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

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.     

Major vegetation trends in the Tertiary of Patagonia (Argentina): A qualitative paleoclimatic approach based on palynological evidence

The patterns of Patagonian vegetation change suggest a strong relationship between the major thermal characters of the flora and the global paleoclimatic trends during Tertiary times. This conclusion was reached from the assessment of fossil pollen data from Patagonia throughout the Paleogene and Early Neogene periods and the subsequent comparison of palynological data to the global deep-sea oxygen isotope record. Four main time intervals were recognized based on the temporal distribution of selected angiosperm key taxa. (1) Paleocene to Early Eocene: presence of megatherm elements (e.g. Nypa, Pandanus), probably integrating mangrove communities in Patagonian lowlands. (2) Middle Eocene to Early Oligocene: rise to dominance of mesotherm and microtherm Nothofagus species. Megatherm taxa were well recorded at the beginning of this interval (e.g. Ilex) but were shown to disappear towards the end. (3) Late Oligocene to Middle Miocene: new increases of megatherm taxa such as palms, Cupania and Alchornea. First occurrences of mesotherm Asteraceae, represented by trailing Mutisieae, were reported. (4) Late Miocene: dispersal of meso-microtherm and arid adapted taxa (e.g. Ephedraceae and Asteraceae) across the non-Andean region of Patagonia. Microtherm Nothofagacean forests probably occurred on the higher rainfall regions of western Patagonia. The current vegetation was most likely reached during this last stage with the forest development under wetter conditions on the Andean sectors, and the steppe throughout the non-Andean region of Patagonia.     

Fossil pollen grains of Asteraceae from the Miocene of Patagonia: Nassauviinae affinity

Fossil pollen grains with morphological features unique in the subtribe Nassauviinae (tribe Mutisieae, Asteraceae) occur in Miocene marine deposits of eastern Patagonia, southern South America. A new morphogenus and two morphospecies are proposed to assemble fossil pollen grains characterized by having a complex bilayered exine structure with delicate columellae, separated by an internal tectum. Subprolate specimens with Trixis exine type (ectosexine thinner than endosexine, straight internal tectum) are referred to Huanilipollis cabrerae. This species is similar to pollen of recent Holocheilus, Jungia, and Proustia. Suboblate specimens with Oxyphyllum exine type (ectosexine and endosexine equally thick, zigzag internal tectum) are referred to Huanilipollis criscii. This species is similar to pollen of recent Triptilion. The spore/pollen sequences in which Nassauviinae pollen types occur suggest a wide range of vegetation types varying from forest dominated during the Early Miocene (Chenque Formation) to virtually xerophytic ones during the Late Miocene (Puerto Madryn Formation). The subtribe Nassauviinae comprises 25 genera and ca. 320 species of vines, shrubs and low trees endemic to America with a wide range of ecological preferences; the nearest living relatives of the fossil types being mostly confined to humid landscapes. The unusual occurrence of these groups during the arid characterized Late Miocene time could be attributed to the complex interplay of the mountain uplift and global circulation patterns. These forcing factors would have created a mosaic of different habitats with both patches of forest and dry-adapted species developing in relatively small regions. This is the first fossil record of Nassauviinae and confirms that this subtribe of Asteraceae was already differentiated in the Miocene.     

Comparative pollen morphology of Brachylena, Tarchananthus and two species of Tubulifloridites (Asteraceae) from the Eocene, Knysna Lignite of South Africa

Two fossil taxa Tubulifloridites antipodica and T. viteauensis recovered from the Eocene Knysna Lignite of South Africa were examined with scanning (SEM) and transmission electron microscopy (TEM). The details of their sculpturing and wall structure are similar to the same species of fossil dispersed pollen taxa recovered from southwestern Africa and South America. Fifteen species of the woody South African taxa, Brachylaena (9 species) and Tarchonanthus (6 species) were investigated with SEM and TEM. All of the taxa are tricolporate, spherical to slightly prolate, microechinate to echinate and have a bilayered columellate infrastructure, except B.ilicifolia, which has a single columellate infrastructural level with the “granularization” of the outer portion of the infrastructural layer or the inner layer of the tectum. There is a similar distribution of plesiomorphic and derived pollen characters in a number of aster subfamilies and tribes suggesting a similar evolutionary progression of pollen, and pollen wall character evolution was occurring synchronously in a variety of aster subfamilies during the middle Tertiary and that these unique pollen features may be important to the evolution and diversification of the Asteraceae.     

First Evidence for Wollemi Pine-type Pollen (Dilwynites: Araucariaceae) in South America

We report the first fossil pollen from South America of the lineage that includes the recently discovered, extremely rare Australian Wollemi Pine, Wollemia nobilis (Araucariaceae). The grains are from the late Paleocene to early middle Eocene Ligorio Márquez Formation of Santa Cruz, Patagonia, Argentina, and are assigned to Dilwynites, the fossil pollen type that closely resembles the pollen of modern Wollemia and some species of its Australasian sister genus, Agathis. Dilwynites was formerly known only from Australia, New Zealand, and East Antarctica. The Patagonian Dilwynites occurs with several taxa of Podocarpaceae and a diverse range of cryptogams and angiosperms, but not Nothofagus. The fossils greatly extend the known geographic range of Dilwynites and provide important new evidence for the Antarctic region as an early Paleogene portal for biotic interchange between Australasia and South America.     

Modern pollen assemblages from human-influenced vegetation in northwestern China and their relationship with vegetation and climate

Modern pollen spectra can improve the interpretation of fossil pollen records used to reconstruct past vegetation, climate and human impacts. It is important, therefore, to carefully examine the relationships between modern pollen spectra, vegetation, climate and human activity. Here, we present the results of an analysis of the pollen spectra of 143 surface pollen samples from farmland, wasteland, desert, steppe/meadow, forest and river valley along a transect from Lanzhou to Urumqi, in northwestern China. The modern pollen assemblages are mainly composed of Amaranthaceae, Artemisia, Poaceae, Asteraceae, Ephedra and Nitraria. The results indicate that in general the surface pollen assemblages of different vegetation types reliably represent the modern vegetation in terms of the composition of the main taxa and the dominant types. Farmland is dominated by cereal-type (≥?15%) and Amaranthaceae (≥?20%), while the pollen assemblages of wasteland (i.e. the vegetation immediately surrounding farmland) are mainly composed of Amaranthaceae (≥?25%), Artemisia (≥?20%), Poaceae (≥?10%), Asteraceae (≥?5%) and Cyperaceae (≥?5%). Amaranthaceae (≥?45%) and Ephedra (≥?10%) are the most important taxa in desert, and Cyperaceae (≥?35%) and Thalictrum (≥?2%) are the dominant pollen types in steppe/meadow. Forest and river valley samples are characterized by high frequencies of Picea (≥?10%) and Cyperaceae (≥?20%). Both constrained and partial canonical ordination techniques (RDA and partial RDA) of the main pollen types and environmental variables show that the modern pollen spectra are primarily controlled by mean annual precipitation (MAP). Cyperaceae, Thalictrum and Brassicaceae are positively correlated with MAP and negatively correlated with mean July temperature (T_July), while the representation of certain other types, such as Amaranthaceae, Ephedra and Nitraria, is negatively correlated with MAP and positively correlated with T_July. The Human Influence Index (HII) is significantly correlated with cereal-type pollen, and it can also differentiate human-influenced and natural vegetation. Our results provide a basis for improving the interpretation of fossil pollen records from arid northwestern China and similar regions.     

Differentiation between Neotropical rainforest,dry forest,and savannah ecosystems by their modern pollen spectra and implications for the fossil pollen record

Accurate differentiation between tropical forest and savannah ecosystems in the fossil pollen record is hampered by the combination of: i) poor taxonomic resolution in pollen identification, and ii) the high species diversity of many lowland tropical families, i.e. with many different growth forms living in numerous environmental settings. These barriers to interpreting the fossil record hinder our understanding of the past distributions of different Neotropical ecosystems and consequently cloud our knowledge of past climatic, biodiversity and carbon storage patterns. Modern pollen studies facilitate an improved understanding of how ecosystems are represented by the pollen their plants produce and therefore aid interpretation of fossil pollen records. To understand how to differentiate ecosystems palynologically, it is essential that a consistent sampling method is used across ecosystems. However, to date, modern pollen studies from tropical South America have employed a variety of methodologies (e.g. pollen traps, moss polsters, soil samples). In this paper, we present the first modern pollen study from the Neotropics to examine the modern pollen rain from moist evergreen tropical forest (METF), semi-deciduous dry tropical forest (SDTF) and wooded savannah (cerradão) using a consistent sampling methodology (pollen traps). Pollen rain was sampled annually in September for the years 1999–2001 from within permanent vegetation study plots in, or near, the Noel Kempff Mercado National Park (NKMNP), Bolivia. Comparison of the modern pollen rain within these plots with detailed floristic inventories allowed estimates of the relative pollen productivity and dispersal for individual taxa to be made (% pollen/% vegetation or ‘p/v’). The applicability of these data to interpreting fossil records from lake sediments was then explored by comparison with pollen assemblages obtained from five lake surface samples.Pollen productivity is demonstrated to vary inter-annually and conforms to a consistent hierarchy for any given year: METF > SDTF > cerradão. This suggests an association between pollen productivity and basic structural characteristics of the ecosystem, i.e. closed canopy vs. open canopy vs. savannah. Comparison of modern pollen and vegetation revealed that some important floristic elements were completely absent from the pollen: Qualea and Erisma (METF), Bauhinia, Simira and Guazuma (SDTF), and Pouteria and Caryocar (cerradão). Anadenanthera was found to be abundant in both the pollen and flora of SDTF (p/v = 3.6), while Poaceae was relatively poorly represented in cerradão (0.2). Moraceae, Cecropia and Schefflera were found to be over-represented palynologically in all ecosystems. Overall, the data demonstrated that no one taxon could be used as a definitive indicator of any of the ecosystems. Instead, associations of taxa were found to be important: METF = Moraceae (> 40%), Cecropia, Hyeronima, Celtis; SDTF = Anadenanthera, Apuleia, Ferdinandusa and non-arboreal Asteraceae, Bromeliaceae, Piper and fern spores; cerradão = Poaceae, Myrtaceae, Borreria, Solanum plus Asteraceae and fern spores. Interpretation of Poaceae pollen was highlighted as problematic, with relatively low abundance in the cerradão (< 20%) in comparison to high abundance in lake environments (c. 30–50%). Re-examination of fossil pollen records from NKMNP revealed that modern vegetation associations were only established in the last few thousand years.     

Revision of the Proteaceae macrofossil record from Patagonia, Argentina

Proteaceae are restricted to the Southern Hemisphere, and of the seven tribes of the subfamily Grevilleoideae, only three (Macadamieae, Oriteae, and Embothrieae) have living members in Argentina. Megafossil genera of Proteaceae recorded from Patagonia includeLomatia, Embothrium, Orites, andRoupala. In this report, we evaluate and revise fossil Argentine Proteaceae on the basis of type material and new specimens. The new collections come from the Tufolitas Laguna del Hunco (early Eocene, Chubut Province), the Ventana (middle Eocene, Río Negro Province), and the Río Ñirihuau (late Oligocene-early Miocene, Río Negro Province) formations, Patagonia, Argentina. We confirm the presence ofLomatia preferruginea Berry,L. occidentalis (Berry) Frenguelli,L. patagonica Frenguelli,Roupala patagonica Durango de Cabrera et Romero, andOrites bivascularis Romero, Dibbern et Gandolfo. Fossils assigned toEmbothrium precoccineum Berry andE. pregrandiflorum Berry are doubtful, and new material is necessary to confirm the presence of this genus in the fossil record of Patagonia. A putative new fossil species of Proteaceae is presented as Proteaceae gen. et sp. indet. Fossil Proteaceae are compared with modern genera, and an identification key for the fossil leaf species is presented. Doubtful historical records of Proteaceae fossils for the Antarctic Peninsula region and Patagonia are also discussed. Based on this revision, the three tribes of Proteaceae found today in Argentina were already present in Patagonia by the early Eocene, where they probably arrived via the Australia-Antarctica-South America connection.     

Modern pollen and vegetation relationships in northeastern Patagonia (Golfo San Matías,Río Negro)

The understanding of modern pollen is a critical component of palaeoecological research. The pollen assemblages reflect general patterns in vegetation distribution; however, pollen representation is biased by several factors such as differences in pollen production, dispersal and preservation. Therefore, this relationship cannot be applied directly in pollen records of the past. The aim is to study the relationship between modern pollen and vegetation and to apply this new information on the interpretation of Holocene pollen records. Classification of the vegetation into groups corresponding to different geomorphological units was carried out by cluster analysis. Discriminant analysis was applied on the surface samples to test if different vegetation types could be distinguished by their pollen assemblages. To evaluate the relationship between pollen assemblages and vegetation types, association (A), under-representation (U) and over-representation (O) indexes were calculated for all present taxa in both plant and pollen dataset. The main vegetation types are reflected in pollen assemblages but with greater differences in the proportions of Poaceae, Hyalis argentea, Chenopodiaceae, Asteraceae subf. Asteroideae and Larrea divaricata. Association and representation indexes provided information related to the production rate and pollen dispersal. This study helps to interpret Holocene vegetation and environmental changes from fossil pollen records of the study area.     

Specialist bees collect Asteraceae pollen by distinctive abdominal drumming (<Emphasis Type="Italic">Osmia</Emphasis>) or tapping (<Emphasis Type="Italic">Melissodes</Emphasis>, <Emphasis Type="Italic">Svastra</Emphasis>)

Four species of western US Osmia (3 Cephalosmia) that are Asteraceae specialists (mesoleges) were observed using a stereotypical means of collecting pollen—abdominal drumming—to gather pollen from 21 flowering species representing nine tribes of Asteraceae. Abdominal drumming is a rapid dorso-ventral motion of the female’s abdomen (467 pats/min) used to directly collect and place pollen in the bee’s ventral scopa. A co-occurring generalist, O. lignaria, never drummed Asteraceae flowers for pollen, but instead used its legs to harvest pollen. Observed drumming by several other osmiines is noted. A different pollen-harvesting behavior, abdominal tapping, is described for two eucerine bees (Melissodes agilis and Svastra obliqua), both oligolectic for the Asteraceae. The behavior also involves a dorso-ventral motion, but they tap their distal abdominal venter against disk flowers at a slower tempo (304 taps/min). These females’ distal sternites have distinctly dense and long hair brushes for acquiring pollen by this behavior. Brief accounts of similar abdominal pollen gathering behaviors by other megachilids are summarized.     

Vegetation changes and human occupation in the Patagonian steppe, Argentina, during the late Holocene

Vegetation changes during the late Holocene are interpreted from four fossil pollen sequences from two caves at the Los Toldos archaeological locality, Santa Cruz province, Argentina. Taphonomic processes are particularly taken into account in order to analyze the effects on the fossil pollen records of biotic factors such as human occupation and animals, and abiotic ones such as volcanic ash fall. Fossil pollen assemblages are interpreted using local modern pollen data. The main vegetation change occurred at ca. 3750 uncal b.p., when a shrub steppe of Asteraceae subf. Asteroideae with Schinus, Ephedra frustillata and a high proportion of grasses was replaced by a shrub steppe of Colliguaja integerrima and Asteraceae subf. Asteroideae. This change is synchronous with an archaeological record change and could be related either to moderate climatic variations or the effects of ash fall on the environment. Plant communities similar to the present-day ones were established in the Los Toldos area from ca. 3750 uncal b.p.     

Assessment of airborne Asteraceae pollen in Brisbane, Australia

In the southern hemisphere, the airborne prevalence and seasonal distribution of Asteraceae pollen are poorly characterized. In this study, we assessed the longitudinal distribution of Asteraceae pollen using an historic aerobiological dataset. The influence of weather parameters on pollen derived from Asteraceae species was additionally explored. Asteraceae pollen was collected using a static Burkard 7-day spore trap during a 5-year (June 1994–May 1999) aerometric surveillance program in Brisbane, Australia. Two discrete seasonal intervals were identified each sampling year. The first interval (September and October) consisted of small quantities of unidentifiable Asteraceae pollen. The second interval (March and April) was characterized by the highest concentrations of Asteraceae pollen that were predominantly derived from Baccharis halimifolia. Associations between daily Asteraceae pollen concentrations and temperature were observed during each sampling year. The results of the study demonstrated that pollen derived from B. halimifolia, an invasive weed species introduced in the late nineteenth century, continue to be in the environment of Brisbane. Given the public health burden associated with personal Asteraceae pollen exposure in other geographic locations, future Australian-based clinical studies should characterize the contribution of Asteraceae pollen, in particular B. halimifolia, to allergic sensitization and respiratory morbidity.     

Two novel reports of semidry stigmatic surface in Asteraceae

Research documents related to the morphology and function of style branches and stigmatic surface of Asteraceae are still rather few, and the literature reports are thus controversial. We report in the present study that the stigmatic surfaces of two non-related species of Asteraceae (Lessingianthus grandiflorus and Lucilia lycopodioides) have features of semidry stigmas. Sporodermis of both species was also analyzed so that we could understand how the stigmatic surface works during pollen deposition and rehydration. Stylar branches and pollen grains (sporodermis) were studied using scanning and transmission electron microscopy (SEM and TEM) and histochemistry techniques. The inner and marginal bands of stylar branches in these species display intermediary features between the dry and wet types of stigma: the cuticle characterizes the dry stigma and cells with secretory activity characterize the wet stigma; these showed differences from what has been described to the Asteraceae family, where stigmatic surface of species from several tribes is considered dry. Pollen grains are medium-size to large with exine ornamentation (echinate and echinolophate) and abundant secretion which latter characterizes pollenkitt. We can assume that two processes might help pollen grain hydration on stigmatic surface in Lessingianthus grandiflorus and Lucilia lycopodioides: (1) the presence of pollenkitt, as observed in the secretory content inside exine cavities and around pollen grains; and (2) the secretory activity of stigmatic surface cells, whose secretion accumulates among intercellular and subcuticular spaces and leads to cuticle disruption during the floral receptive phase. Our results suggest that ultrastructural and histochemical studies should be considered when describing stigmatic surface and that the “semidry” feature within Asteraceae should be investigated still more in detail, so that the taxonomic or adaptation value of this trait in the family can be verified.     

The Subfamily Mutisioideae (Asteraceae)

The subfamily Mutisioideae (74 genera, ca. 865 species), which comprises three tribes, Mutisieae (43 genera, ca. 500 species), Nassauvieae (25 genera, ca. 315 species), and Stifftieae (six genera, 48 species), is analyzed at the generic level. A total of 87 genera traditionally related to Mutisioideae were studied. The genera of Mutisioideae are described and illustrated, and keys to tribes and genera are given. Corollas, anthers, styles, and pollen, are analyzed and discussed. The styles (smooth, rugulose to papillose, papillae short and rounded) constitute the main characters for delimiting the subfamily. The presence and distribution of the style papillae support the recognition of three tribes, although other characters as corolla shape contribute to their definition. The pollen of Nassauvieae can be clearly differentiated from the pollen of Mutisieae and Stifftieae. The morphology supports the exclusion of Brachylaena, Cloiselia, Dicoma, Duseniella, Erythrocephalum, Gladiopappus, Hesperomannia, Macledium, Moquinia, Pasaccardoa, Pleiotaxis, Tarchonanthus, and Warionia but not the exclusion of other taxa, for example, Hecastocleis, the Gochnatia complex, or the Ainsliaea group members.

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Resumen  La subfamilia Mutisioideae (74 géneros, ca. 865 especies), que comprende tres tribus, Mutisieae (43 géneros, ca. 500 especies), Nassauvieae (25 géneros, ca. 315 especies), y Stifftieae (6 géneros, 48 especies), es analizada a nivel genérico. Se estudió un total de 87 géneros que tradicionalmente fueron relacionados a Mutisioideae. Se describen e ilustran los géneros de Mutisioideae, y se proveen claves para las tribus y los géneros. Se analizan y discuten las corolas, anteras y estilos. Los caracteres del estilo (glabro, ruguloso a papiloso, las papilas cortas y redondeadas) son los más importantes para delimitar la subfamilia. La presencia y distribución de las papilas del estilo ayudan al reconocimiento de las tres tribus, aunque otros caracteres como la forma de la corola contribuyen a su definición. El polen de Nassauvieae se puede diferenciar claramente del polen de Mutisieae y Stifftieae. La morfología apoya la exclusión de Brachylaena, Cloiselia, Dicoma, Duseniella, Erythrocephalum, Gladiopappus, Hesperomannia, Macledium, Moquinia, Pasaccardoa, Pleiotaxis, Tarchonanthus, y Warionia, pero no la exclusión de otros taxa, por ejemplo, Hecastocleis, los miembros del complejo Gochnatia o del grupo Ainsliaea.

     

Floral Preference of Melipona eburnea Friese (Hymenoptera: Apidae) in a Colombian Andean Region

Melipona eburnea Friese is a stingless bee kept in some regions of Colombia, where it is reported to be vulnerable to extinction due to habitat disturbance. To contribute to raising conservation strategies, the aim of this study was to identify the floral preferences of this species using melissopalynological analysis. A total of 31 pollen pot samples and 37 honey samples were taken from March 2009 through March 2010 from four colonies in Fusagasuga, Colombia. We found 92 pollen types: 17 from pollen pot samples, 39 from honey samples (indicating the sources of nectar), and 36 in both types of samples. The most frequent pollen types in the pollen pot samples were Myrcia type (100%), Eucalyptus globulus (96.9%), and Fraxinus uhdei (96.9%). The most frequent pollen types in honey samples were E. globulus (97.4%) and Myrcia type (94.9%). The pollen types corresponded mainly to native plants (68%), trees (44.5%), plants whose sexual system is hermaphroditic (56.5%), and plants with inflorescences (76.2%). The most frequent shapes of the flowers were brush-like (type Myrtaceae) and dish-like (type Asteraceae), and the preferred flower colors were white or cream (52.2%). In general, we found that M. eburnea showed a strong preference for trees of the family Myrtaceae to obtain nectar and pollen, including native and introduced species. Some other families are contributing significantly, such as Melastomataceae for pollen collection and Asteraceae for nectar. These results highlight the key plant species for the diet of M. eburnea.     

Pollen Analysis of Natural Honeys from the Central Region of Shanxi,North China

Based on qualitative and quantitative melissopalynological analyses, 19 Chinese honeys were classified by botanical origin to determine their floral sources. The honey samples were collected during 2010–2011 from the central region of Shanxi Province, North China. A diverse spectrum of 61 pollen types from 37 families was identified. Fourteen samples were classified as unifloral, whereas the remaining samples were multifloral. Bee-favoured families (occurring in more than 50% of the samples) included Caprifoliaceae (found in 10 samples), Laminaceae (10), Brassicaceae (12), Rosaceae (12), Moraceae (13), Rhamnaceae (15), Asteraceae (17), and Fabaceae (19). In the unifloral honeys, the predominant pollen types were Ziziphus jujuba (in 5 samples), Robinia pseudoacacia (3), Vitex negundo var. heterophylla (2), Sophora japonica (1), Ailanthus altissima (1), Asteraceae type (1), and Fabaceae type (1). The absolute pollen count (i.e., the number of pollen grains per 10 g honey sample) suggested that 13 samples belonged to Group I (<20,000 pollen grains), 4 to Group II (20,000–100,000), and 2 to Group III (100,000–500,000). The dominance of unifloral honeys without toxic pollen grains and the low value of the HDE/P ratio (i.e., honey dew elements/pollen grains from nectariferous plants) indicated that the honey samples are of good quality and suitable for human consumption.     

Palynological characterization of honeys from the Andean Patagonia (Chubut,Argentina)

The pollen content of 58 honey samples of Apis mellifera L. from the Andean region of Chubut (Argentinian Patagonia) was analyzed. The samples were provided by beekeepers between 1999 and 2004. Eighty‐eight pollen types were identified, 30 of them are not reported in Argentinian honeys. Identified types belong to 47 families, of which the most diverse were Asteraceae (15 pollen types), Fabaceae (13 pollen types), and Rosaceae (four pollen types). From the samples analyzed, 47% were monofloral and corresponded to the following taxa: Trifolium spp. (16%), Rosaceae (10%), Aristotelia chilensis (Molina) Stuntz (7%), Discaria‐Colletia (5%), Escallonia spp. (3%), Schinus patagonica (Phil.) I. M. Johnst. (2%), Phacelia secunda J. F. Gmel. (2%), Myrtaceae (2%). The results of this study show a high level of utilization of native flora by Apis mellifera. Four new types of monofloral honey were recognized: Aristotelia chilensis, Discaria‐Colletia, Phacelia secunda, and Schinus patagonica. The high representation of native flora distinguishes these honeys geographically.     

Vegetation reconstruction on the basis of pollen in Late Pleistocene hyena coprolites from San Teodoro Cave (Sicily, Italy)

Vegetation reconstruction based on pollen from coprolites of extinct spotted hyena (Crocuta crocuta spelaea, Goldfuss 1832) recovered from excavations carried out in 1998 at San Teodoro Cave (Sicily, Italy) supports previous indications of pre-Late Glacial conditions. Eight of the twelve coprolites analysed contained well-preserved pollen grains. There is a general similarity between the pollen contents from the coprolites but they show variability. They suggest a main vegetation type dominated by steppic taxa (Poaceae, Artemisia, Ephedra, Chenopodiaceae and Asteraceae) but also including arboreal taxa (Pinus and Cupressaceae). Low percentages of pollen of mesophilous woody taxa (Quercus, Betula, Abies, Alnus, Pistacia, among others) are noticeable, suggesting the existence of nearby refugia for temperate and Mediterranean vegetation. A reconstruction of the landscape, using the coprolite pollen record and other pollen records from Sicily and south Italy, shows the predominance, during the pre-Late Glacial, of a wooded steppe biome, with elements representing a variety of local environmental conditions.     

Origin and divergence of Afro-Indian Picrodendraceae: linking pollen morphology,dispersal modes,fossil records,molecular dating and paleogeography

The pantropical Picrodendraceae produce mostly spheroidal to slightly oblate, echinate pollen grains equipped with narrow circular to elliptic pori that can be hard to identify to family level in both extant and fossil material using light microscopy only. Fossil pollen of the family have been described from the Paleogene of America, Antarctica, Australia, New Zealand, and Europe, but until now none have been reported from Afro-India. Extant pollen described here include representatives from all recent Picrodendraceae genera naturally occurring in Africa and/or Madagascar and south India and selected closely related tropical American taxa. Our analyses, using combined light microscopy and scanning electron microscopy, show that pollen of the Afro-Indian genera encompass three morphological types: Type 1, comprising only Hyaenanche; Type 2, including Aristogeitonia, Mischodon, Oldfieldia and Voatamalo; Type 3, comprising the remaining two genera, Androstachys and Stachyandra. Based on the pollen morphology presented here it is evident that some previous light microscopic accounts of spherical and echinate fossil pollen affiliated with Arecaceae, Asteraceae, Malvaceae, and Myristicaceae from the African continent could belong to Picrodendraceae. The pollen morphology of Picrodendraceae, fossil pollen records, a dated intra-familial phylogeny, seed dispersal modes, and the regional Late Cretaceous to early Cenozoic paleogeography, together suggest the family originated in the Americas and dispersed from southern America across Antarctica and into Australasia. A second dispersal route is believed to have occurred from the Americas into continental Africa via the North Atlantic Land Bridge and Europe.     

A New Early Miocene Chinchilloid Hystricognath Rodent; an Approach to the Understanding of the Early Chinchillid Dental Evolution

Chinchilloidea is an emblematical group of caviomorph rodents characterized by euhypsodont, laminated cheek teeth. Recent molecular analyses proposed that the extant Dinomys (and implicitly its fossil allies) is also part of this group. Their relationships with fossil caviomorphs with less derived dental features are still obscured by the deficiency of the fossil record documenting its early dental evolution. The new genus and species Garridomys curunuquem, from the early Miocene deposits of the Cerro Bandera Formation, northern Patagonia, is here described. It is represented by numerous mandible and maxillary remains with dentition. This species has protohypsodont cheek teeth with three transverse crests in all ontogenetic stages arranged in a transitory S-shaped pattern, resembling putative early dinomyids. Garridomys curunuquem is here interpreted as the sister group of the clade including the living and fossil chinchillids; both chinchillas and viscaccias would have diverged from a Garridomys-like ancestor and acquired hypsodonty independently. Garridomys and other chinchilloids would have diverged from the lineage leading to chinchillids in pre-Oligocene times, suggesting a very early, still poorly documented chinchilloid radiation.