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Nessariostoma
''Nessariostoma granulosum'' is a lightly armored Pseudopetalichthyida, pseudopetalichthyid placoderm from the Hunsrück Slate, Hunsrückschiefer Lagerstätte of Early Devonian Germany. The Type specimen, type and only known specimen is an articulated, but very incomplete individual, deformed and elongated, consisting of a large, incomplete, tubercle-covered head, a long, beak-like Rostrum (anatomy), rostrum, and some of the Trunk (anatomy), trunk, with a total length of 18 centimeters. ''N. granulosum'' was once placed in Stensioellida, though most other experts regard it at as a pseudopetalichthyid: Denison 1978 regards it as a placoderm ''incertae sedis'' because the specimen is deformed and so poorly preserved so as to stymie proper attempts at classification. References External links ''Pseudopetalichthys''
at the Paleobiology Database Pseudopetalichthyida Fossils of Germany {{placoderm-stub ...
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Pseudopetalichthyida
Pseudopetalichthyida is an extinct order of lightly armored placoderms known only from rare fossils in Lower Devonian strata in Hunsrück, Germany. Like ''Stensioella heintzi'', and the Rhenanida, the Pseudopetalichthids had armor made up of a mosaic of tubercles. Like ''Stensioella heintzi'', the Pseudopetalichthids' placement within Placodermi is suspect. However, due to a gross lack of whole, uncrushed, articulated specimens, there are no other groups that the Pseudopetalichthids could be, for a lack of a better word, pigeonholed into. On the other hand, according to anatomical studies done on the crushed specimens that have been found, those experts who do regard the Pseudopetalichthyida as placoderms consider them to be a group more advanced than the Ptyctodonts. And as such, pro-placoderm experts consider Pseudopetalichthyida to be the sister group of the Arthrodires + Phyllolepida + Antiarchi trichotomy and the Acanthothoraci + Rhenanida dichotomy. The best known s ...
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Emsian
The Emsian is one of three faunal stages in the Early Devonian Epoch. It lasted from 407.6 ± 2.6 million years ago to 393.3 ± 1.2 million years ago. It was preceded by the Pragian Stage and followed by the Eifelian Stage. It is named after the Ems river in Germany. The GSSP is located in the Zinzil'ban Gorge in the Kitab State Geological Reserve of Uzbekistan, above the contact with the Madmon Formation. In North America the Emsian Stage is represented by Sawkill or Sawkillian time. Biological events During this period, earliest known agoniatitid ammonoid fossils began appearing within this stage after first appearing in previous stage and began to evolutionarily radiate within this stage, in which a new ammonoid order Goniatitida rises in the end of Zlichovian stage (Siberian representation; corresponds to early Eifelian and after the end of Early Devonian, before 391.9 mya). Later agoniatitid ammonoids would die out in the Taghanic event in the upper middle Givetian ...
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Animal
Animals are multicellular, eukaryotic organisms in the Kingdom (biology), biological kingdom Animalia. With few exceptions, animals Heterotroph, consume organic material, Cellular respiration#Aerobic respiration, breathe oxygen, are Motility, able to move, can Sexual reproduction, reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of Cell (biology), cells, the blastula, during Embryogenesis, embryonic development. Over 1.5 million Extant taxon, living animal species have been Species description, described—of which around 1 million are Insecta, insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have Ecology, complex interactions with each other and their environments, forming intricate food webs. The scientific study of animals is known as zoology. Most living animal species are in Bilateria, a clade whose members have a Symmetry in biology#Bilate ...
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Chordata
A chordate () is an animal of the phylum Chordata (). All chordates possess, at some point during their larval or adult stages, five synapomorphies, or primary physical characteristics, that distinguish them from all the other taxa. These five synapomorphies include a notochord, dorsal hollow nerve cord, endostyle or thyroid, pharyngeal slits, and a post-anal tail. The name “chordate” comes from the first of these synapomorphies, the notochord, which plays a significant role in chordate structure and movement. Chordates are also Bilateral symmetry, bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit Metameric, metameric segmentation. In addition to the morphological characteristics used to define chordates, analysis of genome sequences has identified two conserved signature indels (CSIs) in their proteins: cyclophilin-like protein and mitochondrial inner membrane protease ATP23, which are exclusively shared by all vertebrates, tunicates and cep ...
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Placodermi
Placodermi (from Greek πλάξ 'plate' and δέρμα 'skin', literally 'Plate (animal anatomy), plate-skinned') is a Class (biology), class of armoured prehistoric fish, known from fossils, which lived from the Silurian to the end of the Devonian period. Their head and thorax were covered by articulated armoured plates and the rest of the body was scale (zoology), scaled or naked, depending on the species. Placoderms were among the first jawed fish; their Fish jaw, jaws likely evolved from the first of their gill arches. Placoderms are thought to be paraphyly, paraphyletic, consisting of several distinct Outgroup (cladistics), outgroups or sister taxon, sister taxa to all living jawed vertebrates, which originated among their ranks. In contrast, one 2016 analysis concluded that placodermi are likely monophyletic, though these analyses have been further dismissed with more transitional taxa between placoderms and modern gnathosthomes, solidifying their paraphyletic status. Plac ...
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Hunsrück Slate
The Hunsrück () is a long, triangular, pronounced upland in Rhineland-Palatinate, Germany. It is bounded by the valleys of the Moselle-Saar (north-to-west), the Nahe (south), and the Rhine (east). It is continued by the Taunus mountains, past the Rhine and by the Eifel past the Moselle. To the south of the Nahe is a lower, hilly country forming the near bulk of the Palatinate region and all of the, smaller, Saarland. Below its north-east corner is Koblenz. As the Hunsrück proceeds east it acquires north-south width and three notable gaps in its southern ridges. In this zone are multi-branch headwaters including the Simmerbach ending at Simmertal on the southern edge. This interior is therefore rarely higher than above sea level. Peaks and escarpments are principally: the (Black Forest) Hochwald, the Idar Forest, the Soonwald, and the Bingen Forest. The highest mountain is the Erbeskopf (816 m; 2,677 ft), towards the region's south-west. Notable towns are Simmern, ...
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Lagerstätte
A Lagerstätte (, from ''Lager'' 'storage, lair' '' Stätte'' 'place'; plural ''Lagerstätten'') is a sedimentary deposit that exhibits extraordinary fossils with exceptional preservation—sometimes including preserved soft tissues. These formations may have resulted from carcass burial in an anoxic environment with minimal bacteria, thus delaying the decomposition of both gross and fine biological features until long after a durable impression was created in the surrounding matrix. ''Lagerstätten'' span geological time from the Neoproterozoic era to the present. Worldwide, some of the best examples of near-perfect fossilization are the Cambrian Maotianshan shales and Burgess Shale, the Silurian Waukesha Biota, the Devonian Hunsrück Slates and Gogo Formation, the Carboniferous Mazon Creek, the Jurassic Posidonia Shale and Solnhofen Limestone, the Cretaceous Yixian, Santana, and Agua Nueva formations, the Eocene Green River Formation, the Miocene Foulden Maar and Ashfall F ...
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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 ...
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Type Specimen
In biology, a type is a particular wiktionary:en:specimen, specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally attached. In other words, a type is an example that serves to anchor or centralizes the defining features of that particular taxon. In older usage (pre-1900 in botany), a type was a taxon rather than a specimen. A taxon is a scientifically named grouping of organisms with other like organisms, a set (mathematics), set that includes some organisms and excludes others, based on a detailed published description (for example a species description) and on the provision of type material, which is usually available to scientists for examination in a major museum research collection, or similar institution. Type specimen According to a precise set of rules laid down in the International Code of Zoological Nomenclature (ICZN) and the International Code of Nomenclature for algae, fungi, and plants (ICN), the ...
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Rostrum (anatomy)
Rostrum (from Latin ', meaning ''beak'') is a term used in anatomy for a number of phylogenetically unrelated structures in different groups of animals. Invertebrates * In crustaceans, the rostrum is the forward extension of the carapace in front of the eyes. It is generally a rigid structure, but can be connected by a hinged joint, as seen in Leptostraca. * Among insects, the rostrum is the name for the piercing mouthparts of the order Hemiptera as well as those of the snow scorpionflies, among many others. The long snout of weevils is also called a rostrum. * Gastropod molluscs have a rostrum or proboscis. * Cephalopod molluscs have hard beak-like mouthparts referred to as the rostrum. File:Washington DC Zoo - Macrobrachium rosenbergii 6.jpg, Crustacean: the rostrum of the shrimp ''Macrobrachium rosenbergii'' is serrated along both edges. File:Gminatus australis with Beetle.jpg, Insect: assassin bug piercing its prey with its rostrum File:Architeuthis beak.jpg, Cephalopod: ...
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Trunk (anatomy)
The torso or trunk is an anatomical term for the central part, or the core, of the body of many animals (including humans), from which the head, neck, limbs, tail and other appendages extend. The tetrapod torso — including that of a human — is usually divided into the ''thoracic'' segment (also known as the upper torso, where the forelimbs extend), the ''abdominal'' segment (also known as the "mid-section" or "midriff"), and the ''pelvic'' and '' perineal'' segments (sometimes known together with the abdomen as the lower torso, where the hindlimbs extend). Anatomy Major organs In humans, most critical organs, with the notable exception of the brain, are housed within the torso. In the upper chest, the heart and lungs are protected by the rib cage, and the abdomen contains most of the organs responsible for digestion: the stomach, which breaks down partially digested food via gastric acid; the liver, which respectively produces bile necessary for digestion; the large and smal ...
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