Candelaria Formation (Nevada, United States), and Mikin Formation (Himachal Pradesh, India), and the Smithian aged assemblages of the Vikinghøgda Formation (Spitsbergen, Norway), Thaynes Formation (western United States), and Helongshan Formation (Anhui, China). Ray-finned fishes diversified during the Triassic and reached peak diversity during the Middle Triassic. This diversification is, however, obscured by a taphonomic megabias during the late Olenekian and early middle Anisian. Marine temnospondyl amphibians, such as the superficially crocodile-shaped trematosaurids Aphaneramma and Wantzosaurus, show wide geographic ranges during the Induan and Olenekian ages. Their fossils are found in Greenland, Spitsbergen, Pakistan and Madagascar. Others, such as Trematosaurus, inhabited freshwater environments and were less widespread. The first marine reptiles appeared during the Olenekian. Hupehsuchia, Ichthyopterygia and Sauropterygia are among the first marine reptiles to enter the scene (e.g. Cartorhynchus, Chaohusaurus, Utatsusaurus, Hupehsuchus, Grippia, Omphalosaurus, Corosaurus). Sauropterygians and ichthyosaurs ruled the oceans during the Mesozoic Era. An example of an exceptionally diverse Early Triassic assemblage is the Paris Biota, fossils of which were discovered near Paris, Idaho and other nearby sites in Idaho and Nevada. The Paris Biota was deposited in the wake of the SSBM and it features at least 7 phyla and 20 distinct metazoan orders, including leptomitid protomonaxonid sponges (previously only known from the Paleozoic), thylacocephalans, crustaceans, nautiloids, ammonoids, coleoids, ophiuroids, crinoids, and vertebrates. Such diverse assemblages show that organisms diversified wherever and whenever climatic an environmental conditions ameliorated. Smithian–Spathian boundary event An important extinction event occurred during the Olenekian age of the Early Triassic, near the Smithian and Spathian subage boundary. The main victims of this Smithian–Spathian boundary event, often called the Smithian–Spathian extinction, were 'disaster taxa': Palaeozoic species that survived the Permian–Triassic extinction event and flourished in the immediate aftermath of the extinction; ammonoids, conodonts, and radiolarians in particular suffered drastic biodiversity losses. Marine reptiles, such as ichthyopterygians and sauropterygians, diversified after the extinction. The flora was also affected significantly. It changed from lycopod dominated (e.g. Pleuromeia) during the Dienerian and Smithian subages to gymnosperm and pteridophyte dominated in the Spathian. These vegetation changes are due to global changes in temperature and precipitation. Conifers (gymnosperms) were the dominant plants during most of the Mesozoic. Until recently the existence of this extinction event about 249.4 Ma ago was not recognised. The Smithian–Spathian boundary extinction was linked to late eruptions of the Siberian Traps, which released warming greenhouse gases, resulting in climate change and in acidification, both