Osmotic tolerance and habitat of early stegocephalians: indirect evidence from parsimony, taphonomy, palaeobiogeography, physiology and morphology

@inproceedings{Laurin2010OsmoticTA,
  title={Osmotic tolerance and habitat of early stegocephalians: indirect evidence from parsimony, taphonomy, palaeobiogeography, physiology and morphology},
  author={M Laurin and Rodrigo Soler‐Gij{\'o}n},
  year={2010}
}
Abstract There are probably many reasons for the widespread belief that temnospondyls and other early stegocephalians were largely restricted to freshwater, but three of the contributing factors will be discussed below. First, temnospondyls have been called amphibians (and thought to be more closely related to extant amphibians than to amniotes). Some authors may have simply concluded that, like extant amphibians, temnospondyls could not live in oceans and seas. Second, under some phylogenies… 

Figures and Tables from this paper

Temnospondyli bite club: ecomorphological patterns of the most diverse group of early tetrapods
TLDR
The skull analysis reveals a concordance between form and feeding function, in amphibious and fully aquatic feeders in temnospondyls, which could be consequences of adaptative or phylogenetical constraints.
Histological skeletochronology indicates developmental plasticity in the early Permian stem lissamphibian Doleserpeton annectens
TLDR
It is proposed that the weak correlation between age and size represents developmental plasticity in D. annectens that typifies extant lissamphibians and is likely only possible with large sample sizes in extinct taxa, and low sample sizes can produce false, misleading results that warrant caution in drawing paleobiological interpretations from such samples.
Reproducibility in phylogenetics: reevaluation of the largest published morphological data matrix for phylogenetic analysis of Paleozoic limbed vertebrates
TLDR
In its present state, even after changes, the matrix cannot provide a robust assessment of the phylogeny of early limbed vertebrates; sufficient improvement of this matrix will be laborious but not difficult.
FISHES AND TETRAPODS IN THE UPPER PENNSYLVANIAN (KASIMOVIAN) COHN COAL MEMBER OF THE MATTOON FORMATION OF ILLINOIS, UNITED STATES: SYSTEMATICS, PALEOECOLOGY, AND PALEOENVIRONMENTS
ABSTRACT A newly discovered vertebrate assemblage is reported from the Upper Pennsylvanian (mid- to upper Kasimovian) Cohn Coal Member of the Mattoon Formation of southeast Illinois, United States.
Phylogenetic relationships of the Cretaceous frog Beelzebufo from Madagascar and the placement of fossil constraints based on temporal and phylogenetic evidence
TLDR
A metric is derived, Δt, to quantify temporal divergence among chronograms and finds that errors resulting from mis‐specified calibrations are localized when additional nodes throughout the tree are properly calibrated.
Unusual Environmental Conditions Preserve a Permian Mesosaur-Bearing Konservat-Lagerstätte from Uruguay
The environmental characterization of the Lower Permian mesosaur-bearing strata of the Mangrullo Formation (Paraná Basin, northeastern Uruguay) has been controversial. Historically, marine conditions
Morphology and Histology of Dorsal Spines of the Xenacanthid Shark Orthacanthus platypternus from the Lower Permian of Texas, USA: Palaeobiological and Palaeoenvironmental Implications
Detailed studies on Carboniferous species of the xenacanth Orthacanthus have shown that the xenacanth dorsal fin spine can be used for skeletochronological analyses and provides valuable information
...
...

References

SHOWING 1-10 OF 254 REFERENCES
CRANIAL MORPHOLOGY AND AFFINITIES OF MICROBRACHIS, AND A REAPPRAISAL OF THE PHYLOGENY AND LIFESTYLE OF THE FIRST AMPHIBIANS
TLDR
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.
THE OLDEST KNOWN STEGOCEPHALIAN (SARCOPTERYGII: TEMNOSPONDYLI) FROM SPAIN
TLDR
The widely held thesis that a tympanum was present in temnospondyls is questioned; the stapes of this group is always more massive than that of similarly-sized extant tetrapods that possess a tyMPanum.
Mitogenomic perspectives on the origin and phylogeny of living amphibians.
TLDR
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.
Phylogenetic Hypotheses of the Relationships of Arthropods to Precambrian and Cambrian Problematic Fossil Taxa
TLDR
A morphological cladistic analysis of seven Vendian "arthropodlike" taxa compared with 21 representative Cambrian arthropods, lobopods, and weird wonders finds no compelling reason to accept the hypothesis that the Vendian organisms included here are not metazoans.
THE UNIVERSITY OF KANSAS PALEONTOLOGICAL CONTRIBUTIONS
Vertebrates occur together with marine-indicating invertebrates in the same facies of the WrefOrd Megacyclothem, Gearyan Stage, Lower Permian, of Kansas. The vertebrates include typically marine
Dates, nodes and character conflict: Addressing the Lissamphibian origin problem
TLDR
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.
METAMORPHOSIS AND NEOTENY: ALTERNATIVE PATHWAYS IN AN EXTINCT AMPHIBIAN CLADE
  • R. Schoch, N. Fröbisch
  • Geography, Environmental Science
    Evolution; international journal of organic evolution
  • 2006
TLDR
These specimens give new insight into patterns of metamorphosis (morphological transformation) in branchiosaurids that are believed to be correlated to a change of habitat, and clearly show that different life‐history pathways comparable to those of modern salamanders were already estabilshed in this Paleozoic clade.
Cranial Morphology of the Loxommatidae (Amphibia: Labyrinthodontia)
TLDR
It is concluded that the antorbital vacuity, which characterizes the Loxommatoidea, evolved as a bulging hole for a large pterygoideus muscle associated with a piscivorous habit and a kinetic inertial system of jaw closure.
CHAPTER 2 – A NEW PERSPECTIVE ON TETRAPOD PHYLOGENY
Ontogenetic evidence for the Paleozoic ancestry of salamanders
TLDR
Comparison of patterns of larval development in Paleozoic and modern amphibians provides a means to test previous phylogenies based primarily on adult characteristics and proves to be highly informative in the case of the origin of salamanders.
...
...