Anne-Laure Decombeix

French National Centre for Scientific Research | CNRS · Botanique et modélisation de l'Architecture des Plantes et des végétations

Tyloses are swellings of parenchyma cells into adjacent water-conducting cells that develop in vascular plants as part of heartwood formation or specifically in response to embolism and pathogen infection. Here we document tyloses in Late Devonian (approximately 360 Myr ago) Callixylon wood. This discovery suggests that some of the earliest woody t...

The first anatomically preserved wood specimens of an upland Carboniferous flora from the Iberian Peninsula are reported from the Erillcastell Basin (Eastern Pyrenees, Catalonia, Spain). Two taxa are described, a calamitacean Equisetales (Arthropitys sp.) and a Cordaitales (Dadoxylon sp.). The Arthropitys specimen has fusiform multiseriate rays com...

Premise of the Research The fossil record shows that seed plants appeared during the Devonian and started to become dominant in the Mississippian. However, the identity of their closest relatives remains uncertain with three candidates: Stenokoleales, Archeopteridalean progymnosperms, and Aneurophytalean progymnosperms. To clarify the relationship...

Background and Aims The complexity of fossil forest ecosystems is difficult to reconstruct due to the fragmentary nature of the fossil record. However, detailed morpho-anatomical studies of well-preserved individual fossils can provide key information on tree growth and ecology, including in biomes with no modern analogue, such as the lush forests...

The various types of spherical microfossils collectively termed fossil fungal “sporocarps” exhibit basic congruities in morphology that have been used to suggest they all may belong to the same higher taxonomic category. Both the Ascomycota and zygomycete fungi have been discussed in this respect, but features that precisely delimit the nature and...

The Jurassic vegetation of Antarctica remains poorly known and, while there have been several reports of large fossil trees from that time period across the continent, detailed anatomical studies of their wood are extremely scarce. Here we describe new silicified woods of Early Jurassic (probably Toarcian) age from Carapace Nunatak, South Victoria...

Palavras-chave: anatomia vegetal; interdisciplinaridade; mundo. O Brasil é reconhecido mundialmente por ser um dos países com maior número de anatomistas vegetais e um dos poucos com vagas abertas anualmente em universidades para esses profissionais. Além disso, também tem sido um dos maio-res exportadores de pessoas com essa especialidade, com ana...

The fossil record of arborescent lignophytes shows an increasing anatomical diversity during the Tournaisian (360-347 Mya), suggesting a morpho-anatomical diversification following the extinction of the progymnosperm Archaeopteris Dawson, 1871 at the Devonian-Carboniferous boundary. This view has been partly constructed on recent investigations of...

Tyloses are protoplasmic swellings of parenchyma cells into the lumen of adjacent conducting cells. They develop as part of the heartwood formation process, or in response to embolism or pathogen infection. Here, we report the oldest fossil evidence to date of tylosis formation that occurs in permineralized wood of the (pro)gymnosperm Dameria hueb...

Our understanding of vegetation changes around the Devonian-Carboniferous boundary remains limited by the small number of plant-yielding deposits close in age to the boundary. In this context, we have started to reinvestigate Devonian-Carboniferous localities of Ireland, with an initial focus on those from which Matten and collaborators (1980, 1983...

Reflectance Transforming Imaging (RTI) produces photographs in which the angle of the light can be changed at will, allowing to investigate remotely minute details of the 3D structure of sub-planar objects. Here we apply this technique to the type specimen of Gingkophyllum grassetii, a vegetative shoot with putative ginkgophyte affinities from the...

Gondwanan floras of Late Devonian age are poorly known. In Australia, the rare studies that have been published on Late Devonian plants are old and need reinvestigation. This paper is an account of the plant macro- and micro-remains found in the Mandowa Mudstone at Barraba, New South Wales. According to the miospores, plants are late to latest Fame...

One of the youngest known occurrences of anatomically preserved Sphenophyllum Brongniart 1828 is reported from the Permian Motuca Formation, Parnaíba Basin, central-north Brazil. At least 31 stems of this extinct sphenophyte, which are densely interwoven to each other and associated with tiny roots and leaves, occur in a silicified state within the...

Premise of research. Periderm is a protective secondary tissue that replaces the epidermis in stems and roots having secondary growth. The first periderm most commonly originates immediately below the epidermis, but in some species, it arises deeper in the stem, usually in the primary phloem. Periderm is a common feature of extant plants and has be...

The Mesozoic is a key period in fern evolution, with the rise of most modern families. Weichselia reticulata is a widely distributed Jurassic–Cretaceous fern that has been suggested to belong to the Matoniaceae or possibly the Marattiaceae. The most accepted classic whole-plant reconstruction for this species is based on stem and foliage material f...

The first plants related to the ferns are represented by several extinct groups that emerged during the Devonian. Among them, the iridopterids are closely allied to the sphenopsids, a group represented today by the genus Equisetum . They have been documented in Middle to early Late Devonian deposits of Laurussia and the Kazakhstan plate. Their Gond...

The biology of trees that grew in high‐latitude forests during warmer geological periods is of major interest in understanding past and future ecosystem dynamics. As we study the different plants that composed these forests, it becomes possible to make comparisons with ecosystem processes that occur today. Here we describe a silicified late Permian...

Sphenophyllum Brongniart, 1828 is the best-known representative of Sphenophyllales, an extinct order of small plants belonging to the Sphenophytes, the group that contains extant horsetails. Sphenophyllum is known from the Devonian to the Triassic, but most specimens are late Carboniferous in age and the anatomy of specimens present at other times...

The origin of xylem in the Silurian was a major step in plant evolution, leading to diverse growth forms with various mechanical and hydraulic properties. In the fossil record, these properties can only be investigated using models based on extant plant physiology. Regarding hydraulics, previous studies have considered either the properties of a si...

Studies of anatomically preserved fossils provide a wealth of information on the evolution of plant vascular systems through time, from the oldest evidence of vascular plants more than 400 million years ago to the rise of the modern angiosperm-dominated flora. In reviewing the key contributions of the fossil record, we discuss knowledge gaps and ma...

Early Carboniferous (Mississippian) permineralized woods from Australia with multiseriate rays have been customarily assigned or compared to the European genus Pitus, despite the absence of information on their primary vascular anatomy. In the context of continuing work on the diversity of Late Devonian and Mississippian floras of Gondwana, we stud...

The study of wood is key to the understanding of water transport and water relationships in trees, shrubs and climbers, and to the responses of these plants to climate change. In turn, the study of fossil wood is key to understanding the evolution of cells and tissues functioning in water conduction, mechanical strength, and storage and biological...

Archaeopterid trees were the main components of most Late Devonian forests. Their aerial axes characterised by a eustele with mesarch primary xylem strands, leaf traces departing radially from cauline bundles and secondary xylem tracheids with radial pits arranged in groups, are referred to the genus Callixylon Zalessky. The nineteen species of Cal...

Roots of Vertebraria from the Permian of Skaar Ridge, Antarctica are widely believed to belong to the Glossopteris plant. Delayed infrafascicular wood development results in deeply lobed wood cylinder geometries and formation of voids before forming an entire wood cylinder. We explored the functional significance of these traits by measuring the di...

Background and Aims Investigating the biology of trees that were growing at high latitudes during warmer geological periods is key to understanding the functioning of both past and future forest ecosystems. The aim of this study is to report the first co-occurrence of epicormic shoots and traumatic growth zones in fossil trees from the Triassic of...

In Australia, lycopsids are abundant in early land plant assemblages, leading to the concepts of a “Baragwanathia flora” extending from the late Silurian to the Early Devonian, and a “Leptophloeum flora” characterizing the Late Devonian. Yet, the taxonomic status and systematic affinities of a large number of lycopsid remains from the Devonian of A...

Les fossiles du Tournaisien (Carbonifère inférieur) de la Montagne Noire (France) et de Kahlleite (Allemagne) sont préservés en impressions/compressions et en perminéralisations. Parmi l’ensemble des restes retrouvés dans ces localités, cette étude se focalise sur les spécimens appartenant au genre Sphenophyllum. Ils sont décrits à partir de l’obse...

The Barraba flora (late Famennian, New South Wales) comprises plant permineralizations and compressions, recorded in the marine deposits of the Mandowa Mudstone formation. Those sediments were deposited in the Drummond foreland basin, inboard of a volcanic arc in eastern Australia during the Late Devonian. Besides the numerous Leptophloeum compress...

Les fossiles du Tournaisien (Carbonifère inférieur) de la Montagne Noire (France) et de Kahlleite (Allemagne) sont préservés en impressions/compressions et en perminéralisations. Parmi l’ensemble des restes retrouvés dans ces localités, cette étude se focalise sur les spécimens appartenant au genre Sphenophyllum. Ils sont décrits à partir de l’obse...

A new taxon of lignophyte is described based on a permineralized stem from the Late Tournaisian (Lower Carboniferous) of the Central Ahnet region, Algeria. It shows similarities with arborescent seed plants described in the Lower Carboniferous of Europe and North America such as Eristophyton waltonii Lacey and Cauloxylon ambiguum Cribbs. However, t...

Evidence of fungal decay is frequently encountered in silicified wood. However, studies focusing on fossil fungal wood degradation remain rare. A characteristic pattern of degradation and decay symptoms congruent with present-day white pocket rot occur in Late Permian silicified glossopteridalean stem and root wood (Australoxylon sp.) from Skaar Ri...

Premise of research. Despite their importance for understanding plant evolution and plant-environmental interactions through geological time, fossil roots have always received less attention than aerial parts. In the case of the lignophytes (i.e., progymnosperms and seed plants), the ability to form abundant secondary vascular tissues (secondary xy...

Two pyrite permineralized stems and one root are reported from the upper Middle to lowermost Late Devonian (middle Givetian to lowermost Frasnian) locality of Ronquières (Belgium) and identified as Brabantophyton runcariense Momont et al. (Stenokoleales). The stems include a three-ribbed protostele with a central protoxylem strand and other strands...

Among the few Lower Jurassic sites with plant remains known from Antarctica, Carapace Nunatak, in South Victoria Land, is emerging as one of the richest. It contains different types of plant fossils (pollen, silicified plants, compressions/impressions, and fusain), which opens the door to promising multidisciplinary studies on past biodiversity and...

The Glossopteridales are an extinct group of seed plants that dominated Gondwanan floras during the Permian. Their remains are found across a wide range of habitats and paleolatitudes, and it is particularly interesting to understand the anatomical characteristics that might have enabled such an extensive distribution. Here, we document for the fir...

During the first Korea Antarctic Geological Expedition (KAGEX I, 2013/2014), fossil wood was collected from the Triassic fluvial deposits of the Beacon Supergroup at Skinner Ridge in northern Victoria Land, Antarctica. The material is coalified and partially silicified; most specimens are slightly compressed due to burial compaction. In spite of th...

The Middle to early Late Devonian aneurophytalean progymnosperms represent the basalmost group of lignophytes and may have included the seed plant ancestor. They are widely recorded in Laurussia. Before this work, the only occurrences of Aneurophytales in Gondwana were in Venezuela and Morocco. In this paper we describe one fertile and two vegetati...

It is usually considered that after the extinction of the Devonian tree Archaeopteris, no new arborescent lignophytes were established before the late Tournaisian. A reassessment of this pattern is presented here based on a three-fold approach: a re-evaluation of the taxic diversity of Tournaisian lignophyte trees based on descriptions of new plant...

We review progress made during the last 25 years in our understanding of the Protopityales, Early Carboniferous plants belonging to the extinct group of the progymnosperms. Recent studies support previous observations that the only genus of this order, Protopitys, included large arborescent plant with trunks up to 1 m in diameter. All branch orders...

Premise of research. Well-preserved Triassic plant fossils from Antarctica yield insights into the physiology of plant growth under the seasonal light regimes of warm polar forests, a type of ecosystem without any modern analogue. Among the many well-known Triassic plants from Antarctica is the enigmatic Petriellaea triangulata, a dispersed seedpod...

Premise of research. Secondary phloem produced by a bifacial vascular cambium is the distinctive feature of lignophytes, the group that comprises the seed plants and the progymnosperms. Because secondary phloem is rarely well preserved in the fossil record, our knowledge of the evolution of this tissue remains incomplete. Methodology. We illustr...

The leaf longevity of trees, deciduous or evergreen, plays an important role in climate feedbacks and plant ecology. In modern forests of the high latitudes, evergreen trees dominate; however, the fossil record indicates that deciduous vegetation dominated during some previous warm intervals. We show, through an integration of palaeobotanical techn...

En paléontologie, les XIXe et XXe siècles corres- pondent à la mise en place de l’anatomie comparée pour interpréter les fossiles, des corrélations stratigraphiques pour dater les terrains sédimentaires et de l’usage de la biostratigraphie, de la paléoécologie et de la paléogéo- graphie, plus tardivement de la paléobiologie et de sa contribution à...

Araucarioxylon Kraus is a widely known fossil genus generally used for woods similar to that of the extant Araucariaceae. However, since 1905, several researchers have pointed out that this name is a junior nomenclatural synonym and, as such, a nomen illegitimum. At least four generic names are in current use for fossil wood of this type: Agathoxyl...

Anatomically preserved trunks and young stems of corystosperm seed ferns are described from the Triassic of Fremouw Peak, Beardmore Glacier area, Antarctica. Based on characters of the primary and secondary vascular system, these new specimens are assigned to Kykloxylon, a genus that was established based on young stems with attached Dicroidium lea...

Araucarioxylon Kraus is a widely known fossil-genus generally applied to woods similar to that of the extant Araucariaceae. However, since 1905, several researchers have pointed out that this name is an illegitimate junior nomenclatural synonym. At least four generic names are in current use for fossil wood of this type: Agathoxylon Hartig, Araucar...

Premise of the study: During the Devonian, the evolution of secondary phloem produced by a bifacial vascular cambium was a key innovation that increased the ability of plants within the lignophyte clade to redistribute photosynthates and other organic compounds throughout their body. Unraveling the secondary phloem anatomy of the first arborescent...

Our knowledge of the evolution of secondary phloem and periderm anatomy in early lignophytes (progymnosperms and seed plants) is limited by the scarcity of well-preserved fossil bark. Here, I describe the bark of a Mississippian (Early Carboniferous) tree from Australia based on macro-and microscopic observation of two permineralized specimens. the...

The evolutionary history of lignophyte roots is poorly known, and direct evidence of root systems in early members of this clade is scant. Whereas Middle Devonian aneurophytalean progymnosperms possessed rhizomatous stems bearing small, shallow roots, the root system of archaeopteridalean trees is expected to have been much more extended and comple...

We present a whole-plant concept for a genus of voltzialean conifers on the basis of compression/impression and permineralized material from the Triassic of Antarctica. The reconstruction of the individual organs is based on a combination of organic connections, structural correspondences, similarities in cuticles and epidermal morphologies, co-occ...

Well-preserved fungi occur in permineralized conifer axes from the Lower Jurassic of northern Victoria Land, Antarctica. The fungus is characterized by septate hyphae extending through the vascular ray system via penetration of cross-field pits. Tyloses are present in large numbers and might have been effective as a physical restraint to the spread...

The uncovering of a large soil surface preserved under sediment for 390 million years has exposed plant remains which show that the world's earliest forests were much more complex than previously thought. See Letter p.78

Anatomically preserved gymnosperm axes are relatively abundant in Permian localities of Antarctica, but their anatomy has rarely been studied in detail, which limits comparison with other Gondwanan morphotaxa. Here we describe a silicified trunk collected from the Upper Permian Buckley Formation at Coalsack Bluff, in the central Transantarctic Moun...

Mycorrhizal root nodules occur in the conifer families Araucariaceae, Podocarpaceae, and Sciadopityaceae. Although the fossil record of these families can be traced back into the early Mesozoic, the oldest fossil evidence of root nodules previously came from the Cretaceous. Here we report on cellularly preserved root nodules of the early conifer No...

Although root suckering and other types of sprouting are well studied in extant woody plants, little is known about the distribution of these traits at a macroevolutionary scale. Anatomically preserved fossil plants represent an excellent but understudied source of information of the distribution of sprouting behavior through time and across taxa....

It is usually considered that after the extinction of the Devonian tree Archaeopteri s, no new arborescent lignophytes were established before the late Tournaisian. A reassessment of this pattern is presented here based on a three-fold approach: a re-evaluation of the taxic diversity of Tournaisian lignophyte trees based on descriptions of new plan...