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Eurycaraspis
''Eurycaraspis incilis'' is an extinct petalichthid placoderm from the Middle Devonian of China. It is closely related to ''Quasipetalichthys''. Anatomy ''Eurycaraspis incilis'' differs from ''Quasipetalichthys'' by having a more circular-shaped skull. Phylogeny ''Eurycaraspis incilis'' is considered a basal petalichthyid, and is placed in Quasipetalichthyidae as ''Quasipetalichthys sister taxon. Quasipetalichthyidae Quasipetalichthyidae is a family of primitive petalichthyid placoderms from Givetian-aged marine strata of Yunnan, China, and possibly Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group ..., in turn, is considered the sister group of Macropetalichthyidae. References Fossil taxa described in 1991 Placoderms of Asia Petalichthyida Placoderm genera {{Placoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Petalichthyida
Petalichthyida is an extinct order of small, flattened placoderm fish. They are typified by their splayed pectoral fins, exaggerated lateral spines, flattened bodies, and numerous tubercles that decorated all of the plates and scales of their armor. They reached a peak in diversity during the Early Devonian and were found throughout the world, particularly in Europe (especially in Germany), North America, Asia, South America, and Australia. The petalichthids ''Lunaspis'' and '' Wijdeaspis'' are among the best known. The earliest and most primitive known petalichthyid is ''Diandongpetalichthys'', which is from earliest Devonian-aged strata of Yunnan. The presence of ''Diandongpetalichthys'', along with other primitive petalichthyids including ''Neopetalichthys'' and ''Quasipetalichthys'', and more advanced petalichthyids, suggest that the order may have arisen in China, possibly during the late Silurian. Because they had compressed body forms, it is speculated they were bot ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasipetalichthyidae
Quasipetalichthyidae is a family of primitive petalichthyid placoderms from Givetian-aged marine strata of Yunnan, China, and possibly Vietnam Vietnam or Viet Nam ( vi, Việt Nam, ), officially the Socialist Republic of Vietnam,., group="n" is a country in Southeast Asia, at the eastern edge of mainland Southeast Asia, with an area of and population of 96 million, making it .... The family contains two confirmed genera, '' Quasipetalichthys'', and '' Eurycaraspis'', which differ from the more advanced macropetalichthyids by having more squared skulls that have the eye sockets placed on the side of their skulls, rather than nearer to the center. More basal petalichthyids, such as '' Diandongpetalichthys'' and '' Neopetalichthys'', differ from the quasipetalichthyids by having comparatively elongated skulls. References Placoderms of Asia Placoderm families Petalichthyida Middle Devonian extinctions Middle Devonian first appearances {{Placoderm-stub ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Quasipetalichthys
''Quasipetalichthys haikouensis'' is the type and only known species of the extinct petalichthid placoderm, ''Quasipetalichthys''. Fossil remains of ''Quasipetalichthys'' have been found in the Middle Devonian, Givetian faunal stage of China. Fossils ''Quasipetalichthys'' is known primarily from two poorly preserved skulls from the Givetian-aged Haikou Formation of Haikou, Kunming, China, where they were found in association with remains of antiarch placoderms such as ''Bothriolepis sinensis'', and ''Hunanolepis''. The larger of the two skulls may have been around in length. Phylogeny ''Q. haikouensis'' is considered a basal petalichthyid (though in 1978 Denison referred to it as being "aberrant"). In Zhu's 1991 redescription of ''Diandongpetalichthys'',Zhu, M. "New information on ''Diandongpetalichthys'' (Placodermi: Petalichthyida)." Early vertebrates and related problems of evolutionary biology. Science Press, Beijing (1991): 179-192. ''Quasipetalichthys'' was place ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Givetian
The Givetian is one of two faunal stages in the Middle Devonian Period. It lasted from million years ago to million years ago. It was preceded by the Eifelian Stage and followed by the Frasnian Stage. It is named after the town of Givet in France. The oldest forests occurred during the late Givetian. The lower GSSP is located at Jebel Mech Irdane Jabal, Jabel, Jebel or Jibal may refer to: People * Jabal (name), a male Arabic given name * Jabal (Bible), mentioned in the Hebrew Bible Places In Arabic, ''jabal'' or ''jebel'' (spelling variants of the same word) means 'mountain'. * Dzhebel, ..., Tafilalt, Morocco. Name and definition The Givetian Stage was proposed in 1879 by French geologist Jules Gosselet and was accepted for the higher stage of the Middle Devonian by the Subcommission on Devonian Stratigraphy in 1981. References Further reading * {{Geological history, p, p Givetian, Middle Devonian Devonian geochronology Devonian Europe, . Devonian ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Animalia
Animals are multicellular, eukaryotic organisms in the biological kingdom Animalia. With few exceptions, animals consume organic material, breathe oxygen, are able to move, can reproduce sexually, and go through an ontogenetic stage in which their body consists of a hollow sphere of cells, the blastula, during embryonic development. Over 1.5 million living animal species have been described—of which around 1 million are insects—but it has been estimated there are over 7 million animal species in total. Animals range in length from to . They have 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#Bilateral symmetry, bilaterally symmetric body plan. The Bilateria include the protostomes, containing animals such as nematodes, arthropods, flatworms, annelids and molluscs, and th ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
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 bilaterally symmetric, have a coelom, possess a circulatory system, and exhibit 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 cephalochordates. These CSIs provi ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Placodermi
Placodermi (from Greek πλάξ 'plate' and δέρμα 'skin', literally ' plate-skinned') is a 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 scaled or naked, depending on the species. Placoderms were among the first jawed fish; their jaws likely evolved from the first of their gill arches. Placoderms are thought to be paraphyletic, consisting of several distinct outgroups or 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. Placoderms were also the first fish to develop pelvic fins, the precursor to hindlimbs in tetrapods, as well ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Devonian
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 domina ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
China
China, officially the People's Republic of China (PRC), is a country in East Asia. It is the world's List of countries and dependencies by population, most populous country, with a Population of China, population exceeding 1.4 billion, slightly ahead of India. China spans the equivalent of five time zones and Borders of China, borders fourteen countries by land, the List of countries and territories by land borders, most of any country in the world, tied with Russia. Covering an area of approximately , it is the world's third List of countries and dependencies by area, largest country by total land area. The country consists of 22 provinces of China, provinces, five autonomous regions of China, autonomous regions, four direct-administered municipalities of China, municipalities, and two special administrative regions of China, Special Administrative Regions (Hong Kong and Macau). The national capital is Beijing, and the List of cities in China by population, most populous cit ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Fossil Taxa Described In 1991
A fossil (from Classical Latin , ) is any preserved remains, impression, or trace of any once-living thing from a past geological age. Examples include bones, shells, exoskeletons, stone imprints of animals or microbes, objects preserved in amber, hair, petrified wood and DNA remnants. The totality of fossils is known as the ''fossil record''. Paleontology is the study of fossils: their age, method of formation, and evolutionary significance. Specimens are usually considered to be fossils if they are over 10,000 years old. The oldest fossils are around 3.48 billion years old to 4.1 billion years old. Early edition, published online before print. The observation in the 19th century that certain fossils were associated with certain rock strata led to the recognition of a geological timescale and the relative ages of different fossils. The development of radiometric dating techniques in the early 20th century allowed scientists to quantitatively measure the absolute ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
