 In one of the earliest phylogenetic analyses of the group , Gardiner ( 1983 ) recognized five characteristics that made Temnospondyli a clade : a bone at the back of the skull , the parasphenoid , is connected to another bone on the underside of the skull , the pterygoid ; large openings called interpterygoid vacuities are present between the pterygoids ; the stapes ( a bone involved in hearing ) is connected to the parasphenoid and projects upward ; the cleithrum , a bone in the pectoral girdle , is thin ; and part of the vertebra called the interdorsal attaches to the neural arch . Additional features were given by Godfrey et al . ( 1987 ) , including the contact between the postparietal and exoccipital at the back of the skull , small projections ( uncinate processes ) on the ribs , and a pelvic girdle with each side having a single iliac blade . These shared characteristics are called synapomorphies . 
 In one of the earliest phylogenetic analyses of the group , Gardiner ( 1983 ) recognized five characteristics <a href='null_relcl' title='1'><mark>that</mark></a>made Temnospondyli a clade : a bone at the back of the skull , the parasphenoid , is connected to another bone on the underside of the skull , the pterygoid ; large openings called interpterygoid vacuities are present between the pterygoids ; the stapes ( a bone involved in hearing ) is connected to the parasphenoid and projects upward ; the cleithrum , a bone in the pectoral girdle , <a href='drop_aux' title='2'><mark>is</mark></a>thin ; and part of the vertebra called the interdorsal <a href='uninflect' title='3'><mark>attaches</mark></a> to the neural arch . Additional features <a href='uninflect' title='4'><mark>were</mark></a> given by Godfrey et al . ( 1987 ) , including the contact between the postparietal and exoccipital at the back of the skull , small projections ( uncinate processes ) on the ribs , and a pelvic girdle with each side having a single iliac blade . These shared characteristics are called synapomorphies . 
In one of da earliest phylogenetic analyses of the group , Gardiner ( 1983 ) recognized five characteristics made Temnospondyli a clade : a bone at the back of the skull , the parasphenoid , is connected to anotha bone on the underside of the skull , the pterygoid ; large openings called interpterygoid vacuities r present between the pterygoids ; tdastapes ( a bone involved in hearing ) is connected to thdaarasphenoid and projects upward ; thedaeithrum , a bone in the datoral girdle , thin ; and part of the vdaebra called the interdorsal attach to the nedal arch . Additional features was given by Godfrey et al . ( 1987 ) , including the contact between the postparietal and exoccipital at the bk dathe skulda small projections ( uncinate processes ) on the ribs , and a pelvic girdle with each side havin a single iliac blade . dese shared characteristics arralled synapomorphies .