ath us : ▁SM NS ▁ 1 2 3 5 2 , ▁a ▁partial ▁sk ull ▁and ▁lower ▁j aws ▁from ▁a ▁larger ▁individual ▁than ▁the ▁hol ot ype , ▁and ▁SM NS ▁ 1 2 3 5 2 a , ▁an ▁isolated ▁left ▁hand . ▁ ▁The ▁genus ▁name ▁Pro com ps ogn ath us , ▁means ▁" before ▁elegant ▁j aw ", ▁and ▁is ▁derived ▁from ▁the ▁name ▁of ▁another ▁din osa ur , ▁Com ps ogn ath us . ▁A ▁later ▁( J ur ass ic ) ▁small ▁pre dat ory ▁din osa ur , ▁Com ps ogn ath us ▁takes ▁its ▁name ▁from ▁the ▁Greek ▁word ▁kom ps os ▁( κ ο μ ψ ό ς ) ▁which ▁can ▁be ▁rendered ▁as ▁" e leg ant ", ▁" ref ined " ▁or ▁" d ain ty " ▁and ▁the ▁Greek ▁word ▁g n ath os ▁( γ ν ά θ ος ) ▁which ▁means ▁" j aw ". ▁The ▁prefix ▁Pro ▁( π ρ ο ) ▁implies ▁" before " ▁or ▁" anc est or ▁of ", ▁although ▁this ▁direct ▁line age ▁was ▁not ▁supported ▁by ▁subsequent ▁research . ▁ ▁The ▁specific ▁name ▁tri ass icus ▁refers ▁to ▁the ▁ge olog ic ▁time ▁period ▁to ▁which ▁this ▁din osa ur ▁belongs , ▁the ▁Tri ass ic . ▁ ▁Description ▁▁ ▁Pro com ps ogn ath us ▁may ▁have ▁been ▁about ▁ ▁long , ▁though ▁Fra as ▁in ▁ 1 9 1 3 ▁estimated ▁a ▁length ▁of ▁. ▁In ▁