Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata)

@article{Ast2001MitochondrialDE,
  title={Mitochondrial DNA Evidence and Evolution in Varanoidea (Squamata)},
  author={J C Ast},
  journal={Cladistics},
  year={2001},
  volume={17}
}
  • J. Ast
  • Published 1 September 2001
  • Biology
  • Cladistics
Varanoidea is a monophyletic group of anguimorph lizards, comprising the New World helodermatids, the Bornean earless monitor Lanthanotus borneensis, and the Old World monitors (Varanus). I use mitochondrial DNA sequences and extensive taxonomic sampling to test alternative hypotheses of varanoid relationships. The most parsimonious hypothesis confirms the monophyly of Varanoidea (Heloderma, Lanthanotus, and Varanus) and Varanus, as well as the sister‐taxon relationship of Varanus and… 
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References

SHOWING 1-10 OF 74 REFERENCES
Biogeographic origins of goannas (Varanidae): a molecular perspective.
TLDR
The results suggest that the Australian species may be derived from an Asian source and are, therefore, in agreement with the hypothesis based on the fossil record suggesting that Varanidae may be Asian in origin.
Evolution of Body Size: Varanid Lizards as a Model System
TLDR
Felsenstein's method of phylogenetically independent contrasts, coupled with information on branch lengths, is exploited to identify several likely instances of relatively rapid evolution of body size, both between and within clades.
Braincase and phylogenetic relationships of Estesia mongoliensis from the late Cretaceous of the Gobi Desert and the recognition of a new clade of lizards. American Museum novitates ; no.3211
TLDR
It is revealed that Estesia mongoliensis is a member of a distinct clade of lizards including the extant Heloderma and its fossil relatives, and recognition of the new clade necessitates revision of the definition and diagnosis of the Helodermatidae.
Chromosomal evolution in the lizard genus Varanus (reptilia).
TLDR
The most likely phylogenetic model based on chromosome morphology, fossil evidence and the current distribution of the genus Varanus is presented and is related to the current taxonomic groupings.
A Concern for Evidence and a Phylogenetic Hypothesis of Relationships among Epicrates (Boidae, Serpentes)
TLDR
High levels of character congruence were observed among 89 biochemical and morphological synapomorphies scored on 10 species of Epicrates, and the consensus cladogram was consistent with the phylogenetic interpretation attached to the resulting hypothesis, which is a consensus of two equally parsimonious cladograms.
Aigialosaurs: mid-Cretaceous varanoid lizards
TLDR
Aigialosaurs share many derived characters with modern varanids (including Lanthanotus and Varanus and the Eocene genus Saniwa), to the exclusion of the Upper Cretaceous varanid...
Molecular phylogenetics, tRNA evolution, and historical biogeography in anguid lizards and related taxonomic families.
TLDR
Phylogenetic analysis of evolutionary changes in the gene encoding tRNA(Cys) suggests gradual reduction of dihydrouridine (D) stems by successive deletion of bases in some lineages, which contrasts with the one observed for parallel elimination of the D-stem in mitochondrial tRNAs of eight other reptile groups, in which replication slippage produces direct repeats.
Multiple independent transpositions of mitochondrial DNA control region sequences to the nucleus.
  • M. Sorenson, R. Fleischer
  • Biology
    Proceedings of the National Academy of Sciences of the United States of America
  • 1996
TLDR
The data suggest that the presumably nonfunctional but more slowly evolving nuclear sequences often will not be identifiable by changes incompatible with function and may be preferentially amplified by PCR primers based on mtDNA sequences from related taxa.
Hemipeneal Morphology of Platynotan l.izards
TLDR
Descriptions of the hemipeneal morphology of Lanthanotus, Heloderma and Varanus are presented and there is great interspecific variation in the ornamentation of the dorsal flounces, and shape and size of the horns.
...
...