The Osteichthyes is evolved from lungs of early bony fish. The fish have many types of evolved.
The Sternum and the Rib Cage protects the lungs.
Ribs!
Well they have limbs and lungs, which I would consider more complex.
Bony fish have scales, fins, and gills for respiration, while frogs have smooth skin, limbs for locomotion, and lungs for breathing. Bony fish also have a swim bladder to control buoyancy, whereas frogs do not have this adaptation.
the rib cage
hi
The placoderm is actually an extinct fish, thought to have lived during the Devonian period and is thought to have had broad flat bony plates covering its body.
Crocodilians have a secondary bony palate that enables them to breathe when partially submerged, even if the mouth is full of water. Their internal nostrils open in the back of their throat, where a special part of the tongue called the "palatal valve" closes off their respiratory system when they are underwater. This way they can open their mouths underwater without choking. Most reptiles lack a secondary palate, but some skinks (family Scincidae) have evolved a bony secondary palate too, to varying degrees. Source: Wikipedia
The bony thorax protects the heart and liver. Wrong... the bone thorax protects the heart and LUNGS as it also allows the respiratory muscle to create a vacuum that will draw air into the lungs. while the Ribs withing in the bone thorax will protect not only the thoracic organs, but as well the spleen, most of the liver and to some extent the kidneys.
I think it was Hafsa bony Umar (r).
Amphibians are devoid of scales because they are descendants of fish, which also lack scales. Early amphibians evolved from lobe-finned fish, which had bony plates in their skin instead of scales. Over time, these bony plates transformed into the smooth, moist skin characteristic of modern amphibians. This adaptation allowed for better gas exchange through the skin, crucial for their semi-aquatic lifestyle.
yes b/c a bony fish has to have a bony body