▁plants , ▁b ival ves , ▁sn ails , ▁cr ust ace ans , ▁insect s , ▁ray s , ▁b ony ▁fish , ▁sal am and ers , ▁t urt les , ▁l iz ards , ▁sn akes , ▁cro cod ili ans , ▁birds , ▁and ▁m amm als . ▁ ▁References ▁ ▁External ▁links ▁ ▁Bah nd w iv ici ▁in ▁the ▁Pale obi ology ▁Database ▁ ▁Category : E oc ene ▁re pt iles ▁of ▁North ▁America ▁Category : L izard ▁gener a ▁Category : E oc ene ▁l iz ards ▁Category : E oc ene ▁United ▁States ▁Category : Pre histor ic ▁re pt ile ▁gener a ▁Category : F oss il ▁tax a ▁described ▁in ▁ 2 0 0 6 <0x0A> </s> ▁Several ▁the or ems ▁proved ▁by ▁the ▁French ▁math ematic ian ▁Claude ▁Che val ley ▁bear ▁his ▁name . ▁▁▁ ▁Che val ley – She ph ard – T odd ▁theorem ▁in ▁invariant ▁theory ▁of ▁finite ▁groups . ▁ ▁Che val ley – Warning ▁theorem ▁concerning ▁sol v ability ▁of ▁polynomial ▁equations ▁over ▁finite ▁fields . ▁ ▁Che val ley ▁restriction ▁theorem ▁ident ifying ▁the ▁invari ants ▁of ▁the ▁ad joint ▁action ▁of ▁a ▁sem is im ple ▁algebraic ▁group ▁with ▁the ▁invari ants ▁of ▁its ▁W ey l ▁group ▁acting ▁on ▁the ▁Cart an ▁sub algebra . ▁ ▁Che val ley ' s ▁structure ▁theorem ▁on ▁algebraic ▁groups : ▁if ▁G ▁is ▁an ▁algebraic ▁group ▁then ▁it ▁contains ▁a ▁unique ▁closed ▁normal ▁subgroup ▁N