dating) and the velvet worm family Peripatopsidae (Allwood et al., 2010;Murienne et al., 2013;Daniels et al., 2016), but only under the lognormal model (Fig. 4). Under the uncorrelated rates model, the divergence of the six exemplars representing the family is estimated to be 51.8 ...
... We further add the caveat that the limited taxonomic sampling in this study, and especially the exclusion of the South African genera, underestimates the age of crown group Bothriuridae; we also did not sample Urophonius, the putative sister genus of Cercophonius (Prendini, 2000;Mattoni et al. 2010). Additional sampling of bothriurid taxa can only increase the estimated crown age (or keep it the same, if the basalmost node has already been sampled), especially in light of the data on other temperate Gondwanan groups, such as Pettalidae and Peripatopsidae, where the basalmost lineages were endemic to South Africa (Murienne et al., 2013;Giribet et al., 2012Giribet et al., , 2016. Because Cercophonius is the only representative of East Gondwanan bothriurids, the emphasis of the present work was to sample this lineage and infer the relative temporal context for the split between East and West Gondwanan clades, a reliable and replicated signal observed in tree topologies of multiple temperate Gondwanan panarthropod groups Giribet 2007, 2009;Giribet et al., 2012Giribet et al., , 2016Murienne et al., 2013). ...
... Additional sampling of bothriurid taxa can only increase the estimated crown age (or keep it the same, if the basalmost node has already been sampled), especially in light of the data on other temperate Gondwanan groups, such as Pettalidae and Peripatopsidae, where the basalmost lineages were endemic to South Africa (Murienne et al., 2013;Giribet et al., 2012Giribet et al., , 2016. Because Cercophonius is the only representative of East Gondwanan bothriurids, the emphasis of the present work was to sample this lineage and infer the relative temporal context for the split between East and West Gondwanan clades, a reliable and replicated signal observed in tree topologies of multiple temperate Gondwanan panarthropod groups Giribet 2007, 2009;Giribet et al., 2012Giribet et al., , 2016Murienne et al., 2013). As indicated by Fig. 4, the age interval of the East-West Gondwanan split in Bothriuridae under the lognormal rate model overlaps the age of the corresponding split in other temperate Gondwanan taxa, albeit with a younger mean age than the geological timing of the East-West Gondwanan split, and affirms the candidacy of Bothriuridae as a temperate Gondwanan group. ...
The scorpion family Bothriuridae occupies a subset of landmasses formerly constituting East and West Gondwana, but its relationship to other scorpion families is in question. Whereas morphological data have strongly supported a sister group relationship of Bothriuridae and the superfamily Scorpionoidea, a recent phylogenomic analysis recovered a basal placement of bothriurids within Iurida, albeit sampling only a single exemplar. Here we reexamined the phylogenetic placement of the family Bothriuridae, sampling six bothriurid exemplars representing both East and West Gondwana, using transcriptomic data. Our results demonstrate that the sister group relationship of Bothriuridae to the clade ("Chactoidea" + Scorpionoidea) is supported by the inclusion of additional bothriurid taxa, and that this placement is insensitive to matrix completeness or partitioning by evolutionary rate. We also estimated divergence times within the order Scorpiones using multiple fossil calibrations, to infer whether the family Bothriuridae is sufficiently old to be characterized as a true Gondwanan lineage. We show that scorpions underwent ancient diversification between the Devonian and early Carboniferous. The age interval of the bothriurids sampled (a derived group that excludes exemplars from South Africa) spans the timing of breakup of temperate Gondwana.
... 35 Ma (McLoughlin, 2001;Prendini, 2003;Ghiglione, 2016;De La Estrella et al., 2019). While this type of distribution pattern has been observed in several other epigean arthropods (Giribet et al., 2012(Giribet et al., , 2016Baker et al., 2020;Dekarabetian et al., 2021), Bothriuridae is the only scorpion family with this kind of distribution. One of the most intriguing questions when studying the diversification of family Bothriuridae is how and when it diverged through east and west southern temperate Gondwana. ...
... Pettalids present an even older diversification time frame (about 150 Ma) than Bothriuridae (Giribet et al., 2012(Giribet et al., , 2016Baker et al., 2020). Dekarabetian et al. (2021) proposed a similar scenario for the trianonichid Americobunus Muñoz-Cuevas, 1972 and its Australian relatives (about 150 Ma), but a much more recent breakup for South American Nuncia Loman, 1902 andAustralian Calliuncus Roewer, 1931 (40 Ma). ...
In this contribution we try to unveil the diversification process of Bothriuridae in temperate Gondwana through dated phylogenomic analyses using UCE and transcriptomics, and including in the analyses species of genera Urophonius and Cercophonius, the most closely related genera of Bothriuridae from South America and Australia respectively. Additionally we explored the hypothesis that the winter activity period of some species of Urophonius, as well as the cold environmental preferences of this genus, could be related to the climatic conditions of the time frame and area in which it evolved. Genus Urophonius was recovered as sister group to Cercophonius using amino acids and UCE. The time frame obtained for the split between South American and Australian bothriurids is 94 Ma., which suggests a dispersal event through temperate Gondwana, before the final breakup of the land bridge of South America-Antarctica-Australia ca. 35 Ma. The split between summer and winter species of Urophonius, taking place at 64 Ma, is considered representative to the turnover time from the summer activity period to the winter activity period in some species of the genus. This time frame is compatible with a period of global warming of the late Cretaceous greenhouse episode that could have triggered this change.
... The family Pettalidae, because of its low dispersal ability and high ecological constraints, has emerged as one of the best examples of Gondwanan vicariance, as it inhabits the terranes once surrounding Antarctica that today constitute mostly the temperate region of the former Gondwana. Extant pettalids are found in southern South America (southern Chile), South Africa, Madagascar, Sri Lanka, Australia and New Zealand (Juberthie and Massoud 1976;Giribet et al. 2016;Oberski et al. 2018;Baker et al. 2020a). The family is currently composed of 10 genera and 81 species (one of these with two subspecies) (Giribet 2020;Kury et al. 2021;Boyer et al. 2022). ...
... We also obtained a sequence of cytochrome c oxidase subunit I (COI) from a UCE library. We then combined these Sanger-sequenced markers and the UCE-derived COI sequence with a curated version of the data set of Giribet et al. (2016). ...
Pettalidae is a family of mite harvestmen that inhabits the former circum-Antarctic Gondwanan terranes, including southern South America, South Africa, Madagascar, Sri Lanka, Australia and New Zealand. Australia is home to two pettalid genera, Austropurcellia, in northern New South Wales and Queensland, and Karripurcellia, in Western Australia, until now showing a large distributional gap between these two parts of the Australian continent. Here we report specimens of a new pettalid from South Australia, Archaeopurcellia eureka, gen. et sp. nov., closing this distributional gap of Australian pettalids. Phylogenetic analyses using traditional Sanger markers as well as ultra-conserved elements (UCEs) reveal that the new genus is related to the Chilean Chileogovea, instead of any of the other East Gondwanan genera. This relationship of an Australian species to a South American clade can be explained by the Antarctic land bridge between these two terranes, a connection that was maintained with Australia until 45 Ma. The UCE dataset also shows the promise of using museum specimens to resolve relationships within Pettalidae and Cyphophthalmi.
ZooBank: urn:lsid:zoobank.org:pub:9B57A054-30D8-4412-99A2-6191CBD3BD7E
... Notable examples include the spider families Gradungulidae (Forster et al. 1987) and Periegopidae (Forster 1995;Vink et al. 2013), the mite family Allothyridae (Krantz and Walter 2009) and a number of families of oribatid mites (Colloff and Cameron 2014). The resolution of the harvestman family Pettalidae (Figure 10.1h) is still ambiguous with respect to the monophyly of New Zealand and at least Western Australia (Boyer and Giribet 2007;de Bivort and Giribet 2010;Giribet et al. 2012;Giribet et al. 2016). However, support for the monophyly of the Australian/New Zealand Enantiobuninae or at least of some Neopilionidae is emerging (Vé lez et al. 2014). ...
... Key players in this debate have been the harvestmen of the family Pettalidae (Boyer et al. 2007a;Giribet and Boyer 2010;Giribet et al. 2012Giribet et al. , 2016Sharma and Wheeler 2013) (Figure 10.1h), where each of the genera Aoraki and Rakaia has a pre-Oligocene origin and radiation. Similar patterns are expected (but remain untested) for other Pangean or Gondwanan lineages in the harvestman families Acropsopilionidae, Neopilionidae (Figure 10.1g) and Triaenonychidae, and in numerous families of both mite superorders. ...
The Arachnida, a class of arthropod animals that includes prominent examples such as spiders, ticks and scorpions (Figure 10.1), comprises some of the most successful biological radiations on Earth. The lineage is extremely ancient and has a fossil record that dates back to the Palaeozoic (Dunlop 2010), but it is also highly diverse, with some 114,000 named species (Zhang 2013). The vast majority of arachnids are terrestrial, but some, such as water mites and marine mites, have independently evolved an aquatic lifestyle (Walter and Proctor 2013).
... In fact, most biogeographical studies on ancient invertebrate lineages have focused on tropical taxa and their biomes, such as velvet worms (Murienne, Benavides, et al., 2013), scorpions (Loria & Prendini, 2020), hoodedtick spiders (Murienne, Daniels, et al., 2013) and mite harvestmen . Fewer data are available for temperate taxa, and with the exception of some (Baker et al., 2020;Derkarabetian et al., 2021), most are geographically restricted (Giribet et al., 2016;Sharma et al., 2018). ...
Aim
Understanding the historical biogeography of the Earth's oldest terrestrial lineages provides insights into lineage diversification in relation to plate tectonics, climate change and biome shifts at maximum timescales. We investigate the biogeography of an ancient arachnid family, dragon pseudoscorpions, which are found today in mesic (mostly temperate) forests on all continents except Antarctica and Europe, have potential origins on Pangea and comprise species with extremely limited dispersal capacities. We evaluate the respective role of continental vicariance (abiotic) and biome shifts (biotic) deep in time and unravel the evolutionary history of this ancient group.
Location
Global.
Taxon
Pseudotyrannochthoniidae (Arachnida: Pseudoscorpiones).
Methods
Five loci were sequenced for 75 Pseudotyrannochthoniidae samples collected across the globe. A matrix was compiled comprising 106 terminals and ~8800 bp, and phylogenetic analyses were performed to uncover relationships. Divergence time and ancestral range estimation analyses were used to reconstruct historical biogeography.
Results
Pseudotyrannochthoniidae was monophyletic with high support but relationships among genera did not reflect current taxonomy and instead showed geographical structuring. Pseudotyrannochthoniidae originated in East Asia during the Middle Triassic and began diversifying in the Early Cretaceous.
Main Conclusions
Diversity and distributional patterns of dragon pseudoscorpions can be explained by the interplay of continental vicariance through Pangaean breakup, and biome shifts via the spread of temperate habitats in the Cretaceous and their ongoing distributional fluctuations. Pseudotyrannochthoniidae diversification began in the Early Cretaceous as they dispersed with temperate forests across the Northern Hemisphere. Cretaceous vicariance, followed by widespread Holarctic extinction in the Late Tertiary–Quaternary, created their disjunct distribution at northern latitudes. Northern and Southern Hemisphere lineages diverged as Gondwana and Laurasia rifted, and Gondwanan breakup resulted in Afrotropical/Indomalayan and Austral clades. Austral lineages spread with temperate forests, however, cooling caused their disappearance from Antarctica and led to disjunct distributions at low latitudes.
... Two decades of molecular phylogenetic study have unveiled high fidelity between harvestman distributions, phylogenetic relationships, and timing of cladogenesis, for various taxonomic levels Derkarabetian et al., 2021a;Giribet et al., 2010), and with few known cases of transoceanic dispersal (Baker et al., 2020b;Pérez-González et al., 2022;Sharma and Giribet, 2012). As examples, mite harvestmen (Cyphophthalmi) have been intensely studied as models of vicariance biogeography, particularly of temperate Gondwanan landmasses (Baker et al., 2020a;Giribet et al., 2012Giribet et al., , 2016Oberski et al., 2018). In the largest harvestman suborder, Laniatores, various subfamilies of Gonyleptoiea have featured prominently in efforts to circumscribe areas of endemism in the Neotropics and examine latitudinal diversity gradients Bragagnolo et al., 2015;Castro-Pereira et al., 2021;DaSilva et al., 2016). ...
Opiliones (harvestmen) have come to be regarded as an abundant source of model groups for study of historical biogeography, due to their ancient age, poor dispersal capability, and high fidelity to biogeographic terranes. One of the least understood harvestman groups is the Paleotropical Assamiidae, one of the more diverse families of Opiliones. Due to a labyrinthine taxonomy, poorly established generic and subfamilial boundaries, and the lack of taxonomic keys for the group, few efforts have been undertaken to decipher relationships within this arachnid lineage. Neither the monophyly of the family, nor its exact placement in the harvestman phylogeny, have been established. Here, we assessed the internal phylogeny of Assamiidae using a ten-locus Sanger dataset, sampling key lineages putatively ascribed to this family for five of the ten markers. Our analyses recovered Assamiidae as a monophyletic group, in a clade with the primarily Afrotropical Pyramidopidae and the southeast Asian Beloniscidae. Internal relationships of assamiids disfavored the systematic validity of subfamilies, with biogeography reflecting much better phylogenetic structure than the existing higher-level taxonomy. To assess whether the Asian assamiids came to occupy Indo-Pacific terranes via rafting on the Indian subcontinent, we performed divergence dating to infer the age of the family. Our results show that Indo-Pacific clades are ancient, originating well before the Cretaceous and therefore predate a vicariant mechanism commonly encountered for Paleotropical taxa.
... These approaches recently used for other Gondwanan harvestman families, including transcriptomics for Pettalidae (Baker et al. 2020a) and ultraconserved elements for Triaenonychidae (Derkarabetian et al. 2021b), have elucidated complex biogeographical patterns (see Derkarabetian et al. 2021a) that had not been satisfactorily resolved with Sanger-based approaches (i.e. Giribet et al. 2016;Baker et al. 2020b). Our phylogenetic knowledge of Neopilionidae also remains frustratingly incomplete given the contrasting results of morphological phylogenetic analyses (Hunt and Cokendolpher 1991;Taylor 2011Taylor , 2013a) and our molecular results (see also Vélez et al. 2014). ...
The Opiliones family Neopilionidae is restricted to the terranes of the former temperate Gondwana: South America, Africa, Australia, New Caledonia and New Zealand. Despite decades of morphological study of this unique fauna, it has been difficult reconciling the classic species of the group (some described over a century ago) with recent cladistic morphological work and previous molecular work. Here we attempted to investigate the pattern and timing of diversification of Neopilionidae by sampling across the distribution range of the family and sequencing three markers commonly used in Sanger-based approaches (18S rRNA, 28S rRNA and cytochrome-c oxidase subunit I). We recovered a well-supported and stable clade including Ballarra (an Australian ballarrine) and the Enantiobuninae from South America, Australia, New Caledonia and New Zealand, but excluding Vibone (a ballarrine from South Africa). We further found a division between West and East Gondwana, with the South American Thrasychirus/Thrasychiroides always being sister group to an Australian–Zealandian (i.e. Australia + New Zealand + New Caledonia) clade. Resolution of the Australian–Zealandian taxa was analysis-dependent, but some analyses found Martensopsalis, from New Caledonia, as the sister group to an Australian–New Zealand clade. Likewise, the species from New Zealand formed a clade in some analyses, but Mangatangi often came out as a separate lineage from the remaining species. However, the Australian taxa never constituted a monophyletic group, with Ballarra always segregating from the remaining Australian species, which in turn constituted 1–3 clades, depending on the analysis. Our results identify several generic inconsistencies, including the possibility of Thrasychiroides nested within Thrasychirus, Forsteropsalis being paraphyletic with respect to Pantopsalis, and multiple lineages of Megalopsalis in Australia. In addition, the New Zealand Megalopsalis need generic reassignment: Megalopsalis triascuta will require its own genus and M. turneri is here transferred to Forsteropsalis, as Forsteropsalis turneri (Marples, 1944), comb. nov.
... Most triaenonychid diversity is found in the Southern Hemisphere, across South America, southern Africa, Madagascar, Australia, and New Zealand (Fig. 2). This geographic pattern reflects a classic temperate Gondwanan distribution, inviting biogeographic comparisons to other groups such as Pettalidae Shear, 1980 (Opiliones) (Shear 1980;Boyer and Giribet 2007;Giribet et al. 2016;Baker et al. 2020), Neopilionidae Lawrence, 1931 (Opiliones) (Taylor 2011;Vélez et al. 2014), Peripatopsidae Bouvier, 1907 (Murienne et al. 2014;Giribet et al. 2018), Orsolobidae Cooke, 1965 (Araneae) (Chousou-Polydouri et al. 2019), and Bothriuridae Simon, 1880 (Scorpiones) (Sharma et al. 2018). However, along with its temperate Gondwanan members, the family also contains monotypic genera in eastern North America (Fumontana deprehendor Shear, 1977 (Thomas andHedin 2008)), and Sardinia (Buemarinoa patrizii Roewer, 1956 (see Karaman 2019)), a species from the oceanic Crozet Islands in the Southern Ocean (Promecostethus unifalculatus Enderlein, 1909), and two species from Grande Terre in New Caledonia (Triconobunus horridus Roewer, 1914 andDiaenobunus armatus Roewer, 1915). ...
Triaenonychidae Sørensen in L. Koch, 1886 is a large family of Opiliones with ~480 described species broadly distributed across temperate forests in the Southern Hemisphere. However, it remains poorly understood taxonomically, as no comprehensive phylogenetic work has ever been undertaken. In this study we capitalise on samples largely collected by us during the last two decades and use Sanger DNA-sequencing techniques to produce a large phylogenetic tree with 300 triaenonychid terminals representing nearly 50% of triaenonychid genera and including representatives from all the major geographic areas from which they are known. Phylogenetic analyses using maximum likelihood and Bayesian inference methods recover the family as diphyletic, placing Lomanella Pocock, 1903 as the sister group to the New Zealand endemic family Synthetonychiidae Forster, 1954. With the exception of the Laurasian representatives of the family, all landmasses contain non-monophyletic assemblages of taxa. To determine whether this non-monophyly was the result of Gondwanan vicariance, ancient cladogenesis due to habitat regionalisation, or more recent over-water dispersal, we inferred divergence times. We found that most divergence times between landmasses predate Gondwanan breakup, though there has been at least one instance of transoceanic dispersal – to New Caledonia. In all, we identify multiple places in the phylogeny where taxonomic revision is needed, and transfer Lomanella outside of Triaenonychidae in order to maintain monophyly of the family.
... All previously analysed species have considerably limited dispersal abilities, which has resulted in distinct genetic differentiation (e.g. Giribet et al., 2016) and most likely in rapid changes in the distribution of NORs. FISH, using the 5S rDNA probe, revealed that in the harvestman Psathyropus tenuipes L. Koch, 1878 (Eupnoi: Sclerosomatidae) there is only one pair of this minor cluster of the rRNA gene (Watanabe et al., 2009). ...
rDNA clusters are an important cytogenetic marker for studying karyotype evolution and chromosomal changes. The variability of this cytogenetic characteristic is, however, still almost unknown in the karyotypes of the entire class Arachnida (Arthropoda: Chelicerata). This situation is particularly evident in harvestmen (Arachnida: Opiliones), with 97 species studied cytogenetically, for which there is information on the number and position of rDNA clusters for only 13. Moreover, previous studies indicate that the number of rDNA loci is highly variable in the species analysed, ranging from one to five pairs of rDNA clusters. Based on this fragmentary information, which is for rare species mainly from the limits of the distribution of their families, it is still not possible to reconstruct the ancestral state for this important cytogenetic feature in this order. Building upon recent research in Central Europe, we analysed the number and position of 18S rDNA in 13 species belonging to the suborder Eupnoi. This revealed that their karyotypes were variable in terms of the diploid number (2n = 16-36) and number of 18S rDNA clusters (from one to seven pairs). For the first time, an 18S rDNA cluster was detected on B chromosomes in harvestmen. Our study sheds new light on the karyotype evolution and 18S rDNA distribution in harvestmen and provides an improved understanding of the ancestral state of karyotypes in the order Opiliones.
... Queensland Giribet et al., 2016;Oberski et al., 2018), and Stylocellidae is found across Southeast Asia (Clouse & Giribet, 2010 Not all purported paleoendemics may be so. Additional examination of results may be required for some published phylogenies. ...
We discuss the fauna of New Caledonia in the context of the prolonged submergence of Grande Terre until its re‐emergence around 37 million years ago and whether the resulting fauna can be entirely explained by over‐water dispersal. The current literature discussing the predominant neoendemism in New Caledonia is reviewed, questioning some of the discourse about how the fact that most animal and plant lineages are neoendemics should weigh in to disregard the fewer cases of paleoendemism (clades that have persisted and diversified in New Caledonia for over 37 million years). We argue that many of the examples used in the literature, selected for other purposes, were not chosen to test this particular hypothesis, but several old lineages of non‐vagile animals show that a non‐trivial number of clades have a history that predates the supposed emergence of New Caledonia. We conclude by posing the question of how much additional evidence should be needed to demonstrate a discordance between the geological history of the archipelago and the evolutionary history of its biota.
... found west of the Nullarbor Plain is P. melania, which suggests a degree of isolation by the Nullarbor. This desert area is a known barrier to dispersal between temperate south-western and eastern Australia leading to endemicity in arachnids (Rix & Harvey, 2012;Giribet et al., 2016;Harvey et al., 2017;Rix et al., 2017) and other taxa (Barendse, 1984;Cracraft, 1986;Hopper & Gioia, 2004;Morgan, Roberts & Keogh, 2007;Schultz et al., 2009;Heads, 2013;Rix et al., 2015). Based on the models of historical biogeography tested in Rix et al. (2015), some species may be susceptible to a form of east-west vicariance, but others (the above taxa) are more able to reliably cross. ...
We revise and monograph the Australasian clade of the araneid subfamily Zygiellinae F.O. Pickard-Cambridge.
Several members of this clade construct conspicuous leaf retreats at the hub of their webs. We gathered and analyzed
a matrix of 95 taxa of zygiellines and close relatives with sequence data from six genetic markers (12S rRNA,
16S rRNA, 18S rRNA, 28S rRNA, cytochrome oxidase c subunit I, and histone H3), in addition to 235 morphological
and behavioral characters. Analyses conducted using parsimony, maximum likelihood, and Bayesian methods indicate
that Phonognatha Simon is paraphyletic as currently circumscribed, which we accommodate by erecting the
genus Artifex gen. nov. Our analyses support Zygiellinae as the earliest diverging araneid subfamily. Biogeographic
analyses using BioGeoBEARS support multiple colonizations of zygiellines to New Caledonia from Australia, congruent
with the island’s geology. Furthermore, analysis of the retreat types show using leaf retreats integrated with
the hub to have arisen at least three times independently. We describe one new species, Phonognatha tanyodon sp.
nov., redescribe three species of Phonognatha, three species of Deliochus Simon, and two species of Artifex gen. nov.
Three species of Araneus Clerck and Phonognatha are synonymized with these taxa, and four species are misplaced
in Zygiellinae.
... Furthermore, in addition to the inclusion of taxa, the use of supplementary genetic markers (such as the commonly used markers 18S, 28S or Actin 5C) that have been shown to be phylogenetically informative at different taxonomic levels in studies on arachnid systematics (e.g. Hormiga, Arnedo & Gillespie, 2003;Hedin & Bond, 2006;Maddison & Needham, 2006;Rix, Harvey & Roberts, 2008;Spagna & Gillespie, 2008;Vink et al., 2008;Giribet et al., 2010Giribet et al., , 2016Miller et al., 2010;Bodner & Maddison, 2012;Hedin et al., 2012;de Busschere et al., 2014;Polotow et al., 2015), would be of great utility to solve, in a global assessment, the 'Ctenus problem'. ...
Recent missions to Mount Nimba in West Africa led to the discovery of remarkable new ctenid morphospecies. Using both morphological and molecular data, we phylogenetically analysed 41 ctenid exemplars, 33 of which originate from Mt. Nimba. Partial fragments of two mitochondrial markers and one nuclear marker (COI, 16S and H3, respectively) were amplified and sequenced for the molecular analyses. The morphological analysis was updated from an earlier one. Our results reveal that Mt. Nimba harbours at least 22 species, and is the most species-rich area for ctenids in West Africa. Using both molecular and morphological data, five new genera are created to accommodate the many species that are misplaced in the genus Ctenus. Eight species new to science are described: Amicactenus mysticus gen. nov., sp. nov.; Macroctenus herbicola gen. nov., sp. nov.; Macroctenus nimba gen. nov., sp. nov.; Macroctenus vandenspiegeli gen. nov., sp. nov.; Nimbanahita montivaga gen. nov., sp. nov.; Perictenus molecula gen. nov., sp. nov.; Piloctenus haematostoma gen. nov., sp. nov.; and Piloctenus gryseelsi gen. nov., sp. nov. The following taxonomic changes are proposed: Ctenus eminens, C. pergulanus Arts, 1912 and C. fallax Steyn & Van der Donckt, 2003 are transferred to Amicactenus gen. nov.; C. kingsleyi and C. occidentalis F. O. Pickard-Cambridge, 1898 are transferred to Macroctenus gen. nov.; C. mirificus Arts, 1912 and C. pilosus Thorell, 1899 are transferred to Piloctenus gen. nov.
South America is the fourth largest continent on the planet; its birds, mammals, and amphibian's biodiversity is relatively well known, but no outright assessment of the continent spider (Araneae) fauna has been done to date. From January 2019 to August 2020, a recompilation of all spider species registered to occur in South America was conducted based on the data available from the World Spider Catalog [2020. Version 18.5. Natural History Museum Bern. [cited Jan 2019–Aug 2020]]. The assessment revealed that the South American spider fauna comprises 83 families, 1018 genera, and 8302 species, representing 17% of the world spider fauna biodiversity; however, 94% of the spider-specific biodiversity is found nowhere else on earth. A total of 78 species have been introduced in South America, while 30 species were exported from the South American continent to other parts of the world. For all South American families, an overview of the current knowledge is presented: distribution, endemism, taxonomical inconsistency, and problems are discussed. The complete checklist of spiders occurring in SA with distribution given by countries and the complete list of introduced and exported species with details of their native region and current known distribution are presented.
Despite advances in biodiversity exploration, the origins of Sri Lanka's fauna and flora have never yet been treated in a synthetic work. This book draws together the threads that make up that fascinating 100-million year story. Encompassing the island's entire biota while emphasising the ecology, biogeography and phylogeography of freshwater fishes, it provides a comprehensive context for understanding how the island's plants and animals came to be as they are. The 258-page text contains more than 200 figures, photographs and maps. It provides a clear account of how, when and from where the ancestors of the plants and animals that now inhabit Sri Lanka came. For the first time, the island's unique biodiversity can be understood and appreciated in its historical and evolutionary context in this invaluable sourcebook, designed for scientists, students and biodiversity enthusiasts alike.
One new species of Pallisentis Van Cleave, 1928 is described from Channa punctatus (Bloch) from Gomti River (tributary of the Ganga River), in Uttar Pradesh, Lucknow district, India. Pallisentis thapari n. sp. is characterized morphologically by individuals having a globular proboscis armed with rooted hooks in 4 circles of 8–10 hooks each, the first circle more than 100 long and hooks gradually declining in size posteriorly. The trunk is cylindrical, with collar spines comprised of 15–17 complete circles of spines, each ring with 12–22 spines. As common in members of the genus, a narrow spine-free zone lies in between the rings of collar and trunk spines. Field of spines extends posteriorly to half of the body length, ending above the level of testes in males and slightly past mid-body in females; trunk spines have an optically-dense Y-shaped core. The trunk is only slightly wider at the anterior end. The syncytial cement gland of males contained 23–30 nuclei. Individuals of Channa striatus Bloch from the same locality also were infected with the new species. A second species of Acanthocephala, Acanthosentis seenghalae Chowhan, Gupta, Khera, 1988, was found as a parasite of Puntius sophore (Hamilton) from the same locality. The proboscis is short, globular, with 3 circles of hooks each circle bearing 6 hooks. The trunk is broad in the middle and tapered at both ends, with the posterior end narrower than the anterior end. Twelve to 16 circles of spines, each with 21–40 spines, extend from anterior end to just past mid-body in males and only to mid-body in females. The syncytial cement gland of males contains 6–10 nuclei. The analysis of 18s rDNA identified two clades of a monophyletic Pallisentis and placed the isolate of P. thapari n. sp. within that clade; previously established subgenera were not supported by the results of the analysis.
Although our inventory of Earth’s biodiversity remains incomplete, we still require analyses using the Tree of Life to understand evolutionary and ecological patterns. Because incomplete sampling may bias our inferences, we must evaluate how future additions of newly discovered species might impact analyses performed today. We describe an approach that uses taxonomic history and phylogenetic trees to characterize the impact of past species discoveries on phylogenetic knowledge using patterns of branch-length variation, tree shape, and phylogenetic diversity. This provides a framework for assessing the relative completeness of taxonomic knowledge of lineages within a phylogeny. To demonstrate this approach, we use recent large phylogenies for amphibians, reptiles, flowering plants, and invertebrates. Well-known clades exhibit a decline in the mean and range of branch lengths that are added each year as new species are described. With increased taxonomic knowledge over time, deep lineages of well-known clades become known such that most recently described new species are added close to the tips of the tree, reflecting changing tree shape over the course of taxonomic history. The same analyses reveal other clades to be candidates for future discoveries that could dramatically impact our phylogenetic knowledge. Our work reveals that species are often added non-randomly to the phylogeny over multiyear time-scales in a predictable pattern of taxonomic maturation. Our results suggest that we can make informed predictions about how new species will be added across the phylogeny of a given clade, thus providing a framework for accommodating unsampled undescribed species in evolutionary analyses.
This chapter deals with the diversity of terrestrial cave invertebrates from the viewpoint of its contribution to global diversity and of the variety of morphological traits and life forms associated with cave habitats. We stress the low diversity of cave compared to non-cave fauna, its uneven taxonomic and geographic distribution, differences in its composition between temperate and tropical bioclimates, and its high originality, due to its richness in endemics, in large radiations and in relictual species. The main morphological traits linked to subterranean life as well as their relevance as markers of troglomorphy are discussed. Life forms classically used for describing morphological features of cave organisms are redefined in a larger context. The diversity patterns of the different subterranean groups are summarized in turn in the same perspective, with a focus on the magnitude of their taxonomic richness, of recent progress in their knowledge, and on life forms.
The Philippine archipelago harbours a remarkable diversity of harvestmen, with respect to both taxonomy and complexity of biogeographic origins. Among the armoured harvestmen (suborder Laniatores), six families of distantly related groups occur in this archipelago. Here, we describe a new species of the family Tithaeidae, Tithaeus odysseus sp. nov., discovered during a collecting campaign on the island of Mindanao. The description of this species expands the known distribution of the family and demonstrates another exception to the zoogeographic boundary known as Huxley’s Line which putatively separates the biota of the Philippines (excluding the Palawan island group) from the Sunda Shelf biota. Given the coincident distributions of Tithaeidae and the mite harvestman family Stylocellidae (Cyphophthalmi), a group renowned for its poor dispersal ability, we inferred phylogenetic relationships and divergence times of the Philippines lineages of both families by using a comprehensive molecular dating analysis of all Opiliones. The internal phylogeny of Tithaeidae mirrored the biogeography of Philippine Stylocellidae, showing a close affinity between the Philippine and Bornean species. Molecular dating showed contemporaneous colonisation of Mindanao by both families in the Cretaceous. We infer these patterns to reflect faunal connections between the southern Philippines and Borneo via the Zamboanga Peninsula. To render the genus Tithaeus monophyletic, we synonymise Metatithaeus with Tithaeus (new synonymy).
Onychophorans, or velvet worms, are cryptic but extremely charismatic terrestrial invertebrates that have often been the subject of interesting biogeographic debate. Despite great interest, a well resolved and complete phylogeny of the group and a reliable chronogram have been elusive due to their broad geographic distribution, paucity of samples, and challenging molecular composition. Here we present a molecular phylogenetic analysis of Onychophora that includes previously unsampled and undersampled lineages and we analyse the expanded dataset using a series of nested taxon sets designed to increase the amount of information available for particular subclades. These include a dataset with outgroups, one restricted to the ingroup taxa, and three others for Peripatopsidae, Peripatidae and Neopatida (= the Neotropical Peripatidae). To explore competing biogeographic scenarios we generate a new time tree for Onychophora using the few available reliable fossils as calibration points. Comparing our results to those of Cyphophthalmi, we reconsider the hypothesis that velvet worms reached Southeast Asia via Eurogondwana, and conclude that a more likely scenario is that they reached Southeast Asia by rafting on the Sibumasu terrane. Our phylogenetic results support the reciprocal monophyly of both families as well as an early division between East and West Gondwana, also in both families, each beginning to diversify between the Permian and the Jurassic. Peripatopsidae clearly supports paraphyly of South Africa with respect to southern South America (Chile) and a sister group relationship of the Southeast Asian/New Guinean Paraperipatus to the Australian/New Zealand taxa. The latter includes a clade that divides between Western Australia and Eastern Australia and two sister clades of trans-Tasman species (one oviparous and one viviparous). This pattern clearly shows that oviparity is secondarily derived in velvet worms. Peripatidae finds a sister group relationship between the Southeast Asian Eoperipatus and the West Gondwanan clade, which divides into the African Mesoperipatus and Neopatida. The latter shows a well supported split between the Pacific Oroperipatus (although it is unclear whether they form one or two clades) and a sister clade that includes the members of the genera Peripatus, Epiperipatus, Macroperipatus and representatives of the monotypic genera Cerradopatus, Plicatoperipatus and Principapillatus. However, Peripatus, Epiperipatus and Macroperipatus are not monophyletic, and all the species from the monotypic genera are related to geographically close species. The same goes for the type species of Macroperipatus (from Trinidad, and sister group to other Trinidad and Tobago species of Epiperipatus) and Epiperipatus (from French Guiana, and related to other Guyana shield species of Epiperipatus and Peripatus). Geographic structure within Neopatida is largely obscured by an unresolved backbone, but many well supported instances of generic non-monophyly challenge the current taxonomic framework, which has often relied on anatomical characters that are untested phylogenetically.
Review of all orders with maps of their geographical distribution.
Using the complementary approaches of morphological and molecular taxonomy is essential to further our understanding of invertebrate diversity, including the identification of cryptic species. Although the species classification of a widespread group of arachnids, the pseudoscorpions, has been based on traditional diagnostic characters for a long time, recent taxonomic studies have suggested that some of these are unreliable for distinguishing species. Thus, the application of molecular taxonomy may be particularly useful in this group. Here, we performed molecular phylogenetic analyses and species delimitation analyses based on partial sequences of mitochondrial DNA cytochrome c oxidase I and nuclear DNA 18S rRNA genes to assess the taxonomy of species and the reliability of morphological characteristics for distinguishing species in the Japanese soil-dwelling genus Mundochthonius (Chthoniidae). Our results revealed the existence of seven major genetic clades, likely corresponding to three described species and four cryptic species. Although two described species, M. kiyoshii and M. itohi, were represented by single clades in the phylogenetic analysis, a third, M. japonicus, was composed of multiple clades, highlighting inconsistencies between phylogenetic relationships and current species classifications using traditional morphological diagnostics. This study exemplifies the need for further exploration of pseudoscorpion taxonomy and species diversity. In particular, detailed morphological examinations are expected to help determine differences among cryptic species.
Sironidae, the first described family of Cyphophthalmi, is among the least understood phylogenetically. After examining recent collections across their distribution range, we provide the first comprehensive treatment of Sironidae by including molecular data from most of the known species, and all genera except for the monotypic Odontosiro Juberthie, 1961. We also revisit the male genitalic morphology for most genera by using confocal laser scanning microscopy and provide descriptions of five new species belonging to Iberosiro de Bivort & Giribet, 2004 (monotypic until now), Paramiopsalis Juberthie, 1962 and Siro Latreille, 1802. While the monophyly of Sironidae remains poorly supported using traditional Sanger-based markers, with the Mediterranean Parasiro Hansen & Sørensen, 1904 and the Japanese Suzukielus Juberthie, 1970b sometimes branching basally with respect to the other sironids, the remaining genera form a well-supported Laurentian/Laurasian clade. This group divides into a Western European/North American clade of Siro and the remaining genera, Iberosiro, Paramiopsalis and Cyphophthalmus Joseph, 1868. Iberosiro and Paramiopsalis form a well-supported clade from the NW corner of the Iberian Peninsula, while Cyphophthalmus is widespread in the Balkan region and Eastern Mediterranean. Finally, the following new taxa are described: Iberosiro rosae Giribet, Merino-Sáinz & Benavides, sp. nov., Paramiopsalis anadonae Giribet, Merino-Sáinz & Benavides, sp. nov., Paramiopsalis ramblae Benavides & Giribet, sp. nov., Siro ligiae Giribet, sp. nov., and Siro richarti Benavides & Giribet, sp. nov.
The genus Karripurcellia is redefined morpho-anatomically.A tripartite sensorial organ on male tarsus IV is described for the first time. A new genus, Milipurcellia n. gen., is established based on Karripurcellia sierwaldae Giribet, 2003. The species Karripurcellia harveyi Giribet, 2003 is synonymised with Karripurcellia peckorum Giribet, 2003, since characters used in species descriptions were found to be preservation artifacts and misinterpretations. Relationships between the two Southwest australian genera within pettalidae are discussed. The superficial approach to pettalidae taxonomy in the present literature is discussed.
Next-generation sequencing technologies are rapidly transforming molecular systematic studies of non-model animal taxa. The arachnid order Opiliones (commonly known as “harvestmen”) includes more than 6,400 described species placed into four well-supported lineages (suborders). Fossil plus molecular clock evidence indicates that these lineages were diverging in the late Silurian to mid-Carboniferous, with some fossil harvestmen representing the earliest known land animals. Perhaps because of this ancient divergence, phylogenetic resolution of subordinal interrelationships within Opiliones has been difficult. We present the first phylogenomics analysis for harvestmen, derived from comparative RNA-Seq data for eight species representing all suborders. Over 30 gigabases of original Illumina short-read data were used in de novo assemblies, resulting in 50–80,000 transcripts per taxon. Transcripts were compared to published scorpion and tick genomics data, and a stringent filtering process was used to identify over 350 putatively single-copy, orthologous protein-coding genes shared among taxa. Phylogenetic analyses using various partitioning strategies, data coding schemes, and analytical methods overwhelmingly support the “classical” hypothesis of Opiliones relationships, including the higher-level clades Palpatores and Phalangida. Relaxed molecular clock analyses using multiple alternative fossil calibration strategies corroborate ancient divergences within Opiliones that are possibly deeper than the recorded fossil record indicates. The assembled data matrices, comprising genes that are conserved, highly expressed, and varying in length and phylogenetic informativeness, represent an important resource for future molecular systematic studies of Opiliones and other arachnid groups.
Aim
We tested the hypothesis that areas that acted as historical refugia during restrictive climate regimes currently harbour higher levels of biodiversity than areas that lacked refugia.
Location
The rain forests of Australia's Wet Tropics, the largest remaining fragments of the humid forest habitats that once covered the Australian continent.
Methods
We generated a model of climatic suitability for arachnids in the genus Austropurcellia, a group of small, dispersal‐limited mite harvestmen that are found throughout the Wet Tropics. We then projected this model onto palaeoclimate data layers from time slices going back to the Last Glacial Maximum and summed suitability over time to arrive at a measure of stability. We compared the power of metrics of present and past climatic suitability and stability to predict diversity (species richness and phylogenetic diversity) across subregions of the Wet Tropics.
Results
We found statistically significant correlations between measures of diversity (species richness and phylogenetic diversity) and present climatic suitability, LGM climatic suitability and our stability metric across subregions of the Wet Tropics. Although stability lost predictive power when analyses were corrected for spatial autocorrelation, and present‐day mean climatic suitability lost predictive power when corrected for spatial autocorrelation under one of our geographical binning schemes, mean climatic suitability during the Last Glacial Maximum had a positive and significant relationship to both number of species and phylogenetic diversity in all analyses.
Main Conclusions
Our results support a model of biodiversity preservation within historical refugia, resulting in higher present‐day diversity in refugial areas than in non‐refugial areas. Although previous studies of the Wet Tropics biota have demonstrated a relationship between habitat stability and diversity, ours is the first such study to consider phylogenetic diversity in addition to number of species.
Because sequence information is now available for the 648bp barcode region of cytochrome c oxidase 1 (COI) from more than 400,000 animal species, this gene segment can be used to probe patterns of mitochondrial evolution. The present study examines levels of amino acid substitution and the frequency of indels in COI from 4177 species of arachnids, including representatives from all 16 orders and 43% of its families (267/625). It examines divergences at three taxonomic levels-among members of each order to an outgroup, among families in each order and among BINs, a species proxy, in each family. Order Distances vary fourfold (0.10-0.39), while the mean of the Family Distances for the ten orders ranges fivefold (0.07-0.35). BIN Distances show great variation, ranging from 0.01 or less in 12 families to more than 0.25 in eight families. Patterns of amino acid substitution in COI are generally congruent with previously reported variation in nucleotide substitution rates in arachnids, but provide some new insights, such as clear rate acceleration in the Opiliones. By revealing a strong association between elevated rates of nucleotide and amino acid substitution, this study builds evidence for the selective importance of the rate variation among arachnid lineages. Moreover, it establishes that groups whose COI genes have elevated levels of amino acid substitution also regularly possess indels, a dramatic form of protein reconfiguration. Overall, this study suggests that the mitochondrial genome of some arachnid groups is dynamic with high rates of amino acid substitution and frequent indels, while it is 'locked down' in others. Dynamic genomes are most prevalent in arachnids with short generation times, but the possible impact of breeding system deserves investigation since many of the rapidly evolving lineages reproduce by haplodiploidy, a mode of reproduction absent in 'locked down' taxa.
We report the recent collection and observation of large numbers of specimens of the troglobitic harvestman Speleosiro argasiformis Lawrence 1931 in the Wynberg Cave system, Table Mountain, South Africa. Specimens were collected and/or photographed in different caves of the system. Live observation showed specimens fleeing bat carcasses when disturbed.
The Wet Tropics of Queensland, Australia, represent the largest remaining fragment of vast rainforests that once covered the entire continent. Over the past few decades the Wet Tropics bioregion has received much attention from biologists interested in the effect of climate change on diversity and distribution of rainforest animals. However, most such studies have focused on vertebrates, and despite considerable interest in the biota of the area, the diversity of many of Wet Tropics invertebrate taxa remains poorly known. Here we describe six new species of mite harvestman from the area, identified using a combination of morphological and molecular data. Our study represents the first detailed phylogenetic study of the genus Austropurcellia, and provides insight into the historical biogeography of these dispersal-limited arachnids.
The genus Cyphophthalmus is one of the most diverse genera of Cyphophthalmi and has been used as a model to study diversification in the Balkan region. However, the taxonomy of the group is deficient and type material is not available for study. Here we describe a new species, Cyphophthalmus solentiensis sp. nov., from the coastal region of Croatia using state-of-the-art techniques for illustrating species of Cyphophthalmi. The species, phylogenetically close to C. gjorgjevici on the basis of a molecular data analysis of four markers, is illustrated by means of stereomicroscopy and scanning electron microscopy, and the genitalia are imaged using confocal laser microscopy and three-dimensional reconstruction techniques, allowing unparalleled visualization of Opiliones genitalia. We hope that this description stimulates research in this diverse but still obscure genus of Cyphophthalmi.
Despite the unique and interesting nature of New Zealand's Opiliones fauna, little work on these animals has been published since the studies of Forster, whose last harvestman publication appeared nearly half a century ago. Since then, most groups of New Zealand Opiliones have been neglected. Here we provide field observations and live photographs of four poorly known species, one for each of the four Opiliones suborders. We also redescribe Rakaia collaris Roewer, 1942, a species of Cyphophthalmi described on the basis of a single female specimen, and considered a nomen dubium in previous studies. The objective of this study is to highlight the incredible New Zealand opiliofauna and to raise interest in this group of terrestrial arthropods commonly used for biogeographical and evolutionary studies.
Aoraki denticulata, a widespread mite harvestman endemic to the NW South Island of New Zealand, was postulated to constitute an old lineage with deep genetic history. Expanding on previous studies, we explored its genetic diversity and population structure, phylogeography and diversification patterns. We also examined the systematic implications of such a complex scenario through species delimitation analyses under coalescent-based and barcoding gap discovery methodologies. Our results depict the deep evolutionary history of the A. denticulata lineage, which shows high geographic structure and low genetic connectivity among modern populations. Aoraki denticulata is further subdivided into three lineages: a lineage presently inhabiting the northern region of the Southern Alps (and including the subspecies A. d. major), a second lineage in the north-eastern part of the sampled land, and a third one occupying the south-eastern localities. When using species delimitation methods based on coalescence approaches, large numbers of cryptic species were estimated. Based on morphological and biological evidence, we thus argue that these methods may overestimate species in cases in which genetic divergence is unusually large and discuss the systematic implications of our findings.
Members of the New Zealand Enantiobuninae constitute some of the most charismatic soil arthropods of the archipelago, and a striking example of sexual dimorphism, with nondescript females but colourful males boasting exaggerated chelicerae many times longer than their bodies. The genera Forsteropsalis and Pantopsalis recently underwent revision, but many questions remained about the validity of species designations owing to historical issues of characters of dubious taxonomic value, female specimens designated as holotypes despite the males holding all the diagnostic characters, and the suspected presence of more than one male form within some species. We present the first phylogeny based on molecular data for the New Zealand species in the genera Forsteropsalis, Pantopsalis and Mangatangi, and comment on the taxonomic implications of our results, including the diagnostic viability of important morphological characters. Our analyses reject the monophyly of Neopilionidae and Forsteropsalis, but support the monophyly of Pantopsalis. Finally, we comment on the taxonomic implications of the results, including the diagnostic validity of morphological characters traditionally used on the groups.
Palpigradi are a poorly understood group of delicate arachnids, often found in caves or other subterranean habitats. Concomitantly, they have been neglected from a phylogenetic point of view. Here we present the first molecular phylogeny of palpigrades based on specimens collected in different subterranean habitats, both endogean (soil) and hypogean (caves), from Australia, Africa, Europe, South America and North America. Analyses of two nuclear ribosomal genes and COI under an array of methods and homology schemes found monophyly of Palpigradi, Eukoeneniidae and a division of Eukoeneniidae into four main clades, three of which include samples from multiple continents. This supports either ancient vicariance or long-range dispersal, two alternatives we cannot distinguish with the data at hand. In addition, we show that our results are robust to homology scheme and analytical method, encouraging further use of the markers employed in this study to continue drawing a broader picture of palpigrade relationships.
The south-western land division of Western Australia (SWWA), bordering the temperate Southern and Indian Oceans, is the only global biodiversity hotspot recognised in Australia. Renowned for its extraordinary diversity of endemic plants, and for some of the largest and most botanically significant temperate heathlands and woodlands on Earth, SWWA has long fascinated biogeographers. Its flat, highly weathered topography and the apparent absence of major geographic factors usually implicated in biotic diversification have challenged attempts to explain patterns of biogeography and mechanisms of speciation in the region. Botanical studies have always been central to understanding the biodiversity values of SWWA, although surprisingly few quantitative botanical analyses have allowed for an understanding of historical biogeographic processes in both space and time. Faunistic studies, by contrast, have played little or no role in defining hotspot concepts, despite several decades of accumulating quantitative research on the phylogeny and phylogeography of multiple lineages. In this review we critically analyse datasets with explicit supporting phylogenetic data and estimates of the time since divergence for all available elements of the terrestrial fauna, and compare these datasets to those available for plants. In situ speciation has played more of a role in shaping the south-western Australian fauna than has long been supposed, and has occurred in numerous endemic lineages of freshwater fish, frogs, reptiles, snails and less-vagile arthropods. By contrast, relatively low levels of endemism are found in birds, mammals and highly dispersive insects, and in situ speciation has played a negligible role in generating local endemism in birds and mammals. Quantitative studies provide evidence for at least four mechanisms driving patterns of endemism in south-western Australian animals, including: (i) relictualism of ancient Gondwanan or Pangaean taxa in the High Rainfall Province; (ii) vicariant isolation of lineages west of the Nullarbor divide; (iii) in situ speciation; and (iv) recent population subdivision. From dated quantitative studies we derive four testable models of historical biogeography for animal taxa in SWWA, each explicit in providing a spatial, temporal and topological perspective on patterns of speciation or divergence. For each model we also propose candidate lineages that may be worthy of further study, given what we know of their taxonomy, distributions or relationships. These models formalise four of the strongest patterns seen in many animal taxa from SWWA, although other models are clearly required to explain particular, idiosyncratic patterns. Generating numerous new datasets for suites of co-occurring lineages in SWWA will help refine our understanding of the historical biogeography of the region, highlight gaps in our knowledge, and allow us to derive general postulates from quantitative (rather than qualitative) results. For animals, this process has now begun in earnest, as has the process of taxonomically documenting many of the more diverse invertebrate lineages. The latter remains central to any attempt to appreciate holistically biogeographic patterns and processes in SWWA, and molecular phylogenetic studies should – where possible – also lead to tangible taxonomic outcomes.
Dating the Opiliones tree of life has become an important enterprise for this group of arthropods, due to their ancient origins and important biogeographic implications. To incorporate both methodological innovations in molecular dating as well as new systematic discoveries of harvestman diversity, we conducted total evidence dating on a data set uniting morphological and/or molecular sequence data for 47 Opiliones species, including all four well-known Palaeozoic fossils, to test the placement of both fossils and newly discovered lineages in a single analysis. Furthermore, we investigated node dating with a phylogenomic data set of 24,202 amino acid sites for 14 species of Opiliones, sampling all extant suborders. In this way, we approached molecular dating of basal harvestman phylogeny using different data sets and approaches to assess congruence of divergence time estimates. In spite of the markedly different composition of data sets, our results show congruence across all analyses for age estimates of basal nodes that are well constrained with respect to fossil calibrations (e.g., Opiliones, Palpatores). By contrast, derived nodes that lack fossil calibrations (e.g., the suborders Cyphophthalmi, and Laniatores) have large uncertainty intervals in diversification times, particularly in the total evidence dating analysis, reflecting the dearth of calibration points and undersampling of derived lineages. Total evidence dating consistently produced older median ages than node dating for ingroup nodes, due to the nested placement of multiple Palaeozoic fossils. Our analyses support basal diversification of Opiliones in the Ordovician-Devonian period, corroborating the inferred ancient origins of this arthropod order, and underscore the importance of diversity discovery—both paleontological and neontological—in evolutionary inference.
New species of mite harvestmen from southeast Queensland, Australia greatly extend the known distribution of the genus Austropurcellia (Arachnida, Abstract Austropurcellia Juberthie 1988 is a genus of mite harvestmen previously known from numerous localities in the Wet Trop-ics of northern Queensland and from one locality in central Queensland, Australia. As a result of the current study, the genus is now also known from localities in far southeast Queensland. We describe three new species of Austropurcellia from museum lots: A. acuta sp. nov., A. barbata sp. nov., and A. superbensis sp. nov. Each new species is known from only one to two localities, and from very few specimens. In addition, we describe a pair of previously overlooked dorsal anterior cuticular structures that may be sensory in nature and are found in all Austropurcellia specimens examined, in-cluding both new and previously described species. We present a new distribution map of Austropurcellia, greatly expand-ing its known range to almost the entire east coast of Queensland, and discuss the biogeography of the genus.
The cyphophthalmid family Pettalidae in South Africa is revised and seven new species are described from museum material collected between 1939 and 1985. Two of these are placed in the genus Purcellia and five in Parapurcellia, bringing the total number of described South African cyphophthalmids to 15. In addition, Purcellia peregrinator is transferred to the genus Parapurcellia. Phylogenetic analyses of discrete morphological and continuous morphometric characters, both separately and in combination, support the generic assignments and contribute towards a more detailed understanding of the systematics of the group in South Africa. In order to assess the stability of our phylogenetic results, the different morphological datasets were analysed under equal and implied weighting, as well as under several weighting schemes that varied the respective contribution to tree length of the discrete and continuous data partitions. These variations generated two phylogenetic hypotheses: (1) monophyly of the South African pettalids + Austropurcellia from north-eastern Australia as a derived clade within Pettalidae; and (2) polyphyly of the South African pettalids with Parapurcellia basal within Pettalidae. The latter hypothesis is congruent with previous molecular phylogenies of Cyphophthalmi, and has moderate bootstrap support. The sisterhood of Purcellia griswoldi, sp. nov. and P. lawrencei, sp. nov. receives high nodal support across analytic methods. New combination: Parapurcellia peregrinator (Lawrence, 1963).
The current distributions of widespread groups of terrestrial animals and plants are supposedly the result of a mixture of either vicariance owing to continental split or more recent trans-oceanic dispersal. For organisms exhibiting a vicariant biogeographic pattern-achieving their current distribution by riding on the plates of former supercontinents-this view is largely inspired by the belief that Pangaea lacked geographical or ecological barriers, or that extinctions and dispersal would have erased any biogeographic signal since the early Mesozoic. We here present a time-calibrated molecular phylogeny of Onychophora (velvet worms), an ancient and exclusively terrestrial panarthropod group distributed throughout former Pangaean landmasses. Our data not only demonstrate that trans-oceanic dispersal does not need be invoked to explain contemporary distributions, but also reveal that the early diversification of the group pre-dates the break-up of Pangaea, maintaining regionalization even in landmasses that have remained contiguous throughout the history of the group. These results corroborate a growing body of evidence from palaeontology, palaeogeography and palaeoclimatic modelling depicting ancient biogeographic regionalization over the continuous landmass of Pangaea.
Rakaia macra sp. nov. is described from three lots of specimens collected by Ray Forster in 1977 from Waipori, Otago, South Island of New Zealand. This species is currently known only from the Waipori area (exact locality unspecified) where it is extremely abundant. Clearly a member of the family Pettalidae, R. macra sp. nov. presents unusual chelicerae, with a conspicuous outer lateral ridge on the second segment, and without the two types of denticles in the mobile digit that characterize the New Zealand pettalids. The relationships between the new species and its closest relatives are discussed, and the distinction between the genera Rakaia and Neopurcellia is questioned.
Global oceans are known to have alternated between aragonite and calcite seas. These oscillations reflect changes in the Mg/Ca ratios of seawater that control biomineralization and the composition of marine carbonates, and are thought to be caused mainly by the time depen- dence of crustal accretion at mid-ocean ridge crests and the associated high-temperature mid-ocean ridge fluid flux. Here we use global ocean basin reconstructions to demonstrate that the fluctuations in hydrothermal ocean inputs are instead caused by the gradual growth and destruction of mid-ocean ridges and their relatively cool flanks during long-term tectonic cycles, thus linking ocean chemistry to off-ridge low-temperature hydrothermal exchange. Early Jurassic aragonite seas were a consequence of supercontinent stability and a minimum in mid-ocean ridge length and global basalt alteration. The breakup of Pangea resulted in a gradual doubling in ridge length and a 50% increase in the ridge flank area, leading to an enhanced volume of basalt to be altered. The associated increase in the total global hydrother- mal fluid flux by as much as 65%, peaking at 120 Ma, led to lowered seawater Mg/Ca ratios and marine hypercalcification from 140 to 35 Ma. A return to aragonite seas with preferential aragonite and high-Mg calcite precipitation was driven by pronounced continental dispersal, leading to progressive subduction of ridges and their flanks along the Pacific rim.
Examination of museum specimens belonging to the cyphophthalmid Gondwanan family Pettalidae has rendered a collection of specimens placed in the new genus Karripurcellia. The genus includes three species, K. peckorum, sp. nov., K. sierwaldae, sp. nov. and K. harveyi, sp. nov., from the Pemberton area in Western Australia. These are the first cyphophthalmid species found outside Queensland in Australia. Karripurcellia, gen. nov. is distinguished from other Australian pettalids by the lack of modifications in the anal plate, as well as the lack of the typical male anal glands of pettalids, sironids and the stylocellid genus Fangensis Rambla, 1994. Two of the species, K. peckorum, sp. nov. and K. sierwaldae, sp. nov., live sympatrically and have been collected in the same litter samples in one locality. The proposition of the new genus is accompanied by a cladistic analysis of all pettalid genera and most species within each genus, with the exception of the species-rich genus Rakaia Hirst, 1925. The cladistic analysis supports the monophyly of the Karripurcellia, gen. nov. species, but their sister-group relationships are unclear. However, the remaining Australian species cluster with the pettalids from New Zealand and South Africa, but not with Karripurcellia, sp. nov.
Among the least-studied families of mite
harvestmen (Opiliones, Cyphophthalmi) is the family
Neogoveidae, a group of arachnids that inhabits
tropical rain forests on both sides of the Atlantic
Ocean around the Equator, and an exquisite example
of Gondwanan vicariance. To evaluate the diversity
within Neogoveidae we studied the morphology of all
currently recognized genera using a recent phylogeny
of the group to provide a framework for the family in
the Neotropics. That study identifies several clades
that correspond to the recognized genera Neogovea,
Huitaca, Metagovea, Canga, and the recently resurrected
genus Brasilogovea, formerly synonymized with
Neogovea. Neogovea is restricted to eastern Amazonia
(Brazil, Guyana, French Guiana, Suriname), Huitaca
remains endemic to Colombia, Canga is restricted to its
type locality in the Serra de Caraja´s (Para´ State, Brazil),
Brasilogovea to Central Amazonas and the Tepuis
region in Colombia, and Metagovea is the most
widespread genus, found along the northern Andes
from Peru´ to Venezuela, and extending to the Amazon
region. All Neotropical genera are diagnosed and
discussed. The formerly monotypic Huitaca is revised
with the description of six additional species, all found
in the high-altitude Colombian mountain areas called
cordilleras, between 2,030 and 3,050 m. These include:
Huitaca bitaco new species, Huitaca boyacaensis new
species, Huitaca caldas new species, Huitaca depressa
new species, Huitaca sharkeyi new species, and
Huitaca tama new species, all from Colombia. Two
additional species, Brasilogovea chiribiqueta new
species, from Colombia, and Neogovea hormigai new
species, from Guyana, are also described.
Global plate motion models provide a spatial and temporal framework for geological data and have been effective tools for exploring processes occurring at the earth's surface. However, published models either have insufficient temporal coverage or fail to treat tectonic plates in a self-consistent manner. They usually consider the motions of selected features attached to tectonic plates, such as continents, but generally do not explicitly account for the continuous evolution of plate boundaries through time. In order to explore the coupling between the surface and mantle, plate models are required that extend over at least a few hundred million years and treat plates as dynamic features with dynamically evolving plate boundaries. We have constructed a new type of global plate motion model consisting of a set of continuously-closing topological plate polygons with associated plate boundaries and plate velocities since the break-up of the supercontinent Pangea. Our model is underpinned by plate motions derived from reconstructing the seafloor-spreading history of the ocean basins and motions of the continents and utilizes a hybrid absolute reference frame, based on a moving hotspot model for the last 100 Ma, and a true-polar wander corrected paleomagnetic model for 200 to 100 Ma. Detailed regional geological and geophysical observations constrain plate boundary inception or cessation, and time-dependent geometry. Although our plate model is primarily designed as a reference model for a new generation of geodynamic studies by providing the surface boundary conditions for the deep earth, it is also useful for studies in disparate fields when a framework is needed for analyzing and interpreting spatio-temporal data.
Incorporation of fossils into biogeographic studies can have a profound effect on the conclusions that result, particularly when fossil ranges are non-overlapping with extant ranges. This is the case in archaeid spiders, where there are known fossils from the Northern Hemisphere, yet all living members are restricted to the Southern Hemisphere. To better understand the biogeographic patterns of archaeid spiders and their palpimanoid relatives we estimate a dated phylogeny using a relaxed clock on a combined molecular and morphological dataset. Dating information is compared by treating the archaeid fossil taxa as both node calibrations and as non-contemporaneous terminal tips, both with and without additional calibration points. Estimation of ancestral biogeographic ranges is then performed, using likelihood and Bayesian methods to take into account uncertainty in phylogeny and in dating. We find that treating the fossils as terminal tips within a Bayesian framework, as opposed to dating the phylogeny based only on molecular data with the dates coming from node calibrations, removes the subjectivity involved in assigning priors, which has not been possible with previous methods. Our analyses suggest that the diversification of the northern and southern archaeid lineages was congruent with breakup of Pangaea into Laurasia and Gondwanaland. This analysis provides a rare example, and perhaps the most strongly supported, where a dated phylogeny confirms a biogeographical hypothesis based on vicariance due to the breakup of the ancient continental plates.
Abstract- Because they are designed to produced just one tree, neighbor-joining programs can obscure ambiguities in data. Ambiguities can be uncovered by resampling, but existing neighbor-joining programs may give misleading bootstrap frequencies because they do not suppress zero-length branches and/or are sensitive to the order of terminals in the data. A new procedure, parsimony jackknifing, overcomes these problems while running hundreds of times faster than existing programs for neighbor-joining bootstrapping. For analysis of large matrices, parsimony jackknifing is hundreds of thousands of times faster than extensive branch-swapping, yet is better able to screen out poorly-supported groups.
Over the last decade, molecular studies carried out on the Australasian biota have revealed a new world of organic structure that exists from submicroscopic to continental scale. Furthermore, in studies of global biogeography and evolution, DNA sequencing has shown that many large groups, such as flowering plants, passerine birds and squamates, have their basal components in this area. Using examples ranging from kangaroos and platypuses to kiwis and birds of paradise, the book examines the patterns of distribution and evolution of Australasian biodiversity and explains them with reference to tectonic and climatic change in the region. The surprising results from molecular biogeography demonstrate that an understanding of evolution in Australasia is essential for understanding the development of modern life on Earth. A milestone in the literature on this subject, this book will be a valuable source of reference for students and researchers in biogeography, biodiversity, ecology and conservation.
We present POY version 5, an open source program for the phylogenetic analysis of diverse data types including qualitative, aligned sequences, unaligned sequences, genomic data, and user‐defined sequences. In addition to the maximum‐parsimony optimality criterion supported by POY 4, POY 5 supports several types of maximum likelihood as well as posterior probability. To make these analyses feasible, new heuristic search algorithms and parallelization options have been implemented for all criteria.
Aim
Our aim was to elucidate the effect of mass extinctions on inferred crown ages of terrestrial clades endemic to ancient islands. We thereby assessed the potential for mass extinction events, such as the Zealandian marine incursion episode in the Oligocene, to skew the interpretation of the evolutionary history of clades of various sizes.
Location
Simulation study focusing on New Zealand.
Methods
Clades of various sizes were simulated under a birth–death model with variable parameters for diversification, invoking a prolonged extinction event, using the R package TreeSim . We measured the scaled root shift J between actual (i.e. first cladogenetic event) and inferred (i.e. most recent common ancestor of extant taxa) clade divergence times in simulated phylogenies incurred by extinction processes.
Results
A pulse of extinction followed by a prolonged period of low cladogenetic potential – modelled after the geological history of Zealandia in the Oligocene – produced large root shifts in clades of all sizes. Small clades with high net diversification rates were especially prone to belying pre‐Oligocene history. In simulations invoking mass extinctions wherein a pre‐extinction root was retained, phylogenies of extant taxa were characterized by anti‐sigmoidal log lineage‐through‐time plots that mimicked an upturn in diversification rate after the extinction period.
Main conclusions
Non‐selective mass extinctions can engender large discrepancies in actual and inferred root ages, particularly in small, old clades. The evolutionary histories of lineages that survive mass extinctions are difficult to distinguish from scenarios of rapid radiation. This outcome challenges previous interpretations of post‐Oligocene crown ages for clades endemic to New Zealand as sufficient evidence for rejecting a pre‐Oligocene evolutionary history. As a corollary, our results suggest that the extant size of a particular clade is the foremost indicator of its potential for historical biogeographical inference. We therefore review the hypothesis of the total submersion of Zealandia, highlighting empirical cases of lineages with demonstrable pre‐Oligocene history that refute the hypothesis of total submersion.
Chelicerata represents one of the oldest groups of arthropods, with a fossil record extending to the Cambrian, and is sister to the remaining extant arthropods, the mandibulates. Attempts to resolve the internal phylogeny of chelicerates have achieved little consensus, due to marked discord in both morphological and molecular hypotheses of chelicerate phylogeny. The monophyly of Arachnida, the terrestrial chelicerates, is generally accepted, but has garnered little support from molecular data, which have been limited either in breadth of taxonomic sampling or depth of sequencing. To address the internal phylogeny of this group, we employed a phylogenomic approach, generating transcriptomic data for 17 species in combination with existing data, including two complete genomes. We analyzed multiple datasets containing up to 1,235,912 sites across 3,644 loci, using alternative approaches to optimization of matrix composition. Here we show that phylogenetic signal for the monophyly of Arachnida is restricted to the 500 slowest-evolving genes in the dataset. Accelerated evolutionary rates in the orders Acariformes, Pseudoscorpiones, and Parasitiformes potentially engender long-branch attraction artifacts, yielding non-monophyly of Arachnida with increasing support upon incrementing the number of concatenated genes. Mutually exclusive hypotheses are supported by locus groups of variable evolutionary rate, revealing significant conflicts in phylogenetic signal. Analyses of gene-tree discordance indicate marked incongruence in relationships among chelicerate orders, whereas derived relationships are demonstrably robust. Consistently recovered and supported relationships include the monophyly of Chelicerata, Euchelicerata, Tetrapulmonata, and all orders represented by multiple terminals. Relationships supported by subsets of slow-evolving genes include Ricinulei + Solifugae; a clade comprised of Ricinulei, Opiliones, and Solifugae; and a clade comprised of Tetrapulmonata, Scorpiones, and Pseudoscorpiones. We demonstrate that outgroup selection without regard for branch length distribution exacerbates long branch attraction artifacts and does not mitigate gene-tree discordance, regardless of high gene representation for outgroups that are model organisms. Arachnopulmonata (new name) is proposed for the clade comprising Scorpiones + Tetrapulmonata (previously named Pulmonata).
We briefly review the potential history of Madagascar as either a Darwinian or a Wallacean island, summarize the phylogenetic evidence regarding the biogeography of Madagascar spiders, examine the dispersal history of the Madagascar Phyxelididae, and monograph the family in Madagascar. Molecular phylogenetic analyses for 32 Malagasy phyxelidid exemplars, nine confamilial outgroup taxa, and seven other more distant outgroups are performed for three nuclear markers and one mitochondrial genetic marker (28S, 18S, H3 and COI) utilizing Bayesian, maximum-likelihood and parsimony methods. These analyses suggest that there are 14 species of Phyxelididae that may be recognized from Madagascar, that these may be divided into three genera, and that the Malagasy phyxelidids form a monophyletic group, probably resulting from a single invasion of the island by an ancestor from Africa. Two new genera, ten new species, and two new combinations are proposed: Manampoka atsimo gen. nov., sp. nov.; Rahavavygen. nov., including R. ida sp. nov. and R. fanivelona (Griswold, 1990) comb. nov. and R. malagasyana (Griswold, 1990) comb. nov.; and Ambohima andrefana sp. nov., A. antsinanana sp. nov., A. avaratra sp. nov., A. maizina sp. nov., A. ranohira sp. nov., A. vato sp. nov., A. zandry sp. nov. and A. zoky sp. nov.
© 2012 The Linnean Society of London, Zoological Journal of the Linnean Society, 2012, 164, 728–810.
This chapter outlines several methods implemented in the MAFFT package. MAFFT is a popular multiple sequence alignment (MSA) program with various options for the progressive method, the iterative refinement method and other methods. We first outline basic usage of MAFFT and then describe recent practical extensions, such as dot plot and adjustment of direction in DNA alignment. We also refer to MUSCLE, another high-performance MSA program.
Relocation of a Fiordland-derived Pliocene conglomerate (Halfway Formation) that is currently exposed >100 km northeast of its source area indicates that the average displacement rate on the Alpine fault, New Zealand, since the Pliocene must have been >27 ±4 mm/yr and probably >35 ±5 mm/yr. This represents at least three-quarters of the currently predicted plate velocity and indicates that a high proportion of plate motion in the region has been partitioned along the Alpine fault since the Pliocene. These results, combined with the apparent absence of major displacement on the Alpine fault for at least the past 250 yr, indicate that a large earthquake may be due. The provenance of the Halfway Formation also allows crude estimates of uplift since the Pliocene of 200-800 m for the west coast (Cascade Valley) and 1-6 km for western Fiordland.
Because they are designed to produced just one tree, neighbor-joining programs can obscure ambiguities in data. Ambiguities can be uncovered by resampling, but existing neighbor-joining programs may give misleading bootstrap frequencies because they do not suppress zero-length branches and/or are sensitive to the order of terminals in the data. A new procedure, parsimony jackknifing, overcomes these problems while running hundreds of times faster than existing programs for neighbor-joining bootstrapping. For analysis of large matrices, parsimony jackknifing is hundreds of thousands of times faster than extensive branch-swapping, yet is better able to screen out poorly-supported groups.
Using the most up-to-the-date information available, we present a considerably revised plate tectonic and paleogeographic model for the Indian Ocean bordering continents, from Gondwana's Middle Jurassic break-up through to India's collision with Asia in the middle Cenozoic. The landmass framework is then used to explore the sometimes complex and occasionally counter-intuitive patterns that have been observed in the fossil and extant biological records of India, Madagascar, Africa and eastern Eurasia, as well those of the more distal continents.