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. 2012 Apr 10;109(15):5767-72.
doi: 10.1073/pnas.1009828109. Epub 2012 Mar 12.

Late Jurassic salamandroid from western Liaoning, China

Ke-Qin Gao  1 , Neil H Shubin
Affiliations

Late Jurassic salamandroid from western Liaoning, China

Ke-Qin Gao et al. Proc Natl Acad Sci U S A. .

Erratum in

  • Proc Natl Acad Sci U S A. 2012 Jul 24;109(30):12260

Abstract

A Jurassic salamander, Beiyanerpeton jianpingensis (gen. et sp. nov.), from a recently found site in western Liaoning Province, China is the earliest known record of Salamandroidea. As a Late Jurassic record of the group, it extends the range of the clade by ~40 Ma. The Late Jurassic taxon is neotenic and represented by exceptionally preserved specimens, including fully articulated cranial and postcranial skeletons and bony gill structures close to the cheek region. The fossil beds, consisting of dark-brown volcanic ash shales of the Upper Jurassic Tiaojishan (Lanqi) Formation (Oxfordian), underlie trachyandesite rocks that have yielded a SHRIMP zircon U-Pb date of 157 ± 3 Ma. The fossiliferous beds are substantially older than the Jehol Group, including the Yixian Formation ((40)Ar/(39)Ar dates of 122-129 Ma), but slightly younger than the Middle Jurassic Daohugou horizon ((40)Ar/(39)Ar date of 164 ± 4 Ma). The early fossil taxon shares with extant salamandroids derived character states, including: separated nasals lacking a midline contact, angular fused to the prearticular in the lower jaw, and double-headed ribs on the presacral vertebrae. In contrast to extant salamandroids, however, the salamander shows a discrete and tooth-bearing palatine, and unequivocally nonpedicellate and monocuspid marginal teeth in large and presumably mature individuals. The finding provides insights into the evolution of key characters of salamanders, and also provides direct evidence supporting the hypothesis that the split between Cryptobranchoidea and Salamandroidea had taken placed before the Late Jurassic Oxfordian time. In this aspect, both paleontological and molecular data now come to agree.

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Conflict of interest statement

The authors declare no conflict of interest.

Figures

Fig. 1.
Fig. 1.
Map and geologic section showing the geographic location and stratigraphic position of the fossil site (Tiaojishan Formation) in relation to Daohugou (Haifanggou Formation) locality in Inner Mongolia (geologic section modified from ref. 12). The nearby Lower Cretaceous Xintaimen site is also shown in the map. Solid diamond denoting fossil localities.
Fig. 2.
Fig. 2.
Holotype of Beiyanerpeton jianpingensis, gen. et sp. nov. (holotype PKUP V0601): a nearly complete skeleton in ventral view. Anatomical abbreviations used in figures: adf, anterodorsal fenestra; at, atlas; bd, branchial denticle; d, dentary; fe, femur; fi, fibula; fr, frontal; hb, hypobranchial; hu, humerus; il, ilium; lac, lacrimal; mx, maxilla; na, nasal; op, operculum; pa, parietal; pal, palatine; prf, prefrontal; pm, premaxilla; pra, prearticular; ps, parasphenoid; pt, pterygoid; qu, quadrate; ra, radius; sc, scapulocoracoid; se, sphenethmoid; sm, septomaxilla; sq, squamosal; sr, sacral rib; st, stapes; ti, tibia; tr, trunk rib; ul, ulna; vo, vomer.
Fig. 3.
Fig. 3.
Skull of Beiyanerpeton jianpingensis, gen. et sp. nov. in dorsal (Upper: PKUP V0605) and palatal (Lower: holotype PKUP V0601) views.
Fig. 4.
Fig. 4.
Calibrated cladogram showing the relationships of Beiyanerpeton to other fossil and extant salamander clades, and the timing of the Salamandroidea splitting from Cryptobranchoidea (solid dot) as indicated by the fossil record. For details on phylogenetic analysis and stratigraphic range of major salamander clades see text and SI Appendix.
See this image and copyright information in PMC

Comment in

References

    1. Cannatella DC, Hillis DM. Amphibian relationships: Phylogenetic analysis of morphology and molecules. Herpetol Monogr. 1993;7:1–7.
    1. Wake DB, Larson A. Multidimensional analysis of an evolving lineage. Science. 1987;238(4823):42–48. - PubMed
    1. Wake DB. Homoplasy: The result of natural selection or evidence of design limitations? Am Nat. 1991;138:543–567.
    1. Shubin N, Wake DB. Phylogeny, variation, and morphological integration. Am Zool. 1996;36(1):51–60.
    1. Gao K-Q, Shubin NH. Late Jurassic salamanders from northern China. Nature. 2001;410:574–577. - PubMed

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