We describe new avian fossils from the Boom Formation of Belgium, which almost double the number of bird taxa known from this part of the Rupelian stratotype. Three galliform species can, at least tentatively, be assigned to the paraortygid species Paraortyx brancoi, P. lorteti, and Pirortyx major. Among the fossils is a partial sternum, which shows that Paraortyx lacks a spina interna. The absence of this structure is plesiomorphic for Galliformes and probably related to the absence of a large crop, thus indicating that Paraortygidae were not yet adapted to the regular processing of coarse and dry food. Two distal humeri belong to Trogoniformes (trogons) and Upupiformes (hoopoes, woodhoopoes, and allies), respectively. A femur is tentatively assigned to Phaethontiformes (tropicbirds), and a carpometacarpus is, likewise tentatively, referred to Threskiornithidae (ibises and spoonbills). We finally comment on the affinities of “Anas” benedeni Sharpe, 1899 and detail that this species most likely belongs to Gaviiformes (loons).
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The Ypresian Cambay Formation at Vastan Mine in Gujarat, western India, has yielded a rich herpetological fauna including snakes, lizards and amphibians, but strangely, lizards are only represented by Acrodonta. Here we describe the acrodontan assemblage based on numerous, diverse and well-preserved dentaries, premaxillae, and maxillae. Among the five taxa described one new genus and species characterised by a short splenial represents the youngest occurrence of the extinct family Priscagamidae. The other four taxa belong to the extant family Agamidae. Two of them previously known, Vastanagama susanae and Tinosaurus indicus, are here revised. The two other taxa are new. The first one, Suratagama neeraae gen. and sp. nov., is characterised by the presence of six small pleurodont teeth with a nearly cylindrical shaft and an obtusely pointed apex. The second one, Indiagama gujarata gen. and sp. nov., has rectangular teeth in lateral view, unicuspid crowns forming a nearly horizontal cutting edge, and wear facets on both the lingual and labial sides of the dentary. Our results confirm that Acrodonta is the only lizard group present in Vastan, whereas many other groups are already present from the beginning of the Early Eocene on the other continents. The diversity of the agamids in Vastan and the absence of non-acrodontan lizard in India tentatively support the Out-of-India hypothesis for agamids.
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L’une des toutes premières ammonites à coquille presque oxycône observée dans les séries fossilifères après la crise faunique de la limite Trias/Jurassique est décrite. Elle provient du Sinémurien inférieur (chronozone à Semicostatum ou à Turneri) de Bourgogne (Mavilly-Mandelot, Côte-d’Or, France). Cette nouvelle forme, Oxyarietites boletzkyi n. gen., n. sp., possède une coquille involute, comprimée et carénée dont le type clairement suboxycône est nouveau pour le Sinémurien inférieur. En raison de son aire ventrale carénée, ce taxon se rattache probablement à la super-famille des Arietitoidea Hyatt, 1875 sensu Guex (1995) mais son attribution familiale est incertaine et son origine évolutive reste énigmatique. Outre son intérêt taxonomique, cette découverte est importante car elle pose le problème de la valeur adaptative des caractères liés à la géométrie des coquilles d’ammonites. Il est actuellement admis que les coquilles involutes, comprimées et carénées de type suboxycône et oxycône favorisent significativement l’hydrodynamisme et donc la mobilité des espèces qui les possèdent. Il est surprenant que l’acquisition de ce probable avantage adaptatif n’ait pas favorisé l’implantation au sein des peuplements du nouveau taxon, qui reste une forme rare. Dans tous les cas, la découverte d’O. boletzkyi n. gen., n. sp. rajeunit d’environ 2 millions d’années la mise en place des morphologies oxycônes au cours de la phase de reconstitution de la biodiversité post-crise Trias/Jurassique. Oxyarietites boletzkyi n.gen., n. sp., a new genus and species of ammonite for the Lower Sinemurian of Burgundy (France): a rare forerunner of the oxycone morphologies for the Jurassic. One of the very first quasi-oxycone ammonites following the Triassic/Jurassic boundary crisis is described. It was collected from the fossiliferous Lower Sinemurian (Semicostatum or Turneri Chronozone) strata of Burgundy (Mavilly-Mandelot, Côte-d’Or, France). The new taxon, Oxyarietites boletzkyi n. gen., n.sp., possesses an involute, compressed and keeled shell of suboxycone morphology, a shell type previously unknown for the Lower Sinemurian. The discovery makes younger by about 2 Ma the emergence of keeled (sub)oxycone shells following the Triassic/Jurassic boundary crisis. Its obviously keeled ventral area allows a probable assignation to the Arietitoidea Hyatt, 1875 sensu Guex (1995) superfamily, but family level assignation and its evolutionary origin remain obscure. Although, it is generally accepted that involute, compressed and keeled suboxycone and oxycone ammonite shells possess the best hydrodynamical abilities and mobility, the acquisition of this probable adaptive advantage in O. boletzkyi n. gen., n. sp. does not go together with abundancy in the fossil record.
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