From Gondwana to Europe: inferring the origins of Mediterranean Macrothele spiders (Araneae : Hexathelidae) and the limits of the family Hexathelidae

Abstract

The family Hexathelidae ranks among the smaller mygalomorph spider families. Most species are endemic to the Australasian region and the family was traditionally considered an example of a Gondwanan lineage. However, recent studies have cast some doubt on the monophyly of the family. Macrothele is the only genus with an out-of-Gondwana distribution. The bulk of the Macrothele diversity is found in South-east Asia, few species are known from central Africa and two species inhabit Europe: Macrothele calpeiana (Walckenaer, 1805) from the Iberian Peninsula and Macrothele cretica Kulczynski, 1903 endemic to Crete. Here we investigate the origins of the European Macrothele species by means of a multi-locus phylogenetic approach and by inferring the time frame of the diversification of the genus using Bayesian relaxed clock methods. We also provide further insights into the phylogenetic status of the family Hexathelidae. Our results indicate that the diversification of Macrothele traces back to the period of the Gondwana break-up and its present-day distribution most likely reflects the subsequent tectonic plate movements. The two European species were not recovered as sister taxa, suggesting that Macrothele colonised the Mediterranean region twice independently. The polyphyly of the family Hexathelidae is further confirmed and the subfamily Atracinae is identified as the conflicting lineage.

Tethyan closure drove tropical marine biodiversity: Vicariant diversification of intertidal crustaceans

“…As described earlier, we used an uncorrelated lognormal relaxed clock model, with a substitution rate of 0.0115 as the informative prior for mtDNA. For the nuclear partition, we could not find a suitable substitution rate from the literature; however, a classic rule of thumb says it is one order of magnitudes lower than mitochondrial rate (Opatova & Arnedo, ; Xu et al., ). Therefore, we set a rate of 0.00115 for the nuclear partition with an interval of 0.0001 to 0.0115 under an uncorrelated lognormal relaxed molecular clock model.…”

Did a Miocene–Pliocene island isolation sequence structure diversification of funnel web spiders in the Taiwan‐Ryukyu Archipelago?

“…To evaluate timeframe of diversification in Taiwan‐Ryukyu endemic Macrothele species, we used five different schemes (Table ): (1) the 1.55 Ma timeframe, which corresponds to the opening of South Okinawa Trough, in Osozawa et al . () of Taiwan‐Ryukyu diversification, (2) a Mygalomorphae mitochondrial molecular clock (4.0% Myr −1 , Bond et al ., ), (3) the initial opening time of the Okinawa Trough (Wang et al ., ), (4) the arthropod mitochondrial molecular clock (2.3% Myr −1 ; Brower, ) and (5) Opatova & Arnedo's () estimated origin of the Asian Macrothele + M. calpeiana clade (40.77 Ma, 95% highest probability density, or 95% highest posterior density [HPD] = 58.0–26.6). Finally, we compared the fit of results to the geological record, and evaluated support for feasibility of each of these temporal frameworks.…”

“… Opatova & Arnedo () used a Jurassic fossil to calibrate Mygalomorphae phylogeny and estimated that Asian+ M. calpeiana clade originated in 40.77 Ma (95% highest posterior density [HPD] = 58.00–26.66 Ma). …”

Multilocus sequence data reveal dozens of putative cryptic species in a radiation of endemic Californian mygalomorph spiders (Araneae, Mygalomorphae, Nemesiidae)

“…Raven (1985) used morphol-60 ogy to revise taxonomy and contributed greatly to our understand-61 ing of higher-level mygalomorph phylogenetic relationships. 62 Recent phylogenetic studies using DNA sequence data have 63 recovered support for some previous morphology-based 64 hypotheses, but have also demonstrated the limitations of mor-65 phological data and revealed some surprising relationships 66 Bond et al, 2012;Starrett et al, 2013;67 Opatova et al, 2013;Opatova and Arnedo, 2014a). 68 In addition to improving our understanding of deeper phyloge-69 netic relationships, DNA sequence data have played a crucial role 70 in uncovering and recognizing species-level diversity in mygalo-71 morphs.…”

“…An examination of female reproduc- Mygalomorph spiders, the radiation that includes tarantulas 48 and trapdoors spiders, are ancient and diverse. Because of general 49 dispersal limitation and high levels of regional endemism, several 50 research groups from different continents have developed mygalo-51 morphs as models for studies of species delimitation, cryptic spe-52 ciation, and historical biogeography (e.g., Bond and Stockman,53 2008; Satler et al, 2013;Hedin et al, 2013;Hendrixson et al, 54 2013; Castalanelli et al, 2014;Hamilton et al, 2014;Opatova 55 and Arnedo, 2014a). Still, many features of mygalomorph biology 56 make them challenging to study.…”