Fertile osmundaceae from the early Jurassic of patagonia, Argentina

Two new compression-impression species of the Osmundaceae described from reproductive and vegetative remains are erected for the first time from the Early Jurassic of Argentina. Todites cacereii sp. nov. and Osmundopsis rafaelii sp. nov. demonstrate that two main osmundaceous reproductive morphologies; i.e., differentiated reduced or unreduced fertile laminae were already present and widespread in Gondwana by this time. On the basis of a discussion of relevant morphological characters, the phylogenetic meaning of the fossils Todites and Osmundopsis is explored. Likewise, the systematics and taxonomy of fossil taxa and their relationships with modern ones are discussed in light of current hypotheses. In this regard, because clear synapomorphies or apomorphies are not yet fully understood, it is suggested that fossil representatives are better placed in morphotaxa (Todites, Osmundopsis) than in any current genus. Nonetheless, the clear record of characters of the leptopteroid clade by the early Jurassic proves to be older than previously assumed, which also points to an earlier time of origination for the osmundaceous ferns.Fil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Cúneo, Néstor Rubén. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentin

Evolution and relationships of the conifer seed cone telemachus: Evidence from the triassic of antarctica

The seed cone Telemachus is known from several Triassic localities in Gondwana. New specimens from two localities in Antarctica provide additional information about the type species, Telemachus elongatus, based on details of morphology and anatomy revealed by using a modified transfer technique on the compressed plants. Seed cones of T. elongatus are up to 6.0 cm long and characterized by conspicuous, elongate bracts. A second Antarctic species, described here as Telemachus antarcticus, is segregated, based on a shorter bract and differences in cone size. Newly recognized features of the genus include the shape, size, and disposition of the ovules; vascularization of the ovuliferous complex; and scale and bract histology. As a result of this new information, it is now possible to compare Telemachus with the permineralized Middle Triassic conifer seed cone Parasciadopitys from the Central Transantarctic Mountains. The similarities between the two genera make it possible to relate organs in different preservational modes and to develop a more complete concept for this widely distributed Gondwana conifer. Placing the Telemachus plant within a phylogenetic context makes it possible to evaluate the relationship with other so-called transitional conifers, an informal group that has been interpreted as intermediate between Paleozoic and modern conifers.Fil: Escapa, Ignacio Hernán. University of Kansas; Estados Unidos. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Decombeix, Anne-Laure. University of Kansas; Estados UnidosFil: Taylor, Edith L.. University of Kansas; Estados UnidosFil: Taylor, Thomas N.. University of Kansas; Estados Unido

Volver al futuro: plantas fósiles y morfología cuando no queda (casi) nada por secuenciar

La familia Araucariaceae posee tres géneros vivientes: Araucaria, Wollemia y Agathis, con distribución mayormente restringida al Hemisferio Sur. Estudios filo- genéticos basados en matrices moleculares, incluyendo un número progresivamente mayor de secuencias, han permitido la estabilización de las topologías y valores de apoyo notablemente altos para la mayoría de los nodos. Sin embargo, este consenso generalizado en cuanto a las relaciones en representantes actuales de Araucariaceae, poco permite colaborar para comprender la historia evolutiva de una familia con al menos 200 millones de años y, para la cual, la diversidad actual representa un muestreo incompleto y sesgado. Aún en el contexto de tales limitaciones, muchos estudios basados exclusivamente en especies actuales proponen teorías e interpretaciones sobre el registro fósil. Por ejemplo, frente a la edad Cenozoica obtenida para el grupo crown de la familia Araucariaceae a partir de dataciones moleculares, se hipotetizó que el extensivo registro Mesozoico del género Araucaria no pertenecía a tal género, sino que representaba la condición plesiomórfica de la familia. Así, la inclusión de la diversidad fósil y consecuentemente de caracteres morfológicos es crucial para la correcta comprensión de la historia evolutiva de este grupo. Sin embargo, actualmente se siguen invirtiendo más recursos en realizar estudios filogenéticos en especies actuales que en estudios que incorporan toda la diversidad del grupo. En este trabajo presentaremos los avances realizados en los últimos años para dilucidar la historia evolutiva del este grupo a partir del análisis de múltiples fuentes de evidencia: morfología, moléculas e incluyendo especies fósiles y actuales.Fil: Escapa, Ignacio Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Catalano, Santiago Andres. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico - Tucumán. Unidad Ejecutora Lillo; Argentina. Universidad Nacional de Tucumán. Facultad de Ciencias Naturales e Instituto Miguel Lillo; ArgentinaXIII Reunión Argentina de Cladística y BiogeografíaSan Miguel de TucumánArgentinaUniversidad Nacional de Tucumán. Facultad de Ciencias NaturalesInstituto Miguel Lill

Seed cone anatomy of cheirolepidiaceae (coniferales): Reinterpreting pararaucaria patagonica wieland

• Premise of the study: Seed cone morphology and anatomy reflect some of the most important changes in the phylogeny and evolutionary biology of conifers. Reexamination of the enigmatic Jurassic seed cone Pararaucaria patagonica reveals previously unknown systematically informative characters that demonstrate affinities with the Cheirolepidiaceae. This paper documents, for the first time, internal anatomy for seed cones of this important extinct Mesozoic conifer family, which may represent the ghost lineage leading to modern Pinaceae. • Methods: Morphology and anatomy of cones from the Jurassic La Matilde Formation in Patagonia are described from a combination of polished wafers and thin section preparations. New photographic techniques are employed to reveal histological details of thin sections in which organic cell wall remains are not preserved. Specific terminology for conifer seed cones is proposed to help clarify hypotheses of homology for the various structures of the cones. • Key results: Specimens are demonstrated to have trilobed ovuliferous scale tips along with a seed enclosing pocket of ovuliferous scale tissue. Originally thought to represent a seed wing in P. patagonica, this pocket-forming tissue is comparable to the flap of tissue covering seeds of compressed cheirolepidiaceous cones and is probably the most diagnostic character for seed cones of the family. • Conclusions: Pararaucaria patagonica is assigned to Cheirolepidiaceae, documenting anatomical features for seed cones of the family and providing evidence for the antiquity of pinoid conifers leading to the origin of Pinaceae. A list of key morphological and anatomical characters for seed cones of Cheirolepidiaceae is developed to facilitate assignment of a much broader range of fossil remains to the family. This confirms the presence of Cheirolepidiaceae in the Jurassic of the Southern Hemisphere, which was previously suspected from palynological records.Fil: Escapa, Ignacio Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; Argentina. University of Alberta; CanadáFil: Rothwell, Gar. State University of Oregon; Estados Unidos. Ohio University; Estados UnidosFil: Stockey, Ruth. State University of Oregon; Estados UnidosFil: Cúneo, Néstor Rubén. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; Argentin

Integrative paleobotany: Affirming the role of fossils in modern plant biology - Introduction and dedication

If you are interested in plant evolution, try this quick exercise: take a phylogenetic tree of the plant kingdom, close your eyes, and point your finger randomly to a node of the phylogeny. Irrespective of the clade to which you are pointing, there is one thing you should know about it: the living representatives of that clade have evolved as a result of a long process in which failed attempts are the rule, and as a result, the diversity of extinct forms accumulated in the fossil record far exceeds that recorded in the extant flora. From this simple concept, Gar W. Rothwell made his career. Because of that, here is a second thing you should know about the plant clade to which you pointed at random: Gar has, more likely than not, contributed information about evolution in that clade at some point in his career. Gar was one of the principal contributors to the revival of paleobotany from a largely descriptive discipline to a vibrant field of investigation at the forefront of modern evolutionary sciences that contributes crucial insights into plant evolution, equal in importance to those provided by genetics and molecular biology. Because of this, the impact of Gar’s scientific contributions reaches far beyond the field of paleobotany, with important implications for wide areas of plant biology, including anatomy and morphology, development, systematics, phylogeny, and evolution. Gar earned a master’s degree in the laboratory of Thomas N. Taylor (University of Illinois at Chicago, 1966) studying Paleozoic seeds in the genus Conostoma (Rothwell and Eggert 1970; Rothwell 1971a). He subsequently earned his PhD degree in the laboratory of Wilson N. Stewart (University of Alberta, 1973), where he reconstructed the plants in the seed fern genus Callistophyton (Rothwell 1972b, 1975, 1980, 1981). His work was instrumental in ushering in studies of fossil plants as whole living organisms, looking at both structure and development. These early experiences launched Gar on a career in plant evolutionary biology that stretched over a half century, during which he occupied positions at the University of Alberta, University of London–Chelsea College, Ohio University, and Oregon State University. Throughout his career, Gar’s scholarly work and contributions have been recognized by numerous awards and honors: the Isabel Cookson Award, the Edgar T. Wherry Award, the Michael A. Cichan Award, the Merit Award of the Botanical Society of America, and honorary membership in the International Organization of Palaeobotany, where he served for 12 years as secretary-treasurer and president.Fil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Tomescu, Alexandru M. F.. Humboldt State University. Department of Biological Sciences; Estados UnidosFil: Dunn, Michael T.. Cameron University. Department of Agriculture, Biology and Health Science; Estados UnidosFil: Stockey, Ruth A.. State University of Oregon; Estados Unido

A new cupressaceous wood from the Lower Cretaceous of central Patagonia reveals possible clonal growth habit

A new genus and species, Austrocupressinoxylon barcinense, based on remains of cupressaceous wood is described for the Lower Cretaceous of central Patagonia, Argentina. The studied specimens are silicified fragments of picnoxylic and homoxylic wood that exhibit a combination of characters not previously reported, therefore a new genus is erected. The characters are: 1- growth ring boundaries distinct, 2- transition from earlywood to latewood gradual, 3- axial parenchyma diffuse,4- radial tracheid pitting predominantly abietinean,5- cross-field pitting cupressoid, arranged in both cupressoid and araucarioid patterns, 6- rays uniseriate heterocellular, 7- end and horizontal walls of ray parenchyma cells smooth or slightly nodular, and 8- ray tracheids with smooth walls. The cross-field pitting patterns and the presence of ray tracheids are two traits of particular interest in the context of systematic affinities. The fragments were collected from two stumps found in life position attached to each other by a main root, consequently, the disposition of the stumps suggests a case of clonal growth by root suckering. This is the second report of such mechanisms in the fossil records worldwide and the first one for South America.Fil: Nunes, Cristina Isabel. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Bodnar, Josefina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - La Plata; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo; ArgentinaFil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; ArgentinaFil: Gandolfo, Maria Alejandra. Cornell University; Estados UnidosFil: Cúneo, Néstor Rubén. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Patagonia Norte; Argentin

FIB analysis of fossils plant remains: Technical and experimental aspects

We present a comprehensive study about the technical aspects of the application of focused ion beam (FIB) to thestudy of cuticles and compressions of fossil leaves.The technique allowed us to cross section and image fossil coalified plant remains with a spatial resolution withinthe 10 nm range, far higher than any other method employed so far.At various stages of the milling process, we observed significant gallium redeposition on the trench walls, particularly pronounced in the case of cavities. These highly unwanted artefacts can be greatly reduced, but not wholly eliminated, by lowering either or both the beam current and acceleration voltage; nevertheless, great care is needed when interpreting cross-sectional images.Fil: Benedetti, Alessandro. Universidad de Vigo; EspañaFil: Sender Palomar, Luis Miguel. Universidad de Zaragoza; EspañaFil: Escapa, Ignacio Hernán. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Cúneo, Rubén. Museo Paleontológico Egidio Feruglio; ArgentinaFil: Diez, José Bienvenido. Universidad de Vigo; Españ

Conifer root nodules colonized by arbuscular mycorrhizal fungi in Jurassic geothermal settings from Patagonia, Argentina

Premise of research. Despite the ecological significance of arbuscular mycorrhizae in modern terrestrial ecosystems, knowledge about their evolution based on the fossil record is still scarce, especially concerning the case of root nodules harboring arbuscular mycorrhizal fungi, as in some extant gymnosperms and angiosperms. Exceptionally preserved conifer nodular roots were found in the Jurassic fossil-bearing chert deposits of the Deseado Massif (Santa Cruz, Argentina), raising the possibility of studying them in association with arbuscular mycorrhizal fungi. The aim of this study is to describe the plant organs and their fungal partners and to discuss the ecological significance of the interactions observed, particularly with respect to their occurrence in the hot spring settings. Methodology. Thin sections of chert samples from the Cañadón Nahuel locality of the La Matilde Formation, Deseado Massif (Santa Cruz, Argentina) were observed using light microscopy. Pivotal results. The cortex of the nodules is occupied by several glomeromycotan fungal structures. The structures occur in a specific zone of the cortex—toward its center—and include intracellular hyphal coils and arbuscules. Glomoid spores and coenocytic hyphae possibly penetrating the epidermal cells are also described and analyzed. Conclusions. The root nodules have affinities with the Araucariales, representing the oldest record of such structures for this conifer clade. This is also the first record of nodules harboring arbuscular mycorrhizal fungi for the Jurassic; it extends our knowledge of the fossil record for this particular type of fungal association.Fil: Nunes, Cristina Isabel. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: García Massini, Juan Leandro. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Universidad Nacional de Catamarca. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Secretaría de Industria y Minería. Servicio Geológico Minero Argentino. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja. - Provincia de La Rioja. Centro Regional de Investigaciones Científicas y Transferencia Tecnológica de La Rioja; ArgentinaFil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Guido, Diego Martin. Instituto de Recursos Minerales; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Naturales y Museo. Instituto de Recursos Minerales. Provincia de Buenos Aires. Gobernación. Comisión de Investigaciones Científicas. Instituto de Recursos Minerales; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Campbell, Kathleen. University of Auckland; Nueva Zeland

New records of ferns and conifers from the lower cretaceous in the upper magdalena valley basin, Colombia

En este trabajo se describen nuevos registros de la macroflora del Cretácico Inferior (Aptiano-Albiano) de Colombia. El material estudiado fue colectado en la Cuenca del Valle Superior del Magdalena en tres localidades del departamento del Tolima, en las formaciones Yaví y Caballos. Los restos fósiles comprenden especímenes de filicopsidas y coníferas. Entre los helechos se encuentra la familia Marsileaceae, un grupo importante identificado en la flora fósil ya que se propone como el primer registro de un helecho acuático para el Cretácico Inferior en Colombia. Adicionalmente, abundantes restos de frondes estériles al menos bipinnadas con pínulas lanceoladas y venación pecopteridea son asignadas al morfogénero Cladophlebis sp. Las coníferas por su parte, presentan estructuras vegetativas asociadas a estructuras reproductivas. Los ejes con hojas más frecuentes fueron asignados al morfogénero Brachyphyllum sp. mientras que las escamas ovulíferas aisladas poseen características morfológicas de tipo Araucarites sp. (Araucariaceae). En conjunto, estos hallazgos constituyen un punto clave para entender la biogeografía y evolución de estos grupos y así mismo contribuyen a ampliar el conocimiento de la flora del Cretácico en Colombia.Descriptions of new plant macrofossils from the Lower Cretaceous (Aptian-Albian) of Colombia are presented. The studied material was collected in the Upper Magdalena Valley Basin in three exposing levels from the Yaví and Caballos formations. The fossil remains are associated to filicopsids and conifers. Within the ferns, the family Marsileaceae, constitutes an important group identified in the fossil flora because it is proposed as the first record of aquatic ferns for the Lower Cretaceous of Colombia. Additionally, abundant sterile bipinnate fronds with lanceolate pinnule and pecopteridea venation remains were included in the morphogenus Cladophlebis sp. The studied conifers presented vegetative structures associated to reproductive organs. The most abundant sterile fragments were included within the morphogenus Brachyphyllum sp. and ovuliferous scales of Araucarites sp. (Araucariaceae) type. Together these new findings represent a key aspect to understand the biogeography of the mentioned groups and, simultaneously, contribute to the knowledge of the Cretaceous plant fossils from Colombia.Fil: Dussán, Camila Monje. Universidad de los Andes; ColombiaFil: Martínez, Camila. Cornell University; Estados UnidosFil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Madriñan, Santiago. Universidad de Los Andes, Colombia; Colombi

A new Neocalamites (Sphenophyta) with prickles and attached cones from the Upper Triassic of China

Remains of the extinct sphenophyte (horsetail) . Neocalamites are most widespread in the Middle-Upper Triassic and are typically represented by stem and leaf fragments. Here we report on spectacular new finds of . Neocalamites from the Late Triassic Yangcaogou Formation in Liaoning Province, China that include bedding surfaces dominated by nearly complete aerial stems with attached leaf whorls and rare bractless cones. They reveal a monopodial growth habit for the stems, which are covered with downward projecting prickles that probably provided protection against herbivores. These features provide the basis for a new proposed species, . Neocalamites horridus. The nodes bear whorls of very long leaves mainly free to their bases, and one specimen bears an attached cone on a long peduncle. Identical dispersed cones have also been recovered. The leaves of adjacent monopodial stems most likely interlocked to support growth in large stands akin to the role now played by branches in large modern . Equisetum species. The new Chinese . Neocalamites is among the most confidently reconstructed species, and indicates a greater diversity of sphenophyte morphology during the Mesozoic than previously realized.Fil: Zan, Shuqin. Geological Museum Of China; ChinaFil: Axsmith, Brian J.. University of Alabama at Birmingahm; Estados UnidosFil: Escapa, Ignacio Hernán. Museo Paleontológico Egidio Feruglio; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas; ArgentinaFil: Fraser, Nicholas. National Museum Of Scotland; Reino UnidoFil: Liu, Feng Xiang. Geological Museum Of China; ChinaFil: Xing, De-He. Shenyang Institute Of Geology And Mineral Resources; Chin