Josep Fortuny & J.-SÃbastien Steyer (2019)
New insights into the evolution of temnospondyls.
Iberian Geology (advance online publication)
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The term "Temnospondyli" was originally coined in 1887â1890 by the German paleontologist Karl Alfred von Zittel (1839â1904) to define fossil amphibians with very peculiar vertebrae (spondylus in Greek) composed of several (temno in Greek) elements, namely the inter-, the neuro- and the pleuro-centrum. Since Zittel, our understanding of this group has evolved thanks to many other paleontologists over the world who excavated and revealed (they are still doing it!) the intriguing nature and the hidden questions of these enigmatic amphibians. Today, the temnospondyls still remain one of the most challenging groups, which allows to better understand "(on) the origin of species" (Darwin 1859). Temnospondyls are indeed of great interest for the sciences of evolution because:
They show a high diversity (+290 species described and gathered in about 200 genera, see, e.g., Schoch 2013) together with a wide disparity and a huge range of sizes (from a few centimeters to more than 5 m in adult body length);
They are sometimes fossilized and delicately preserved during their larval or juvenile grow stage, i.e. not only during their adult stage, making them very important for studies dealing with ontogeny-phylogeny (e.g., Steyer 2000) or, in a wider range, evo-devo (e.g., Sanchez et al. 2010);
They may include the Lissamphibia; i.e. the modern amphibians represented today by the Anurans (frogs and toads), the Caudata (salamanders and newts) and the more discrete Gymniophiona (limbless caecilians), the origin(s) of which remain(s) very controversial (e.g., Ruta and Coates 2007; Pardo et al. 2017, and references therein);
They are very abundant in Paleozoic and early Mesozoic continental layers: they correspond to the most diverse group of early tetrapods (e.g., Schoch and Milner 2014; Ruta et al. 2007) and show a striking capacity to survive mass extinctions, particularly to the greatest Permian one (e.g., Ruta and Benton 2008; Fortuny et al. 2016).
Khaing Khaing San, Nicholas C. Fraser, Davide Foffa, Olivier Rieppel, and Stephen L. Brusatte (2019)
The first Triassic vertebrate fossils from Myanmar: Pachypleurosaurs in a marine limestone.
Acta Palaeontologica Polonica (in press)
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As ecosystems recovered from the end-Permian extinction, many new animal groups proliferated in the ensuing Triassic. Among these were the sauropterygians, reptiles that evolved from terrestrial ancestors and transitioned to a marine environment. The first sauropterygians were small, marine-adapted taxa such as pachypleurosaurs, which are known from MiddleâLate Triassic deposits, particularly in the Tethyan realm of Europe, and more recently from LagerstÃtten in southwestern China. Here we report two pachypleurosaurs from Myanmar, the first Triassic vertebrate fossils from the country. These specimens demonstrate that their entombing rocks in northern Shan State, which have received less study than terrestrial sediments in southern Shan State and whose ages have long been uncertain, are Triassic. The specimens may be among the oldest pachypleurosaurs globally, potentially corroborating biogeographic scenarios that posit an eastern Tethyan origin for pachypleurosaurs, and raise the potential for future discoveries of well-preserved Triassic reptiles in Myanmar.
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