|
Bennettitales
Bennettitales (also known as cycadeoids) is an extinct order of seed plants that first appeared in the Permian period and became extinct in most areas toward the end of the Cretaceous. Bennettitales were amongst the most common seed plants of the Mesozoic, and had morphologies including shrub and cycad-like forms. The foliage of bennettitaleans is superficially nearly indistinguishable from that of cycads, but they are distinguished from cycads by their more complex flower-like reproductive organs, at least some of which were likely pollinated by insects. Although certainly gymnosperms ''sensu lato'' (cone-bearing seed plants), the relationships of bennettitaleans to other seed plants is debated. Their general resemblance to cycads is contradicted by numerous more subtle features of their reproductive systems and leaf structure. Some authors have linked bennettitaleans to angiosperms (flowering plants) and gnetophytes (a rare and unusual group of modern gymnosperms), forming a ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Pterophyllum (plant)
''Pterophyllum'' is an extinct Form classification, form genus of leaves known from the Carnian to the Maastrichtian, belonging to the Bennettitales (family Williamsoniaceae). It contains more than 50 species, and is mainly found in Eurasia and North America. Description ''Pterophyllum'' are characterized by their completely segmented leaves, with slender leaflets more than twice as long as they are high. The leaflets are regularly spaced, arranged opposite to each other, and have nearly parallel edges, only slightly broader at their bases and narrower at their tips. They are covered with fine longitudinal veins with minor bifurcation. The leaflets slightly lengthen towards the middle of the leaf and shrink towards its tip, for an overall lanceolate (long and tapered) or oblong shape to the leaf. At the tip of the leaf sits a terminal leaflet which can vary in shape from the rest. Like other bennettitaleans, the leaf's cuticle was syndetocheilic (with guard and subsidiary cell ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Nilssoniopteris
''Nilssoniopteris'' is an extinct form genus of leaves belonging to the Bennettitales. Leaves are slender and often entire-margined (smooth-edged), though some species have dissected leaves with numerous small segments extending down to the rachis of the leaf. ''Nilssoniopteris''-like leaves are distinguished by their syndetocheilic stomata, indicating bennettitalean affinities. Similar "taeniopterid" leaves are placed in the genus '' Nilssonia'' if their stomata are instead haplocheilic (indicating cycad affinities), or ''Taeniopteris'' if the cuticle A cuticle (), or cuticula, is any of a variety of tough but flexible, non-mineral outer coverings of an organism, or parts of an organism, that provide protection. Various types of "cuticle" are non- homologous, differing in their origin, structu ... is not preserved. Leaves of ''Nilssoniopteris vittata'' from the Middle Jurassic of England are associated with bisexual '' Williamsoniella'' reproductive structures. References ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ptilophyllum
''Ptilophyllum'' is an extinct form genus of leaves belonging to the extinct seed plant order Bennettitales. The leaves, like other Bennettitales morphogenera are generally pinnate Pinnation (also called pennation) is the arrangement of feather-like or multi-divided features arising from both sides of a common axis. Pinnation occurs in biological morphology, in crystals, such as some forms of ice or metal crystals, and .... Leaves possibly attributable to the genus are known from the Oligocene of Australia, which may be the last known representatives of the order. References Prehistoric plant genera Bennettitales Triassic plants Jurassic plants Cretaceous plants Fossil taxa described in 1840 Prehistoric plants of North America {{cretaceous-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gnetophyta
Gnetophyta () is a division of plants (alternatively considered the subclass Gnetidae or order Gnetales), grouped within the gymnosperms (which also includes conifers, cycads, and ginkgos), that consists of some 70 species across the three relict genera: '' Gnetum'' (family Gnetaceae), '' Welwitschia'' (family Welwitschiaceae), and '' Ephedra'' (family Ephedraceae). The earliest unambiguous records of the group date to the Jurassic, and they achieved their highest diversity during the Early Cretaceous. The primary difference between gnetophytes and other gymnosperms is the presence of vessel elements, a system of small tubes (xylem) that transport water within the plant, similar to those found in flowering plants. Because of this, gnetophytes were once thought to be the closest gymnosperm relatives to flowering plants, but more recent molecular studies have brought this hypothesis into question, with many recent phylogenies finding them to be nested within the conifers. Though it ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycadeoidea
''Cycadeoidea'' is an extinct genus of bennettitalean plants known from the Cretaceous (and possibly the Jurassic) of North America, Europe and Asia. They grew as cycad-like plants with a short trunk topped with a crown of leaves. Taxonomy William Buckland originally gave the name to two species he described, ''C. megalophylla'' and ''C. microphylla'', in 1828, seeing characteristics akin to living cycads. Robert Brown and Mr. Loddiges of Loddiges Nursery in Hackney had seen living cycads and urged him to name the fossils after them. The original type specimens of both taxa have not been located, so new type material has been chosen. Classification of species within the genus is very difficult, as several trunks have been described as species, and a further fourteen species are known from detached leaf remains, but there is no way of telling which leaf remains go with which trunk remains (if any). Description ''Cycadeoidea'' stems were "short and barrel-shaped," with a "cr ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gymnosperm
The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetophyta, gnetophytes, forming the clade Gymnospermae. The term ''gymnosperm'' comes from the composite word in ( and ), and literally means 'naked seeds'. The name is based on the unenclosed condition of their seeds (called ovules in their unfertilized state). The non-encased condition of their seeds contrasts with the seeds and ovules of flowering plants (angiosperms), which are enclosed within an Ovary (botany), ovary. Gymnosperm seeds develop either on the surface of scales or Leaf, leaves, which are often modified to form Conifer cone, cones, or on their own as in Taxus, yew, ''Torreya'', and ''Ginkgo''. The life cycle of a gymnosperm involves alternation of generations, with a dominant diploid sporophyte phase, and a reduced haploid gam ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycad
Cycads are seed plants that typically have a stout and woody (ligneous) trunk (botany), trunk with a crown (botany), crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or female. Cycads vary in size from having trunks only a few centimeters to several meters tall. They typically grow slowly and have long lifespans. Because of their superficial resemblance to Arecaceae, palms or ferns, they are sometimes mistaken for them, but they are not closely related to either group. Cycads are gymnosperms (naked-seeded), meaning their fertilization, unfertilized seeds are open to the air to be directly fertilized by pollination, as contrasted with angiosperms, which have enclosed seeds with more complex fertilization arrangements. Cycads have very specialized pollinators, usually a specific beetle, and more rarely a thrips or a moth. Both male and female cycads bear cones (strobilus, stro ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cycadeoidaceae
Cycadeoidaceae is a family of bennettitalean plants which flourished in the Mesozoic era. Two genera, '' Cycadeoidea'' and '' Monanthesia'', are currently recognised though most species are poorly known. They had a similar morphology to cycads Cycads are seed plants that typically have a stout and woody (ligneous) trunk with a crown of large, hard, stiff, evergreen and (usually) pinnate leaves. The species are dioecious, that is, individual plants of a species are either male or ..., with thick, branchless trunks covered in scale leaves. References Bennettitales Jurassic plants Cretaceous plants Prehistoric plant families Jurassic first appearances Cretaceous extinctions {{cretaceous-plant-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Williamsoniaceae
''Williamsoniaceae'' is a family within the Bennettitales, an extinct group of seed plants. Members of this family are believed to have been around two meters tall and with widely serrate leaves along a central stem. Reproductive organs of the Williamsoniaceae have varied widely in the fossil record but almost all have been found to be borne on stalks emerging from a ring of leaves. Reproduction This family is different from Cycadeoidaceae by having the presence of cones leaving the major axis and lateral branches associated with a long peduncle covered by bracts. Some of this family reproduce by sporangia and others only produce ovule or pollen Pollen is a powdery substance produced by most types of flowers of seed plants for the purpose of sexual reproduction. It consists of pollen grains (highly reduced Gametophyte#Heterospory, microgametophytes), which produce male gametes (sperm ... sacs. [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Spermatophyte
A seed plant or spermatophyte (; New Latin ''spermat-'' and Greek ' (phytón), plant), also known as a phanerogam (taxon Phanerogamae) or a phaenogam (taxon Phaenogamae), is any plant that produces seeds. It is a category of embryophyte (i.e. land plant) that includes most of the familiar land plants, including the flowering plants and the gymnosperms, but not ferns, mosses, or algae. The term ''phanerogam'' or ''phanerogamae'' is derived from the Ancient Greek, Greek (), meaning "visible", in contrast to the term "cryptogam" or "cryptogamae" (, and (), 'to marry'). These terms distinguish those plants with hidden sexual organs (cryptogamae) from those with visible ones (phanerogamae). Description The extant spermatophytes form five divisions, the first four of which are classified as gymnosperms, plants that have unenclosed, "naked seeds": * Cycadophyta, the cycads, a subtropical and tropical group of plants, * Ginkgophyta, which includes a single living species of tree in t ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Anthophyta
The anthophytes are a paraphyletic grouping of plant taxa bearing flower-like reproductive structures. The group, once thought to be a clade, contained the angiosperms – the extant flowering plants, such as roses and grasses – as well as the Gnetales and the extinct Bennettitales. Detailed morphological and molecular studies have shown that the group is not actually monophyletic, with proposed floral homologies of the gnetophytes and the angiosperms having evolved in parallel. This makes it easier to reconcile molecular clock data that suggests that the angiosperms diverged from the gymnosperm The gymnosperms ( ; ) are a group of woody, perennial Seed plant, seed-producing plants, typically lacking the protective outer covering which surrounds the seeds in flowering plants, that include Pinophyta, conifers, cycads, Ginkgo, and gnetoph ...s around 320-300 mya. Some more recent studies have used the word anthophyte to describe a hypothetical group which includes the ang ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Thérèse Ekblom
Thérèse Ekblom (1867–1941) was a Swedish botanical and zoological illustrator. She often collaborated with her husband, Axel Richard Ekblom (1858–1914). Ekblom was born Lovisa Teresia Jansson, in Stockholm, Sweden, to a family of artists. Her father and brothers were scene painters at the Royal Swedish Opera. Ekblom attended the Academy of Art in Stockholm, where she met her husband. They married in 1895 and had five children. While pursuing their studies, the Ekbloms worked with Veit Brecher Wittrock, Professor at the Bergius Botanic Garden. They painted watercolors of species that Professor Wittrock was investigating. From the 1890s, the Ekbloms worked in various departments at the Swedish Museum of Natural History and for botanists at the botanical garden. After the death of artist Carl Axel Hedelin in 1894, Ekblom succeeded him to work on a project creating pencil illustrations of plant fossils from Iceland being studied by paleobotanist Alfred Gabriel Nathorst. She w ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
