The salamandrid Chelotriton paradoxus from Enspel and Randeck Maars (Oligocene–Miocene, Germany)

Abstract

The late Paleogene to early Neogene salamander Chelotriton paradoxus is redescribed on the basis of new and excellent material from two deposits, the late Oligocene Enspel locality and the Miocene Randeck Maar. C. paradoxus is characterised by the following features: (1) skull outline broad and parabolic, (2) snout abbreviated, with nasal only half the length of the frontal, (3) quadratojugal with a series of 3-5 spikes on the lateral margin, and (4) osteoderms larger than in other genera. Like extant Echinotriton, its trunk ribs bear extensive spikes (epipleural processes), with an elongated one on the 3rd rib. The Enspel sample of C. paradoxus shows greater variation in the size and number of quadratojugal spikes, whereas the best-preserved Randeck specimen bears exceptionally tall tubercles on all dermal bones and osteoderms and has a larger quadratojugal. Based on preliminary taphonomical data, we suggest that C. paradoxus probably led a predominantly aquatic life.

Late Miocene (Early Turolian) vertebrate faunas and associated biotic record of the Northern Caucasus: Geology, palaeoenvironment, biochronology

“…It is assigned to Ch. paradoxus POMEL, 1853 (according to Schoch et al 2015) based on the heavily ossifi ed skull bones and extensive tubercular ornamentation.…”

An Extremely Peramorphic Newt (Urodela: Salamandridae: Pleurodelini) from the Latest Oligocene of Germany, and a New Phylogenetic Analysis of Extant and Extinct Salamandrids

“…By alluding to a “different head width/length ratio”, [ 4 ] must have meant the fact that Chelotriton (including C . ogygius : [ 21 ]: 59, 66) has an unusually wide skull that is broad-parabolic in dorsal or ventral view, as pointed out in [ 30 ]; this appears to be an autapomorphy and manifests also as an unusually high ratio of interorbital width to skull length.…”

“…The bluntly pentagonal shape of the nasals which are about as wide as long [ 30 ] appears to be a further autapomorphy.…”

“…pliocenicus Bailon, 1989, which has been found in an upper Pliocene site in France [ 18 ] and possibly a lower to middle Miocene site in Germany [ 19 ]; and the type species, C . paradoxus Pomel, 1853, to which material from lower Oligocene to upper Miocene sites of France, Germany, Austria, Romania and Spain has been referred [ 4 , 20 – 30 ]. Recently [ 31 , 32 ], two additional types of isolated Chelotriton skull bones were reported (“ Chelotriton sp., type I” and “ Chelotriton sp., type II”), both of which occur in the early Miocene site of Mokrá in the Czech Republic and in the late Miocene site of Rudabánya in Hungary; the atlantes referred to “type I” in [ 32 ] further differ from both those from the early Miocene Czech site of Merkur North and those from the middle Miocene French site of Sansan, while the other vertebrae referred to the same type are identical to those from Sansan ([ 32 ]: 474) even though they differ from the single (postatlantal) vertebra referred to “type II” ([ 32 ]: 475).…”

Peer Review #1 of "Phylogeny of Paleozoic limbed vertebrates reassessed through revision and expansion of the largest published relevant data matrix (v0.2)"

“…We have added Chelotriton to the matrix to see the effects, if any, of its unexpected peramorphic features on caudate and lissamphibian intra-and interrelationships. For this purpose, we took MB.Am.45 (scored mostly from the silicone cast MB.Am.45.3) at face value wherever possible rather than scoring polymorphism; missing data were filled in from the less extremely peramorphic Chelotriton individuals described and figured by Roček & Wuttke (2010) and Schoch, Poschmann & Kupfer (2015). Seymouriamorph Karpinskiosaurus may help clarify seymouriamorph phylogeny and relationships.…”