▁Add itional ▁lo bes ▁developing ▁towards ▁the ▁inner ▁edge ▁of ▁a ▁wh or l ▁are ▁label led ▁um bil ical ▁lo bes , ▁which ▁increase ▁in ▁number ▁through ▁am m ono id ▁evolution ▁as ▁well ▁as ▁an ▁individual ▁am m ono id ' s ▁development . ▁Lob es ▁and ▁s add les ▁which ▁are ▁so ▁far ▁towards ▁the ▁center ▁of ▁the ▁wh or l ▁that ▁they ▁are ▁covered ▁up ▁by ▁succeed ing ▁wh or ls ▁are ▁label led ▁internal ▁lo bes ▁and ▁s add les . ▁Three ▁major ▁types ▁of ▁s uture ▁patterns ▁are ▁found ▁in ▁the ▁Am m ono idea : ▁ ▁G oni at it ic ▁- ▁numerous ▁und iv ided ▁lo bes ▁and ▁s add les ; ▁typically ▁ 8 ▁lo bes ▁around ▁the ▁con ch . ▁This ▁pattern ▁is ▁characteristic ▁of ▁the ▁Pale oz o ic ▁am m ono ids . ▁ ▁Cer at it ic ▁- ▁lo bes ▁have ▁sub div ided ▁tips , ▁giving ▁them ▁a ▁saw - to oth ed ▁appearance , ▁and ▁rounded ▁und iv ided ▁s add les . ▁This ▁s uture ▁pattern ▁is ▁characteristic ▁of ▁Tri ass ic ▁am m ono ids ▁and ▁appears ▁again ▁in ▁the ▁C ret ace ous ▁" pse ud oc er at ites ". ▁ ▁Am mon it ic ▁- ▁lo bes ▁and ▁s add les ▁are ▁much ▁sub div ided ▁( fl uted ); ▁sub div isions ▁are ▁usually ▁rounded ▁instead ▁of ▁saw - to oth ed . ▁Am m ono ids ▁of ▁this ▁type ▁are ▁the