房室海绵化石的微机研究:性状演化北大核心

利用微机对房室海绵进行了１）属的清理工作，２）标准化术语的建立与属的标准化术语描述，３）建数据库，４）性状的统计分析。并发现了房室海绵出水管类型、房室排列方式、房室充填物类型、孔和管、体型和房室形态方面的六大演化趋向。

COMPUTER ANALYSIS OF THALAMIDS:EVOLUTIONARY TENDENCIES

Data base of 117 genera of thalamids has been established with CDS/ISIS system.The definition of all of the genera are checked and standardized.Three genera are revised.Four genera are new.Statistic analysis of theis features of 117genera shows the following evolu tionary tendencies.(1) Exhalent systems were aslphonate/amblyslponate/proslphonate/retroslphonate/ guadaluslphonate Incambrlan,cryptoslphonate/pseudoslphonate/tebagaslphonate/ zankllslphonate Inordovlclan,welslphonate InCarbonlferous,lemoslphonate/lmbrlslPhonate/glomoslPhonate/PolcystoslPhonate In Permlan,and veslcoslPhonate/battagslphonate In Trlasslc.(2)The arrangement ofchambers were single-chambered/catenulate/ single-layerdIn Cambrlan,and multiple-layered/platy/multi-rowed In Permlan.(3)The filling tissues were veslcular or empty In Cambrlan,sepia-like In Sllurlan,reticular InDevonlan,pillar-like/pore-like/compoundlnPermlan,andtubular/concentrllamlnar In Trlasslc.(4)The openings and other tubes were pores In Cambrlan,ostla/pore-fields/exaulos or lmperforated/panchambered tubes/pore-tubes In Ordovlclan,and converging tubes In Carbonlferous.(5)The growth forms were columnar/conical In Cambrlan,irregular In Ordovlclan,platy/bowl-like/hemlspherlc In Permlan,and spheric In Trlasslc.(6)The forms ofchambers were spheric/domed InCambrlan,conical/ bowl-like/elllpsoldal In Ordovlclan,tubular In Carbonlferous,cylindrical/ prismatic/ hemltubular In Permlan,and frustoconlc In Trlasslc.