The Icacinaceae occur pantropically today, but are well represented by fossil fruits of the warm Early Middle Eocene, when tropical plants that currently occupy low latitudes were more widely ...distributed in higher latitudes. Members of this family are first known in the Late Cretaceous; however, fossil fruits of tribe Iodeae are quite rare before the Eocene. In this paper we describe the first formally recognized Late Paleocene icacinaceous taxa from western North America. We name two new species of Icacinicarya based on anatomically preserved fruits and establish a new genus, Icacinicaryites, for impressions with a strong similarity to Icacinicarya that lack anatomical preservation. These new records from the Almont/Beicegel Creek flora in North Dakota and several localities in Wyoming, Colorado, and Montana complement records known from the Early Eocene of England and document an increased diversity of Iodeae and related forms in the Paleogene of western North America.
Hamawilsonia boglei Benedict, Pigg & DeVore gen. et sp. nov. (Hamamelidaceae) is described from the Late Paleocene Almont flora of central North Dakota. The infructescence is an anatomically ...preserved spike with up to 20 sessile, robust, cuboidal to ovoid capsules borne on an elongate, thick axis up to
\documentclass{aastex}
\usepackage{amsbsy}
\usepackage{amsfonts}
\usepackage{amssymb}
\usepackage{bm}
\usepackage{mathrsfs}
\usepackage{pifont}
\usepackage{stmaryrd}
\usepackage{textcomp}
\usepackage{portland,xspace}
\usepackage{amsmath,amsxtra}
\usepackageOT2,OT1{fontenc}
\newcommand\cyr{
\renewcommand\rmdefault{wncyr}
\renewcommand\sfdefault{wncyss}
\renewcommand\encodingdefault{OT2}
\normalfont
\selectfont}
\DeclareTextFontCommand{\textcyr}{\cyr}
\pagestyle{empty}
\DeclareMathSizes{10}{9}{7}{6}
\begin{document}
\landscape
$$9.2\,\mathrm{cm}\,\,\mathrm{long}\,\times 0.5\,\mathrm{cm}\,\,\mathrm{wide}\,$$
\end{document}
. Individual fruits are 10-12 mm across and bilocular, with paired persistent, recurved styles borne on the distal carpel face. One locule is often larger than the other. Anatomically, the fruit wall is composed of a sclerified endocarp and a poorly preserved exocarp. Seeds are elliptical to slightly obovate with a sclerotic seed coat. Hamawilsonia is an extinct Late Paleocene genus with a combination of characters not seen in any extant hamamelid genus. Hamawilsonia is similar to the Asian endemic genus Sinowilsonia in its elongate spikelike infructescence, resembles the witch hazel Hamamelis in fruit and seed morphology, and has seed anatomy that combines features found in several extant genera. Affinities with Sinowilsonia are further supported by the co-occurrence of associated pollen catkins and in situ tricolpate pollen with a distinctive reticulate sculpturing. Like several other Almont taxa (Amersinia, Beringiaphyllum, Davidia, and Palaeocarpinus), Hamawilsonia is a genus with strong North American-Asian affinities.
Paleoactea nagelii Pigg & DeVore gen. et sp. nov. is described for a small, ovoid ranunculaceous fossil fruit from the Late Paleocene Almont and Beicegel Creek floras of North Dakota, USA. Fruits are ...5-7 mm wide, 4.5-6 mm high, 10-13 mm long, and bilaterally symmetrical, containing 10-17 seeds attached on the upper margin in 2-3 rows. A distinctive honeycomb pattern is formed where adjacent seeds with prominent palisade outer cell layers abut. Seeds are flattened, ovoid, and triangular. To the inside of the palisade cells, the seed coat has a region of isodiametric cells that become more tangentially elongate toward the center. The embryo cavity is replaced by an opaline cast. This fruit bears a striking resemblance to extant Actaea, the baneberry (Ranunculaceae), an herbaceous spring wildflower of North Temperate regions. A second species, Paleoactaea bowerbanki (Reid & Chandler) Pigg & DeVore nov. comb., is recognized from the Early Eocene London Clay flora, based on a single fruit. This fruit shares most of the organization and structure of P. nagelii but is larger and has a thicker pericarp. This study documents a rare Paleocene occurrence of a member of the buttercup family, a family that is today primarily herbaceous, and demonstrates a North Atlantic connection for an Actaea-like genus in the Paleogene.
Well-preserved seeds from the early Eocene of Wutu, Shandong, China are assigned to the genus Nuphar (Nymphaeaceae) based on morphology and anatomy. The seeds of Nuphar wutuensis sp. nov. are ...ellipsoidal to ovoid, 4-5 mm long with a clearly visible raphe ridge, and a truncate apex capped by a circular operculum ca. 1 mm in diameter bearing a central micropylar protrusion. These features, along with the testa composed of a uniseriate outer layer of equiaxial pentagonal to hexagonal surface cells and a middle layer 4-6 cells thick composed of thick-walled, periclinally elongate sclereids, correspond to the morphology and anatomy of extant Nuphar and distinguish this fossil species from all other extant and extinct genera of Nymphaeales. These seeds provide the oldest record for the genus in Asia and are supplemented by a similar well-preserved specimen from the Paleocene of North Dakota, USA. These data, together with the prior recognition of Brasenia (Cabombaceae) in the middle Eocene, indicate that the families Nymphaeaceae and Cabombaceae had differentiated by the early Tertiary.
A pollen and spore assemblage of 50 species was recovered from the late Paleocene (pollen zone P5) Almont locality in the Williston Basin, central North Dakota, USA. This palynoflora was extracted ...from the same layer containing a diverse megaflora preserved in a silicified shale with compressed leaves, and anatomically preserved fruits and seeds. More than 44 megafossil genera assignable to 26 extant plant families thus far have been recognized. The palynomorphs, which are of exceptional preservation, were examined using the same-grain technique with both light microscopy (LM) and scanning electron microscopy (SEM). Additional LM and SEM studies augmented the same grain studies to provide an understanding of sculptural features, and additional, rare taxa. Of particular note are the in situ pollen types known from catkins and pollen cones, allowing for confirmation of the dispersed pollen's systematic position by tying it to its parent plant. Taxa for which in situ pollen is known from Almont include taxodiaceous conifers, Betulaceae, Hamamelidaceae, Juglandaceae, and Platanaceae, and several catkins of uncertain affinities, some with monosulcate grains. This study emphasizes the role of palynology in providing an expanded view of the flora from palynomorphs for comparison with a rich megafossil assemblage.
The Juglandaceae (walnuts, hickories, pecans) has one of the best-documented fossil records in the Northern Hemisphere. The oldest modern genus, Cyclocarya, today restricted to China, first appears ...in the late Paleocene (57 ma) of North Dakota, USA. Unlike walnuts and pecans that produce edible fruits dispersed by mammals, Cyclocarya fruits are small nutlets surrounded by a prominent circular wing, and are thought to be wind- or water-dispersed. The current study provides the first evidence that fossil fruits were different from modern forms in the number and organization of their attachment to reproductive branches, and in their anatomical structure. Unlike the modern genus that bears separate pistillate and staminate flowers the fossil fruits had attached pollen-bearing structures. Unisexual pollen catkins are also present, suggesting the fossil Cyclocarya may have differed from its modern relative in this feature. Like several other plants from the late Paleocene Almont/Beicegel Creek floras, Cyclocarya shows a mosaic combination of characters not seen in their modern counterparts. Fossils were collected from the field, and examined for specimens exposed on the weathered rock surface. Specimens from Almont were photographed with reflected light, while those from Beicegel Creek cut into slabs and prepared by etching the rock matrix in 49% hydrofluoric and re-embedding the exposed plant material in cellulose acetate and acetone to make "peels". Selected specimens are cut out, mounted on microscope slides, and studied with light microscopy. These fossil fruits were studied because they are the earliest fossil evidence of Cyclocarya. They are exceptionally preserved and thus provide critical structural evidence for changes in that occurred during the evolution of plants within this lineage. Because Cyclocarya fruits are winged, they might be assumed to be wind-dispersed. Their radial symmetry does not have the aerodynamic qualities typical of wind-dispersed fruits, and may have been dispersed by water.
Joffrichthys triangulpterus, sp. nov. is a new species of the family Osteoglossidae, and is described based on two nearly complete, and two partial, articulated specimens from the Sentinel Butte ...Formation in the Fort Union Group (Paleocene) of central North Dakota, USA. The familial placement is based on three diagnostic characters: uroneurals absent; six hypurals; and a kidney shaped opercle. The generic placement into Joffrichthys is based on two diagnostic characters and eight similar morphologies and meristics shared between the new species and previously described J. symmetropterus: two complete or partial neural spines present on preural 2; one spine or no spines present on ural 1; similar shapes of the maxillary, dentary, preopercle, opercle, and frontal; a similar body silhouette; and a similar vertebral and supraneural count. The specimens are identified as a new species by nine diagnostic characteristics distinguishing it from J. symmetropterus, the most closely related taxon: more posteriorly-placed pelvic fins; a greater dorsal fin ray count (30 total); a triangular dorsal and anal fin; asymmetrically positioned dorsal and anal fins (anterior pterygiophore insertions separated by 8 to 9 vertebrae); the third dorsal and fifth anal pterygiophores being the longest; and two complete spines on preural 2. The North Dakota fish is important because it represents a new species of Joffrichthys and represents the most southern occurrence of the genus to date.
Provider: - Institution: - Data provided by Europeana Collections- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain ...Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
Provider: - Institution: - Data provided by Europeana Collections- La tesis analiza los procesos que han conducido a la actual situación ambiental y urbanística de las costas de Almonte, centrándose ...en el periodo que abarca los últimos treinta y cuatro años. Plantea la hipótesis de que, en un territorio como el analizado, resulta imprescindible un planeamiento global, que, de alguna forma, integre las propuestas ambientales y conservacionistas con el desarrollo del territorio. Mediante un método disciplinar, basado en el estudio y la profundización en el conocimiento de los procesos reales que han producido la transformación del territorio, se determinan las claves interpretativas de la actual situación de esta parte del litoral y se esbozan las bases de un nuevo modelo territorial en un ámbito esencialmente turístico; en Doñana, planteando, a su vez, las aportaciones que el planeamiento urbanístico debe realizar para propiciar una nueva forma de hacer y gestionar el plan, que haga posible la articulación estructural de este espacio y su conversión en un territorio humanizado. Pero el eje estructural de la Tesis nos debe conducir hacia el conocimiento del territorio desde la posición del urbanista, con el objeto de profundizar en el conocimiento urbanístico desde su origen hasta nuestros días, para sentar las bases necesarias que permitan abordar soluciones urbanísticas que hagan posible equilibrar esta zona del litoral mediante su integración en una estructura territorial coherente y plantear las características propias de la organización de un espacio turístico en el territorio.|- All metadata published by Europeana are available free of restriction under the Creative Commons CC0 1.0 Universal Public Domain Dedication. However, Europeana requests that you actively acknowledge and give attribution to all metadata sources including Europeana
PDF
