Calicioid lichens and fungi in amber – Tracing extant lineages back to the Paleogene

Calicioid lichens and fungi are a polyphyletic grouping of tiny ascomycetes that accumulate a persistent spore mass (mazaedium) on top of their usually well-stalked ascomata (‘mazaediate fungi’). In addition to extant forms, six fossils of the group were previously known from European Paleogene amber. Here we report nine new fossils and analyze the preserved features of all fossils to assess their applicability for dating molecular phylogenies. Many fossils are extremely well preserved, allowing detailed comparisons with modern taxa. SEM investigation reveals that even fine details of ascospore wall ultrastructure correspond to those seen in extant specimens. All fossils can confidently be assigned to modern genera: three to Calicium (Caliciaceae, Lecanoromycetes), five to Chaenotheca (Coniocybaceae, Coniocybomycetes), six to Chaenothecopsis (Mycocaliciaceae, Eurotiales), and one to Phaeocalicium (Mycocaliciaceae, Eurotiales). Several Calicium and Chaenotheca fossils are assignable to specific lineages within their genera, while the Chaenothecopsis fossils demonstrate the extent of intraspecific variation within one such lineage. Some features in the morphology of Chaenotheca succina nov. sp. seem to be ancestral as they have not been reported from modern species of the genus.     

Contribución al conocimiento de los líquenes epifíticos del Valle de Sanabria (Zamora,España)

A catalogue of epiphytic lichens from the Sanabria valley (Zamora) is presented in this study. A total of 145 taxa are reported. According to our data, 137 taxa are new records for Zamora Province. For each species, ecological and chorological remarks are included. Chaenotheca furfuracea, Chromatochlamys muscorum, Cladina arbuscula subsp. mitis, Degelia atlantica, Julella lactea, Mycobilimbia hypnorum, Nephroma parile, Pannaria ignobilis, Pannaria pezizoides, Peltigera britannica, P. hymenina, Pertusaria ophthalmiza, Rinodina archaea, R. conradii, Thelenella modesta and Xylographa abietina are specially considered, due to their chorological implications in the Iberian Peninsula. We highlight the area “arroyo de las Truchas”, in Cobreros, because of the particularly wide diversity of epiphytic lichens.     

Der Krienser Hochwald (Kanton Luzern): Ein wertvoller Lebensraum für zahlreiche, in der Schweiz gef?hrdete Flechtenarten

Dietrich M., Bürgi-Meyer K., Bergamini A., Scheidegger C. and Stofer S. 2008. The Forest of Kriens (canton of Lucerne): A valuable habitat for many threatened lichens of Switzerland. Bot. Helv. 118: 149 – 164. In Switzerland almost half of the epiphytic lichen species are listed as threatened. Lichens, especially epiphytic species, contribute significantly to the biological diversity of forest ecosystems. Many of them are important indicator species and thus used for designing successful conservation strategies in woodlands. This study documents the importance of the Forest of Kriens near the city of Lucerne (Central Switzerland) as a habitat for epiphytic lichens. A rich flora comprising 182 species was recorded, thirty seven species being threatened in Switzerland and four being protected at the national level. Chaenotheca sphaerocephala, Micarea xanthonica and Psilolechia clavulifera are reported for the first time from Switzerland. More than sixty recorded lichen species are indicators of environmental continuity in woodlands. The sub-oceanic-montane climate at this north-facing slope at the border of the Northern Pre-Alps and the extensive, close to nature forest management, which guarantees environmental continuity, facilitate a high species diversity among epiphytic lichens. Thus, the Forest of Kriens is an important refuge for endangered species whence they might invade lichen-impoverished areas of the Central Plateau. For several epiphytic lichen species it represents the only known locality in the canton of Lucerne and one of few in Switzerland. Eingereicht am 21. Juni 2008, Angenommen am 24. September 2008 Redaktion: A. Leuchtmann     

No support for the emergence of lichens prior to the evolution of vascular plants

The early‐successional status of lichens in modern terrestrial ecosystems, together with the role lichen‐mediated weathering plays in the carbon cycle, have contributed to the long and widely held assumption that lichens occupied early terrestrial ecosystems prior to the evolution of vascular plants and drove global change during this time. Their poor preservation potential and the classification of ambiguous fossils as lichens or other fungal–algal associations have further reinforced this view. As unambiguous fossil data are lacking to demonstrate the presence of lichens prior to vascular plants, we utilize an alternate approach to assess their historic presence in early terrestrial ecosystems. Here, we analyze new time‐calibrated phylogenies of ascomycete fungi and chlorophytan algae, that intensively sample lineages with lichen symbionts. Age estimates for several interacting clades show broad congruence and demonstrate that fungal origins of lichenization postdate the earliest tracheophytes. Coupled with the absence of unambiguous fossil data, our work finds no support for lichens having mediated global change during the Neoproterozoic‐early Paleozoic prior to vascular plants. We conclude by discussing our findings in the context of Neoproterozoic‐Paleozoic terrestrial ecosystem evolution and the paleoecological context in which vascular plants evolved.     

天山森林生态系统树生地衣植物群落数量分类及其物种多样性的研究

地衣是由低等植物中的藻类与菌类中的真菌和兰细菌共生而成的一群特殊的植物。由于耐寒耐旱对生活中的养分要求不高,在养纷贫瘠、环境恶劣的高山寒漠、平原、戈壁和沙漠中地衣都能生长,因而广泛地分布和生长在不同的生态环境中。有关新疆地衣方面的研究报道集中在物种分类水平上,对于地衣群落结构方面的研究比较少。因此,我们应用多元分析中的主分量分析及聚类分析方法对分布在天山森林生态系统中树生地衣植物群落进行数量分类并对群落结构物种多样性、相似性和均匀度等群落参数进行了比较系统的研究。结果表明, 在西部天山不同森林生态系统中树生地衣群落的分布与海拔高度和树种有密切的关系, 不同海拔的不同类型的森林生态系统中分布着不同种类的树生地衣植物。 根据多元分析结果和生境的综合特征,该地区的树生地衣可划分为4种类型: 1) 茎口果粉衣+金黄茶衣群丛Chaenotheca stemonea+Candellaria aurella Association; 2)叉小孢衣+裸扁枝衣+粉唇蜈蚣衣群丛Bryoria furcellata+Evernia esorediosa+Physcia tribacoides Association; 3)亚广开梅衣+槽梅衣+疑小梅衣群丛Parmelia fertilis+Parmelia sulcata+Parmeliopsis ambigua Association; 4)睫毛黑蜈蚣衣+黑蜈蚣衣群丛Phaeophyscia ciliata+Phaeophyscia nigricans Association。其群落多样性指数以亚广开梅衣+槽梅衣+疑小梅衣群丛为最高 (1.920), 叉小孢衣+裸扁枝衣+粉唇蜈蚣衣群丛为最低 (1.562)。     

The Atapuerca human fossils

After 20 years of research, the Atapuerca sites have provided a large amount of archaeological and palaeontological remains. Human fossils have been found in three sites: Gran Dolina, galería and Sima de los Huesos. The Early Pleistocene human fossils from Gran Dolina have been ascribed to a new species,Homo antecessor, that represent the last common ancestor of Neandertals and modern humans. The Sima de los Huesos fossils and all the European Middle Pleistocene human fossils are the ancestors exclusively of the Neandertals, which evolved in Europe in conditions of geographic and genetic isolation.     

The human cranial remains from Gran Dolina Lower Pleistocene site (Sierra de Atapuerca, Spain).

In this article we study the cranial remains of the late Lower Pleistocene human fossils from Gran Dolina (Sierra de Atapuerca, Spain), assigned to the new species Homo antecessor. The cranial remains belong to at least five individuals, both juveniles and adults. The most outstanding feature is the totally modern human morphology of the very complete face ATD6-69, representing the earliest occurrence of the modern face in the fossil record. The Gran Dolina fossils show in the face a suite of modern human apomorphies not found in earlier hominids nor in contemporary or earlier Homo erectus fossils. There are also traits in the Gran Dolina fossils shared with both Neandertals and modern humans, which reinforce the hypothesis that Neandertals and modern humans form a clade, and that the Gran Dolina fossils are a common ancestor to both lineages.     

Problematic megafossils in Cambrian palaeosols of South Australia

Abstract: Red calcareous Middle Cambrian palaeosols from the upper Moodlatana Formation in the eastern Flinders Ranges of South Australia formed in well‐drained subhumid floodplains and include a variety of problematic fossils. The fossils are preserved like trace fossil endichnia but do not appear to be traces of burrows or other animal movement. They are here regarded as remains of sessile organisms, comparable with fungi or plants living in place, and are formally named as palaeobotanical form genera under provisions of the International Code of Botanical Nomenclature. Most common are slender (0.5–2 mm) branching filaments flanked by green‐grey reduction haloes within the red matrix of palaeosol surface horizons (Prasinema gracile gen. et sp. nov.). Other axial structures (Prasinema nodosum and P. adunatum gen. et spp. nov.) are larger and show distinctive surface irregularities (short protuberances and irregular striations, respectively). The size and form of these filaments are most like rhizines of soil‐crust lichens. Other evidence of life on land includes quilted spheroids (Erytholus globosus gen. et sp. nov.) and thallose impressions (Farghera sp. indet.), which may have been slime moulds and lichens, respectively. These distinctive fossils in Cambrian palaeosols represent communities comparable with modern biological soil crusts.     

Evaluating the conservation status of epiphytic lichens of Italy: A red list

Despite the fact that Italy is among the lichenologically best known areas worldwide, a national red list of lichens is still lacking. The aim of this work was to provide a red list of the epiphytic lichens of Italy which could facilitate the inclusion of lichens in national conservation plans. The evaluation of the species against International Union for Conservation of Nature (IUCN) criteria was based on data from multiple sources which represent the best available information on the epiphytic lichens of Italy. The species were assigned to the IUCN categories mainly using criteria D and B. A total of 368 species were evaluated: for 23 species, information is missing from more than 50 years and they were listed as regionally extinct, 64 as critically endangered, 75 as endangered, 74 as vulnerable, 58 as near threatened, 20 as least concern and 54 species as data deficient. Our results indicate that more than one-fourth of the epiphytic lichens of Italy are likely to be threatened, so that further research and effort are needed to include lichens in the main national conservation plans. Our results also highlight the lack of information that still hampers the rigorous evaluation of Italian lichens against IUCN criteria.     

Seasonal variation of diet and food availability in a group of Sichuan snub-nosed monkeys in Shennongjia Nature Reserve, China

We studied the diet and food availability of a group of Sichuan snub-nosed monkeys for 14 months (July 2003 to September 2004, except for February) in the Shennongjia Nature Reserve, China. This species is primarily a lichen eater, with lichens (Usneaceae) accounting for 43.28% of feeding records (n=3,452). Other food types in the diet were young leaves (28.71%), fruits or seeds (14.57%), buds (5.36%), mature leaves (3.51%), herbs (2.09%), bark (1.36%), and flowers (1.13%). The monkeys used 23 plant species. Their diet showed a complicated seasonal variation: the monthly diet varied from primarily lichens in November-April, to a mixture of leaves and lichens in May-July, to a mixture of fruits or seeds and lichens in August-October (the latter depended on annual fruit and seed availability). The proportion of fruits or seeds in the diet was negatively correlated with that of lichens, which suggests that the monkeys prefer fruits or seeds to lichens when all of these items are available. The fruit or seed availability varied greatly between the two study years. The proportion of lichens, young leaves, flowers, and fruits or seeds in the diet was positively associated with their availability. The monkeys appeared to be selective feeders. They preferred 10 tree species for plant parts, and nine tree species for lichens. The selection index of tree species for lichens was positively related to lichen coverage per branch on tree species, demonstrating that the monkeys preferred tree species with abundant lichens, as well as dead trees for lichens. The results suggest that dead-tree harvesting in the reserve could significantly reduce the quality of habitat for these monkeys, and should therefore be prohibited. Connus controversa, Cerasus discadenia, Salix willichiana, and Malus halliana should be conserved as top priority species because the monkeys preferred them for both their vegetative parts and the lichens that grow on them.     

Lichens

The prion diseases sheep scrapie and cervid chronic wasting disease are transmitted, in part, via an environmental reservoir of infectivity; prions released from infected animals persist in the environment and can cause disease years later. Central to controlling disease transmission is the identification of methods capable of inactivating these agents on the landscape. We have found that certain lichens, common, ubiquitous, symbiotic organisms, possess a serine protease capable of degrading prion protein (PrP) from prion-infected animals. The protease functions against a range of prion strains from various hosts and reduces levels of abnormal PrP by at least two logs. We have now tested more than 20 lichen species from several geographical locations and from various taxa and found that approximately half of these species degrade PrP. Critical next steps include examining the effect of lichens on prion infectivity and cloning the protease responsible for PrP degradation. The impact of lichens on prions in the environment remains unknown. We speculate that lichens could have the potential to degrade prions when they are shed from infected animals onto lichens or into environments where lichens are abundant. In addition, lichens are frequently consumed by cervids and many other animals and the effect of dietary lichens on prion disease transmission should also be considered.     

Fossil Araceae from a Paleocene neotropical rainforest in Colombia

Both the fossil record and molecular data support a long evolutionary history for the Araceae. Although the family is diverse in tropical America today, most araceous fossils, however, have been recorded from middle and high latitudes. Here, we report fossil leaves of Araceae from the middle-late Paleocene of northern Colombia, and review fossil araceous pollen grains from the same interval. Two of the fossil leaf species are placed in the new fossil morphogenus Petrocardium Herrera, Jaramillo, Dilcher, Wing et Gomez-N gen. nov.; these fossils are very similar in leaf morphology to extant Anthurium; however, their relationship to the genus is still unresolved. A third fossil leaf type from Cerrejón is recognized as a species of the extant genus Montrichardia, the first fossil record for this genus. These fossils inhabited a coastal rainforest ～60-58 million years ago with broadly similar habitat preferences to modern Araceae.     

A thalloid organism with possible lichen affinity from the Jurassic of northeastern China

Documentation of fossil lichens is rare, despite the fact that lichenization in fungi is believed to be ancient and many paleoecosystems should have provided ample suitable habitats for these organisms. Impression fossils of a cm-sized thalloid organism, Daohugouthallus ciliiferus nov. gen. et spec., are described from a Middle Jurassic deposit nearby Daohugou village, Inner Mongolia, China. The thallus comprises elongate primary axes from which extend lateral and terminal branches that fork once to repeatedly. Extending from all branches (mostly from the lateral margins and tips) are filiform appendages that closely resemble the cilia of certain extant lichens. Some branch tips appear ruptured and covered by minute irregularities, and appear similar to lichen soralia. One specimen is associated with a small seed cone and suggestive of epiphytic growth. The structural similarities with extant lichens, close association with land plants, and the environment in which the organism lived, suggest that the affinity of D. ciliiferus is with the lichens.     

Lichens: Unexpected anti-prion agents?

The prion diseases sheep scrapie and cervid chronic wasting disease are transmitted, in part, via an environmental reservoir of infectivity; prions released from infected animals persist in the environment and can cause disease years later. Central to controlling disease transmission is the identification of methods capable of inactivating these agents on the landscape. We have found that certain lichens, common, ubiquitous, symbiotic organisms, possess a serine protease capable of degrading prion protein (PrP) from prion-infected animals. The protease functions against a range of prion strains from various hosts and reduces levels of abnormal PrP by at least two logs. We have now tested more than twenty lichen species from several geographical locations and from various taxa and found that approximately half of these species degrade PrP. Critical next steps include examining the effect of lichens on prion infectivity and cloning the protease responsible for PrP degradation. The impact of lichens on prions in the environment remains unknown. We speculate that lichens could have the potential to degrade prions when they are shed from infected animals onto lichens or into environments where lichens are abundant. In addition, lichens are frequently consumed by cervids and many other animals and the effect of dietary lichens on prion disease transmission should also be considered.Key words: prion, lichen, degradation, environment, Chronic Wasting disease, protease, transmissible spongiform encephalopathy     

Genomic signatures of evolution in Nautilus—An endangered living fossil

Living fossils are survivors of previously more diverse lineages that originated millions of years ago and persisted with little morphological change. Therefore, living fossils are model organisms to study both long‐term and ongoing adaptation and speciation processes. However, many aspects of living fossil evolution and their persistence in the modern world remain unclear. Here, we investigate three major aspects of the evolutionary history of living fossils: cryptic speciation, population genetics and effective population sizes, using members of the genera Nautilus and Allonautilus as classic examples of true living fossils. For this, we analysed genomewide ddRAD‐Seq data for all six currently recognized nautiloid species throughout their distribution range. Our analyses identified three major allopatric Nautilus clades: a South Pacific clade, subdivided into three subclades with no signs of admixture between them; a Coral Sea clade, consisting of two genetically distinct populations with significant admixture; and a widespread Indo‐Pacific clade, devoid of significant genetic substructure. Within these major clades, we detected five Nautilus groups, which likely correspond to five distinct species. With the exception of Nautilus macromphalus, all previously described species are at odds with genomewide data, testifying to the prevalence of cryptic species among living fossils. Detailed F_ST analyses further revealed significant genome‐wide and locus‐specific signatures of selection between species and differentiated populations, which is demonstrated here for the first time in a living fossil. Finally, approximate Bayesian computation (ABC) simulations suggest large effective population sizes, which may explain the low levels of population differentiation commonly observed in living fossils.     

Miocene Ethiopian amber: A new source of fossil cryptogams

Amber is renowned for the exceptional preservation state of its inclusions, allowing detailed morphological analysis and providing relevant environmental, palaeoecological, geographical, and geological information. Amber deposits are predominantly known from North America, Europe, and Asia, and are considered to be rare on the continents that formed Gondwana. The recent discovery of fossiliferous amber deposits in Ethiopia, therefore, provides an inimitable opportunity to close gaps in the fossil record of African terrestrial biota and to study organisms which are otherwise rare in the fossil record. Here we show that diverse cryptogams are preserved in highest fidelity in Miocene Ethiopian amber. We describe gametophyte fragments of four liverworts: Thysananthus aethiopicus sp. nov. (Porellales, Lejeuneaceae), Lejeunea abyssinicoides sp. nov. (Porellales, Lejeuneaceae), Frullania shewanensis sp. nov. (Porellales, Frullaniaceae), and Frullania palaeoafricana sp. nov. (Porellales, Frullaniaceae). Furthermore, we describe a pleurocarpous moss of the extant genus Isopterygium (Hypnales, Pylaisiadelphaceae) and a lichen representing the order Lecanorales. These new specimens represent the first amber fossils of liverworts, mosses, and lichens from the African continent and render Ethiopian amber as one of the few worldwide amber deposits preserving bryophytes (mosses and liverworts) or lichens. Fossil species of Thysananthus were recorded in Eocene Baltic and Oligocene Bitterfeld as well as Miocene Dominican and probably also Miocene Mexican ambers. Fossils that can unequivocally be assigned to Lejeunea have only been found in Dominican amber so far. Neotropical ambers contain only one taxon of Frullania to date, while the genus is most diverse in Baltic, Bitterfeld, and Rovno ambers, formed in temperate regions. The new fossils support a tropical to subtropical origin of Ethiopian amber. The new African liverwort fossils are included in an updated list of leafy liverworts described from worldwide Cenozoic ambers to date.     

Fossil oak galls preserve ancient multitrophic interactions

Trace fossils of insect feeding have contributed substantially to our understanding of the evolution of insect-plant interactions. The most complex phenotypes of herbivory are galls, whose diagnostic morphologies often allow the identification of the gall inducer. Although fossil insect-induced galls over 300Myr old are known, most are two-dimensional impressions lacking adequate morphological detail either for the precise identification of the causer or for detection of the communities of specialist parasitoids and inquilines inhabiting modern plant galls. Here, we describe the first evidence for such multitrophic associations in Pleistocene fossil galls from the Eemian interglacial (130000-115000 years ago) of The Netherlands. The exceptionally well-preserved fossils can be attributed to extant species of Andricus gallwasps (Hymenoptera: Cynipidae) galling oaks (Quercus), and provide the first fossil evidence of gall attack by herbivorous inquiline gallwasps. Furthermore, phylogenetic placement of one fossil in a lineage showing obligate host plant alternation implies the presence of a second oak species, Quercus cerris, currently unknown from Eemian fossils in northwestern Europe. This contrasts with the southern European native range of Q. cerris in the current interglacial and suggests that gallwasp invasions following human planting of Q. cerris in northern Europe may represent a return to preglacial distribution limits.     

Miocene Fossils Reveal Ancient Roots for New Zealand’s Endemic Mystacina (Chiroptera) and Its Rainforest Habitat

The New Zealand endemic bat family Mystacinidae comprises just two Recent species referred to a single genus, Mystacina. The family was once more diverse and widespread, with an additional six extinct taxa recorded from Australia and New Zealand. Here, a new mystacinid is described from the early Miocene (19–16 Ma) St Bathans Fauna of Central Otago, South Island, New Zealand. It is the first pre-Pleistocene record of the modern genus and it extends the evolutionary history of Mystacina back at least 16 million years. Extant Mystacina species occupy old-growth rainforest and are semi-terrestrial with an exceptionally broad omnivorous diet. The majority of the plants inhabited, pollinated, dispersed or eaten by modern Mystacina were well-established in southern New Zealand in the early Miocene, based on the fossil record from sites at or near where the bat fossils are found. Similarly, many of the arthropod prey of living Mystacina are recorded as fossils in the same area. Although none of the Miocene plant and arthropod species is extant, most are closely related to modern taxa, demonstrating potentially long-standing ecological associations with Mystacina.     

Differences between Neandertal and modern human infant and child growth models

Studying the emergence of distinctive human growth patterns is essential to understanding the evolution of our species. The large number of Neandertal fossils makes this species the best candidate for a comparative study of growth patterns in archaic and modern humans. Here, Neandertal height growth during infancy and early childhood is described using a mathematical model. Height growth velocities for individuals five years old or younger are modelled as age functions based on different estimates of height and age for a set of ten Neandertal infants and children. The estimated heights of each Neandertal individual are compared with those of two modern human populations based on longitudinal and cross-sectional data. The model highlights differences in growth velocity during infancy (from the age of five months onward). We find that statural growth in Neandertal infants is much slower than that seen in modern humans, Neandertal growth is similar to modern humans at birth, but decreases around the third or fourth month. The markedly slower growth rates of Neandertal infants may be attributable to ontogenetic constraints or to metabolic stress, and contribute to short achieved adult stature relative to modern humans.