Systematic paleontology, biostratigraphy, paleobiogeography of. Loftusiaforaminifera and. Rudistassemblages in a regressive sequence in the Hekimhan Malatya area Eastern Anatolia Turkey. The Maastrichtian regressive sequence of the Hekimhan Malatya area in Eastern Turkey consists of dolomitic limestones, limestones and calcareous mudstones which are dominated by rudists and Loftusia foraminifera assemblages. Several Loftusia species indicating middle to late Maastrichtian age such as Loftusia anatolica Meri, L. Meri, L. coxi Henson, L. Cox, L. minor Cox and L. Douvill have been recorded. Other benthic foraminifers present include Orbitoides medius d Archiac, Omphalocyclus macroporus Lamarck, Laffitteina conica Drooger, Laffitteina mengaudi Astre and Laffitteina oeztuerki Inan. The rudists are abundant in the dolomitic limestones in the study area. The genus Miseia Patrulius is dominant and represented by Miseia bilacunosa zer and Miseia hekimhanensis Karacabey ztemr. The Loftusia species and the Rudists assemblage indicates middle to late Maastrichtian age for the formation. The paleobiogeographic distribution of the assemblage has been discussed taking this find into account. Keywords. Loftusia Foraminifera Rudists Maastrichtian Hekimhan Malatya Eastern Turkey. To discuss paleontology since the advent of plate tectonics, which we shall take as the beginning of 1969, is really a reportorial rather than an historical task. Fake Drivers License Picture Generator. It. Morphological differences between successive species which sum to great differences over long spans of time seemed to constitute a series showing gradual. Protist Wikipedia. A protist is any eukaryoticorganism that is not an animal, plant or fungus. The protists do not form a natural group, or clade, but are often grouped together for convenience, like algae or invertebrates. In some systems of biological classification, such as the popular five kingdom scheme proposed by Robert Whittaker in 1. Protista, composed of organisms which are unicellular or unicellular colonial and which form no tissues. ABesides their relatively simple levels of organization, protists do not necessarily have much in common. When used, the term protists is now considered to mean similar appearing but diverse taxa that are not related through an exclusive common ancestor, and have different life cycles, trophic levels, modes of locomotion, and cellular structures. In the classification system of Lynn Margulis, the term protist is reserved for microscopic organisms, while the more inclusive term Protoctista is applied to a biological kingdom which includes certain large multicellular eukaryotes, such as kelp, red algae and slime molds. Others use the term protist more broadly, to encompass both microbial eukaryotes and macroscopic organisms that do not fit into the other traditional kingdoms. Treatise Paleontology Pdf' title='Treatise Paleontology Pdf' />In cladistic systems, there are no equivalents to the taxa Protista or Protoctista, both terms referring to a paraphyletic group which spans the entire eukaryotic tree of life. In cladistic classification, the contents of Protista are distributed among various supergroups SAR, Archaeplastida, Excavata, Opisthokonta, etc. Protista, Protoctista and Protozoa are considered obsolete. However, the term protist continues to be used informally as a catch all term for eukaryoticmicroorganisms. For example, the phrase protist pathogen may be used to denote any disease causing microbe which is not bacteria, virus, viroid or metazoa. SubdivisionseditThe term protista was first used by Ernst Haeckel in 1. Protists were traditionally subdivided into several groups based on similarities to the higher kingdoms such as Protozoa the unicellular animal like heterotrophicparasitic protozoa which was further sub divided based on motility such as flagellated Flagellata, ciliated Ciliophora, phagocytic amoeba and spore forming Sporozoans. Protophyta the plant like autotrophic protophyta mostly unicellular algaeMolds the fungus like saprophytic slime molds and water molds. Some protists, sometimes called ambiregnal protists, have been considered to be both protozoa and algae or fungi e. ICN and the ICZN. Conflicts, such as these for example the dual classification of Euglenids and Dinobryons, which are mixotrophic is an example of why the kingdom Protista was adopted. These traditional subdivisions, largely based on superficial commonalities, have been replaced by classifications based on phylogenetics evolutionary relatedness among organisms. Molecular analyses in modern taxonomy have been used to redistribute former members of this group into diverse and sometimes distantly related phyla. For instance, the water molds are now considered to be closely related to photosynthetic organisms such as Brown algae and Diatoms, the slime molds are grouped mainly under Amoebozoa, and the Amoebozoa itself includes only a subset of Amoeba group, and significant number of erstwhile Amoeboid genera are distributed among Rhizarians and other Phyla. However, the older terms are still used as informal names to describe the morphology and ecology of various protists. For example, the term protozoa is used to refer to heterotrophic species of protists that do not form filaments. ClassificationeditHistorical classificationseditAmong the pioneers in the study of the protists, which were almost ignored by Linnaeus except for some genera e. Vorticella, Chaos, Volvox, Corallina, Conferva, Ulva, Chara, Fucus1. Leeuwenhoek, O. F. Mller, C. G. Ehrenberg and Flix Dujardin. The first groups used to classify microscopic organism were the Animalcules and the Infusoria. In 1. 81. 7, the German naturalist Georg August Goldfuss introduced the word Protozoa to refer to organisms such as ciliates and corals. After the cell theory of Schwann and Schleiden 1. Carl von Siebold to include only animal like unicellular organisms, such as foraminifera and amoebae. The formal taxonomic category Protoctista was first proposed in the early 1. John Hogg, who argued that the protists should include what he saw as primitive unicellular forms of both plants and animals. He defined the Protoctista as a fourth kingdom of nature, in addition to the then traditional kingdoms of plants, animals and minerals. The kingdom of minerals was later removed from taxonomy in 1. Ernst Haeckel, leaving plants, animals, and the protists Protista, defined as a kingdom of primitive forms. In 1. 93. 8, Herbert Copeland resurrected Hoggs label, arguing that Haeckels term Protista included anucleated microbes such as bacteria, which the term Protoctista literally meaning first established beings did not. In contrast, Copelands term included nucleatedeukaryotes such as diatoms, green algae and fungi. This classification was the basis for Whittakers later definition of Fungi, Animalia, Plantae and Protista as the four kingdoms of life. The kingdom Protista was later modified to separate prokaryotes into the separate kingdom of Monera, leaving the protists as a group of eukaryotic microorganisms. These five kingdoms remained the accepted classification until the development of molecular phylogenetics in the late 2. Modern classificationsedit. Phylogenetic and symbiogenetic tree of living organisms, showing the origins of eukaryotes. Many systematists today do not treat Protista as a formal taxon, but the term protist is still commonly used for convenience in two ways. The most popular contemporary definition is a phylogenetic one, that identifies a paraphyletic group 2. Microsporidia fungi, many Chytridiomycetes fungi, and yeasts fungi, and also a non unicellular group included in Protista in the past, the Myxozoa animal. Some systematists judge paraphyletic taxa acceptable, and use Protista in this sense as a formal taxon as found in some secondary textbooks, for pedagogical purpose. The other definition describes protists primarily by functional or biological criteria protists are essentially those eukaryotes that are never multicellular,2. The taxonomy of protists is still changing. Newer classifications attempt to present monophyletic groups based on morphological especially ultrastructural,2. DNA sequence molecular research information. However, there are sometimes discordances between molecular and morphological investigations these can be categorized as two types i one morphology, multiple lineages e. Because the protists as a whole are paraphyletic, new systems often split up or abandon the kingdom, instead treating the protist groups as separate lines of eukaryotes. The recent scheme by Adl et al. This is intended to make the classification more stable in the long term and easier to update. Some of the main groups of protists, which may be treated as phyla, are listed in the taxobox, upper right. Many are thought to be monophyletic, though there is still uncertainty. For instance, the excavates are probably not monophyletic and the chromalveolates are probably only monophyletic if the haptophytes and cryptomonads are excluded. MetabolismeditNutrition can vary according to the type of protist. Most eukaryotic algae are autotrophic, but the pigments were lost in some groups. Other protists are heterotrophic, and may present phagotrophy, osmotrophy, saprotrophy or parasitism. Some are mixotrophic. Some protists that do not have lost chloroplastsmitochondria have entered into endosymbiontic relationship with other bacteriaalgae to replace the missing functionality.