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Gosslingia
''Gosslingia'' was a genus of Early Devonian land plant with branching axes. Fossils have been from the Lochkovian to the Pragian, . A cladogram published in 2004 by Crane et al. places ''Gosslingia'' in the core of a paraphyletic stem group of broadly defined "zosterophylls", basal to the lycopsids (living and extinct clubmosses and relatives). Hao and Xue in 2013 used the absence of terminal sporangia to place the genus in the family Gosslingiaceae in the paraphyletic order Gosslingiales, a group considered to have indeterminate growth, with fertile branches generally showing circinate vernation (initially curled up). Kenrick and Crane in 1997 also placed the genus in the family Gosslingiaceae, but they place this family in the order Sawdoniales The Sawdoniales are an order or plesion of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and share an ancestor with the living lycophytes. The group has been divided up in ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gosslingiales
Gosslingiales is an order of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and share an ancestor with the living lycophytes. The group has been divided up in various ways. Hao and Xue in 2013 used the presence or absence of terminal sporangia as a major dividing feature. The order Zosterophyllales was used for species with terminal as well as lateral sporangia, which were considered to have determinate growth, with their sporangia generally being arranged in spikes. The paraphyletic order Gosslingiales was used for species without terminal sporangia (i.e. with only lateral sporangia), which were considered to have indeterminate growth, with fertile branches generally circinate (initially curled up). Species assignable to the Gosslingiales made up about 9% of all confirmed species in the Early Devonian flora. Taxonomy Classification Hao and Xue consider the order Gosslingiales to be one of the two major divisions of the zost ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Gosslingiaceae
Gosslingiaceae is a family of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and are considered to share an ancestor with the living lycophytes. The family is variously placed in the order Sawdoniales or the order Gosslingiales Gosslingiales is an order of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and share an ancestor with the living lycophytes. The group has been divided up in various ways. Hao and Xue in 20 .... Genera Genera that have been placed in this family by Kenrick and Crane in 1997 and Hao and Xue in 2013 are shown in the table below. References Zosterophylls Prehistoric plant families {{paleobotany-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sawdoniales
The Sawdoniales are an order or plesion of extinct zosterophylls. The zosterophylls were among the first vascular plants in the fossil record, and share an ancestor with the living lycophytes. The group has been divided up in various ways. In their major cladistic study of early land plants, Kenrick and Crane placed most of the zosterophylls in the Sawdoniales (which they treated as a plesion). Like other zosterophylls, members of the Sawdoniales bore lateral, reniform sporangia. They branched dichotomously, and grew at the ends by unrolling (circinate vernation). Some had smooth stems, others were covered in small spines; fungal bodies have been reported in some spines. Taxonomy In 1997, Kenrick and Crane placed most of the zosterophylls in the plesion Sawdoniales, characterizing the group as having "marked bilateral symmetry". Their summary cladogram did not resolve the taxa within the Sawdoniales, other than placing '' Zosterophyllum divaricatum'' within the zosterophylls bu ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zosterophylls
The zosterophylls are a group of extinct land plants that first appeared in the Silurian period. The taxon was first established by Banks in 1968 as the subdivision Zosterophyllophytina; they have since also been treated as the division Zosterophyllophyta or Zosterophyta and the class or plesion Zosterophyllopsida or Zosteropsida. They were among the first vascular plants in the fossil record, and had a world-wide distribution. They were probably stem-group lycophytes, forming a sister group to the ancestors of the living lycophytes. By the late Silurian (late Ludlovian, about ) a diverse assemblage of species existed, examples of which have been found fossilised in what is now Bathurst Island in Arctic Canada. Morphology The stems of zosterophylls were either smooth or covered with small spines known as enations, branched dichotomously, and grew at the ends by unrolling, a process known as circinate vernation. The stems had a central vascular column in which the protoxylem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Zosterophyll
The zosterophylls are a group of extinct land plants that first appeared in the Silurian period. The taxon was first established by Banks in 1968 as the subdivision Zosterophyllophytina; they have since also been treated as the division Zosterophyllophyta or Zosterophyta and the class or plesion Zosterophyllopsida or Zosteropsida. They were among the first vascular plants in the fossil record, and had a world-wide distribution. They were probably stem-group lycophytes, forming a sister group to the ancestors of the living lycophytes. By the late Silurian (late Ludlovian, about ) a diverse assemblage of species existed, examples of which have been found fossilised in what is now Bathurst Island in Arctic Canada. Morphology The stems of zosterophylls were either smooth or covered with small spines known as enations, branched dichotomously, and grew at the ends by unrolling, a process known as circinate vernation. The stems had a central vascular column in which the protoxylem ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Paraphyly
In taxonomy, a group is paraphyletic if it consists of the group's last common ancestor and most of its descendants, excluding a few monophyletic subgroups. The group is said to be paraphyletic ''with respect to'' the excluded subgroups. In contrast, a monophyletic group (a clade) includes a common ancestor and ''all'' of its descendants. The terms are commonly used in phylogenetics (a subfield of biology) and in the tree model of historical linguistics. Paraphyletic groups are identified by a combination of synapomorphies and symplesiomorphies. If many subgroups are missing from the named group, it is said to be polyparaphyletic. The term was coined by Willi Hennig to apply to well-known taxa like Reptilia ( reptiles) which, as commonly named and traditionally defined, is paraphyletic with respect to mammals and birds. Reptilia contains the last common ancestor of reptiles and all descendants of that ancestor, including all extant reptiles as well as the extinct synapsids, ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian Plants
The Devonian ( ) is a geologic period and system of the Paleozoic era, spanning 60.3 million years from the end of the Silurian, million years ago (Mya), to the beginning of the Carboniferous, Mya. It is named after Devon, England, where rocks from this period were first studied. The first significant adaptive radiation of life on dry land occurred during the Devonian. Free-sporing vascular plants began to spread across dry land, forming extensive forests which covered the continents. By the middle of the Devonian, several groups of plants had evolved leaves and true roots, and by the end of the period the first seed-bearing plants appeared. The arthropod groups of myriapods, arachnids and hexapods also became well-established early in this period, after starting their expansion to land at least from the Ordovician period. Fish reached substantial diversity during this time, leading the Devonian to often be dubbed the Age of Fishes. The placoderms began dominating al ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Lycophyte Genera
Prehistory, also known as pre-literary history, is the period of human history between the use of the first stone tools by hominins 3.3 million years ago and the beginning of recorded history with the invention of writing systems. The use of symbols, marks, and images appears very early among humans, but the earliest known writing systems appeared 5000 years ago. It took thousands of years for writing systems to be widely adopted, with writing spreading to almost all cultures by the 19th century. The end of prehistory therefore came at very different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilisation, and ancient Egypt were the first civilizations to develop their own scripts and to keep historical records, with their neighbors following. Most other civilizations reached the end of prehistory during the following Iron Age. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Circinate Vernation
Vernation (from ''vernal'' meaning ''spring'', since that is when leaves spring forth in temperate regions) is the formation of new leaves or fronds. In plant anatomy, it is the arrangement of leaves in a bud. In pine species, new leaves are short and encased in sheaths. Each leaf bundle consists of 2 to 5 needles. All the leaves on one section of branch grow in length together. In cabbage species, new leaves are folded over, each covered by the previous leaf. Circinate vernation Circinate vernation is the manner in which most fern fronds emerge. As the fern frond is formed, it is tightly curled so that the tender growing tip of the frond (and each subdivision of the frond) is protected within a coil. At this stage it is called a '' crozier'' (after the shepherd's crook) or ''fiddlehead'' (after the scrollwork at the top of a violin). As the lower parts of the frond expand and toughen up, they begin to photosynthesize, supporting the further growth and expansion of the frond. B ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Early Devonian
The Early Devonian is the first of three Epoch (geology), epochs comprising the Devonian period, corresponding to the Lower Devonian Series (stratigraphy), series. It lasted from and began with the Lochkovian Stage , which was followed by the Pragian from and then by the Emsian, which lasted until the Middle Devonian began, . During this time, the first Ammonoidea, ammonoids appeared, descending from Bactritida, bactritoid Nautiloidea, nautiloids. Ammonoids during this time period were simple and differed little from their nautiloid counterparts. These ammonoids belong to the order Agoniatitida, which in later epochs evolved to new ammonoid orders, for example Goniatite, Goniatitida and Clymeniida. This class of cephalopod molluscs would dominate the marine fauna until the beginning of the Mesozoic Era. References {{Geological history Early Devonian, Geological epochs Devonian geochronology, *01 ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Lochkovian
The Lochkovian is one of three faunal stages in the Early Devonian Epoch. It lasted from 419.2 ± 3.2 million years ago to 410.8 ± 2.8 million years ago. It marked the beginning of the Devonian Period, and was followed by the Pragian Stage. It is named after the village of Lochkov in the Czech Republic, now part of the city of Prague Prague ( ; cs, Praha ; german: Prag, ; la, Praga) is the capital and largest city in the Czech Republic, and the historical capital of Bohemia. On the Vltava river, Prague is home to about 1.3 million people. The city has a temperate .... The GSSP is located within the Lochkow Formation at the Klonk Section in Prague. In North America the Lochkovian Stage is represented by Gedinnian or Helderbergian time. References Early Devonian {{geochronology-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Sporangium
A sporangium (; from Late Latin, ) is an enclosure in which spores are formed. It can be composed of a single cell or can be multicellular. Virtually all plants, fungi, and many other lineages form sporangia at some point in their life cycle. Sporangia can produce spores by mitosis, but in nearly all land plants and many fungi, sporangia are the site of meiosis and produce genetically distinct haploid spores. Fungi In some phyla of fungi, the sporangium plays a role in asexual reproduction, and may play an indirect role in sexual reproduction. The sporangium forms on the sporangiophore and contains haploid nuclei and cytoplasm. Spores are formed in the sporangiophore by encasing each haploid nucleus and cytoplasm in a tough outer membrane. During asexual reproduction, these spores are dispersed via wind and germinate into haploid hyphae. Although sexual reproduction in fungi varies between phyla, for some fungi the sporangium plays an indirect role in sexual reprod ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
