▁at ▁the ▁end ▁as ▁in ▁modern ▁sp iders . ▁They ▁were ▁probably ▁ground - d well ing ▁pred ators , ▁living ▁in ▁the ▁giant ▁club m oss ▁and ▁f ern ▁for ests ▁of ▁the ▁mid - late ▁Pala e oz o ic , ▁where ▁they ▁were ▁pres umably ▁pred ators ▁of ▁other ▁primitive ▁ar th rop ods . ▁Sil k ▁may ▁have ▁been ▁used ▁simply ▁as ▁a ▁protect ive ▁covering ▁for ▁the ▁eggs , ▁a ▁l ining ▁for ▁a ▁retre at ▁hole , ▁and ▁later ▁perhaps ▁for ▁simple ▁ground ▁sheet ▁web ▁and ▁trap door ▁construction . ▁ ▁As ▁plant ▁and ▁insect ▁life ▁divers ified ▁so ▁also ▁did ▁the ▁sp ider ' s ▁use ▁of ▁sil k . ▁Sp iders ▁with ▁sp inner ets ▁at ▁the ▁end ▁of ▁the ▁ab d omen ▁( My g alom or pha e ▁and ▁A rane om or pha e ) ▁appeared ▁more ▁than ▁ 2 5 0 ▁million ▁years ▁ago , ▁pres umably ▁prom oting ▁the ▁development ▁of ▁more ▁elaborate ▁sheet ▁and ▁ma ze ▁web s ▁for ▁pre y ▁capture ▁both ▁on ▁ground ▁and ▁fol i age , ▁as ▁well ▁as ▁the ▁development ▁of ▁the ▁safety ▁drag line . ▁The ▁oldest ▁my gal omorph , ▁Ros am yg ale , ▁was ▁described ▁from ▁the ▁Tri ass ic ▁of ▁France ▁and ▁belongs ▁to ▁the ▁modern ▁family ▁H ex ath el idae . ▁Meg ar ach ne ▁serv ine i ▁from ▁the ▁P ermo - Car bon ifer ous ▁was ▁once ▁thought ▁to ▁be ▁a ▁giant ▁my gal omorph