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geography. ( 英 文 ). Piras P; Delfino M; Del FaveroL; Kotsakis T. Acta palaeontologica Polonica,2007, 52(2): 315-328A cladistic analysis of Megadontosuchus arduinifrom the middle Eocene of Monte Duelloconfirms its tomistomine relationships, but thelow number of scorable characters determines alow resolution within the tomistomine clade. Asummary of tomistomine palaeobiogeographysuggests that despite only one species with arather restricted range survives at present, such aclade had a glorious past with a world wide distributiondocumented by a conspicuous fossilrecord that starts at least in the early Eocene. Atpresent, a detailed knowledge of tomistominepalaeobiogeography is hindered by the lack ofmodern taxonomic revisions of some fossil remainsand therefore by the poor understandingof phylogenetic relationships.2008040425日 本 早 白 垩 世 的 Monjurosuchus 属 = Thechoristoderan reptile Monjurosuchus from theEarly Cretaceous of Japan. ( 英 文 ). Matsumoto R;Evans S E; Manabe M. Acta palaeontologicaPolonica, 2007, 52(2): 329-350This is the first report of Monjurosuchus fromJapan, but a long-necked choristodere, Shokawa,has already been recorded from these deposits.Monjurosuchus was first described from theLower Cretaceous Jehol Biota of China, althoughit has only recently been recognized as achoristodere. A cladistic analysis was performedin order to place Japanese and Chinese taxa, includingthe incompletely described Chineselong-necked Hyphalosaurus lingyanensis, intochoristoderan phylogeny. The results support themonophyly of Neochoristodera and of a Sino-Japanese clade of long necked choristoderes.The placement of the European Tertiary Lazarussuchusremains problematic, but the analysissupports its placement within Choristoderarather than on the stem. The identification Monjurosuchusfrom Japan provides an additionallink between the fossil assemblages of the TetoriGroup and those of the slightly younger JeholBiota of China.2008040426绝 不 会 偶 然 发 生 “ 巨 大 绝 灭 ”: 从 恐 龙 死 亡 思考 = The "Great Extinction" that never happened:the demise of the dinosaurs considered. ( 英 文 ).Sarjeant W A; Currie P J. Canadian Journal ofEarth Sciences, 2001, 38(2): 239-247The concept of a sudden extinction of the dinosaurs,consequent upon the impact of someextraterrestrial object, is so dramatic that it hastaken hold upon the imaginations of many scientists,as well as of the general public. The evidencefor an impact, at approximately the levelof the Cretaceous–Tertiary boundary, is impressive.Whether it was the cause for the iridiumconcentrations, so widely distributed at that level,remains disputable. The wave of extinctions, sooften attributed to the impact, is equally disputable.It is now evident that no clear line can bedrawn between the smaller theropod dinosaursand the birds. In that sense, the dinosaurs are notextinct. The dating of the extinction of the largersaurischians and of the ornithischians, based as itis upon evidence from only one small corner ofthe globe, is equally disputable. Whenever ithappened, that extinction appears to have beenthe product of natural causes — a slow decline,occasioned by environmental changes, and notan extraterrestrially induced catastrophe.Whether the impact had any effect at all uponthe dinosaurs is questionable; if so, it appears tohave been not worldwide, but confined to a limitedregion of the Americas2008040427产 自 德 国 下 二 叠 统 Dimetrodon 属 一 新 种 记 录了 该 属 在 北 美 之 外 的 首 次 发 现 = A new speciesof Dimetrodon (Synapsida: Sphenacodontidae)from the Lower Permian of Germany recordsfirst occurrence of genus outside of NorthAmerica. ( 英 文 ). Berman D S; Reisz R R; MartensT; Henrici A C. Canadian Journal of EarthSciences, 2001, 38(5): 803-812A new species of the sphenacodontid synapsidDimetrodon, D. teutonis, is described on the basisof a single, adult specimen consisting of alarge portion of the presacral vertebral column.The holotype was collected from the LowerPermian Tambach Formation, lowermost formationalunit of the Upper Rotliegend, of the Bromackerquarry locality in the midregion of theThuringian Forest near Gotha, central Germany.This is the first record of the genus outside ofNorth America and, therefore, provides not onlyadditional biological evidence of a continuousEuramerican landmass during the Early Permian,but also the absence of any major physical orbiological barrier to faunal interchange of terrestrialvertebrates. An estimated weight of 14 kgfor D. teutonis is half that of the smallest, previouslyrecognized species, D. natalis. Sphenacodontidphylogeny indicates that the diminutivesize of D. teutonis represents an autapomorphyand is in general accord with the absence oflarge-sized, basal synapsid predators at this trulyterrestrial upland locality. It is speculated thatthe diminutive size of D. teutonis was probablyan adaptation to a truly terrestrial, relatively uplandsexistence like that represented by the Bromackerlocality. Here it subsisted on small vertebrates(and possibly large invertebrates) of theBromacker assemblage, in which the dominant131