Abstract
A new salamandroid salamander, Qinglongtriton gangouensis (gen. et sp. nov.), is named and described based on 46 fossil specimens of juveniles and adults collected from the Upper Jurassic (Oxfordian) Tiaojishan Formation cropping out in Hebei Province, China. The new salamander displays several ontogenetically and taxonomically significant features, most prominently the presence of a toothed palatine, toothed coronoid, and a unique pattern of the hyobranchium in adults. Comparative study of the new salamander with previously known fossil and extant salamandroids sheds new light on the early evolution of the Salamandroidea, the most species-diverse clade in the Urodela. Cladistic analysis places the new salamander as the sister taxon to Beiyanerpeton, and the two taxa together form the basalmost clade within the Salamandroidea. Along with recently reported Beiyanerpeton from the same geological formation in the neighboring Liaoning Province, the discovery of Qinglongtriton indicates that morphological disparity had been underway for the salamandroid clade by early Late Jurassic (Oxfordian) time.
Highlights
Salamandroidea [1] are the most species-diverse group of salamanders (Caudata, Urodela), including approximately 610 extant species in seven families [2, 3]
Because the stem caudate Karaurus has a lacrimal, the presence of this element in extant salamanders is probably a plesiomorphic feature. In those salamanders in which the lacrimal is present at the adult stage, it is a small plate between the maxilla and the nasal/prefrontal (Fig 10)
As seen in the strict consensus tree (Fig 12), all the three most parsimonious trees (MPTs) have the new taxon placed as the sister taxon with Beiyanerpeton, and the two taxa together form the basalmost clade within the Salamandroidea
Summary
Salamandroidea [1] are the most species-diverse group of salamanders (Caudata, Urodela), including approximately 610 extant species in seven families [2, 3]. Whether Sirenidae (sirens and their closely related fossil taxa) should be classified in Salamandroidea is a matter of debate, as recent phylogenetic results based on molecular, morphological, or combined data incompatibly place the family as the basalmost clade of Urodela [4, 5], sister clade with the Salamandroidea [6], or nested within Salamandroidea [7,8,9,10,11,12,13]; see [14] for a review). The evolutionary history of the salamandroids can be traced back to the Mesozoic, and recent fossil discoveries from China have provided critical evidence indicating that the split of Salamandroidea from Cryptobranchoidea had taken place no later than.
Sign-in/Register to view highlights & summary Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
