Some of the items most closely watched by the readers of The Mirror of Science peculiarly belong to the series now gets a new episode, not surprisingly, three of his works have been among the twelve most read entries this Blog. Mollusca
Edge is a huge biological group formed by more than one hundred thousand living species currently described, popularly called "Mollusks" today home to nearly all ecosystems of the world except the arid deserts, but their greatest diversity biological states on the coasts of all continents made up of more edge of the Animal Kingdom after the arthropods. Animals are lacking spine and triblásticos coelomate protostomes, featuring almost always bilateral symmetry which exceptions are secondary. They are characterized mainly by calcareous shell secreted by an underlying integument called Manto though exceptionally it is absent in certain groups, the radula, the power authority formed by rows of keratinous teeth is unique in the animal kingdom. Also have a muscular foot that facilitates locomotion either as a lever or "ribbon" of lubricated sliding mucosa.
Thanks to their calcified shells, mollusks have left a deep mark along the Earth's geological history over the last hundred million years, so much so that make the elementary matter of some sedimentary rocks. To date they have been described about forty thousand fossil species of this phylum, although the actual historical figure could reach one million Taxa that are well before the Cambrian period to the present.
After numerous taxonomic changes prompted by the difficulty of classifying so lax and diverse group show, promoting infinite interpretations, revisions and evolutionary theories of the most varied, the Taxonomy has also had to consider in more recent cladistic system, which has shaken again all traditional classification proposals for years. The most accepted Cladograma today is the proposed eight different classes, divided into several subclasses, and numerous orders Infraclass, these classes are Caudofoveata, Cephalopoda, Bivalvia, Gastropoda, Monoplacophora, Polyplacophora, Scaphopoda and Solenogastres.
After this brief introduction, I present a small sample of the extensive fossil record that illustrates an overview of the appearance of the two classes most notable of Philo, the gastropods, popularly called "Snails" and bivalves; excluyo intencionadamente a los Cefalópodas con el fin de dedicarles un capítulo íntegro en el futuro. Todas las piezas aquí expuestas proceden de mi colección personal que incluye un mayor número de especímenes cuya presentación prolongaría en exceso este artículo.
Las primeras piezas que pueden verse conforman un raro ejemplo de Arqueogasterópodos primitivos. Archaeogastropoda es el nombre aplicado a un viejo Orden actualmente en desuso, ubicado en la Subclase Prosobranchia, siempre bajo los dogmas de la clasificación clásica; la ubicación actual de estos antiguos Gasterópodos, cuya representación se mantiene en la actualidad dado que aún es posible hallar especies vivas en litorales rocosos warm and temperate seas around the globe unknown to me after losing its location along the many changes that have taken the classification of the group. The specimens in question belong to the genus Rhombella, Jupiter come from training in the middle of the Silurian Anticosti Island (Québec), Canada.
Edge is a huge biological group formed by more than one hundred thousand living species currently described, popularly called "Mollusks" today home to nearly all ecosystems of the world except the arid deserts, but their greatest diversity biological states on the coasts of all continents made up of more edge of the Animal Kingdom after the arthropods. Animals are lacking spine and triblásticos coelomate protostomes, featuring almost always bilateral symmetry which exceptions are secondary. They are characterized mainly by calcareous shell secreted by an underlying integument called Manto though exceptionally it is absent in certain groups, the radula, the power authority formed by rows of keratinous teeth is unique in the animal kingdom. Also have a muscular foot that facilitates locomotion either as a lever or "ribbon" of lubricated sliding mucosa.
Thanks to their calcified shells, mollusks have left a deep mark along the Earth's geological history over the last hundred million years, so much so that make the elementary matter of some sedimentary rocks. To date they have been described about forty thousand fossil species of this phylum, although the actual historical figure could reach one million Taxa that are well before the Cambrian period to the present.
After numerous taxonomic changes prompted by the difficulty of classifying so lax and diverse group show, promoting infinite interpretations, revisions and evolutionary theories of the most varied, the Taxonomy has also had to consider in more recent cladistic system, which has shaken again all traditional classification proposals for years. The most accepted Cladograma today is the proposed eight different classes, divided into several subclasses, and numerous orders Infraclass, these classes are Caudofoveata, Cephalopoda, Bivalvia, Gastropoda, Monoplacophora, Polyplacophora, Scaphopoda and Solenogastres.
After this brief introduction, I present a small sample of the extensive fossil record that illustrates an overview of the appearance of the two classes most notable of Philo, the gastropods, popularly called "Snails" and bivalves; excluyo intencionadamente a los Cefalópodas con el fin de dedicarles un capítulo íntegro en el futuro. Todas las piezas aquí expuestas proceden de mi colección personal que incluye un mayor número de especímenes cuya presentación prolongaría en exceso este artículo.
Las primeras piezas que pueden verse conforman un raro ejemplo de Arqueogasterópodos primitivos. Archaeogastropoda es el nombre aplicado a un viejo Orden actualmente en desuso, ubicado en la Subclase Prosobranchia, siempre bajo los dogmas de la clasificación clásica; la ubicación actual de estos antiguos Gasterópodos, cuya representación se mantiene en la actualidad dado que aún es posible hallar especies vivas en litorales rocosos warm and temperate seas around the globe unknown to me after losing its location along the many changes that have taken the classification of the group. The specimens in question belong to the genus Rhombella, Jupiter come from training in the middle of the Silurian Anticosti Island (Québec), Canada.
Rhombella sp. The following sample receives nomenclature Glauconia sp. and represents by itself the stereotype of marine gastropods. Much more recent in time and in fact significantly more advanced than Gender previous was alive Glauconia equipped with a voluminous and extensive visceral muscular foot that allowed him to move along the sunny coastal bed. Although unaware of the exact provenance of this piece in particular, the fossils of this genus are common in Cretaceous sediments of most of the world and is very popular throughout Europe shelly deposits.
Exemplary Glauconia sp. would be possible to fill hundreds of pages showing and commenting extinct species of gastropods, but respecting the general character of this text, the following species I present is included in another of the major classes of mollusks, bivalves.
Lower Cretaceous is also Exogira flabelata, a member of the Family Gryphaeidae, for the Order Ostrea. It is not the only component of this family in my file represented fossil, but if one of the most beautiful. Here you see one of the leaflets decorated with bones and bumps. Because Exogira Gender, popularly called "Oyster honeycomb, used to anchor in the rocky coast of tropical coastal costal position, the left valve used to be more developed than the right, used the latter as a of "front" generating a random asymmetry.
Lower Cretaceous is also Exogira flabelata, a member of the Family Gryphaeidae, for the Order Ostrea. It is not the only component of this family in my file represented fossil, but if one of the most beautiful. Here you see one of the leaflets decorated with bones and bumps. Because Exogira Gender, popularly called "Oyster honeycomb, used to anchor in the rocky coast of tropical coastal costal position, the left valve used to be more developed than the right, used the latter as a of "front" generating a random asymmetry.
fossil Balvan Exogira flabelata . Spectacular might be a good adjective to define perfectly preserved shells that until today have come from Myophorella lusitanica, a medium-sized Trigoniidae from the Middle Jurassic of Europe. The piece in question has some deformities because of the weight located sediment and some erosion of the lateral spines, but in any event has retained much of its original, native of Portugal, is close to the average size of the species.
Myophorella lusitanica. Far from forming a reference work, this article I hope to have aroused the interest of the reader for this colossal Filo and large fossil record. If you prefer, you find pictures and references of a greater number of fossil species of molluscs on the fan page of The Mirror of Science in Facebook, just have to visit the photo album dedicated to this article. All participation is welcome.
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