▁mother ▁providing ▁n our ishment ▁to ▁the ▁emb ry o ▁and ▁giving ▁birth ▁to ▁live ▁young . ▁With ▁this ▁discovery , ▁the ▁pla cod erm ▁became ▁the ▁oldest ▁verte br ate ▁known ▁to ▁have ▁given ▁birth ▁to ▁live ▁young ▁(" viv ip ar ous "), ▁pushing ▁the ▁date ▁of ▁first ▁viv ip ar ity ▁back ▁some ▁ 2 0 0 ▁million ▁years ▁earlier ▁than ▁had ▁been ▁previously ▁known . ▁Spec im ens ▁of ▁the ▁ar th rod ire ▁In cis os cut um ▁rit che i , ▁also ▁from ▁the ▁G ogo ▁Form ation , ▁have ▁been ▁found ▁with ▁emb ry os ▁inside ▁them ▁indicating ▁this ▁group ▁also ▁had ▁live ▁bearing ▁ability . ▁The ▁males ▁reprodu ced ▁by ▁inserting ▁a ▁long ▁clas per ▁into ▁the ▁female . ▁El ong ated ▁bas ip ter yg ia ▁are ▁also ▁found ▁on ▁the ▁ph yl lo le pid ▁pla cod erm s , ▁such ▁as ▁Aust roph yl lo le pis ▁and ▁Cow rale pis , ▁both ▁from ▁the ▁Middle ▁Dev onian ▁of ▁Australia , ▁suggesting ▁that ▁the ▁bas ip ter gia ▁were ▁used ▁in ▁cop ulation . ▁ ▁The ▁pla cod erm ▁cl asp ers ▁are ▁not ▁hom olog ous ▁with ▁the ▁cl asp ers ▁in ▁cart il agin ous ▁fish es . ▁The ▁similar ities ▁between ▁the ▁structures ▁has ▁been ▁revealed ▁to ▁be ▁an ▁example ▁of ▁conver gent ▁evolution . ▁While ▁the ▁cl asp ers ▁in ▁cart il agin ous ▁fish es ▁are ▁special ized ▁parts ▁of ▁their ▁pa ired ▁pel vic ▁fins ▁that