▁in ▁weight l ifting ▁Category : Weight l if ters ▁at ▁the ▁ 2 0 1 0 ▁Asian ▁Games ▁Category : As ian ▁Games ▁silver ▁medal ists ▁for ▁China ▁Category : L iving ▁people ▁Category : Weight l if ters ▁at ▁the ▁ 2 0 1 6 ▁Summer ▁Olympics ▁Category : O lymp ic ▁medal ists ▁in ▁weight l ifting ▁Category : Ch inese ▁female ▁weight l if ters ▁Category : Med al ists ▁at ▁the ▁ 2 0 1 0 ▁Asian ▁Games <0x0A> </s> ▁The ▁C rypt od ont a ▁are ▁a ▁nearly - ext inct ▁subclass ▁of ▁the ▁b ival ves . ▁It ▁contains ▁a ▁single ▁ext ant ▁order , ▁So le my ida , ▁while ▁the ▁Pra ec ardi ida ▁are ▁known ▁only ▁from ▁foss ils . ▁ ▁The ▁val ves ▁of ▁the ▁shell ▁are ▁relatively ▁thin ▁and ▁somewhat ▁el ong ated . ▁Un like ▁most ▁other ▁b ival ves , ▁species ▁in ▁this ▁group ▁have ▁no ▁h inge ▁teeth ▁on ▁their ▁shell s . ▁They ▁have ▁relatively ▁primitive , ▁" proto branch iate ", ▁g ills . ▁ ▁Tax onomy ▁▁ ▁C rypt od ont a ▁ ▁Order ▁† P ra ec ardi ida ▁ ▁Family ▁† But ov ic ell idae ▁ ▁Gen us ▁† But ov ic ella ▁ ▁Family ▁† P ra ec ardi idae ▁ ▁Gen us ▁† S lava ▁ ▁Gen us ▁† Card i ola ▁ ▁Family ▁† Ant i ple ur idae ▁ ▁Gen us ▁† D ual ina ▁ ▁Gen us