Geometry.Net - Science: Cephalopods

Cephalopods: Squids, Octopus, And Other Squishy Things
The cephalopods are probably the oddest group of animals in the ocean, perhapsthe world. The cephalopods belong to the mollusk group (phylum Mollusca).
http://home.earthlink.net/~water_monkey/Cephalo.htm

Extractions: The cephalopods are probably the oddest group of animals in the ocean, perhaps the world. The most common members are the octopus, the squid, and the cuttlefish. The cepalopods are the sea monsters of old sailor stories. These denizens of the deep have been as much a mystery as they have been a fear. Imagine a beast that could pluck a sailor off the deck of a ship without making a sound, or crush a ship with its mighty tentacles. This is definately one creature that doe not deserve its fearsome reputation (at least with humans). The cephalopods belong to the mollusk group (phylum Mollusca). One of the main characteristics of the mollusks (clams, oysters, snails) is the presence of a shell. This brings up the question of where the shell is on an octopus or a squid. The squid has a reduced inner shell, while a shell is absent in the octopus. It is the reduce shell in the squid that gives it a somewhat stiff appearance. Within the cephalopods the presence of a visible shell is a major characterisitc that is used to classify them. Probably the body part that is most commonly identified with the cephalopods are the tentacles. The tentacles are powerful arms covered with suction cups. The tentacles are so strong that an octopus can tear apart almost any creature of comparable size. Cephalopods are so adept at using their tentacles, they can function independently. However, it is when all the tentacles are functioning together that the true power of these appendages is realized.
Cephalopods
Taxonomic Status. Phylum Mollusca Class - Cephalopoda Introduction.cephalopods are highly specialized free-swimming marine organisms.
http://geoindia.8m.com/palaeo/cephalopod.htm

Extractions: Class - Cephalopoda Cephalopods are highly specialized free-swimming marine organisms. The body consists of a single shell with the front end of the foot developing a series of tentacles that surround the head. We will study features and evolution of cephalopods under three subheads representing the three subclasses Nautiloidea, Ammonoidea and Coleoidea. Nautiloids occur in rocks over a wide range of ages from Cambrian to Recent . It is represented by the living genus Nautilus. The animal protect itself inside the shell which has an opening called aperture . The animal lives inside the body cavity and it keeps on adding body cavities by depositing walls known as septa . The cavities thus formed are called camerae . The chambers are filled with gas which provides the necessary buoyancy for the animal to float. The septa are all concave towards the body cavity. The camerae are connected to each other by a tube called siphuncle . The siphuncle is held by a series of septal necks from all the septa. The septal necks point away from the aperture. The septa meets the inner wall of the cephalopod shell to form
Fossil Cephalopods In Utah
A pictorial guide to fossil cephalopods of Utah including Ammonoidea, Nautiloidea, and Coeloidea.Category Science Earth Sciences United States UtahOld Calamari Fossil cephalopods in Utah The Webpage of Kevin Bylund.Fossil cephalopods in Utah. Some Large Ammonites from Utah.
http://ammonoid.topcities.com/
Llanvirn Cephalopods
Llanvirn (Ordovician) cephalopods (Whiterockian Series/Rangerian Stage). Ordoviciancephalopodsare numerous and varied in the Pogonip Group of westcentral Utah.
http://ammonoid.topcities.com/whiterock.htm
Cephalopods
cephalopods. All the recent cephalopod shells are composed of aragonitic layers prismatic layers, nacreous layers and spherulitic prismatic layers.
http://biomin.geol.u-psud.fr/ydweb/cephalo/

Extractions: Cephalopods It must be noticed that the "prismatic" layers in Cephalopod shells are not similar to those of other Molluscs ; they are always aragonitic, and composed of small fibres, ressembling to the fibres of the coral skeletons. The outer layer of the outer wall is spherulitic prismatic in Nautilus and Sepia , and prismatic in Spirula . The nacreous middle layer is almost entirely organic in the Spirula shell, more or less mineralized in the Sepia shell. The inner layer is prismatic in the three genera. It may be supposed that the rostra of belemnites and other fossil Coleoids are hypertrophied outer spherulitic prismatic layers. Return to Studied material Last Updated on 2 October 1997 by Dauphin
Cephalopods
Home Marine Zoology Mediterranean cephalopods. Some cephalopods are able to emitthe exact amount of light to disguise themselves as the shining waves.
http://www.sportesport.it/cephalopods.htm

Extractions: Bibliography ... the Architeuthis princeps , the Mediterranean Giant squid, is the king of marine monsters: it is a fast, efficient and ferocious predator moving in dark abysses, with ten strong and sinuous arms provided with suckers and claws; the jaw is a powerful, crooked beak and the tongue is covered by sharp teeth; the skin can instantaneously change colour and the mantle is adorned by scattered, multicoloured brigt lights; just the titanic Sperm-whale can stuggle with the Architeuthis : the largest known Giant squids specimens are more than 18m long...
Cephalopods In Action--Young, Vecchione And Donovan, 1998
cephalopods in ActionYoung, Vecchione and Donovan, 1998 1998 The evolutionof coleoid cephalopods and their present biodiversity and ecology.
http://www.mnh.si.edu/cephs/yvd98/yvd98.html

Extractions: ABSTRACT: The present status of phylogeny and classification in coleoid cephalopods and the effect of evolution on the present ecology and biodiversity in the group are examined. The basis of knowledge of cephalopod phylogeny was formulated by Naef in the early 1920s, and his ideas and the progress made in the intervening 75 years are investigated. In the process, the roles that transitions between pelagic and benthic habitats played in the evolution of of cephalopods are noted, and the possibility is advanced that the most recent "oceanic anoxic event" may have established a time marker for the divergence of some oegopsid families. The major advances since Naef's work are: 1. The unusual nature of Vampyroteuthis has been recognized; 2. The sister-group relationship between the Neocoleoidea and the Belemnoidea has been established, but requires further confirmation; 3. Monophyly has been confirmed for the Decapodiformes (new name), Octopodiformes and Octopoda by molecular and morphological methodologies; 4. The dates of origin of the Belemnoidea, Neocoleoidea, Sepioidea and fossil teuthoids have been extended to considerably earlier times. The major unsolved phylogenetic problems in need of immediate attention are the position of the Myopsida, relationships within the Sepioidea, the identification of basal nodes with the Oegopsida, and the relationships of most "fossil teuthoids."
Cephalopods In Action--Taxonomic Index
cephalopods in Action Taxonomic Index. This index is modified from TaxonomicIndex, Jan 28, 2002. NMNH Home cephalopods at NMNH.
http://www.mnh.si.edu/cephs/cephtaxuf.html

Extractions: Cephalopoda Nautiloidea Coleoidea Octopodiformes Octopoda Cirrata ... Opisthoteuthidae Opisthoteuthis Grimpoteuthis Stauroteuthidae Incirrata Tremoctopodidae Alloposidae Haliphron atlanticus Octopodidae Bathypolypus Benthoctopus Vitreledonellidae Vitreledonella richardi Decapodiformes Oegopsida Brachioteuthidae Brachioteuthis Chiroteuthidae Chiroteuthis Mastigoteuthidae ... Histioteuthidae Histioteuthis Pholidoteuthidae Pholidoteuthis Ommastrephidae Illex Nototodarus Ornithoteuthis Myopsida Loliginidae Loligo Pickfordiateuthis Pickfordiateuthis bayeri This page modified with permission from The Tree of Life Cephalopod Taxonomic Index , Jan 28, 2002. NMNH Home Cephalopods at NMNH
Cephalopods
cephalopods. CLASSIFICATION GEOLOGIC RANGES. Class CEPHALOPODA. The cephalopodsare a class of mobile mollusks, most of which are nektic or nektobenthic.
http://paleo.cortland.edu/tutorial/Ceph&Gast/cephalopods.htm

Extractions: CEPHALOPODA, GASTROPODA CEPHALOPODS Phylum Mollusca (Precambrian-Recent) Class Cephalopoda (Cambrian-Recent) Subclass Coleoidea (Devonian-Recent) Subclass Nautiloidea (Cambrian-Recent) Subclass Ammonoidea (Devonian-Cretaceous) Class CEPHALOPODA The cephalopods are a class of mobile mollusks, most of which are nektic or nekto-benthic. Cephalopods have a bilaterally symmetrical body, a prominent head, and a modified foot in the form of tentacles. Although during the Paleozoic and Mesozoic, cephalopods achieved great diversity and abundance in marine habitats, only two genera possessing skeletons are known today. See the example of a Nautilus. Superficially the shell or conch of cephalopods resemble gastropods; however, most cephalopods coil in a plane, whereas gastropods are helicoiled. Furthermore, in cephalopods with an external conch, the coiled shell is chambered. Cephalopod Morphology Some morphologic terms you should become familiar with are given below.
Virtual Silurian Reef -- Cephalopods
CEPHALOPOD. cephalopods of today live only in seawater and includethe squid, octopus and pearly nautilus. Cephalopod shells may
http://www.mpm.edu/reef/cephalopod.html

Extractions: C EPHALOPODS of today live only in seawater and include the squid, octopus and pearly nautilus. Cephalopod shells may be coiled, slightly curved, or straight, and all are characterized by internal chambers. The cephalopod body, which included a head with eyes, mouth and tentacles, occupied the final and largest chamber. All modern cephalopods are carnivores that capture and eat other animals. All cephalopods are swimmers, but some, such as the octopus, spend most of their time on the seafloor. A t least 33 species of cephalopods lived as dwellers in the Silurian reefs of Wisconsin. Five of these species, shown above, have been placed in the Silurian reef diorama, and their tentacled heads (figures 2 and 5a) have been reconstructed from the appearance of modern cephalopods. Although the cephalopods in the diorama are shown as active swimmers, the larger forms may have spent most of their time lying on the reef surface.
Cephalopods
cephalopods Phylum Mollusca intelligent. They are probably the most intelligentof all the invertebrates. There are four types of cephalopods 1
http://www.cyhaus.com/marine/cephalopod.htm

Extractions: Because of the many movies in which cephalopods, especially octopi and squids, attack people, boats, etc., there is a misconception that they are aggressive and dumb creatures. In fact, there are only two species of octopi that are aggressive (they are located in Austrailia), and they are highly intelligent. They are probably the most intelligent of all the invertebrates. Octopi they have eight symmetric arms (tenticles) which are used for their protection and for obtaining food. They have an interesting mating ritual: The males and females do not mate with any other partners besides the chosen one. Shortly after the female has her children, she dies, but the male stays with herhe does not mate again. This example is one of the only monogamous relationship that exists among animals. The octopus also has the most advanced sensory systems of any other invertebrate. Squids have ten polymorphic armstwo special arms that an octopus doesn not have. They use Rajiform (after Raja=skate) swimming motions in which they undulate their lateral fins like a skate or ray does. They also have something called jet propulsion. This is caused by the squid taking water into its mantle cavaties and then expelling it at high speeds through a nozzle like siphon in the opposite direction that the squid wants to move. The siphon can be aimed in any direction for course corrections and maneuvering purposes. The squid uses its tenticles for food and for protection. The myth of the Giant Squid is in fact true. It is a very shy creature and is usually only seen if it dies and washes up on shore.
FishBase Glossary Searched Term
http://www.fishbase.org/Glossary/Glossary.cfm?TermEnglish=cephalopods
ISGS Cephalopods
Squids, octopuses, cuttlefish, and the pearly nautilus are among the cephalopodsliving in modern seas. All are members of the large phylum Mullusca.
http://www.isgs.uiuc.edu/fossils/cephalopods.htm

Extractions: Coiled Cephalopod (Metacoceras) (sef' ah lo pods) Cephalopod fossils have been found in rocks of many ages, and numerous representatives are alive today. Squids, octopuses, cuttlefish, and the pearly nautilus are among the cephalopods living in modern seas. All are members of the large phylum Mullusca. Cephalopods are the most advanced class of the mulluskes. They have a distinct head, a highly developed nervous system, and eyes much like those of humans. The cephalopod's mouth is surrounded by long tentacles commonly armed with suckers. Beneath the tentacles is a tube, the siphon, through which the animal can force a jet of water and thus move about by jet propulsion. Coiled cephalopods live today only in the South Pacific, but in the geologic past they were scattered throughout the world. Modern squids live in shallow coastal waters over much of the globe. Most of the cephalopods we find as fossils had a calcareous outer shell. Some were loosely coiled, some tightly coiled, and others were shaped like a tapered tube.
Miscellaneous Cephalopods
Missing Link Fossil Enterprises Fossil Catalog Miscellaneous cephalopods.
http://www.fossilhut.com/miscellaneous_cephalopods.htm
Cephalopods
cephalopods. Return to Lecture Index Morphology, Pelagic Adaptations,Groups, Adaptive History. Forward to Trilobites.
http://www.eos.ubc.ca/courses/eosc326/lecture/ceph/ceph.htm
Cephalopod Printouts - EnchantedLearning.com
cephalopods are a class of mollusks that includes the octopus, squid, cuttlefish,and nautilus. cephalopods cephalopods are a class of fastswimming mollusk.
http://www.enchantedlearning.com/subjects/invertebrates/mollusk/cephalopod/Cepha

Extractions: Cephalopods are a class of fast-swimming mollusk . Some have a hard external shell, but most do not. Cephalopods are marine predators; these carnivores eat fish, worms, crustaceans, and other mollusks. Some cephalopods include the octopus, squid, cuttlefish, nautilus, and ammonite (and other extinct animals). There are about 650 living cephalopods and over 7,500 known extinct cephalopods. Cephalopod means "head-foot." The foot of the cephalopod is a cluster of tentacles that connects directly to the head. The brain, the eyes, and the other sensory organs are well-developed. Cephalopods breathe using gills. They swim by jet-propulsion; they rapidly expel water from the mantle cavity through a specialized, tube-like organ called the hyponome. Many can also eject a cloud of ink to confuse enemies.
Paleontology And Geology Glossary: Ce To Cf
tenuicornis (found in Norway). CEPHALOPOD cephalopods (meaning head foot )are mollusks with tentacles and a large head. These softbodied
http://www.enchantedlearning.com/subjects/dinosaurs/glossary/indexc2.shtml

Extractions: (pronounced SEED-er-oh-SAWR-us) Cedarosaurus ( meaning "Cedar Mountain Formation lizard") was a sauropod dinosaur that lived during the early late Cretaceous period . It had a long neck, a long tail, and a small head. Fossils were found in Utah, USA . It was named by paleontologist Tidwell, Carpenter and Brooks in 1999. The type species is Cedarosaurus weiskopfae
The Cephalopods
cephalopods All the recent cephalopod shells are composed of aragonitic layers prismatic layers, nacreous layers and spherulitic prismatic layers.
http://www.palaeos.com/Invertebrates/Molluscs/Cephalopoda/Cephalopoda.htm

Extractions: Coleoidea The name Cephalopoda literally means "head feet" and refers to the fact that these animals have a foot (actually a cluster of tentacles) directly abutting their head. The group includes cuttlefish, octopi, squid, the pearly nautilus, and a large number of ancient (mostly Paleozoic and Mesozoic) forms. All are active marine predators (although some early types were drifters), able to swim swiftly, and easily competing with fish in the marine habitat. There are 650 living species, but more than 7,500 fossil forms are known (and as in all cases like this this number is obviously a gross underestimate of the real number of Cephalopod species that have ever lived through the Phanerozoic time). Like fish they are equipped with highly developed eyes and other sense organs, include both active swimmers and bottom-dwellers, and in many cases have a streamlined body for more efficient locomotion. Swimming is by rapidly expelling water from the mantle cavity. The water is forced out through a funnel or siphon - the hyponome - actually a tube-like flap of modified foot, thus driving the animal in the opposite direction. This is the key to the so-called "jet-propulsion" of these animals The funnel is highly maneuverable and can be directed in any direction, allowing motion backwards or forwards. the fastest movement however is backward escape swimming, with powerful contractions of the mantle ejecting water through the forward facing funnel. A cloud of "ink" can also be ejected as a sort of underwater smoke screen to hide the fleeing animal.
Worldwideconchology.com - Cephalopods
The Worldwide Conchology Web Site is designed for shell collectors with a variety of interests in the hobby and science of conchology, and for anyone who
http://www.worldwideconchology.com/Cephalopods.htm
Cephalopods.html
Fish vs. cephalopods In marine environments, cephalopods clearly rank at the topof the Protostomes, in terms of size, intellegence, and trophic dominance.
http://www.cco.caltech.edu/~brokawc/Bi11/cephalopods.html

Extractions: In marine environments, cephalopods clearly rank at the top of the Protostomes, in terms of size, intellegence, and trophic dominance. At the top of the Deuterostomes are either the modern teleost fish or the marine mammals. For my purposes, I am going to use fish as the Deuterostome example, because they reflect a more primary adaptation to aquatic habitats, and occur in a wider range of sizes and habitats. (Competition between fish and marine mammals may be relevant to the more recent success of the teleosts, compared to other groups of fish, but that's a story for another day.) "The constraints on cephalopods: why squid aren't fish", R. K. O'Dor & D. M.Webber, Canadian Journal of Zoology, 64: 1591-1605 (1986). They summarize by saying: "Despite the functional similarities created by competition in the nekton, ... squid are no longer so much competing with fish as trying to stay out of their way."

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