Interrelationships of basal synapsids: cranial and postcranial morphological partitions suggest different topologies

@article{Benson2012InterrelationshipsOB,
  title={Interrelationships of basal synapsids: cranial and postcranial morphological partitions suggest different topologies},
  author={Roger B. J. Benson},
  journal={Journal of Systematic Palaeontology},
  year={2012},
  volume={10},
  pages={601 - 624}
}
  • R. Benson
  • Published 1 December 2012
  • Biology
  • Journal of Systematic Palaeontology
Basal synapsids (‘pelycosaurs’) form the basalmost portion of the mammalian stem lineage and document the transition from primitive ‘reptile-like’ basal amniotes to derived, mammal-like therapsids. They dominated terrestrial ecosystems of the latest Carboniferous and Early Permian (∼300–271 million years ago), producing large-bodied terrestrial animals (3–6.5 metres long), high-fibre herbivores, and macropredators for the first time in vertebrate history, alongside an array of smaller-bodied… Expand
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References

SHOWING 1-10 OF 161 REFERENCES
GHOST LINEAGES AND MAMMALNESS : ASSESSING THE TEMPORAL PATTERN OF CHARACTER ACQUISITION IN THE SYNAPSIDA
The origin of mammals has been characterized as a gradual process, a claim based pri- marily on a well-preserved series of extinct nonmammalian synapsids ("mammal-like reptiles") that span some 200Expand
New Information on the Basal Pelycosaurian-Grade Synapsid Oedaleops
TLDR
Oedaleops is confirmed as an extremely basal synapsid taxon, but the addition of postcranial data from OedALEops to data matrices of earlier phylogenetic analyses unexpectedly weakens, as opposed to strengthens, support for the hypotheses of a monophyletic Eothyrididae. Expand
Cranial Anatomy of Ennatosaurus tecton (Synapsida: Caseidae) from the Middle Permian of Russia and the Evolutionary Relationships of Caseidae
TLDR
Phylogenetic analysis of Caseidae yields a single most parsimonious tree and its topology reveals that the pattern of dental complexity in terms of the number of apical cuspules is homoplasious, cautioning against its use as a unidirectional phylogenetic character. Expand
A new specimen of Biseridens qilianicus indicates its phylogenetic position as the most basal anomodont
TLDR
A new well-preserved basal therapsid skull from the Xidagou Formation, Middle Permian of China, is identified as Biseridens qilianicus and is found to be the most basal anomodont, which highlights separate Laurasian and Gondwanan basal anamodont clades and suggests that dicynodonts had their origins in the Gondwana clade. Expand
First record of a basal synapsid (‘mammal-like reptile’) in Gondwana
  • D. Dilkes, R. Reisz
  • Geology
  • Proceedings of the Royal Society of London. Series B: Biological Sciences
  • 1996
Elliotsmithia longiceps is a rare synapsid (‘mammal-like reptile’) from the middle part of the Tapinocephalus Assemblage Zone (Beaufort Group; Late Permian) of South Africa that belongs to the basalExpand
The origin and early radiation of the therapsid mammal‐like reptiles: a palaeobiological hypothesis
  • T. Kemp
  • Biology, Medicine
  • Journal of evolutionary biology
  • 2006
TLDR
An hypothesis is presented in which the origin of the therapsids resulted from a correlated progression of character evolution leading to higher levels of metabolic activity and homeostatic regulation of the body. Expand
CHAPTER 4 – BIOGEOGRAPHY OF PRIMITIVE AMNIOTES
TLDR
Despite minor differences in recent phylogenetic analyses, the phylogenetic relationships and biogeographic distributions of the following taxa are considered by all to be critical to an understanding of the origin of Amniotes. Expand
A reevaluation of early amniote phylogeny
TLDR
It is indicated that three major clades of amniotes extend from the present to the Palaeozoic, and these three clades are the Synapsida (including Mammalia), Parareptilia (including Testudines), and Eureptili (including Sauria). Expand
Evolutionary Patterns Among Permo-Triassic Therapsids*
TLDR
Synapsids form the bulk of tetrapod diversity from Early Permian to Middle Triassic times and thus can provide critical information on the nature of the Permo-Triassic extinction in the terrestrial realm. Expand
Eothyris and Oedaleops: Do These Early Permian Synapsids from Texas and New Mexico form a Clade?
TLDR
Although they appear relatively late in synapsid evolution, both eothyridids are significantly older than all other caseasaurs, forcing the establishment of a long unrecorded lineage for caseids. Expand
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