 Most aquatic stereospondyls have flattened heads . When feeding , they probably opened their mouths by lifting their skulls instead of lowering their lower jaws . The jaw mechanics of the plagiosaurid Gerrothorax is well known , and is one of the most highly adapted . Gerrothorax is thought to have lifted its skull to around 50 ° above horizontal through the flexing of the atlanto @-@ occipital joint between the occipital condyles of the skull and the atlas vertebra of the neck . As the skull is raised , the quadrate bone pushes forward and causes the lower jaw to protrude outward . Other stereospondyls probably also lifted their skulls , but they are not as well adapted for such movement . D.M.S. Watson was the first to suggest skull lifting as a means of feeding in temnospondyls . He envisioned that Mastodonsaurus , a much larger temnospondyl than Gerrothorax , was able to make the same movement . Paleontologist A.L. Panchen also supported the idea in 1959 , suggesting that Batrachosuchus also fed in this way . At the time it was thought that these temnospondyls lifted their heads with strong jaw muscles , but it is now thought that they used larger muscles in the neck that were attached to the large pectoral girdle . Plagiosuchus , a close relative of Gerrothorax , also has a hyobranchial skeleton that muscles may have attached to . Plagiosuchus has very small teeth and a large area for muscle attachment behind the skull , suggesting that it could suction feed by rapidly opening its mouth . 
 Most aquatic stereospondyls <a href='been_done' title='1'><mark>have</mark></a> flattened heads . When feeding , they probably opened their mouths by lifting their skulls instead of lowering their lower jaws . The jaw mechanics of the plagiosaurid Gerrothorax <a href='drop_aux' title='2'><mark>is</mark></a>well known , and is one of the most highly adapted . Gerrothorax is thought to <a href='been_done' title='3'><mark>have</mark></a> lifted its skull to around 50 ° above horizontal through the flexing of the atlanto @-@ occipital joint between the occipital condyles of the skull and the atlas vertebra of the neck . As the skull is raised , the quadrate bone <a href='uninflect' title='4'><mark>pushes</mark></a> forward and <a href='uninflect' title='5'><mark>causes</mark></a> the lower jaw to protrude outward . Other stereospondyls probably also lifted their skulls , but they <a href='negative_concord' title='6'><mark>are</mark></a> <a href='negative_concord' title='7'><mark>not</mark></a>as well adapted for such movement . D.M.S. Watson was the first to suggest skull lifting as a means of feeding in temnospondyls . He envisioned that Mastodonsaurus , a much larger temnospondyl than Gerrothorax , was able to make the same movement . Paleontologist A.L. Panchen also supported the idea in 1959 , suggesting that Batrachosuchus also fed in this way . At the time it was thought that these temnospondyls lifted their heads with strong jaw muscles , but it is now thought that they used larger muscles in the neck <a href='null_relcl' title='8'><mark>that</mark></a><a href='uninflect' title='9'><mark>were</mark></a> attached to the large pectoral girdle . Plagiosuchus , a close relative of Gerrothorax , also <a href='got' title='10'><mark>has</mark></a> a hyobranchial skeleton that muscles may <a href='been_done' title='11'><mark>have</mark></a> attached to . Plagiosuchus <a href='got' title='12'><mark>has</mark></a> very small teeth and a large area for muscle attachment behind the skull , suggesting that it could suction feed by rapidly opening its mouth . 
Most aquatic stereospondyls done flattened heads . When feeding , they probably opened their mouths by liftin their skulls instead of lowering their lower jaws . The jaw mechanics of the plagiosaurid Gerrothorax well known , and is one of da most highly adapted . Gerrothorax is thought to done lifted its skull to around 50 ° above horizontal through tdaflexing of the atlanto @-@ occipital joint between the occipital condyles of the skull and thdatlas vertebra of the neck . As the skull is raised , the quadrate bone push forward and cause the lower jaw to protrude outward . Other stereospondyls probably also lifted their skulls , but they ain't as well adapted for such movement . D.M.S. Watson was the first to suggest skull lifting as a means of feeding in temnospondyls . He envisioned that Mastodonsaurus , a much larger temnospondyl than Gerrothorax , was able to make the same movement . Paleontologist A.L. Panchen also supported the idea in 1959 , suggesting that Batrachosuchus also fed in dis way . At the time it was thought that these temnospondyls lifted their heads w/ strong jaw muscles , but it is now thought that they used larger muscles in the neck was attached to the large pectoral girdle . Plagiosuchus , a close relative of Gerrothorax , also got a hyobranchial skeleton dat muscles may done attached to . Plagiosuchus got very small teeth and a large area for muscle attachment behind thedaull , suggesting that it could suction feed by rapidly opening its mouth .