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Optimising conservation efforts requires an accurate record of the extant species as well as their geographic distributions. Nevertheless, most current conservation strategies start from an incomplete biodiversity inventory. Argentina has an extraordinary diversity of species, however, until now an updated inventory of its fauna has not been carried out. In this context, the main objective of this work is to present the results of the first national inventory of vertebrate species. Experts from each major vertebrate taxonomic group assembled and compiled its respective inventory. The information gathered included taxonomic rank, conservation status, endemism and geographic distribution. Species richness and representativeness were calculated for each taxonomic group, distinguishing between native, endemic and exotic, for each Argentinian province. Our results show Argentina harbours 3,303 species: 574 marine fish, 561 freshwater fish, 177 amphibians, 450 reptiles, 1,113 birds, and 428 mammals. Native species constitute 98.1% of the total taxa. The results achieved were spatially represented showing a pattern of higher richness from north to south and from east to west. Species considered as threatened account for 17.8% and 15.2% are endemic. There are five Extinct species. These results provide key information on developing strategies and public policies at the national and provincial levels and constitute a tool for the management and conservation of biodiversity.
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BACKGROUND AND AIMS: Morphological, molecular and biogeographical information bearing on early evolution of the sunflower alliance of families suggests that the clade containing the extant daisy family (Asteraceae) differentiated in South America during the Eocene, although palaeontological studies on this continent failed to reveal conclusive support for this hypothesis. Here we describe in detail Raiguenrayun cura gen. & sp. nov., an exceptionally well preserved capitulescence of Asteraceae recovered from Eocene deposits of northwestern Patagonia, Argentina. METHODS: The fossil was collected from the 47·5 million-year-old Huitrera Formation at the Estancia Don Hipólito locality, Río Negro Province, Argentina. KEY RESULTS: The arrangement of the capitula in a cymose capitulescence, the many-flowered capitula with multiseriate-imbricate involucral bracts and the pappus-like structures indicate a close morphological relationship with Asteraceae. Raiguenrayun cura and the associated pollen Mutisiapollis telleriae do not match exactly any living member of the family, and clearly represent extinct taxa. They share a mosaic of morphological features today recognized in taxa phylogenetically close to the root of Asteraceae, such as Stifftieae, Wunderlichioideae and Gochnatieae (Mutisioideae sensu lato) and Dicomeae and Oldenburgieae (Carduoideae), today endemic to or mainly distributed in South America and Africa, respectively. CONCLUSIONS: This is the first fossil genus of Asteraceae based on an outstandingly preserved capitulescence that might represent the ancestor of Mutisioideae-Carduoideae. It might have evolved in southern South America some time during the early Palaeogene and subsequently entered Africa, before the biogeographical isolation of these continents became much more pronounced. The new fossil represents the first reliable point for calibration, favouring an earlier date to the split between Barnadesioideae and the rest of Asteraceae than previously thought, which can be traced back at least 47·5 million years. This is the oldest well dated member of Asteraceae and perhaps the earliest indirect evidence for bird pollination in the family.
Assuntos
Asteraceae/anatomia & histologia , Asteraceae/classificação , Asteraceae/genética , África , Argentina , Evolução Biológica , Flores/anatomia & histologia , Flores/genética , Fósseis , Filogenia , Filogeografia , América do SulRESUMO
The evolution of the inflorescence head in Asteraceae is important in the diversification of this largest angiosperm family. The aggregation of heads into higher-order capitulescences (secondary heads or syncephalia) is considered evolutionarily advanced. The genera Moscharia, Nassauvia, Polyachyrus, and Triptilion of the subtribe Nassauviinae (Mutisieae) have syncephalia with differing degrees of capitula condensation. ITS and plastid trnL-trnF regions were analyzed separately and together using maximum parsimony and maximum likelihood to examine the evolution of syncephalia in the Nassauviinae. The four genera displaying syncephalia do not form a clade minus taxa without syncephalia, indicating that secondary heads in Nassauviinae have either convergently evolved twice in the subtribe (or, very unlikely) once with multiple reversions. Strong support was obtained for a sister relationship between Leucheria (without syncephalium) and Polyachyrus, and both sister to Moscharia. Nassauvia and Triptilion form a distinct clade but are sister to other genera, Perezia and Panphalea, without syncephalium. Previous hypotheses postulated the evolution from simple to more complex secondary heads. We show that the ancestor of Moscharia, Polyachyrus, and Leucheria, in a more arid habitat, had a complex type of secondary head, and loss of complexity occurred in response to a shift from arid to mesic conditions.
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Abstract-Cyttaria Berkeley (Cyttariaceae, Cyttariales, Class Discomycetes), is a genus of eleven species, seven from South America and four from Australasia (Australia, Tasmania, and New Zealand). Cyttaria is a monophyletic genus defined by the following synapomorphies: fleshy to gelatinous stromata with endostromatic apothecia; and complete lack of fungal chitin in the cell walls, having instead ß-1-3-glucan. All Cyttaria are exclusive parasites of Nothofagus species. A cladistic analysis of the genus was performed using 18 characters from macromorphology, micro-morphology, and phenology. Polarity of characters is based on the outgroup comparison method (using the Class Discomycetes as a whole) and on the ontogenetic criterion. A hypothetical outgroup was constructed using all plesiomorphic states. Two equally parsimonious cladograms were produced, each with 40 steps and a consistency index of 0.70. These differed in the position of the South American species C. hookeri and C. johowii. In one cladogram, C. hookeri is the sister group to the rest of the genus, and in the other, both species form a monophyletic group (ascospores ovoid) that is the sister group of the rest of the genus. Our analysis of the two characters causing this difference (position of apothecia on stroma, and shape of ascospores) supports the latter hypothesis. In both cladograms, all of the Australasian species form a monophyletic group (thick ectostroma), and, within that, two subgroups are defined: C. gunnii-C. pallida (papillae present), and C. nigra-C. septentrionalis (ectostroma with black incrustations). The Australasian species form a monophyletic group (spermatangia absent) with C. berteroi, and this last group forms a monophyletic group (conidia absent) with C. espinosae. Cytlaria darwimi and C. exigua form another monophyletic group (very thick ectostroma). Excluding C. hookeri and C. johowii, C. hariotii is the sister group to the remaining eight species.