▁sole ▁element ▁still ▁present ▁consists ▁of ▁a ▁seven ▁mill imet re ▁long ▁piece ▁of ▁the ▁tra che a ▁of ▁which ▁about ▁ten ▁tra che al ▁rings ▁are ▁visible , ▁the ▁most ▁anterior ▁of ▁which ▁are ▁open ▁at ▁the ▁top , ▁giving ▁them ▁a ▁C - shape . ▁They ▁have ▁an ▁average ▁length ▁of ▁ 0 . 3 3 ▁mill imet res ▁and ▁are ▁separated ▁by ▁ 0 . 1 7 ▁mill imet re ▁thick ▁inter spaces . ▁The ▁tra che a ▁is ▁quite ▁thin , ▁with ▁a ▁preserved ▁width ▁of ▁one ▁mill imet re ▁about ▁half ▁as ▁wide ▁as ▁would ▁be ▁expected ▁for ▁an ▁animal ▁the ▁size ▁of ▁the ▁hol ot ype , ▁and ▁position ed ▁rather ▁low ▁in ▁the ▁neck ▁base , ▁embedded ▁in ▁connect ive ▁t issue . ▁ ▁Liver , ▁heart , ▁s ple en ▁and ▁th ym us ▁In ▁the ▁front ▁part ▁of ▁the ▁thor ax ▁a ▁consp ic uous ▁red ▁h alo ▁is ▁visible , ▁forming ▁a ▁roughly ▁circular ▁st ain ▁with ▁a ▁diameter ▁of ▁sevent een ▁mill imet res . ▁In ▁ 1 9 9 8 ▁it ▁was ▁suggested ▁this ▁might ▁represent ▁the ▁remains ▁of ▁the ▁decay ed ▁li ver , ▁a ▁blood - rich ▁organ . ▁That ▁the ▁red ▁p ig ment ▁was ▁indeed ▁derived ▁from ▁blood ▁was ▁in ▁ 2 0 1 1 ▁confirmed : ▁a ▁sc anning ▁electron ▁mic ros cope ▁analysis ▁indicated ▁that ▁the ▁subst ance ▁consisted ▁of ▁lim on ite , ▁hyd r ated ▁iron ▁ox ide , ▁a ▁likely ▁transformation ▁product