gracieteoliveira [licensed for non-commercial use only] / Classe Cephalopoda. Cuvier, G. Second Mémoire sur l’organisation et les rapports des animaux à sang blanc, dans lequel on traite de la structure des Mollusques et de leur. Mollusks are divided into seven classes with most species residing in gastropoda . The class Cephalopoda is a remarkable group of mollusks.

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Some reports of Ennucula puelcha have referred the species to the Pacific coast of South America [Bernard, Spatial and temporal variation of a nearshore benthic community in southern Brazil: The former optimization is shown in Fig. As in Dentaliida, the structure is decentralized.

This study deals with detailed morphology and anatomy of 4 species of Scaphopoda and 5 species of protobranch Bivalvia. Pericardium and kidney with similar characters of previous species. Both crustacean groups have a pair of adductor muscles.

Spirula spirula – Wikipédia, a enciclopédia livre

What can 18S rDNA do for bivalve phylogeny? Academy of Sciences, Leningrad, p. Palaeontographica AbstractsA Of course the basic form of the foot in Bivalvia and Scaphopoda was modified several times along their evolution.

Another five species are outgroups, but they are clqsse analyzed as part of the ingroup. A reduction of the number of pedal retractors is one of the synapomorphies that substantiates a branch of the Conchifera that excludes Monoplacophora, and groups Cyrtosoma and Diasoma. Bulletins of American Paleontology9: Cephalopoda es un classe de Mollusca.


Type specimens of Quaternary marine bivalves from Argentina. The gill suspensory stalk is a reinforced rod located between both demibranchs that support the posterior region of the gills. Mission Scientifique du Cap Horn6-H. Longitudinal striae are, however, found as basal stock, having smooth and annulated forms as derived states in scaphopod analyses e. Your Web browser is not enabled for JavaScript.

Protobranchia a monomyarian solemyid and possible living actinodont. The evolution of the ligament systems in the Bivalvia. Amphineura, Scaphopoda and Bivalvia.

A reevaluation of Wiwaxia and the polychaetes of the Burgess Shale. Anus simple, sessile Figs.

Classes and sub-classes of Phylum Mollusca

Posterior half of each muscle incompletely divided longitudinally in two portions of equivalent sizes. Representatives of other molluscan classes were also selected as outgroups, however, some of them, as explained below, were operationally analyzed as part of the ingroup. Beyond these morphological characters, the absence of haemocyanin of the lamellibranch blood, a common feature in protobranchs and other mollusks Morse et al.

Family Pseudolividae Caenogastropoda, Muricoidea: However, with the introduction of phylogenetic methodologies, the discussion becomes more intelligible. In the discussion of the character, a short descriptive sentence is given for each one, followed by plesiomorphic and apomorphic states and conditions in the most parsimonious hypothesis.

Besides this character, no others are hereby applied to scaphopods because of polarization problems; however, further exploration of shell characters can be found in previous comparative analyses e. Similar Items Related Subjects: A monograph of the Silurian fossils of the Girvan District in Ayrshire.


Moluscos y su taxocenoses el nos fondos someros del setor sur de la plataforma continental del Caribe colombiano. Cclasse pedal retractor muscle running anteriorly thought haemocoel, flanking some intestinal loops Fig. This is exactly the way that the bivalve palps appear and remain during the course of a lifetime. The “proboscis” form is based on structural similarities between the gadilid foot and the gastropod proboscis.

Posterior vertical posterior flap Fig.

Paleontological Journal of the American Geological Institute8: C,asse de la Sociedad Malacologica del Uruguay4 Comparative morphology and systematics of Brazilian Terebridae Mollusca, Gastropoda, Conoideawith descriptions of three new species.

The ligament of the bivalve shell is one of the conspicuous synapomorphies of the class. Pair of anterior pedal retractor muscle, very broad and thick Cehalopoda. There is no clear ventral tensor muscles of the radula, although the pair of dorsal tensor muscles is very thick Figs.