how does the positioning of the ribs and pectoral girdle of the turtle differ from other tetrapods?
918405
The pectoral girdle of turtles,terrapines, and tortoises lacks the breast bone or the Sternum, whereas the other tetrapods have a well developed Sternum, to which the ribs are attached anteriorly.\n\nThe difference exists because turtles have a shell , like the tortoises , which is used as a defensive covering. since, the weight of this shell is added to their thorax , if sternum wouldve been there, it wouldnt be able to bear the entire weight. so, instead of that, their ribs are directly present in circles. the more the no. of bones, the more weight they can share together instead of a single bone .
251534
There are many, you could try investigating different systems separately:\n- skeleton: detachment of pectoral girdle from skull, attachment of pelvic girdle to column; vertebrae with zygapophyses, limbs with digits, etc.\n- tegument: keratinization, impermeabilization, glands; thermal and hydric regulation.\n- sensory: eye pigments, middle ear with tympanum, loss of lateral line system.\n- other systems: lungs, kidney structure, large intestin, double circulation, etc.
194656
Reptiles dont have the ability to move jaws laterally, so they cant chew the way mammals can.
107213
Pectoral girdle.\nIt corresponds to the pelvic girdle at the other end of the vertebral column.
855593
I would look here for your answer and/or a link that could get you your answer http://en.wikipedia.org/wiki/Vertebrate\n\nGood Luck!!!
172776
The tail of lizards is an important element for locomotion and balance. These animals move by mean of undulations of their entire body axis (vertebral column), and the motions of the tail counteract those of the trunk.\nIn addition, most lizards are capable of autotomy, that is, they can shed their tail at need, usually when threatened by a predator or in other highly stressful conditions, and then grow a new tail. \nThis is achieved by means of special intravertebral fracture planes, that is, each of the autotomic vertebrae has a weak transversal plane through which it can break into two pieces. In addition, the tail muscles of the autotomic region are arranged in small "brick-like" packages that can become separated without much tissue damage; the blood vessels in the area also have the ability of closing and clotting rapidly so as to avoid excess blood loss.\nUnder stressful conditions, the animal will experience reflex contraction of those specialized muscles and a fragment of the tail will become separated from the rest of the body. This fragment continues to thrash and move for some minutes after autotomy, thus attracting the would-be predator while the lizard escapes to safety.\nAfterwards, a new tail will grow (this can take several months, according to the metabolic rate and general conditions of the individual); but this new tail does not have real vertebrae, only a rod-like support tissue. It usually has a blunt tip and different color/texture from the original tail. \nThere are _no_ autotomic vertebrae inside this new stump; therefore, the next autotomy will have to occur in vertebrae that are closer to the trunk. The number of these special vertebrae is limited, so the amount of autotomies is also limited. \nAutotomy is obviously advantageous as a means of escape. However, tail loss also implies a disadvantage, basically because: 1) as other users have answered, many lizards store fat supplies in the tail (although normally the basal part of the tail is not autotomic); 2)"growing back" a new tail requires more energetic resources that might have been used for other purposes; 3)until the new tail grows, locomotion may be somewhat impaired.\nAnd I'm leaving out other (e.g. social communication) uses of the tail.\nInterestingly, the tail won't grow back if the severance does not occur at the special fracture planes.
1173981
Er...more that just mammals have dual lungs buddy.  \n\nIn fact, any creature that has lungs (amphibians/turtles, reptiles/birds, and mammals) have a set of two lungs.  The listed classes of animals all have bilateral symmetry, meaning they have two identical sides.  Hence, they have two lungs!
699256
I would probably say the atlas. The skull rests directly onto the atlas (the first vertebra of the cervical region), which is a relatively heavy part of the body. The thoracic region bears little weight (articulates with the ribs), the lumber region would be distributed by the pelvic girdle (pain in humans is atributed to the upright nature of the spine, not something that would probably occur to most spp.)and the caudal bones (tail bones) probably wouldnt bear any weight but their own in most spp(and muscle if the animal has a tail). It may depend, however on the species as some animals can bear their entire weight through the tail (monkey with a prehensile tail, macropods etc), but overall, I would probably say the atlas and to a degree the axis as they are constantly bearing the weight of the skull... Hope that helps!
167611
To the above mention person, idiot this is english if you are not versed in scientific terms don't go spouting nonsense. Cartilages are not true bone material, they are soft tissue like what our noses and most non skeletal fishes such as sharks and rays are composed of. But a toad has a skeletal structure and the cartilages are the same as a humans, found at the bridge of the nose area.
1081049
Many organisms possess vestigial structures that have no apparent function, but that resemble structures their presumed ancestors had. Humans, for example, possess a complete set of muscles for wiggling their ears, just as a coyote does (table 22.1). \n\nBoa constrictors have hip bones and rudimentary hind legs. Manatees (a type of aquatic mammal often referred to as "sea cows") have fingernails on their fins (which evolved from legs). Figure 22.17 illustrates the skeleton of a baleen whale, which contains pelvic bones, as other mammal skeletons do, even though such bones serve no known function in the whale. The human vermiform appendix is apparently vestigial; it represents the degenerate terminal part of the cecum, the blind pouch or sac in which the large intestine begins. In other mammals such as mice, the cecum is the largest part of the large intestine and functions in storageusually of bulk cellulose in herbivores. Although some suggestions have been made, it is difficult to assign any current function to the vermiform appendix. In many respects, it is a dangerous organ: quite often it becomes infected, leading to an inflammation called appendicitis; without surgical removal, the appendix may burst, allowing the contents of the gut to come in contact with the lining of the body cavity, a potentially fatal event.\n    \nThe skeleton of a baleen whale, a representative of the group of mammals that contains the largest living species, contains pelvic bones. These bones resemble those of other mammals, but are only weakly developed in the whale and have no apparent function.\n    \nIt is difficult to understand vestigial structures such as these as anything other than evolutionary relicts, holdovers from the evolutionary past. They argue strongly for the common ancestry of the members of the groups that share them, regardless of how different they have subsequently become. \nComparisons of the anatomy of different living animals often reveal evidence of shared ancestry. In some instances, the same organ has evolved to carry out different functions, in others, an organ loses its function altogether. Sometimes, different organs evolve in similar ways when exposed to the same selective pressures.
316505
The only living chordates that do not have backbones are the "protochordates", that is, the members of phyla Urochordata or Tunicata (sea squirts) and Cephalochordata (lancelets). These chordates have the primitive support structure, a dorsal notochord. \nAdult Tunicates lack notochords, except for the planktoninc and tiny Appendiculaceans.  Tunicate larvae (known as "tadpole larvae") _do_ have a notochord that supports their tails. \nThere are many genera and species of Tunicata; so if you do a Google Image search for either "Tunicata", "Urochordata" "sea squirt" or "salp" you'll get many good photographs.\nOn the other hand, the lancelets are much less diverse. Almost all are included in genus Branchiostoma, so if you look for "Branchiostoma" or "lancelet" you'll get what you're searching.
1008290
the ribs and the ribcage protect th heart and other organs.  the daiphram is the big muscle that controlls your breathing and expanding of your lungs
60070
Trunk bones? like ribs pelvis, spine?
470232
Vertebrae and ribs/intercostals.
574744
I hoped that there might be some sensible answers here, but it appears sadly no. Most snakes have only one lung, as the other has shrunk considerably, but the one lung can be quite long. They do not breath through their anus, although some Australian freshwater turtles do. Their tongue has nothing to do with beathing, it is a chemical brush. \nThey breathe through their nostrils and their mouths (Through the hole in the front that the tongue goes in and out of) and they do no have a diaphram that moves up and down like we do, rather they inflate their lung by moving muscles attached to the ribs, so the ribs move slightly in and out. The have a reinforced trachea so they can still breathe when swallowing prey considerably larger than their usual diameter.\n\nI hope this helps.
112685
Isn't this something they're trying to teach you at school? Think of the origins and insertions of these muscles, and of the movements achieved when each muscle layer contracts. Look at the pictures in any good Comparative Anatomy book and check the difference between the muscles of fishes and tetrapods (hint: new feature- lungs).
407668
They have mouth openings often with flagellum to help with their filter feeding.  The tail end is thinner and is lighter in color/more transparent.  Just do an image search for amphioxus and see!