A new leaf inhabiting ascomycete from the Jurassic (ca 170 Mya) of Yorkshire, UK, and insights into the appearance and diversification of filamentous Ascomycota.

Leaf-associated fungi, the fungi that depend on leaves to sporulate, have a rich Cenozoic record, however their earlier diversity is poorly characterized. Here we describe Harristroma eboracense gen. et sp.

Christine Strullu-Derrien.

Interview with Christine Strullu-Derrien, who studies the origin and early evolution of microorganisms, as well as their interactions with plants, at the Natural History Museum in London and the National Museum of Natural History in Paris.

A fungal plant pathogen discovered in the Devonian Rhynie Chert.

Fungi are integral to well-functioning ecosystems, and their broader impact on Earth systems is widely acknowledged. Fossil evidence from the Rhynie Chert (Scotland, UK) shows that Fungi were already diverse in terrestrial ecosystems over 407-million-years-ago, yet evidence for the occurrence of Dikarya (the subkingdom of Fungi that includes the phyla Ascomycota and Basidiomycota) in this site is scant. Here we describe a particularly well-preserved asexual fungus from the Rhynie Chert which we examined using brightfield and confocal microscopy.

Hapalosiphonacean cyanobacteria (Nostocales) thrived amid emerging embryophytes in an early Devonian (407-million-year-old) landscape.

Cyanobacteria have a long evolutionary history, well documented in marine rocks. They are also abundant and diverse in terrestrial environments; however, although phylogenies suggest that the group colonized land early in its history, paleontological documentation of this remains limited. The Rhynie chert (407 Ma), our best preserved record of early terrestrial ecosystems, provides an opportunity to illuminate aspects of cyanobacterial diversity and ecology as plants began to radiate across the land surface.

Structure and specialization of mycorrhizal networks in phylogenetically diverse tropical communities.

Background: The root mycobiome plays a fundamental role in plant nutrition and protection against biotic and abiotic stresses. In temperate forests or meadows dominated by angiosperms, the numerous fungi involved in root symbioses are often shared between neighboring plants, thus forming complex plant-fungus interaction networks of weak specialization. Whether this weak specialization also holds in rich tropical communities with more phylogenetically diverse sets of plant lineages remains unknown.

An expanded diversity of oomycetes in Carboniferous forests: Reinterpretation of Oochytrium lepidodendri (Renault 1894) from the Esnost chert, Massif Central, France.

335-330 million-year-old cherts from the Massif Central, France, contain exceptionally well-preserved remains of an early forest ecosystem, including plants, fungi and other microorganisms. Here we reinvestigate the original material prepared by Renault and Roche from collections of the Muséum National d'Histoire Naturelle, Paris, and present a re-evaluation of Oochytrium lepidodendri (Renault 1894), originally described as a zoosporic fungus. Confocal laser scanning microscopy (CLSM) was used to study the microfossils, enabling us in software to digitally reconstruct them in three-dimensional detail.

Genomic and fossil windows into the secret lives of the most ancient fungi.

Fungi have crucial roles in modern ecosystems as decomposers and pathogens, and they engage in various mutualistic associations with other organisms, especially plants. They have a lengthy geological history, and there is an emerging understanding of their impact on the evolution of Earth systems on a large scale. In this Review, we focus on the roles of fungi in the establishment and early evolution of land and freshwater ecosystems.

Aquatic stem group myriapods close a gap between molecular divergence dates and the terrestrial fossil record.

Identifying marine or freshwater fossils that belong to the stem groups of the major terrestrial arthropod radiations is a longstanding challenge. Molecular dating and fossils of their pancrustacean sister group predict that myriapods originated in the Cambrian, much earlier than their oldest known fossils, but uncertainty about stem group Myriapoda confounds efforts to resolve the timing of the group's terrestrialization. Among a small set of candidates for membership in the stem group of Myriapoda, the Cambrian to Triassic euthycarcinoids have repeatedly been singled out.

The Rhynie chert.

In 1912, William Mackie, a medical practitioner surveying the regional geology west of Aberdeen, Scotland, happened on some unusual rocks (Figure 1) near the village of Rhynie. Dark gray to nearly black and shot through with cylindrical structures a few millimeters in diameter, these rocks differed markedly from the shales and volcanic rocks of local hills. Mackie had discovered the Rhynie chert - paleobotany's most iconic deposit - with its exceptionally preserved fossils that provide a uniquely clear view of early terrestrial ecosystems in statu nascendi.

Reconstructing trait evolution in plant evo-devo studies.

Our planet is teeming with an astounding diversity of plants. In a mere single group of closely related species, tremendous diversity can be observed in their form and function - the colour of petals in flowering plants, the shape of the fronds in ferns, and the branching pattern of the gametophyte in mosses. Diversity can also be found in subtler traits, such as the resistance to pathogens or the ability to recruit symbiotic microbes from the environment.

Testate Amoebae in the 407-Million-Year-Old Rhynie Chert.

The Lower Devonian Rhynie chert is justly famous for the clear glimpse it offers of early terrestrial ecosystems [1]. Seven species of stem- and crown-group vascular plants have been described from Rhynie, many preserved in growth position [2], as well as 14 species of invertebrate animals, all arthropods [3] save for a single nematode population [4]. While these shed welcome light on early tracheophytes and land animals, modern terrestrial ecosystems additionally contain a diversity of microscopic organisms that are key to ecosystem function, including fungi, protists, and bacteria.

Fossil filamentous microorganisms associated with plants in early terrestrial environments.

Microorganisms are ubiquitous in modern environments, where they have a variety of essential functions but little is known about their diversity and roles in early terrestrial environments. The earliest direct evidence of filamentous microorganisms associated with plants occurs around 407 million years ago in landscapes dominated by an herbaceous flora. 100 million years later, forests were well established and associations had increased in diversity.

The origin and evolution of mycorrhizal symbioses: from palaeomycology to phylogenomics.

Contents Summary 1012 I. Introduction 1013 II. The mycorrhizal symbiosis at the dawn and rise of the land flora 1014 III.

Fertile : a basal ascomycete with inoperculate, polysporous asci lacking croziers.

The affinities of have been debated ever since its fossils, some attaining tree-trunk proportions, were discovered in Canadian Lower Devonian rocks in 1859. Putative assignations include conifers, red and brown algae, liverworts and fungi (some lichenised). Detailed anatomical investigation led to the reconstruction of the type species, , as a giant sporophore (basidioma) of an agaricomycete (= holobasidiomycete), but evidence for its reproduction remained elusive.

New insights into the evolutionary history of Fungi from a 407 Ma Blastocladiomycota fossil showing a complex hyphal thallus.

Zoosporic fungi are key saprotrophs and parasites of plants, animals and other fungi, playing important roles in ecosystems. They comprise at least three phyla, of which two, Chytridiomycota and Blastocladiomycota, developed a range of thallus morphologies including branching hyphae. Here we describe gen.

Early Diverging Fungi: Diversity and Impact at the Dawn of Terrestrial Life.

As decomposers or plant pathogens, fungi deploy invasive growth and powerful carbohydrate active enzymes to reduce multicellular plant tissues to humus and simple sugars. Fungi are perhaps also the most important mutualistic symbionts in modern ecosystems, transporting poorly soluble mineral nutrients to plants and thus enhancing the growth of vegetation. However, at their origin over a billion years ago, fungi, like plants and animals, were unicellular marine microbes.

A New Chytridiomycete Fungus Intermixed with Crustacean Resting Eggs in a 407-Million-Year-Old Continental Freshwater Environment.

The 407-million-year-old Rhynie Chert (Scotland) contains the most intact fossilised remains of an early land-based ecosystem including plants, arthropods, fungi and other microorganisms. Although most studies have focused on the terrestrial component, fossilised freshwater environments provide critical insights into fungal-algal interactions and the earliest continental branchiopod crustaceans. Here we report interactions between an enigmatic organism and an exquisitely preserved fungus.

The origin and early evolution of roots.

Geological sites of exceptional fossil preservation are becoming a focus of research on root evolution because they retain edaphic and ecological context, and the remains of plant soft tissues are preserved in some. New information is emerging on the origins of rooting systems, their interactions with fungi, and their nature and diversity in the earliest forest ecosystems. Remarkably well-preserved fossils prove that mycorrhizal symbionts were diverse in simple rhizoid-based systems.

Fungal associations in Horneophyton ligneri from the Rhynie Chert (c. 407 million year old) closely resemble those in extant lower land plants: novel insights into ancestral plant-fungus symbioses.

Fungi (Eumycota) form close associations with plants, with which they have co-existed since the dawn of life on land, but their diversity in early terrestrial ecosystems is still poorly understood. We studied petrographic sections of exceptionally well-preserved petrified plants from the 407 million yr-old Rhynie Chert (Scotland, UK). For comparative purposes, we illustrate fungal associations in four extant lower land plants.

A simple type of wood in two Early Devonian plants.

The advent of wood (secondary xylem) is a major event of the Paleozoic Era, facilitating the evolution of large perennial plants. The first steps of wood evolution are unknown. We describe two small Early Devonian (407 to 397 million years ago) plants with secondary xylem including simple rays.