94 research outputs found
Mitogenomics of the Olive Seed Weevil, Anchonocranus oleae Marshall and Implications for Its Phylogenetic Position in Curculionidae
Anchonocranus oleae Marshall (Coleoptera: Curculionidae) is a seed-feeding weevil native to southern Africa; its larvae are known to develop in the fruits of the African Wild Olive and, more rarely, cultivated olives. The species has been mainly found in the Western Cape province of South Africa, but it has remained in relative obscurity because it does not seem to represent a current threat to commercial olive production. As part of an ongoing effort to produce baseline genetic data for olive-associated entomofauna in South Africa, we generated reference DNA barcodes for A. oleae collected from wild and cultivated olives and sequenced its mitogenome for assessment of the phylogenetic position of the species in the family Curculionidae. The mitochondrial phylogeny estimate indicated that A. oleae shares a common ancestor with Elaidobius (tribe Derelomini), but a definite and close relationship to this tribe and the precise tribal placement of A. oleae in the subfamily Curculioninae could not be inferred due to the lack of representative mitogenomes of other relevant curculionine tribes and genera. This study will assist future work on the DNA-based species identification, genetic diversity, and phylogenetic position of the genus Anchonocranus and related taxa
Cretaceous fossils from the Orapa Diamond Mine
Main articleThe Orapa kimberlite pipe, situated in north-central Botswana, is well-known for its rich reserves
of diamonds. It is indeed one of the largest and richest diamond mines in the world. The kimberlite
magma transporting the diamonds from the upper mantle erupted through a sequence ofKaroo-aged
rocks before the deposition ofthe Kalahari Sands. This eruption has been radiometrically dated at
early Late Cretaceous (Cenomanian-Coniacian). When volcanism ceased, a succession of epiclastic
crater lake sediments was deposited above the kimberlite plug. Analysis of these sediments, which
mostly comprise the results of mudflows and debris flows and fmer sediments during quiescenttimes,
suggests that most of the sediments within the crater were deposited rapidly as mass flows, and were
therefore mobilised soon after the volcanic eruption. Buried within the fine-grained sediments is a
unique assemblage of fossils including flowering plants and many whole-bodied insects. The fossils
are commonly exquisitely preserved in extremely fine-grained mudstone. Interpretation of the
sedimentary facies and fossils is that the mid-Cretaceous climate of central Botswana was temperate,
seasonal and wet, and the area surrounding the crater was forested. The fossils represent the recovery
of the biota of the area after the violent eruptions of Orapa and other nearby kimberlite fissures and
pipes. The fossils have contributed considerably to our understanding of mid-Cretaceous insects and
flowering plants and suggest intimate relationships between the two at an early stage in the radiation
of flowering plants. It seems that southern Gondwana (including southern Africa) was a centre of
diversification for both insects and angiosperms in the mid-Cretaceous.Friends of the Museum,
Gaborone; Debswana (Orapa); University of the Witwatersrand;
South African Foundation for Research Developmen
Historical Isolation versus Recent Long-Distance Connections between Europe and Africa in Bifid Toadflaxes (Linaria sect. Versicolores)
Background: Due to its complex, dynamic and well-known paleogeography, the Mediterranean region provides an ideal framework to study the colonization history of plant lineages. The genus Linaria has its diversity centre in the Mediterranean region, both in Europe and Africa. The last land connection between both continental plates occurred during the Messinian Salinity Crisis, in the late Miocene (5.96 to 5.33 Ma). Methodology/Principal Findings: We analyzed the colonization history of Linaria sect. Versicolores (bifid toadflaxes), which includes c. 22 species distributed across the Mediterranean, including Europe and Africa. Two cpDNA regions (rpl32-trnL UAG and trnK-matK) were sequenced from 66 samples of Linaria. We conducted phylogenetic, dating, biogeographic and phylogeographic analyses to reconstruct colonization patterns in space and time. Four major clades were found: two of them exclusively contain Iberian samples, while the other two include northern African samples together with some European samples. The bifid toadflaxes have been split in African and European clades since the late Miocene, and most lineage and speciation differentiation occurred during the Pliocene and Quaternary. We have strongly inferred four events of post-Messinian colonization following long-distance dispersal from northern Africa to the Iberian Peninsula, Sicily and Greece. Conclusions/Significance: The current distribution of Linaria sect. Versicolores lineages is explained by both ancien
Can enemy release explain the invasion success of the diploid Leucanthemum vulgare in North America?
Changes to the Fossil Record of Insects through Fifteen Years of Discovery
The first and last occurrences of hexapod families in the fossil record are compiled from publications up to end-2009. The major features of these data are compared with those of previous datasets (1993 and 1994). About a third of families (>400) are new to the fossil record since 1994, over half of the earlier, existing families have experienced changes in their known stratigraphic range and only about ten percent have unchanged ranges. Despite these significant additions to knowledge, the broad pattern of described richness through time remains similar, with described richness increasing steadily through geological history and a shift in dominant taxa, from Palaeoptera and Polyneoptera to Paraneoptera and Holometabola, after the Palaeozoic. However, after detrending, described richness is not well correlated with the earlier datasets, indicating significant changes in shorter-term patterns. There is reduced Palaeozoic richness, peaking at a different time, and a less pronounced Permian decline. A pronounced Triassic peak and decline is shown, and the plateau from the mid Early Cretaceous to the end of the period remains, albeit at substantially higher richness compared to earlier datasets. Origination and extinction rates are broadly similar to before, with a broad decline in both through time but episodic peaks, including end-Permian turnover. Origination more consistently exceeds extinction compared to previous datasets and exceptions are mainly in the Palaeozoic. These changes suggest that some inferences about causal mechanisms in insect macroevolution are likely to differ as well
FIGURE 8 in Annotated catalogue of Australian weevils (Coleoptera: Curculionoidea)
FIGURE 8. Numbers and percentages of valid species of Australian Curculionidae by subfamily.Published as part of <i>Pullen, Kimberi R., Jennings, Debbie & Oberprieler, Rolf G., 2014, Annotated catalogue of Australian weevils (Coleoptera: Curculionoidea), pp. 1-481 in Zootaxa 3896 (1)</i> on page 18, DOI: 10.11646/zootaxa.3896.1.1, <a href="http://zenodo.org/record/10086744">http://zenodo.org/record/10086744</a>
FIGURE 1 in Annotated catalogue of Australian weevils (Coleoptera: Curculionoidea)
FIGURE 1. The course of description of the species of Australian weevils (valid species names).Published as part of <i>Pullen, Kimberi R., Jennings, Debbie & Oberprieler, Rolf G., 2014, Annotated catalogue of Australian weevils (Coleoptera: Curculionoidea), pp. 1-481 in Zootaxa 3896 (1)</i> on page 8, DOI: 10.11646/zootaxa.3896.1.1, <a href="http://zenodo.org/record/10086744">http://zenodo.org/record/10086744</a>
- …