Late Cambrian hard substrate communities from Montana/
نویسندگان
چکیده
Brerr. Carlton E.. LiddeU. W. David & Dersder. Krlie L. 198310 15. h t e Cmbnan hard substrate LETHAIA cammunitin imm ~onunwWyornmg. (he oldcsr *now hardpound encrusten irmaia, ib~. LC. pp. a 31-3 0 5 1 0 . ISSE WS-1163. W a r d p n d surfaces from rhe Late Cambnan S n o w Range Formatron In Moulonran~IVyomtng are the oldest known non-reefal hard substrat& exhtb~tlng encrusrlng losals. These surfaces range In age from Early Francon~an to early TrempenIeauan. Hardpunds were developed on slighrly hurnrnoclrr tv planzr. truncated surfaces of glauconire-nch. carbonarc. Bat pebble mnglornerates, which were dewsired dunng episodes of stom scouring In shallow subt~dd cnwmnments of the IviontanuWromtng shelf Soon7 Range hardgrounds are encrusted by a low dixcmty assemblage of fossiIs dornlnaterf by srmple &xo~Cal hoidfasrs of peImatozoans. probably cnno~&. and indudlog mati conlcal spon~ornorph &at ' and grobable stromatolites. M a a o w n n g (e g. Tcpm~res) are notably absent from aU nardground su&zes. although sharpwalled. vemcal. cylindrical holes (bonngs') o m In mlcnte <lasts [mbedded rn c e m n flat pebble conglomerata Yo endcnce of faunal succession or microecologc pacrttionlng ur ~rreguiuiar surfaces was obxrvcd on there Cambnan hardgrounds. O Hmdgromcls, epibionrr rracrohor ings. p h t o z o a n echmmdarrrr. palewcology, Cumbmn. .MonmdWyornrrrg.
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