| Moyeria Temporal range: | |
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| Transmitted white light micrographs of Moyeria sp. showing pellicle strips (arrows). Scale bar: 10 μm. | |
Scientific classification  | |
| Domain: | Eukaryota |
| Phylum: | Euglenozoa |
| Class: | Euglenida |
| Genus: | † Moyeria Thusu, 1973 |
| Type species | |
| Moyeria uticana Thusu, 1973 | |
| Species | |
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Moyeria is a genus of fossils interpreted as euglenids, a type of microbial eukaryotes characterized for their cells surrounded by a pellicle composed of proteinaceous strips. [2]
Moyeria is a genus of fossils initially considered acritarchs, of unknown evolutionary affinity. They were widely interpreted as resting cysts of marine algae. Its vesicle wall has a distinct ultrastructure that resembles the pellicle of euglenids, which is composed of proteinaceous strips. For this reason, during the 20th century some authors proposed Moyeria as part of the Euglenida. [1] After examinations through transmission electron microscopy, the stripes in the wall of these microfossils were revealed to correspond to the pellicle strips of modern euglenids, and Moyeria was formally transferred to the Euglenida in 2019. [2]
Moyeria was first described in 1973 by paleontologist Brinda Thusu from microfossils located along the south branch of Moyer Creek, near the town of Ilion, New York. The fossils originate from the Wenlock epoch, in the Silurian, and were assigned to the species Moyeria uticaensis. Thusu published four illustrated specimens along with the species description, but he did not specify which one was the holotype. [3] In 1976, some authors proposed Moyeria uticaensis as a junior synonym of another species of striated acritarchs, Eupoikilofusa cabottii. [4] However, the genus Eupoikilofusa was rejected by other authors because the vesicle was not consistently fusiform, and the species E. cabottii was instead transferred to Moyeria as M. cabottii. [5] Subsequently, several helically striated acritarchs with variable shape that were found in Ordovician and Silurian rocks were assigned to M. cabottii. [1]
In 2019, Paul K. Strother and coauthors located the original intended holotype specimen according to the coordinates given by Thusu in 1973, consequently validaitng the genus Moyeria. They corrected the type species epithet to M. uticana. After analyzing more material from the original rocks, they managed to further investigate and distinguish the two proposed fossil species. Thus, two species are currently accepted in this genus: [2]
Acritarchs are organic microfossils, known from approximately 1800 million years ago to the present. The classification is a catch all term used to refer to any organic microfossils that cannot be assigned to other groups. Their diversity reflects major ecological events such as the appearance of predation and the Cambrian explosion.
Euglenids or euglenoids are one of the best-known groups of flagellates. They are excavate eukaryotes of the phylum Euglenophyta, classified as class Euglenida or Euglenoidea. Euglenids are commonly found in freshwater, especially when it is rich in organic materials, with a few marine and endosymbiotic members. Many euglenids feed by phagocytosis, or strictly by diffusion. A monophyletic group known as Euglenophyceae have chloroplasts and produce their own food through photosynthesis. This group is known to contain the carbohydrate paramylon.
Palynology is the study of microorganisms and microscopic fragments of mega-organisms that are composed of acid-resistant organic material and occur in sediments, sedimentary rocks, and even some metasedimentary rocks. Palynomorphs are the microscopic, acid-resistant organic remains and debris produced by a wide variety of plants, animals, and Protista that have existed since the late Proterozoic.
Micropaleontology is the branch of paleontology (palaeontology) that studies microfossils, or fossils that require the use of a microscope to see the organism, its morphology and its characteristic details.
Chitinozoa are a group of flask-shaped, organic walled marine microfossils produced by an as yet unknown organism. Common from the Ordovician to Devonian periods, the millimetre-scale organisms are abundant in almost all types of marine sediment across the globe. This wide distribution, and their rapid pace of evolution, makes them valuable biostratigraphic markers.
Ottoia is a stem-group archaeopriapulid worm known from Cambrian fossils. Although priapulid-like worms from various Cambrian deposits are often referred to Ottoia on spurious grounds, the only clear Ottoia macrofossils come from the Burgess Shale of British Columbia, which was deposited 508 million years ago. Microfossils extend the record of Ottoia throughout the Western Canada Sedimentary Basin, from the mid- to late- Cambrian. A few fossil finds are also known from China.
A microfossil is a fossil that is generally between 0.001 mm and 1 mm in size, the visual study of which requires the use of light or electron microscopy. A fossil which can be studied with the naked eye or low-powered magnification, such as a hand lens, is referred to as a macrofossil.
In the geological timescale, the Llandovery Epoch occurred at the beginning of the Silurian Period. The Llandoverian Epoch follows the massive Ordovician-Silurian extinction events, which led to a large decrease in biodiversity and an opening up of ecosystems.
Nematothallus is a form genus comprising cuticle-like fossils. Some of its constituents likely represent red algae, whereas others resemble lichens.
The Nematophyta or nematophytes are a paraphyletic group of land organisms, probably including some plants as well as algae known only from the fossil record, from the Silurian period until the early Devonian Rhynie chert. The type genus Nematothallus, which typifies the group, was first described by Lang in 1937, who envisioned it being a thallose plant with tubular features and sporophytes, covered by a cuticle which preserved impressions of the underlying cells. He had found abundant disaggregated remains of all three features, none of which were connected to another, leaving his reconstruction of the phytodebris as parts of a single organism highly conjectural. No reproductive or vegetative structures common to the land plants are known, and certain members of the nematophyte plexus seem to belong to the fungi.
Ornatifilum is an artificial form genus, which is used to categorise any small, branched filaments with external ornamentation.
Euglenaceae is a family of flagellates in the phylum Euglenozoa. The family includes the most well-known euglenoid genus, Euglena.
Phacus is a genus of unicellular excavates, of the phylum Euglenozoa, characterized by its flat, leaf-shaped structure, and rigid cytoskeleton known as a pellicle. These eukaryotes are mostly green in colour, and have a single flagellum that extends the length of their body. They are morphologically very flat, rigid, leaf-shaped, and contain many small discoid chloroplasts.
Peranema is a genus of free-living phagotrophic euglenids. There are more than 20 nominal species, varying in size between 8 and 200 micrometers. Peranema cells are gliding flagellates found in freshwater lakes, ponds and ditches, and are often abundant at the bottom of stagnant pools rich in decaying organic material. Although they belong to the class Euglenoidea, and are morphologically similar to the green Euglena, Peranema have no chloroplasts, and do not conduct autotrophy. Instead, they capture live prey, such as yeast, bacteria and other flagellates, consuming them with the help of a rigid feeding apparatus called a "rod-organ." Unlike the green euglenids, they lack both an eyespot (stigma), and the paraflagellar body (photoreceptor) that is normally coupled with that organelle. However, while Peranema lack a localized photoreceptor, they do possess the light-sensitive protein rhodopsin, and respond to changes in light with a characteristic "curling behaviour."
Alfred Eisenack was a German paleontologist. He was a pioneer of micropaleontology and palynology. His botanical and mycological author abbreviation is "Eisenack".
Petalomonas is a genus of phagotrophic, flagellated euglenoids. Phagotrophic euglenoids are one of the most important forms of flagellates in benthic aquatic systems, playing an important role in microbial food webs. The traits that distinguish this particular genus are highly variable, especially at higher taxa. However, general characteristics such as a rigid cell shape and single emergent flagellum can describe the species among this genus.
Heteronema is a genus of phagotrophic, flagellated euglenoids that are most widely distributed in fresh water environments. This genus consists of two very distinguishable morphogroups that are phylogenetically closely related. These morphogroups are deciphered based on shape, locomotion and other ultrastructural traits. However, this genus does impose taxonomic problems due to the varying historical descriptions of Heteronema species and its similarity to the genus Paranema. The species H. exaratum, was the first heteronemid with a skidding motion to be sequenced, which led to the discovery that it was not closely related to H. scaphrum, contrary to what was previously assumed, but instead to a sister group of primary osmotrophs. This suggests that skidding heteronemids can also be distinguished phylogenetically, being more closely related to Anisoma, Dinema and Aphageae, than to other species within Heteronema.
Eathiestrobus mackenziei is a fossil pine cone found in the Kimmeridge Clay Formation near Eathie, on the Black Isle in Scotland. It is the oldest fossil pine currently known.
Spirocuta is a clade of euglenids, single-celled eukaryotes or protists belonging to the phylum Euglenozoa. They are distinguished from other euglenids by active deformation of their cell shape, a process called euglenid motion or metaboly. This is made possible by a high number of spirally arranged protein strips that run below their cell membrane and confer the cell with flexibility. These strips compose the helicoidal pellicle, a trait referenced by the alternative name Helicales.
Neometanema is a genus of phagotrophic flagellates belonging to the Euglenida, a diverse group of flagellates in the phylum Euglenozoa. It is the sole genus within the monotypic family Neometanemidae and suborder Metanemina. It composes the order Natomonadida together with a closely related clade of osmotrophs known as Aphagea.