An extinct Eocene taxon of the daisy family (Asteraceae): evolutionary, ecological and biogeographical implications

Thaumastocoris peregrinus is a recently introduced invertebrate pest of non-native Eucalyptus plantations in the Southern Hemisphere. It was first reported from South Africa in 2003 and in Argentina in 2005. Since then, populations have grown explosively and it has attained an almost ubiquitous distribution over several regions in South Africa on 26 Eucalyptus species. Here we address three key questions regarding this invasion, namely whether only one species has been introduced, whether there were single or multiple introductions into South Africa and South America and what the source of the introduction might have been. To answer these questions, bar-coding using mitochondrial DNA (COI) sequence diversity was used to characterise the populations of this insect from Australia, Argentina, Brazil, South Africa and Uruguay. Analyses revealed three cryptic species in Australia, of which only T. peregrinus is represented in South Africa and South America. Thaumastocoris peregrinus populations contained eight haplotypes, with a pairwise nucleotide distance of 0.2-0.9% from seventeen locations in Australia. Three of these haplotypes are shared with populations in South America and South Africa, but the latter regions do not share haplotypes. These data, together with the current distribution of the haplotypes and the known direction of original spread in these regions, suggest that at least three distinct introductions of the insect occurred in South Africa and South America before 2005. The two most common haplotypes in Sydney, one of which was also found in Brisbane, are shared with the non-native regions. Sydney populations of T. peregrinus, which have regularly reached outbreak levels in recent years, might thus have served as source of these three distinct introductions into other regions of the Southern Hemisphere.

The first systematic analysis of the Danian carditids of Patagonia is presented, which includes four genera—one new genus and the first records of three other genera in South America. They consist ofClaibornicardia paleopatagonica(Ihering, 1903), a widely distributed species occuring in the Jagüel, Roca and Salamanca formations (Neuquén, Río Negro and Chubut Provinces);RotundicardiaHeaslip, 1968, represented by the new speciesR.mariobrosorumn. sp., which is restricted to the Roca Formation (Río Negro Province);Cardites feruglioi(Petersen, 1846) (Roca and Lefipán formations, Río Negro and Chubut Provinces); and byKalelianew genus, which includesK.burmeisteri(Böhm, 1903) from the Salamanca and Roca formations (Río Negro and Chubut Provinces), which is related to the Paris Basin speciesK.multicostata(Lamarck, 1806) n. comb. andK.pectuncularis(Lamarck, 1806) n. comb. ‘Venericardia’ iheringi(Böhm, 1903), a species known only from internal molds, is described and regarded as a carditid with uncertain affinities. The presence ofClaibornicardia,Rotundicardia, andCarditesin Patagonia constitutes the most ancient record of these genera and confirms biogeographical connections previously established between the Danian Argentinian and North American/European fossil faunas.

Cione, A.L. & Gouiric-Cavalli, S., June 2012. Metaceratodus kaopen comb. nov. and M. wichmanni comb. nov., two Late Cretaceous South American species of an austral lungfish genus (Dipnoi). Alcheringa 36, 203–216. ISSN 0311-5518. Metaceratodus wollastoni, an Australian species, was reported from Upper Cretaceous beds of Patagonia in 1997. Later, three new species (Ceratodus wichmanni, Ptychoceratodus kaopen and Ptychoceratodus cionei), based on scarce material, were described from the same region. Two of these species were later referred to Ferganoceratodus. After examining much more abundant and better-preserved material, we conclude that neither the occurrence of Metaceratodus wollastoni nor those of Ptychoceratodus and Ferganoceratodus in the Cretaceous of South America are supported. We consider that C. wichmanni and P. cionei are synonyms and we reassign the three putative species to Metaceratodus under two new combinations: M. kaopen comb. nov. and M. wichmanni comb. nov. Both differ from the other species of the genus in having pits over most of the occlusal surface and a different occlusal profile of the tooth plate, and most have four ridges in the lower and upper tooth plates. Metaceratodus wichmanni differs from M. kaopen in oclussal profile, inner angle, and symphysis development among other features. Metaceratodus kaopen is known from the upper Santonian–lower Campanian Anacleto Formation of Río Negro province and M. wichmanni from upper Campanian–lower Maastrichtian units of Chubut, Río Negro, Neuquén and Mendoza provinces, Argentina. The occurrence of Metaceratodus in southern South America corroborates a close biogeographical relationship with Australia in the latest Cretaceous. Alberto Luis Cione [acione@museo.fcnym.unlp.edu.ar] and Soledad Gouiric-Cavalli [sgouiric@museo.fcnym.unlp.edu.ar], División Paleontología Vertebrados, Museo de La Plata, Paseo del Bosque s/n, W1900FWA La Plata, Argentina. Received 23.11.2010, revised 11.7.2011, accepted 7.8.2011.

A diverse assemblage of extinct mammals of early–middle Eocene age (Ypresian–Lutetian boundary) come from the Patagonian localities of La Barda and Laguna Fría around Paso del Sapo in northwestern Chubut Province (Argentina). Metatherians are well represented, mostly by dental remains of ‘Didelphimorphia’, Paucituberculata, Sparassodonta, Microbiotheria, and Polydolopimorphia. Here we analyse three calcanea and one astragalus referable to the same, indeterminate taxon, from La Barda, showing the fusion of their ectal and sustentacular facets. This facet arrangement characterizes the Australidelphia, a marsupial clade represented by Microbiotheria from South America and Antarctica, plus all Australasian lineages. Other australidelphian features shown by these tarsals include: in the calcanea, a reduced peroneal process and a tripartite cuboid facet; in the astragalus, a round, very small astragalar head in relation to the body; a convex trochlea with a half for the tibia and half, in slightly lower position, for the fibula. Their size and other anatomical features suggest that the new tarsals cannot be referred to the Microbiotheria. Phylogenetic analysis suggests that the La Barda taxon lies within the Australidelphia, and that it is either closely related or belongs to, the Diprotodontia. The existence of advanced australidelphians in Patagonia adds further evidence of the close relationship between Patagonia, Antarctica, and Australia during the Late Cretaceous – early Palaeogene.

An extinct Eocene taxon of the daisy family (Asteraceae): evolutionary, ecological and biogeographical implications

Although it was the subject of much controversy among geologists and palaeontologists until well into the 1960s, the former existence of a land connection between Africa and South America no longer needs to be demonstrated. Within the general framework of plate tectonics and continental drift, it is now clear that Africa and South America were once part of the southern super-continent Gondwana, itself a constituent of Pangaea during the Late Palaeozoic and the Early Mesozoic. The distribution of some fossil amphibians and reptiles was one of the important palaeobiogeographical arguments in favour of such reconstructions. The occurrence of very closely related representatives of a group of small early reptiles, the mesosaurs, in the Permian of South America and South Africa, for instance, was used as evidence of a connection between Africa and South America in the Late Palaeozoic, well before continental drift became generally accepted. The Late Triassic dinosaur faunas of South Africa and South America also exhibit resemblances—which is not surprising in a palaeo-biogegraphical situation of global faunal similarity, due to the existence of Pangaea. Although it may seem paradoxical, the Africa-South America connection becomes an interesting scientific problem mainly when it ceases to exist, when the opening of the proto-Atlantic Ocean sometime in the Cretaceous separates the two continents from each other and makes faunal interchange increasingly difficult. A comparative history of amphibians and reptiles in South America and Africa, through the Cretaceous and into the Tertiary, reveals similarities and divergences suggesting a pattern of faunal exchanges in which vicariant evolution and dispersal across barriers both played a part.

Background: Endogenous digoxin has been related to the pathogenesis of chronic calcific pancreatitis, endomyocardial fibrosis, multinodular goitre and mucoid angiopathy which are seen in South India, South Africa, Australia and South America. Phytoplasmas, viroids and rutile in beach sands have been related to root wilt disease of coconut seen in the same endemic area. The possibility of endogenous digoxin synthesis by actinide based primitive organism like archaea with a mevalonate pathway and cholesterol catabolism as well as a RNA viroid role in pathogenesis of these endemic diseases was considered. The study aims to link actinidic nanoarchaea to etiology of these diseases and postulates their common geographic epidemiology to the existence of a pre-historic Lemurian supercontinent linking these geographic areas. It also postulates a role for actinidic surfaces in the evolution of life, eukaryote, primates and humans.Methods: 10 cases each of chronic calcific pancreatitis, endomyocardial fibrosis, multinodular goitre and mucoid angiopathy before starting treatment and 10 age and sex matched healthy controls from general population were chosen for the study. Cholesterol substrate was added to the plasma of the patients and the generation of cytochrome F420, free RNA, free DNA, polycyclic aromatic hydrocarbon, hydrogen peroxide, serotonin, pyruvate, ammonia, glutamate, cytochrome C, hexokinase, ATP synthase, HMG CoA reductase, digoxin and urease were studied. The changes with the addition of antibiotics and rutile to the patient’s plasma were also studied. The statistical analysis was done by ANOVA.Results: The parameters mentioned above were increased the patient’s plasma with addition of cholesterol substrate. The addition of antibiotics to the patient’s plasma caused a decrease in all the parameters while addition of rutile increased their levels. Conclusions: An actinide dependent shadow biosphere of archaea and viroids is described in endomyocardial fibrosis, chronic calcific pancreatitis, multinodular goitre and mucoid angiopathy contributing to their pathogenesis. The coexistence of EMF, CCP and MNG in South India, South Africa, Australia and South America is thus an indirect evidence for the existence of the Lemurian supercontinent containing these land masses and rich in actinidic minerals. It also is evidence of abiogenesis on radioactive actinidic beach sands through the process of surface metabolism in the course of evolution. This gives credence to the role of actinidic archaea as the third element that controls life and its role in the evolution of the multicellular eukaryote, primates and humans. Key words: Archaea; Viroids; Endomyocardial fibrosis; Chronic calcific pancreatitis; Multinodular goitre; Mucoid angiopathy; Lemuria

SUMMARYWe present a tomographic model of the crust, upper mantle and transition zone beneath the South Atlantic, South America and Africa. Taking advantage of the recent growth in broadband data sampling, we compute the model using waveform fits of over 1.2 million vertical-component seismograms, obtained with the automated multimode inversion of surface, S and multiple S waves. Each waveform provides a set of linear equations constraining perturbations with respect to a 3-D reference model within an approximate sensitivity volume. We then combine all equations into a large linear system and solve it for a 3-D model of S- and P-wave speeds and azimuthal anisotropy within the crust, upper mantle and uppermost lower mantle. In South America and Africa, our new model SA2019 reveals detailed structure of the lithosphere, with structure of the cratons within the continents much more complex than seen previously. In South America, lower seismic velocities underneath the transbrasilian lineament (TBL) separate the high-velocity anomalies beneath the Amazon Craton from those beneath the São Francisco and Paraná Cratons. We image the buried portions of the Amazon Craton, the thick cratonic lithosphere of the Paraná and Parnaíba Basins and an apparently cratonic block wedged between western Guyana and the slab to the west of it, unexposed at the surface. Thick cratonic lithosphere is absent under the Archean crust of the São Luis, Luis Álves and Rio de La Plata Cratons, next to the continental margin. The Guyana Highlands are underlain by low velocities, indicating hot asthenosphere. In the transition zone, we map the subduction of the Nazca Plate and the Chile Rise under Patagonia. Cratonic lithosphere beneath Africa is more fragmented than seen previously, with separate cratonic units observed within the West African and Congo Cratons, and with cratonic lithosphere absent beneath large portions of Archean crust. We image the lateral extent of the Niassa Craton, hypothesized previously and identify a new unit, the Cubango Craton, near the southeast boundary of the grater Congo Craton, with both of these smaller cratons unexposed at the surface. In the South Atlantic, the model reveals the patterns of interaction between the Mid-Atlantic Ridge (MAR) and the nearby hotspots. Low-velocity anomalies beneath major hotspots extend substantially deeper than those beneath the MAR. The Vema Hotspot, in particular, displays a pronounced low-velocity anomaly under the thick, high-velocity lithosphere of the Cape Basin. A strong low velocity anomaly also underlies the Cameroon Volcanic Line and its offshore extension, between Africa and the MAR. Subtracting the global, age-dependent VS averages from those in the South Atlantic Basins, we observe areas where the cooling lithosphere is locally hotter than average, corresponding to the location of the Tristan da Cunha, Vema and Trindade hotspots. Beneath the anomalously deep Argentine Basin, we image unusually thick, high-velocity lithosphere, which suggests that its anomalously great depth can be explained, at least to a large extent, by isostatic, negative lithospheric buoyancy.

The largest genus of salamanders, Bolitoglossa (Plethodontidae), is widespread in tropical America, where it occurs in diverse habitats and elevations, from high elevation grasslands to lowland rain forest. It has the most extensive geographical range of any salamander genus. While most species occur in Middle America, it ranges throughout most of tropical South America as well. Phylogenetic analysis of 1196 bp of two mitochondrial genes (cytochrome b, 16S RNA) from 55 species offers strong support for the monophyly of the genus and sorts the species into a number of clades. Taking into account morphology, distribution, general ecology, and prior systematic and taxonomic studies, we recognize seven subgenera, four of them new: Bolitoglossa Dumeril, Bibron et Dumeril, 1854, Eladinea Miranda Ribeiro, 1937, Magnadigita Taylor, 1944, Mayamandra, Nanotriton, Oaxakia and Pachymandra. All South American and some lower Middle American species are included in a single well supported clade, Eladinea. At the species level our analyses uncover the existence of large genetic diversity within morphologically homogeneous taxa. We propose the new combination: B. (Eladinea) paraensis (Unterstein, 1930) stat. nov., for Brazilian salamanders previously included under B. altamazonica. We evaluate evidence for the multiple colonization of the tropical lowlands by morphologically derived species groups. South America was invaded by members of one clade, Eladinea, which we infer to have dispersed to South America prior to closure of the Panamanian Portal. Despite the relatively long history of salamanders in South America, that continent now accounts for a relatively small proportion of the lineages and species of neotropical salamanders. (C) 2004 The Linnean Society of London,

The fourth biennial meeting of the International Biogeography Society (IBS) in Merida, Yucatan in January 2009 represented a double opportunity for Mexican biologists. First, it fostered the integration of the large community of Mexican biogeographers with the activities of the IBS. Second, the meeting allowed us to welcome a large number of delegates from distant parts of the world who were able to visit what has been considered an obligate destination for nature lovers and cultural tourists alike: the Yucatan peninsula. As Edward O. Wilson pointed out, besides economic power every country has two additional and important types of wealth: cultural and natural. Cultural richness is a naturally embedded component of the Mexican way of life.

Comments on Steadman, D.W., Martin, P.S., MacPhee, R.D.E., Jull, A.J.T., McDonald, H.G., Woods, C.A., Iturralde-Vinent, M. & Hodgins, G.W.L. (2005) Asynchronous extinction of late Quaternary sloths on continents and islands. Proceedings of the National Academy of Sciences USA, 102, 11763–11768. The debate over the causes of the Pleistocene megafaunal extinction dates back to the early 19th century (Grayson, 1984), and continues to generate considerable controversy (e.g. Grayson & Meltzer, 2003; Araujo et al., 2004; De Vivo & Carmignotto, 2004; Fiedel & Haynes, 2004; Burney & Flannery, 2005; Wroe et al., 2006). Typically, protagonists in this debate can be classified into two groups. One group argues that Late Pleistocene megafaunal extinctions were primarily caused by direct and indirect human action through hunting, habitat modification or introduction of new predators (Burney & Flannery, 2005, 2006; Barnosky et al., 2004; Fiedel & Haynes, 2004). The other interpretation is that humans had at most a minor role in the megafaunal extinction, and that the loss was attributable principally to a climatic cause (Ficcarelli et al., 2003; Grayson & Meltzer, 2003, 2004; Barnosky et al., 2004; De Vivo & Carmignotto, 2004; Boeskorov, 2006; Guthrie, 2006; Wroe et al., 2006; Wroe & Field, 2006). Here we contest the position of Steadman et al. (2005), who favour the overkill hypothesis to explain the ground sloth extinction in the Americas. Although making an important contribution to the debate on extinction of the New World megafauna, Steadman et al. (2005) make some important assumptions in their analysis. Steadman et al. (2005) argue that the extinction of ground sloths in the New World was concomitant with, and a consequence of, the human occupation of the Americas. Their argument is two-fold. First, the radiocarbon dates (14C) accepted by them for the last appearance dates (LADs) of these animals roughly correspond to megafaunal extinction dates in South and North America and the West Indies. These dates coincide with the human colonization of these regions and they argue that this supports the thesis that human arrival caused extinction of the ground sloth. Second, according to Steadman et al., extinctions caused by climatic fluctuation would result in concomitant LADs across the entire continent and associated islands, as they viewed these fluctuations as being widespread and uniform, whilst they found that the LADs for the West Indies, around 4400 14C yr bp [c. 4800–5050 calibrated years before present (cal. bp); dates calibrated with calib 5.0, Stuiver et al., 2005], are much younger than those found in the continent (c. 11,000 14C yr bp; c. 12,880–12,950 cal. bp for North America and c. 10,500 14C yr bp; c. 12,390–12,640 cal. bp for South America). We contend that the chronological data presented by Steadman et al. (2005) are incomplete, especially when considering South America. While Steadman et al. (2005) suggest that there are no acceptable Holocene LADs for ground sloths, a large number of Holocene dates generated through direct dating of bone and dung remains are indeed available in the literature. Barnosky et al. (2004; supporting material) revised the radiocarbon dates available for megafaunal remains throughout the world. In South America, they listed four articles with remains of megafauna dated within the Holocene, based both on direct and indirect dates. Even when considering only the results based on direct dates of bone remains, sufficient evidence still supports Holocene LADs for subequatorial ground sloths. For instance, from Argentina, Borrero et al. (1998) presented a total of seven 14C dates consistent with a Holocene survival of megafauna, albeit two of these ages are potentially unreliable, and four were obtained from one single specimen (indeed, one of the unreliable dates comes from this specimen; Table 1). Other reports not included in Barnosky et al. (2004) provide two direct radiocarbon ages of megafaunal bone remains from central Brazil at the Pleistocene/Holocene boundary (Table 1; Neves & Piló, 2003; Araujo et al., 2004). Politis et al. (2004; also not included in Barnosky et al., 2004) presented two additional Holocene direct radiocarbon ages of Megatherium americanum (Blumenbach) specimens (Table 1) and a third one from the Holocene/Pleistocene boundary (10,190 ± 120 14C yr bp; c. 11,820–12,020 cal. bp; Table 1), all in Argentina; and Marshall et al. (1984; also not included in Barnosky et al., 2004) reported a single Holocene age of 8910 ± 200 14C yr bp (c. 9780–10,150 cal. bp; GIF-4116) of a Scelidodon chiliensis (Lydekker) in Peru (Marshall et al., 1984;Pujos & Salas, 2004). Four of the sites where these dates were obtained are located in Argentina, while two are located in central Brazil and the last in Peru (Fig. 1). All the Argentinean sites (Arroyo Seco 2, La Moderna, Campo Laborde and Paso Otero 5) are open-air archaeological sites, i.e. the megafaunal remains are associated with prehistoric human occupations (see Borrero et al., 1998; Politis et al., 2004 for detailed descriptions). Arroyo Seco 2 is interpreted as a base camp where a large variety of activities were undertaken (Politis et al., 2004), including the exploitation of ground sloths and other megafauna by humans. However, Borrero et al. (1998) and Politis et al. (2004) do not state clearly if the two specimens (M. americanum and Equus neogeus Lund) that dated to the Holocene (Table 1) showed marks of human manipulation. The remaining open-air sites are believed to be sites used for specific activities (Politis et al., 2004): La Moderna is interpreted as an occasional megafaunal processing site, where the remains of a single glyptodont (Doedicurus clavicaudatus Owen) dated to the Holocene (Table 1) were recovered; Campo Laborde presents evidence that it was used as a hunting and processing site for ground sloths (M. americanum; Table 1); and Paso Otero 5, was also identified as a hunting and processing site for local megafauna. Archaeological and palaeontological sites in South America presenting direct Late Pleistocene/Early Holocene radiocarbon (14C) dates for megafaunal remains. Circles represent sites with no evidence of human exploitation of the megafaunal remains, whereas triangles represent sites with evidence of human exploitation of megafauna. 1, Gruta Cuvieri; 2, Escrivânia 5; 3, Gruta del Indio; 4, La Moderna; 5, Campo Laborde; 6, Arroyo Seco 2; 7, Paso Otero 5; 8, Pampa de los Fósiles. The two Brazilian sites, in contrast, are exclusively palaeontological, i.e. they are not associated with human occupations, and are located in limestone caves in the karstic region of Lagoa Santa. Gruta Cuvieri is a cave where three vertical chambers functioned as natural traps for the now extinct megafauna and other animals. The only megafauna species found so far is Catonyx cuvieri (Lund), a medium-sized ground sloth. The Holocene date presented in Table 1 was obtained from one of these ground sloths, found at the surface of one of the chambers. The other Brazilian site, Escrivânia 5, is part of a complex of caves, generically referred to as Escrivânia, representing one of the richest palaeontological limestone outcrops known at Lagoa Santa. Together with tons of animal fossil bones, in one of the chambers (Escrivânia 3) an almost complete human skeleton was also recently recovered, dated to 7650 ± 80 14C yr bp (c. 8370–8420 cal. bp; Beta 174734). The Peruvian site, Pampa de los Fósiles, is also a palaeontological site located in the Cupisnique Desert. Several archaeological sites in the region have revealed no evidence of human interaction with the megafauna in the region (Pujos & Salas, 2004). In addition to these reported dates, Steadman et al. (2005; supporting material) disqualified two other Holocene dates as unreliable (they also rejected a third date, but it has a very large margin of error). These were the only Holocene dates found in their bibliographical revision and they ‘have means that are up to 1000 years younger than means of any [of the accepted LADs] [Supplementary online material]’. As 10 reliable Holocene direct radiocarbon dates for megafauna are described here, there is no further reason to reject the dates of 8990 ± 90 14C yr bp (c. 9920–10,190 cal. bp; LP-925; Garcia, 2003) and 9560 ± 90 14C yr bp (c. 10,680–10,860 cal. bp; GrN-5772; Long et al., 1998) as unacceptable outliers. These two dates are from an Argentinean site, Gruta del Indio (Fig. 1; see Long et al., 1998; Garcia, 2003 for detailed descriptions). This site is a rockshelter, and although it presents chronological information placing humans together with megafauna in time, there is no evidence of humans exploiting the local megafauna (Long et al., 1998; Garcia, 2003). As presented in Table 1, from the 14 existing Holocene dates we found for megafaunal remains in South America eight are derived from ground sloths, which severely weakens the position of Steadman et al. (2005), that there are no acceptable Holocene LADs for ground sloths in the Americas. Assuming that human groups already inhabited South America around 12,500 14C yr bp (c. 14,300–14,950 cal. bp; Dillehay, 2000), the argument that the ground sloth LADs were concomitant with the human arrival in the New World can no longer be accepted, at least not as an immediate phenomenon. The second argument presented by Steadman et al. (2005) is that the apparent delay observed in the LADs of Central America islands, when compared with the continental ones, favours the overkill hypothesis. Delayed LADs in insular regions have been found in other parts of the world, independent of human presence (Guthrie, 2004; Boeskorov, 2006). Boeskorov (2006) showed that in northern Eurasian islands, megafauna survived into the Holocene, e.g. the mammoths of Wrangel Island. Nonetheless, the extinction of megafauna in Eurasia as a whole is believed to be primarily due to climatic changes (Barnosky et al., 2004; Boeskorov, 2006), particularly because no human presence is found in the Wrangel Islands until well after the extinction of the megafauna (Boeskorov, 2006). Although these data do not peremptorily disqualify Steadman’s argument, they do bring into question whether the overkill hypothesis is the most parsimonious explanation for megafaunal extinctions. Finally, it must be emphasized that there is a general lack of evidence of sloth remains in archaeological contexts in the Americas as a whole (but see Politis et al., 2004 for an exception), which also speaks against the overkill hypothesis. Specifically, in Lagoa Santa, despite the excavation of dozens of archaeological sites dated to the Pleistocene/Holocene transition (showing human evidence as old as 11,000–11,500 14C yr bp; c. 12,880–13,400 cal. bp; Neves et al., 1999), evidence is lacking of megafaunal use by humans, either as a source of food or raw material (Kipnis, 1998; Prous & Fogaça, 1999). In North America, a similar situation is observed. According to Grayson & Meltzer (2003), there are only two genera of megafauna (Mammuthus Burnett, 1830 and Mammut Blumenbach, 1799) known to have been hunted by humans during the Clovis period (Grayson & Meltzer, 2003). This scenario is accepted even by Fiedel & Haynes (2004), strong defenders of the overkill hypothesis. Thus, at least in South America (and most probably in North and Central America as well), the idea that ground sloths went extinct due to overkill lacks archaeological support. In conclusion, the ground sloth overkill hypothesis, as defended by Steadman et al. (2005), is not sufficiently supported in the empirical world. As we have briefly pointed out: (1) a considerable number of reliable Holocene dates for megafaunal specimens in South America already exist, including for ground sloths; (2) the existence of late megafaunal LADs in Central America islands can be equally well explained through overkilling or environmental changes; and (3) the general lack of megafaunal killing sites and megafaunal remains in archaeological contexts is inconsistent with the overkill hypothesis. Nonetheless, it is important to emphasize that the amount of information regarding the presence of megafauna in archaeological sites is still too small to be considered as strong evidence against human predation of megafauna, and thus this piece of information must be interpreted as complementary to the others. Collectively, the data presented here are more consistent with a model explaining megafaunal extinction through climatic fluctuations, although in South America the poor chronological contextualization of the megafaunal decline does not yet allow for a percentage estimate of megafaunal genera that survived until human arrival. In North America (Grayson & Meltzer, 2002, 2003) and in Australia (Wroe et al., 2006; Wroe & Field, 2006), this percentage seems to have been small, suggesting that the megafaunal extinction was a protracted process, beginning much earlier than the human settlement of these continents. Such a decline may have been the case in South America, as only a few megafaunal genera apparently survived until the Holocene. While a human presence could have accelerated the process of extinction of the remaining megafaunal genera, climatic fluctuations could also have been responsible. Araujo et al. (2005) suggested a period of drought during the mid-Holocene in central Brazil, based on a general abandonment of the region by humans and also on palaeoenvironmental data. At least for central Brazil, megafaunal extinction could thus be also explained by the dry period that started between 8500 and 7500 14C yr bp (c. 9520–8190 cal. bp). Furthermore, according to Araujo et al. (2005) several authors recognize the existence of dry climatic periods during the early and mid-Holocene in South America. Bush et al. (2005) also found evidence suggesting the existence of this drier period in the Andes region (between 0° and 24°), although in this case it was not a single or synchronous event. Even if asynchronous, the important point here is that this dry period seems to have been a widespread phenomenon in South America. Thus, we concur with Borrero et al. (1998, p. 197) who propose that ‘people played at most a secondary role in the mega mammal extinctions, perhaps accelerating a process already underway before human arrival in South America’. We would like to thanks Rodolfo Salas for his kindness in assisting us in determining the Holocene date in Peru. Our long-term research in Lagoa Santa is funded by FAPESP (grant 04/01321-6) and by scholarships given to AH (FAPESP 04/11485-6), MH (FAPESP 04/01253-0) and to WAN (CNPQ 305918/85-0). Alex Hubbe is a graduate student at the Laboratory for Human Evolutionary Studies, Instituto de Biociências, Universidade de São Paulo. His main interests are the palaeoecology and extinction of the South America megafauna. Mark Hubbe is an investigator at the Instituto de Investigaciones Arqueológicas y Museo, Universidad Católica del Norte, Chile. His main research interest is the origin and dispersion of the First Americans. Walter Neves is the coordinator of the Laboratory for Human Evolutionary Studies, Instituto de Biociências, Universidade de São Paulo. His main research interest is the origins and adaptations of the First Americans. Editor: Mark Bush

Polypropylene (PP) fibres and yarns are sometimes called polyolefin (PO) when, along with PP, reference is made to polyethylene (PE), which comprise a minor part of them or fibres based on ethylene and propylene polymers. Currently, in terms of global production volume, PP fibres occupy the second place among all types of chemical fibres, lagging much behind polyester fibres [1], but taking part in realization of a growing raw material potential (Fig. 1) that will maintain the trend toward rising demand and capacities of the original polymer for a foreseeable period [2]. In Europe, to which PO fibres owe their origin, they comprise, according to European Textile Polyolefin Association data, 45.2 % of the chemical fibres produced [3]. On the average, about 12 % of the PP granulate produced is processed into fibres and yarns in the world, including Russia, although higher figures are often cited in some sources, which depends on specific regions, the range of products manufactured there, technological direction, level of development of the processing branches, and other factors. In 2011, all polyolefins (PO) of most widespread types of fibre products (Table 1), primarily film yarns, registered growth (+3 %) [4]. Outputs of complex yarns, which include BCF carpet tow, monofilament, and spunbond, attained a high level in Western Europe, China, USA, and Africa, and India, Canada, and South America recorded the highest growth rate. Large PP staple fibre production plants are concentrated in Western Europe, USA, and China (the growth rate relative to 2010 was the highest in the latter). In addition to spunbond, the most actively growing textile products from PP are film yarns (raffia) where China, Western Europe, Africa, Turkey, USA, South America, and Eastern Europe remain the leaders in terms of production volume, and South America, Japan, and Africa, in terms of growth rate in 2011 (+9, +7, and +5 %, respectively). From an analysis of Table 1 we find that a marked decline in production of all types of PO fibres in USA and Mexico. In USA, for example, complex yarn production capacity shrunk by 6 % over the past five years [5], and production of other yarns remained practically at the same level (Table 2). Let us describe in some more detail the situation in the European market since it significantly affects the Russian market. The share of PP fibres in the demand for all types of textile raw material in Europe is 38.9 % and in chemical fibre output is 44.3 % [3]. In this continent, 24.1 % of PP granulate is used for producing fibrous materials (Fig. 2). In the above-noted figures the share of polyethylene is minuscule. New PP spunbond production capacities are being actively introduced in Europe, especially in its eastern part, primarily in Russia where the annual growth rate is the highest in the world, and in Turkey (Table 3). In the context of the European Commission Directive 94/62/EC, PP spunbond must substitute PE film for making packages because it has the best performance properties (high strength, attractive exterior look, and wide-ranging decorative possibilities), reduces deleterious effect on the environment, the packages are capable of being used in a variety of ways and of undergoing secondary processing. Production of PP spunbond has been rising steadily: since 2010 the number of applications from different continents rose to 23 for installation of high-efficiency plants with total capacities of 400,000 tons/yr, which will meet in the period 2012-2015 the rising demand for this relatively light and strong material [6]. Appearance of new plants in South Africa, China, South America, and Indonesia is contributing to the growth of PP spunbond output in these regions. Among the known methods of nonwoven materials (spunlaid, airlaid, carding, spunlace, etc.) production, spunbond is the most popular right now. It accounts for almost one-half of the global production of all types of nonwoven materials (NM), more than 36 % of which is manufactured from PP (Fig. 3). In output volume, the second place belongs to NM produced by carding technique (cloth making from staple fibre) with an output of 3.4M tons in 2012 [4]. Needle-

My own connexion with the southern ocean has been primarily during a ten-year residence in South Africa. I have also spent a year in Australia, but this was concerned with tropical shores. During the South African period a survey was made which revealed the presence of a cold temperate area on the South African coast, lying outside the Subtropical Convergence but affected by the upwelling of a body of cold water which may be antarctic intermediate water, although this attribution has been queried. Since then similar areas have been identified in southern Australia, Tasmania and New Zealand, and it was always clear that South America must possess such an area, although only recently do we know much about the ecology of its seashores. It has been possible to compare the populations of these several areas with one another and with those of some of the southern islands, not only by means of the published accounts, but in the light of conversations and correspondence with those who have visited them, assisted by very large numbers of photographs, both in colour and in monochrome. General studies of seashores are apt to lead to unexpected conclusions, especially if anything is taken for granted beforehand. For example, such work leads one to expect that any well-stocked shore will have representatives of various animal groups on it, such as periwinkles, barnacles, whelks, crabs, anemones and limpets. But in practice one can find shores on which any one of these groups (if not more than one) is missing. This is not necessarily because of special conditions, such as those prevailing in estuaries, where reductions would seem natural, but for no reason which has (as yet) been clearly determined. Similarly, where there is a circumpolar marine climate and a West Wind Drift, one would expect circumpolar marine populations. But this is just what we do not find. While acknowledging immediately that there are circumpolar species, genera and even families, we must realize that these have attracted so much attention as to obscure the other side of the picture, which is equally important and perhaps more surprising. The South African, South Australian and South American shores all have a high proportion of endemic species, particularly marked in Australia; they are very independent. More than this, the combinations of common plants and animals which form the communities characteristic of the South African shores are very distinctive, and they are not found, so far as we know, on any other shores. The same applies to South Australia and South America: nobody familiar with any one of these would confuse them with the others. Probably the same applies to the oceanic islands, or at least to those which are widely separated. This view of the situation does not conflict with the recent work of Knox, though at first sight it may appear to do so. We know from this work that certain dominant species are recurrent round the southern ocean or part of it, and that there is a standard type of zonation. But similarities in zonation exist not only in the southern ocean but all over the world, and they demonstrate not so much a similarity between communities, as a similar reaction to environmental circumstances of any communities which exist at a particular place. Widespread dominant species show more affinity between one area and another, but it may still remain true that the combinations of common species (i. e. the communities) characteristic of any one southern cold temperate area are distinctive of that area and on the whole paralleled but not repeated in the others. The limpets of South Africa may be mentioned in this connexion. South Africa possesses a limpet population which is perhaps unrivalled in the world. There are more than 25 common species, belonging to more than nine genera, and some of these are present in countless thousands and are large in size. Now southern Australia, New Zealand and Tasmania are by no means lacking in limpets, but few if any of them are the same as the South African ones, most if not all of which are endemic to South Africa. South America again has limpets, but a different selection. These three limpet populations are therefore very independent of one another, and although a few circumpolar limpets are known, they occur in regions farther south than South Africa.

Cunoniaceae are woody plants with a distribution that suggests a complex history of Gondwanan vicariance, long-distance dispersal, diversification and extinction. Only four out of ~27 genera in Cunoniaceae are native to South America today, but the discovery of extinct species from Argentine Patagonia is providing new information about the history of this family in South America. We describe fossil flowers collected from early Danian (early Palaeocene, ~64 Mya) deposits of the Salamanca Formation. We compare them with similar flowers from extant and extinct species using published literature and herbarium specimens. We used simultaneous analysis of morphology and available chloroplast DNA sequences (trnL-F, rbcL, matK, trnH-psbA) to determine the probable relationship of these fossils to living Cunoniaceae and the co-occurring fossil species Lacinipetalum spectabilum. Cunoniantha bicarpellata gen. et sp. nov. is the second species of Cunoniaceae to be recognized among the flowers preserved in the Salamanca Formation. Cunoniantha flowers are pentamerous and complete, the anthers contain in situ pollen, and the gynoecium is bicarpellate and syncarpous with two free styles. Phylogenetic analysis indicates that Cunoniantha belongs to crown-group Cunoniaceae among the core Cunoniaceae clade, although it does not have obvious affinity with any tribe. Lacinipetalum spectabilum, also from the Salamanca Formation, belongs to the Cunoniaceae crown group as well, but close to tribe Schizomerieae. Our findings highlight the importance of West Gondwana in the evolution of Cunoniaceae during the early Palaeogene. The co-occurrence of C. bicarpellata and L. spectabilum, belonging to different clades within Cunoniaceae, indicates that the diversification of crown-group Cunoniaceae was under way by 64 Mya.

AimThe genusPodocarpus(Podocarpaceae) provides an opportunity to contrast biogeographical hypotheses within and among continents, and to analyse divergence between disjunct tropical and temperate forests of South America. We developed a calibrated phylogeny ofPodocarpusto reconstruct the ancestral areas and potential expansion routes within Podocarpaceae.LocationPodocarpusconsists of two extant subgenera:Foliolatusfrom Asia and Oceania, andPodocarpuslocated in Gondwanan continents and north to the Caribbean. The paper focuses mainly on the area occupied by the latter subgenus.MethodsWe combined previously published and novelDNAsequences with fossil records. New species sequenced are members ofPodocarpussubgenusPodocarpusfrom South and Central America. We assembledDNAsequences of the chloroplast (matK andrbcL) and nuclear (ITS1 andITS2) to analyse phylogenetic relationships withinPodocarpussubgenusPodocarpusby Bayesian methods, which were calibrated using macrofossils that could be confidently identified as modern genera. Ancestral areas were inferred using the dispersal–extinction–cladogenesis model.ResultsThe phylogenetic reconstruction inferred a minimum age for the origin ofPodocarpuss.l. in the late Cretaceous–early Palaeogene (63 Ma) and strongly supported monophyly of the genusPodocarpusand of subgeneraPodocarpusandFoliolatus. SubgenusPodocarpusconsists of two monophyletic, latitudinally structured clades. One clade consists of temperate American species while the other includes species from tropical‐subtropical Africa and South America.Main conclusionsThe history of the subgenera withinPodocarpusis older than previously reported: they can be traced back to late Cretaceous–early Palaeocene biogeographical connections between Australasia and South America through Antarctica. Latitudinally disjunct lineages within South America most probably diverged from widespread ancestors as a result of a persistent arid barrier that was established prior to the late Palaeogene. The calibrated age for the Tropical–Subtropical clade suggests an Atlantic–subtropical biogeographical corridor between South America and Africa long after the breakup of Gondwana and the stabilization of the circum‐Antarctic current.