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Erdtmanithecales
Erdtmanithecales is an extinct order of gymnosperm plants known from the Mesozoic era. Known remains include pollen organs and seeds associated with '' Eucommiidites'' pollen, which is considered diagnostic for the order. The order was first described in 1996. While ''Eucommiidites'' pollen first appears in the Early Jurassic, associated floral remains are not found until the Early Cretaceous. It is thought that the group are closely related to Gnetales as well as possibly Bennettitales. Systematics * Order Erdtmanithecales Friis and Pedersen 1996 **family Erdtrnanithecaeae Friis and Pedersen 1996 ***'' Erdtmanitheca'' Pedersen, Crane & Friis, 1989 (pollen organ) ****''Erdtmanitheca portucalensis'' Mendes et al., 2010 (Aptian-Albian), Lusitanian Basin, Portugal ****''Erdtmanitheca texensis'' Pedersen, Crane & Friis, 1989 Woodbine Formation, Texas, USA, Cenomanian ***'' Erdtmanispermum'' Pedersen, Crane & Friis, 1989 (seeds) ****''Erdtmanispermum juncalense'' Mendes et al., ... [...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] |
Eucommiidites
''Eucommiidites'' is an angiosperm look-alike pollen type from the Mesozoic Era. When it was first described in Sweden, it was thought to represent pollen from the earliest angiosperms. However, it was subsequently shown, due to morphology, that it could not be angiospermous. Later, ''Eucommidites'' pollen was discovered in the pollen chambers of fossil gymnosperm seeds. It was later shown to be the pollen of the extinct gymnosperm order Erdtmanithecales, suggested to have close affinities with Bennettitales and Gnetales. ''Eucommidites'' is tricolpate, which is why it was originally thought to be angiospermous. However, the three colpi are not equal in length, and the exine of the pollen grain is similar to a gymnosperm. ''Eucommidites'' is important in biostratigraphy, and it ranges from the Triassic to the Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Meso ... [...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] |
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] |
Mesozoic Plants
The Mesozoic Era is the era of Earth's geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Periods. It is characterized by the dominance of archosaurian reptiles such as the dinosaurs, and of gymnosperms such as cycads, ginkgoaceae and Araucariaceae, araucarian conifers; a hot Greenhouse and icehouse earth, greenhouse climate; and the tectonic break-up of Pangaea. The Mesozoic is the middle of the three eras since Cambrian explosion, complex life evolved: the Paleozoic, the Mesozoic, and the Cenozoic. The era began in the wake of the Permian–Triassic extinction event, the largest mass extinction in Earth's history, and ended with the Cretaceous–Paleogene extinction event, another mass extinction whose victims included the non-avian dinosaurs, Pterosaur, pterosaurs, Mosasaur, mosasaurs, and Plesiosaur, plesiosaurs. The Mesozoic was a time of significant tectonic, climatic, and evolutionary activity. The supercontinent Pangaea#Rifting and ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Prehistoric Plant Orders
Prehistory, also called pre-literary history, is the period of human history between the first known use of stone tools by hominins 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 years ago. It took thousands of years for writing systems to be widely adopted, with writing having spread to almost all cultures by the 19th century. The end of prehistory therefore came at different times in different places, and the term is less often used in discussing societies where prehistory ended relatively recently. It is based on an old conception of history that without written records there could be no history. The most common conception today is that history is based on evidence, however the concept of prehistory hasn't been completely discarded. In the early Bronze Age, Sumer in Mesopotamia, the Indus Valley Civilis ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Crato Formation
The Crato Formation is a geologic formation (stratigraphy), formation of Early Cretaceous (Aptian) age in northeastern Brazil's Araripe Basin. It is an important Lagerstätten, Lagerstätte (undisturbed fossil accumulation) for palaeontology, palaeontologists. The strata were laid down mostly during the Aptian age (geology), age, about 113 million years ago. It thought to have been deposited in a semi-arid Lake, lacustrine wetland environment.Ribeiro et al., 2021 The Crato Formation earns the designation of Lagerstätte due to an exceedingly well preserved and diverse fossil faunal assemblage. Some 25 species of fossil fishes are often found with stomach contents preserved, enabling paleontologists to study predator-prey relationships in this ecosystem. There are also fine examples of pterosaurs, reptiles and amphibians, invertebrates (particularly insects), and plants. Even dinosaurs are represented: a new maniraptor was described in 1996. The unusual taphonomy of the site resul ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Incertae Sedis
or is a term used for a taxonomy (biology), taxonomic group where its broader relationships are unknown or undefined. Alternatively, such groups are frequently referred to as "enigmatic taxa". In the system of open nomenclature, uncertainty at specific taxonomic levels is indicated by (of uncertain family), (of uncertain suborder), (of uncertain order) and similar terms. Examples * The fossil plant ''Paradinandra, Paradinandra suecica'' could not be assigned to any family, but was placed ''incertae sedis'' within the order Ericales when described in 2001. * The fossil ''Gluteus minimus (fossil), Gluteus minimus'', described in 1975, could not be assigned to any known animal phylum. The genus is therefore ''incertae sedis'' within the kingdom Animalia. * While it was unclear to which order the New World vultures (family Cathartidae) should be assigned, they were placed in Aves ''incertae sedis''. It was later agreed to place them in a separate order, Cathartiformes. * Boc ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Jydegaard Formation
The Jydegaard Formation (also spelled as 'Jydegård') is a geological formation dating to the Early Cretaceous, about 145–139 million years ago. It is on the island of Bornholm, Denmark. Vertebrate fossils have been found in the formation. Fossil content Thin bone fragments have been uncovered that may belong to pterosaurs or birds. Dinosaurs A tooth possibly belonging to a juvenile titanosaur has been found in the formation. Crocodylomorphs Fish Fish remains have been found in coprolites possibly belonging to the dromaeosaur '' Dromaeosauroides'' or marine turtles. Also, unidentified pycnodont jaws and two small stem- teleosteans have been uncovered. Amioid scales have also been revealed. Turtles Unidentified turtle carapaces have been uncovered in the Formation. Lizards A lower jaw from a lizard Lizard is the common name used for all Squamata, squamate reptiles other than snakes (and to a lesser extent amphisbaenians), encompassing over 7,000 speci ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
