that, prior to thatdiscovery, palaeobiological ideas were essentially unconstrained. The study of bedding plane assemblages, growth and wear of elements, and modelling of multielement architecture gives a framework on which to develop palaeobiological concepts; he noted that the issue of zoological affinity is a subject that interests a large number of people. He presented evidence for paired sensory organs, ray- supported caudal fin, extrinsic eye musculature, and his lines of argument supporting chordate affinities.
Papers then covered evolution, palaeobiology and geochemistry. Hubert Szaniawski (Polska Akademia Nauk) discussed evolutionary relationships between the earliest protoconodonts, paraconodonts and euconodonts based on interpretations of element morphology of some unusual forms such as Coelocerodontus. Karen Cochrane (Univ. Leicester) pursued the issue from a histological perspective challenging the traditional view of euconodont evolution from protoconodonts via paraconodonts. She used an unusual presentation graphic representing 'white matter' in black. Petrovna Kasatkina (Russian Academy of Sciences, Vladivostok) argued from soft tissue homology and analogy that euconodonts are more appropriately considered as close to chaetognaths and proposed a new superphylum the Chaetodonta consisting of euconodonts and chaetognaths. Stephanie Barrett (Univ. Leicester) outlined her work on functional morphology of the feeding apparatus via the study of occlusion patterns in prioniodontid Pa elements and speculated on the impact of this on evolutionary patterns during the Ordovician.
Two geochemical papers were cautionary in tone. Studies of rare earth elements in Triassic conodonts by Yasmin Haunold (Inst. Paleo., Vienna) concluded that variations reflect only very local conditions. A study by Julie Trotter (CSIRO Division of Petroleum Resources, Australia) of strontium isotopes from conodonts from the Early Ordovician Emanual Formation of the Canning Basin show remarkable heterogeneity within single elements; this has serious implications for the development of a global strontium curve. This paper generated the most intense and varied discussion of the session, if not the conference.
The next session ran concurrently with the first IGCP 421 meeting, wherein the general state of the project was assessed. Focus then went on the early Palaeozoic and dealt with more traditional conodont topics of biostratigraphy and taxonomy: three biostratigraphic papers spanning the Cambrian and Ordovician; conodonts from the central Appalachians (John Repetski, U.S.G.S.), conodonts from the subsurface western Canada and Williston Basins (Godfrey Nowlan, Geol. Surv. Canada), and Cambrian-Ordovician of the Argentine Precordillera (Guillermo Albanesi, Museo de

PaleontologÌa, Univ. Nacional Cordoba). Two papers focussed on Upper Ordovician conodont faunas from opposite sides of the Atlantic; from Wales (Annalisa Ferretti, Univ. Modena), and central Nevada (Walter Sweet, Ohio State Uni.). The final two papers focussed on palaeoecology and taxonomy: Zhang Jianhua (Univ. Stockholm) presented analysis indicating the Ordovician conodont Spinodus spinatusis a deep-water indicator and Anita Löfgren (Lund Uni.) presented a septimembrate reconstruction of Cornuodus.
Day 2 dealt with Silurian conodonts and biostratigraphy. Peep Männik (Inst. Geol., Tallinn) carved up the late Llandovery and early Wenlock celloniand amorphognathoideszones into 10 new zones based on the Pterospathoduslineage. Carlo Corradini (Univ. Modena, our energetic Sardinian guide) presented a Silurian zonal scheme for Sardinia similar to the classic approach of Walliser (1964). Viive Vira (Inst. Geol., Tallinn) subdivided the Baltic Ludlow to Pridoli using the 'remscheidensis' group. Andrew Simpson (then Univ. Queensland) presented Silurian conodont faunas from the Jack Formation of northern Australia.
The Early Devonian followed: Jose Ignacio Valenzuela-Rios (Univ. Valencia) reinterpreted the A. eleanorelineage; Pierre Bultynck (Inst. Roy. Sci. Naturelles de Belgique) showed the facies relationships of Morroccan Emsian to Eifelian conodonts (dehiscensto partituszones). Other Devonian studies by Bill Kirchgasser (State Uni. New York) reported on biostratigraphic implications of the widespread discovery of "North Evans" conodont faunas. Willi Ziegler (Forsch. Senckenberg) reviewed recent developments in high-resolution conodont biochronology in the Devonian noting that it was more useful than sequence stratigraphy, graphic correlation or alternate zonal schemes, and tying their phylogenetic-zone concept to recent radiometric data. Charles Sandberg (U.S.G.S.) focussed on the use of conodonts in establishing the timing of the Late Devonian Alamo Impact Meggabreccia. Gilbert Klapper (Dept Geol., Univ. Iowa) compared the original 13-fold Frasnian conodont zonation based on the Montagne Noire sequence with 9-fold "standard" zonation of the German and Great Basin sequences, highlighting taxonomic and methodological differences. This offering generated the most biostratigraphic "heat" of the meeting. Willi Ziegler (Forsch. Senckenberg) presented conodont data through the Frasnian-Famennian boundary of the Rheinisches Schiefergebirge. Immo Schülke (Univ. Hannover) reviewed early Famennian conodonts of the Montagne Noire. Norman Savage (Univ. Oregon) completed with a report on Late Devonian conodont faunas from Timan.
A break in the conodont flow followed with a session dedicated entirely to IGCP421: Alison Basden (MUCEP) covered Early Devonian fish of the Tyers-Boola area of