NEWLY DISCOVERED DIVERSE MM-SCALE FOSSILS OF THE EDIACARA BIOTA THE EARLIEST FOSSIL EVIDENCE OF COMPLEX MACROSCOPIC COMMUNITIES WITHIN THE EDIACARA MEMBER OF SOUTH AUSTRALIA OFFER THE UNIQUE OPPORTUNITY TO TEST WHETHER ANIMAL TAXA THAT ARE ABUNDANT TODAY WERE PRESENT PRIOR TO THE CAMBRIAN EXPLOSION OF COMPLEX ANIMAL LIFE. WHILE CLASSIC EVOLUTIONARY BIOLOGY PREDICTS THAT COMPLEX ANIMALS SHOULD BE PRESERVED WITHIN THE EDIACARA BIOTA SUCH TAXA HAVE PROVEN DIFFICULT TO DEFINITIVELY RECOGNIZE PERHAPS AS A CONSEQUENCE OF THEIR PREDICTED SMALL SIZE. NEW MATERIAL FROM THE EDIACARA MEMBER THE MOST RICHLY FOSSILIFEROUS DEPOSIT OF THE EDIACARA BIOTA REPRESENTS A UNIQUE AND PROMISING OPPORTUNITY TO IDENTIFY EARLY ANIMALS INCLUDING POTENTIAL BILATERIANS IN THE PRECAMBRIAN FOR SEVERAL REASONS: 1) THIS NEW FOSSIL MATERIAL CONSISTS OF FINE-GRAINED SANDSTONE ATYPICAL OF THE EDIACARA MEMBER PROVIDING THE RESOLUTION NECESSARY TO IDENTIFY SUB-MM TO MM-SCALE POTENTIAL STEM- AND CROWN-GROUP BILATERIANS; 2) IT CONTAINS ABUNDANT MM-SCALE BODY FOSSILS THAT PRELIMINARY ANALYSES INDICATE SHARE SEVERAL CHARACTERS WITH BOTH MODERN AND FOSSIL BILATERIANS; 3) THIS MATERIAL PRESERVES ABUNDANT HELMITHOIDICHNITES SMALL-SCALE BILATERIAN-PRODUCED TRACE FOSSILS; AND 4) IT OCCURS IN SEDIMENTARY SUCCESSIONS THAT HAVE BEEN EXTENSIVELY STUDIED AS PART OF A PREVIOUS NASA EXOBIOLOGY GRANT PROVIDING A PLATFORM FOR DETAILED CHARACTERIZATION OF THE PALEOENVIRONMENTAL AND PRESERVATIONAL CONTEXT OF THESE SMALL-SCALE FOSSILS. ADDITIONALLY RECENT ADVANCES IN DIGITAL PHOTOGRAPHY 3D LASER IMAGING AND COMPUTER PROCESSING SOFTWARE WILL FACILITATE INVESTIGATION OF SUB-MM TO MM-SCALE FOSSILS TO A GREATER EXTENT THAN WAS PREVIOUSLY POSSIBLE. WE PROPOSE THE STUDY OF SMALL-SCALE EDIACARA BODY AND TRACE FOSSILS PRESERVED IN FINE-GRAINED SANDSTONES OF THE EDIACARA MEMBER IN ORDER TO REEVALUATE A SIGNIFICANT BUT PREVIOUSLY INTRACTABLE QUESTION: WERE ANIMALS INCLUDING BILATERIANS A SIGNIFICANT COMPONENT OF THE EDIACARA BIOTA? TO ADDRESS THIS QUESTION WE WILL PURSUE THREE MAIN OBJECTIVES: 1) DETERMINE THE MORPHOLOGY AND DEVELOPMENT OF NEW MM-SCALE BODY FOSSILS TO IDENTIFY ANATOMICAL AND BEHAVIORAL CHARACTERS INDICATIVE OF PARTICULAR PHYLOGENETIC AFFINITIES; 2) DESCRIBE HELIMINTHOIDICHNITES TRACE FOSSILS INCLUDING THE MORPHOLOGY PALEOECOLOGICAL ASSOCIATIONS AND SEDIMENTOLOGICAL DISTRIBUTION OF THESE STRUCTURES; AND 3) CHARACTERIZE THE PALEOENVIRONMENTS IN WHICH EDIACARA SMALL-SCALE CANDIDATE BILATERIANS OCCUR AND IDENTIFY THE ENVIRONMENTAL AND DIAGENETIC CONDITIONS THAT PROMOTED THEIR PRESERVATION. THE RESULTS OF THIS WORK WILL SHED NEW LIGHT ON THE LONG-STANDING QUESTION OF WHETHER ABUNDANT DIVERSE STEM- AND/OR CROWNGROUP BILATERIANS WERE PRESENT IN THE EDIACARA BIOTA OR WHETHER THESE EARLY COMMUNITIES WERE LARGELY COMPOSED OF EXTINCT FAILED EVOLUTIONARY EXPERIMENTS. REGARDLESS WE WILL GAIN A COMPREHENSIVE UNDERSTANDING OF THE MORPHOLOGY DEVELOPMENTAL BIOLOGY AND ECOLOGY OF SOME OF THE FIRST COMPLEX MACROSCOPIC ORGANISMS PRESERVED IN THE FOSSIL RECORD AND OF THE ENVIRONMENTAL SETTINGS IN WHICH THEY EVOLVED WITH IMPLICATIONS FOR UNDERSTANDING THE ORIGINS AND EVOLUTIONARY TRAJECTORY OF COMPLEXITY ON EARTH AS WELL AS PROVIDING A SEARCH IMAGE FOR COMPLEX LIFE AND THE ENVIRONMENTS THAT COULD POTENTIALLY HOST IT ELSEWHERE IN THE UNIVERSE. THIS WILL EXPLICITLY ADDRESS THE GOAL OF NASA ROSES SECTION C.5 EXOBIOLOGY AIMED AT UNDERSTANDING THE EARLY EVOLUTION OF LIFE THE POTENTIAL OF LIFE TO ADAPT TO DIFFERENT ENVIRONMENTS AND THE IMPLICATIONS FOR LIFE ELSEWHERE.