A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders

  title={A stem batrachian from the Early Permian of Texas and the origin of frogs and salamanders},
  author={Jason S. Anderson and Robert R. Reisz and Diane M. Scott and Nadia B Fr{\"o}bisch and Stuart S. Sumida},
The origin of extant amphibians (Lissamphibia: frogs, salamanders and caecilians) is one of the most controversial questions in vertebrate evolution, owing to large morphological and temporal gaps in the fossil record. Current discussions focus on three competing hypotheses: a monophyletic origin within either Temnospondyli or Lepospondyli, or a polyphyletic origin with frogs and salamanders arising among temnospondyls and caecilians among the lepospondyls. Recent molecular analyses are also… 

Focal Review: The Origin(s) of Modern Amphibians

The present paper reviews the impact of this fossil on morphological and molecular phylogenies, and divergence timing estimates based on molecular models and the fossil record, and raises questions over either the validity of morphological analyses that support lissamphibian polyphyly or about the possibility of long branch attraction given the short internal divergences and long subsequent branches.

Stem caecilian from the Triassic of Colorado sheds light on the origins of Lissamphibia

The hypothesis of caecilian origins closes a substantial morphologic and temporal gap and explains the appeal of morphology-based polyphyly hypotheses for the origins of Lissamphibia while reconciling molecular support for the group’s monophyly.

Triassic stem caecilian supports dissorophoid origin of living amphibians

The provenance of these fossils suggests a Pangaean equatorial origin for caecilians, implying that living caecilian biogeography reflects conserved aspects of caecian function and physiology in combination with vicariance patterns driven by plate tectonics, and new and compelling evidence supporting a single origin of living amphibians within dissorophoid temnospondyls.

The origin(s) of extant amphibians: a review with emphasis on the “lepospondyl hypothesis”

It is proposed that the complex of characters called the salamander mode of autopodium development is (in its less extreme forms) plesiomorphic for limbed vertebrates, so the apparent presence of this mode of development in temnospondyls cannot support the TH or the PH.

A New Amphibamid (Temnospondyli: Dissorophoidea) from the Early Permian of Texas

A new genus and species of amphibamid, Rubeostratilia texensis, represented by a skull from the Early Permian of Texas, shows many similarities with a recent described species from Richards Spur, Oklahoma, Pasawioops mayi.

Phylogeny of the amphibamiform temnospondyls: the relationship of taxa known by adults, larvae and neotenes

  • R. Schoch
  • Biology, Environmental Science
    Journal of Systematic Palaeontology
  • 2022
The present analysis finds the hypothesized olsoniform larvae from Nýřany to be adults of Branchiosaurus salamandroides, whereas some of the larvae from Mazon Creek are not branchiosaurids, but immature specimens of the amphibamid Amphibamus grandiceps.

The armoured dissorophid Cacops from the Early Permian of Oklahoma and the exploitation of the terrestrial realm by amphibians

The skull of C. morrisi has several features associated with predatory behaviour, indicating that this dissorophid may have been one of the top terrestrial predators of its time.

A Triassic stem-salamander from Kyrgyzstan and the origin of salamanders

A new specimen of Triassurus sixtelae is reported, a hitherto enigmatic tetrapod from the Middle/Late Triassic of Kyrgyzstan, which is identified as the geologically oldest stem-group salamander, shedding light not only on the early evolution of the salamanders body plan, but also on the origin of the group as a whole.

First Record of the Amphibamiform Micropholis stowi from the Lower Fremouw Formation (Lower Triassic) of Antarctica

  • B. GeeC. Sidor
  • Environmental Science, Geography
    Journal of Vertebrate Paleontology
  • 2021
ABSTRACT The fossil record of temnospondyl amphibians in the immediate wake of the Permo-Triassic mass extinction captures extensive taxic and ecological diversity, with most records known from high

The lower permian dissorophoid «doleserpeton» (temnospondyli), and the evolution of modern amphibians

The origin and evolution of modern amphibians is still a subject of controversy. The amphibamid temnospondyl Doleserpeton has often been suggested as a close relative of modern amphibians, but the

Dates, nodes and character conflict: Addressing the Lissamphibian origin problem

Tests of different crown topologies show that placement of amphibians within lepospondyls is not a significantly worse fit for the whole character set than a close temnospondyl‐lissamphibian relationship, and the latter phylogenetic hypothesis best captures the most coherent assembly of derived lissampshibian apomorphies.

The Palaeozoic Ancestry of Salamanders, Frogs and Caecilians

Recognition of a sister-group relationship between Permo-Carboniferous branchiosaurids and crown-group salamanders makes it possible to determine the sequence of changes in the anatomy and ways of life that occurred during the origin of urodeles, and to determine their time of divergence relative to that of frogs and caecilians.


The balance of evidence favors a monophyletic origin of all lissamphibians from within the tem- nospondyls but the number of character states involved is not so great that this theory can be considered robust.

Initial Diversification of Living Amphibians Predated the Breakup of Pangaea

A robust molecular phylogeny based on the nuclear RAG1 gene as well as results from a variety of alternative independent molecular clock calibrations suggest that the origin and early divergence of the three living amphibian orders dates back to the Palaeozoic or early Mesozoic, before the breakup of Pangaea, and soon after the divergence from lobe‐finned fishes.

Mitogenomic perspectives on the origin and phylogeny of living amphibians.

It is suggested that the temnospondyl-origin hypothesis for lissamphibians is more credible than other hypotheses, and under this timescale, the potential geographic origins of the main living amphibian groups are discussed.


An anatomical study of Microbrachis reveals inaccuracies in previous studies, especially in the palate and cranial proportions, which corroborates previous suggestions that lissamphibians are part of a clade that includes the taxa classically referred to as “lepospondyls,” and that seymouriamorphs and temnospONDyls are not part of Tetrapoda.

Earliest known crown-group salamanders

The discovery of well-preserved Middle Jurassic salamander from China constitutes the earliest known record of crown-group urodeles (living salamanders and their closest relatives) and provides evidence to support the hypothesis that the divergence of the Cryptobranchidae from the Hynobiidae had taken place in Asia before the Middle Jurassic period.

Georgenthalia clavinasica, A New Genus and Species of Dissorophoid Temnospondyl from the Early Permian of Germany, and the Relationships of the Family Amphibamidae

Several features support a highly terrestrial habitus of G. clavinasica, which is consistent with the interpretation of the fossiliferous beds of the Bromacker quarry as representing an upland terrestrial environment in which limnic conditions were characterized by ephemeral lakes and ponds.