▁regarded ▁as ▁an ▁early ▁fish , ▁and ▁therefore ▁as ▁one ▁of ▁the ▁first ▁verte br ates . ▁Zh ong j ian ich th ys ▁is ▁named ▁after ▁Zh ong j ian ▁in ▁China . ▁ ▁Phys ical ▁characteristics ▁ ▁The ▁eyes ▁are ▁located ▁behind ▁the ▁an tero - d ors al ▁lo be ▁and ▁the ▁mouth ▁apparently ▁did ▁not ▁have ▁a ▁j aw . ▁It ▁lack ed ▁scales , ▁and ▁had ▁a ▁thick ▁skin . ▁We ▁know ▁it ▁had ▁a ▁th icker ▁skin ▁than ▁other ▁ch ord ates ▁at ▁that ▁time ▁because , ▁unlike ▁My l lo k un ming ia , ▁no ▁impress ions ▁of ▁its ▁my om eres ▁have ▁been ▁found . ▁The ▁vent ral ▁fin ▁is ▁low ▁in ▁height , ▁and ▁runs ▁much ▁of ▁the ▁body ' s ▁length . ▁ ▁Although ▁Zh on j ian ich th ys ▁appears ▁more ▁advanced ▁than ▁its ▁relatives ▁due ▁to ▁the ▁back - position ed ▁eyes ▁and ▁the ▁th icker ▁skin , ▁this ▁may ▁be ▁conver gent ▁evolution ▁and ▁it ▁may ▁not , ▁therefore , ▁be ▁particularly ▁closely ▁related ▁to ▁the ▁ancest ors ▁of ▁modern ▁ch ord ates . ▁ ▁E col ogy ▁ ▁Zh ong j ian ich th ys ' ▁reduced ▁fins ▁may ▁indicate ▁that ▁it ▁was ▁mainly ▁bottom - d well ing ▁and ▁did ▁not ▁sw im ▁much . ▁This ▁could ▁have ▁been ▁a ▁factor ▁in ▁its ▁evolution ▁of ▁th icker ▁skin , ▁as ▁protection ▁from ▁pred ators . ▁ ▁Loc ations ▁ ▁Zh ong j ian ich th ys