▁ 2 0 1 8 , ▁a ▁study ▁looked ▁at ▁the ▁lim b ▁morph ology ▁of ▁modern ▁and ▁foss il ▁North ▁American ▁wol ves . ▁The ▁major ▁lim b ▁b ones ▁of ▁the ▁dire ▁w olf , ▁Ber ing ian ▁w olf , ▁and ▁most ▁modern ▁North ▁American ▁gray ▁wol ves ▁can ▁be ▁clearly ▁distinguished ▁from ▁one ▁another . ▁Late ▁Ple ist oc ene ▁wol ves ▁on ▁both ▁sides ▁of ▁the ▁Laurent ide ▁Ice ▁She et ▁— ▁Cord iller an ▁Ice ▁She et ▁possessed ▁shorter ▁legs ▁when ▁compared ▁with ▁most ▁modern ▁wol ves . ▁The ▁Late ▁Ple ist oc ene ▁wol ves ▁from ▁the ▁Natural ▁T rap ▁C ave , ▁Wy oming ▁and ▁Ran cho ▁La ▁B rea , ▁southern ▁California ▁were ▁similar ▁in ▁lim b ▁morph ology ▁to ▁the ▁Ber ing ian ▁wol ves ▁of ▁Al aska . ▁Modern ▁wol ves ▁in ▁the ▁Mid western ▁USA ▁and ▁north western ▁North ▁America ▁possess ▁longer ▁legs ▁that ▁evol ved ▁during ▁the ▁Hol oc ene , ▁possibly ▁driven ▁by ▁the ▁loss ▁of ▁slower ▁pre y . ▁However , ▁shorter ▁legs ▁surv ived ▁well ▁into ▁the ▁Hol oc ene ▁after ▁the ▁ext inction ▁of ▁much ▁of ▁the ▁Ple ist oc ene ▁meg af a una , ▁including ▁the ▁Ber ing ian ▁w olf . ▁Hol oc ene ▁wol ves ▁from ▁Middle ▁But te ▁C ave ▁( dated ▁less ▁than ▁ 7 , 6 0 0 ▁Y B P ) ▁and ▁Mo ons h iner ▁C ave ▁( dated ▁over ▁ 3 , 0 0 0 ▁Y