Assessing Confidence Intervals for Stratigraphic Ranges of Higher Taxa: The Case of Lissamphibia

  title={Assessing Confidence Intervals for Stratigraphic Ranges of Higher Taxa: The Case of Lissamphibia},
  author={David Marjanovi{\'c} and Michel Laurin},
To evaluate stratigraphic evidence for the time of origin of the clade of extant amphibians (Lissamphibia), we attempt to establish a confidence interval on the lower bound of the stratigraphic range of this clade. This is based on the stratigraphic distribution of 1207 fossiliferous localities that have yielded lissamphibians, the relative area of sedimentary rocks from various periods (upper Paleozoic to present) exposed on the continents, and ten exponential-growth models of lissamphibian… 

An updated paleontological timetree of lissamphibians, with comments on the anatomy of Jurassic crown-group salamanders (Urodela)

The conclusion that the fossil record of Lissamphibia is dense enough to provide reliable calibration constraints for molecular divergence dating is upheld and some of the divergence dates the authors infer from the tree are up to 15 Ma younger than previously published.

Fossils and the Tree of Life : ghost ranges, stratigraphic congruence and data quality

A novel script was developed to automatically carry out continuous taxon jackknifing to investigate the effect of taxon sampling on the stability of phylogenetic trees and it was found that measures of homoplasy and support could serve as partial indicators of whether a tree was likely to be sensitive toTaxon sampling.

The Lissamphibian Fossil Record of South America

Anurans, along with urodeles and caecilians are the extant representatives of the clade Lissamphibia. Nowadays, lissamphibians are widely distributed in all continents, except Antarctica, but are

Recent progress in paleontological methods for dating the Tree of Life

  • M. Laurin
  • Environmental Science
    Front. Gene.
  • 2012
Progress has been made in compiling databases and supertrees incorporating paleontological data, in computing confidence intervals on the true stratigraphic range of taxa, and in using birth-and-death processes to assess the probability distribution of the time of origin of specified taxa.

Measuring Stratigraphic Congruence Across Trees, Higher Taxa, and Time

The center of gravity of FO dates had not been investigated hitherto, and this was found to correlate most strongly with some measures of stratigraphic congruence in this empirical study, and the modified GER was the index least susceptible to bias.

Histological study of karaurids, the oldest known (stem) urodeles

Bone histology reveals that the growth of Marmorerpeton and the related unnamed caudate was fairly slow and cyclic, a characteristic of extant lissamphibians, and strengthens the case for the presence of neoteny in these taxa.

Incorporating phylogenetic uncertainty on phylogeny‐based palaeontological dating and the timing of turtle diversification

Evaluating the uncertainty on the phylogenetic position of extinct taxa through non‐parametric bootstrapping for the age of first appearance of a given clade in the fossil record results in extensive uncertainty ranges of topology‐dependent minimal divergence dates for these clades.

Phylogenetic relationships of the Cretaceous frog Beelzebufo from Madagascar and the placement of fossil constraints based on temporal and phylogenetic evidence

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.

A review of the fossil record of caecilians (Lissamphibia: Gymnophionomorpha) with comments on its use to calibrate molecular timetrees

The caecilian fossil record is revisited, providing a brief description of all known extinct taxa described so far, along with general remarks about their impact on systematics, time range, and geographical distribution of the clade, as well as prospects for future research.

Recent Progress in Assessing Palaeobiodiversity and Its Evolution

  • M. Laurin
  • Environmental Science, Geography
  • 2014
Until recently, these models made very little use, if any, of fossil data, but recent developments allow extinct taxa represented by fossils and incorporated directly into time trees to inform the analyses and reduce estimation errors.



Fossils, molecules, divergence times, and the origin of lissamphibians.

A review of the paleontological literature shows that the early dates of appearance of Lissamphibia recently inferred from molecular data do not favor an origin of extant amphibians from

Fossil gap analysis supports early Tertiary origin of trophically diverse avian orders

The quality of the fossil record is consistent with the classical view that trophically diverse extant bird orders arose and diversified rapidly following the widespread extinction of other terrestrial groups at the K-T boundary.

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.

Confidence intervals on stratigraphic ranges

  • C. Marshall
  • Environmental Science, Geography
  • 1990
Observed stratigraphic ranges almost always underestimate true longevities. Strauss and Sadler (1987, 1989) provide a method for calculating confidence intervals on the endpoints of local

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.

Effects of sampling standardization on estimates of Phanerozoic marine diversification

  • J. AlroyC. Marshall A. Webber
  • Environmental Science, Geography
    Proceedings of the National Academy of Sciences of the United States of America
  • 2001
A new database of this kind for the Phanerozoic fossil record of marine invertebrates is introduced and four substantially distinct analytical methods that estimate taxonomic diversity by quantifying and correcting for variation through time in the number and nature of inventories are applied.

Global patterns of diversification in the history of modern amphibians

A phylogenetic timetree based on a multigene data set of 3.75 kb for 171 species reveals several episodes of accelerated amphibian diversification, which do not fit models of gradual lineage accumulation.

Continental breakup and the ordinal diversification of birds and mammals

THE classical hypothesis for the diversification of birds and mammals proposes that most of the orders diverged rapidly in adaptive radiations after the Cretaceous/Tertiary (K/T) extinction event 65

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 fact that both morphometric and discrete characters fail to support species-level identification of isolated ilia of extant Bufo indicates that identifications should be restricted to higher taxonomic levels until new ilial characters are established.