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Asterolepidoidei
Antiarchi ("opposite anus") is an order of heavily armored placoderms. The antiarchs form the second-most successful group of placoderms after the arthrodires in terms of numbers of species and range of environments. The order's name was coined by Edward Drinker Cope, who, when examining some fossils that he thought were armored tunicates related to '' Chelyosoma'', mistakenly thought that the orbital fenestra (i.e., the hole in the headshield for the eyes, nose and pineal foramen) was the opening for the mouth, or oral siphon, and that the opening for the anal siphon was on the other side of the body, as opposed to having both oral and anal siphons together at one end. The front portions of their bodies were heavily armored, to the point of literally resembling a box with eyes, with the sometimes scaled, sometimes naked rear portions often becoming sinuous, particularly with later forms. The pair of pectoral fins were modified into a pair of caliper-like, or arthropod-like l ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Ludfordian
In the geologic timescale, the Ludfordian is the upper of two chronostratigraphic stages within the Ludlow Series. Its age is the late Silurian Period, and within both the Palaeozoic Era and Phanerozoic Eon. The rocks assigned to the Ludfordian date to between 425.6 ± 0.9 Ma and 423.0 ± 2.3 Ma (million years ago). The Ludfordian Stage succeeds the Gorstian Stage and precedes the Pridoli Epoch. It is named for the village of Ludford in Shropshire, England. The GSSP for the Ludfordian is represented as a thin shale seam, coincident with the base of the Leintwardine Formation, overlying the Bringewood Formation in England. Paleoclimate The Lau event is a rapid pulse of cooling during the Ludfordian, about ; it is identified by a pulse of extinctions and oceanic changes. It is one of the series of fast sea-level and excursions in oxygen isotope ratios that signal fast switches between warm and cold climate states, characteristic of the Silurian climatic instability. T ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Cephalaspidomorphi
Cephalaspidomorphi (alternatively called Monirhina, or simply cephalaspids) is a Class (biology), class of agnatha, jawless fishes that is presently regarded as uniting the Osteostraci, osteostracans, Galeaspida, galeaspids and Pituriaspida, pituriaspids. Most biologists regard this taxon as extinct, but the name is still sometimes used in the classification of lampreys because they were once thought to be descended. If lampreys are included they would extend the known range of the group from the Silurian and Devonian periods, when they are traditionally assumed to have lived, to the Holocene, present day. Modern works typically assume the cephalaspidimorphs to be the closest relatives of jawed fishes, who may have emerged from within them; if this is true, they would survive if the Gnathostomata, jawed fish are included. The cephalaspidomorphs possessed armored head-shields, a heterocercal tail fin, and in some groups paired pectoral fins. Biology and morphology Cephalaspidomorphs ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bothriolepididae
Bothriolepididae is a family of antiarch placoderms, known from the Emsian, to Famennian. Taxonomy The cladogram is fromBothriolepid antiarchs (Vertebrata, Placodermi) from the Devonian of the north-western part of the East European Platform. {{Clade, style={{Clade , label1= Bothriolepidoidei , 1={{Clade , 1={{Clade , 1='' Microbrachius'' , 2='' Wudinolepis'' , 2={{Clade , 1={{Clade , 1='' Dianolepis'' , 2='' Jiangxilepis'' , 3='' Kirgisolepis'' , 4='' Tenizolepis'' , 2={{Clade , 1='' Monarolepis'' , 2={{Clade , 1=''Bothriolepis ''Bothriolepis'' (from , 'trench' and 'scale') was a widespread, abundant and diverse genus of antiarch placoderms that lived during the Middle to Late Devonian period of the Paleozoic Era. Historically, ''Bothriolepis'' resided in an array ...'' , 2='' Grossilepis'' , 3='' Vietnamaspis'' References { ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
Bothriolepidoidei
Bothriolepidoidei is a suborder of antiarch placoderm fishes. The group is considered paraphyletic. Taxonomy The cladogram is taken from Bothriolepid antiarchs (Vertebrata, Placodermi) from the Devonian of the north-western part of the East European Platform. {{Clade, style={{Clade , label1=Bothriolepidoidei , 1={{Clade , 1={{Clade , 1='' Microbrachius'' , 2='' Wudinolepis'' , 2={{Clade , 1={{Clade , 1='' Dianolepis'' , 2='' Jiangxilepis'' , 3='' Kirgisolepis'' , 4='' Tenizolepis'' , 2={{Clade , 1='' Monarolepis'' , 2={{Clade , 1=''Bothriolepis ''Bothriolepis'' (from , 'trench' and 'scale') was a widespread, abundant and diverse genus of antiarch placoderms that lived during the Middle to Late Devonian period of the Paleozoic Era. Historically, ''Bothriolepis'' resided in an array ...'' , 2='' Grossilepis'' , 3='' Vietnamaspis'' ... [...More Info...] [...Related Items...] OR: [Wikipedia] [Google] [Baidu] |
