. ▁In ▁ 1 9 6 6 – 1 9 6 7 , ▁Harry ▁B . ▁Wh itt ington ▁found ▁another ▁good ▁spec imen , ▁and ▁in ▁ 1 9 7 5 ▁he ▁published ▁a ▁detailed ▁description ▁based ▁on ▁very ▁thorough ▁dis section ▁of ▁some ▁spec im ens ▁and ▁photograph s ▁of ▁these ▁spec im ens ▁lit ▁from ▁a ▁variety ▁of ▁angles . ▁Wh itt ington ' s ▁analysis ▁did ▁not ▁cover ▁Op ab in ia ▁media : ▁Wal c ott ' s ▁spec im ens ▁of ▁this ▁species ▁could ▁not ▁be ▁identified ▁in ▁his ▁collection . ▁In ▁ 1 9 6 0 ▁Russian ▁pale ont olog ists ▁described ▁spec im ens ▁they ▁found ▁in ▁the ▁Nor il sky ▁region ▁of ▁Si ber ia ▁and ▁label led ▁Op ab in ia ▁nor il ica , ▁but ▁these ▁foss ils ▁were ▁poor ly ▁preserved , ▁and ▁Wh itt ington ▁did ▁not ▁feel ▁they ▁provided ▁enough ▁information ▁to ▁be ▁class ified ▁as ▁members ▁of ▁the ▁genus ▁Op ab in ia . ▁ ▁Occ urrence ▁▁ ▁All ▁the ▁recognized ▁Op ab in ia ▁spec im ens ▁found ▁so ▁far ▁come ▁from ▁the ▁" Ph yl lop od ▁bed " ▁of ▁the ▁Burg ess ▁Sh ale , ▁in ▁the ▁Canadian ▁Rock ies ▁of ▁British ▁Columbia . ▁ ▁In ▁ 1 9 9 7 , ▁Brig gs ▁and ▁Ned in ▁reported ▁from ▁South ▁Australia ▁a ▁new ▁spec imen ▁of ▁My os co lex ▁that ▁was ▁much ▁better ▁preserved ▁than ▁previous ▁spec im ens , ▁leading ▁them ▁to ▁conclude