From AdAPTiVe rAdiATions T o BioTic crises in PAlAeoZoic Ver TeBrATes: A GeoBioloGicAl APProAch

摘要: The oldest vertebrates are Early Cambrian, cephalized unossified species (craniates) from China. armoured (euvertebrates) Ordovician in age. After Talimaa's Gap, have their first adaptive radiation during the Silurian when jawless ('ostracoderms') dominant; they second Devonian jawed (gnathostomes), and particularly placoderms (armoured fishes), dominant. Tetrapods appear Middle among sarcopterygians (bony fishes with lobed fins); were probably aquatic all period. Vertebrates did not freshwater but marine environments. Similarly, tetrapods most appeared very shallow occupy environments of epicontinental platforms. Vertebrate assemblages high energy ('ostracoderms' particular), took place development late- post-tectonic Old Red Sandstone facies (ORS). So, vertebrate known both marginal marine, intermediate continental ORS, platforms (carbonate siliciclastic facies). encounter two end-Devonian biological crises: disappearance 'ostracoderms' at Frasnian-Famennian crisis, Devonian-Carboniferous boundary, a major ecological turnover beginning Carboniferous chondrichthyans (cartilaginous fishes) osteichthyans fishes, mainly actinopterygians) became Terrestrial (both amphibians reptiles) occured only after earliest Romer's Gap. suffered Mid-Permian Olson's Gap drastic decline basal (amphibians) followed by reptiles. end-Permian extinction does seem to been strong for vertebrates, except tetrapods. On geobiological point view, least bioevents which characteristic rise Palaeozoic may be related an increase global oxygen rate, viz., appearance euvertebrates Great Biodiversification Event (GOBE), large gnathostomes (in particular placoderms) Predation Revolution vertebrates. However, coincidence mean causal relationship. we must cautious scenarios that scientific literature recent years.