Dimetrodon Is Not a Dinosaur: Using Tree Thinking to Understand the Ancient Relatives of Mammals and their Evolution

@article{Angielczyk2009DimetrodonIN,
  title={Dimetrodon Is Not a Dinosaur: Using Tree Thinking to Understand the Ancient Relatives of Mammals and their Evolution},
  author={K. D. Angielczyk},
  journal={Evolution: Education and Outreach},
  year={2009},
  volume={2},
  pages={257-271}
}
  • K. Angielczyk
  • Published 5 February 2009
  • Biology
  • Evolution: Education and Outreach
The line of descent that includes all living mammals extends back in time over 300 million years. Many of the ancient relatives of mammals that fall along this line are very different in appearance from living mammals and are frequently mistaken for reptiles such as dinosaurs. This misconception is reinforced by the fact that these animals are often referred to as “mammal-like reptiles,” a term reflecting outdated methods for classifying organisms. In reality, these ancient mammal-relatives… Expand
The Evolutionary Emergence of Vertebrates From Among Their Spineless Relatives
The evolutionary origin of vertebrates has been debated ad nauseam by anatomists, paleontologists, embryologists, and physiologists, but it is only now that molecular phylogenetics is providing aExpand
Mammals, Origin of
TLDR
The first true mammals were found in the Late Triassic, and they diversified extensively throughout the Mesozoic, with the end-Cretaceous extinction, placental and marsupial mammals survived and diversified in the modern groups of mammals. Expand
Non-mammaliaform cynodonts from western Gondwana and the significance of Argentinean forms in enhancing understanding of the group
Abstract Terrestrial Triassic assemblages are an important component of the heritage of Argentina, particularly because of their diverse record of fossil vertebrates. Triassic basins from westernExpand
FROM UNDERSTANDING EVOLUTION A Name by Any Other Tree
If you read other articles in this issue carefully, you might begin to wonder if animal life is going through a hushed up identity crisis: Hummingbirds and canaries have finally come out as dinosaursExpand
Nervous systems and scenarios for the invertebrate-to-vertebrate transition
  • N. Holland
  • Biology, Medicine
  • Philosophical Transactions of the Royal Society B: Biological Sciences
  • 2016
TLDR
Diversity in diversity makes it challenging to establish plausible homologies between component parts (e.g. nervous system regions) and the current understanding of the relation between genotype and phenotype is too preliminary to permit us to convert gene network data into structural features in any simple way. Expand
A Name by Any Other Tree
TLDR
The widespread availability of evolutionary trees is reshaping how biologists ask and answer biological questions, and this is the reason that elephants are left on the fence about their identity, while birds have landed in the dinosaur camp, and snakes can boast the paradoxical title of tetrapod. Expand
Re-evaluation of the historic Canadian fossil Bathygnathus borealis from the Early Permian of Prince Edward Island
The holotype and only known specimen of Bathygnathus borealis is a partial snout with maxillary dentition of a presumed sphenacodontid from the Lower Permian (Artinskian 283–290 Ma) redbeds of PrinceExpand
A review of the “venomous therocephalian” hypothesis and how multiple re-portrayals of Euchambersia have influenced its success and vice versa
TLDR
A review of the literature on Euch Chambersia shows that the venomous therocephalian hypothesis is often based on inaccurate drawings of the canine and, for post-1986 authors, it is even based on the assumption that the canine of Euchambersia is grooved, whereas it is actually only ridged. Expand
A New Eutherocephalian (Therapsida, Therocephalia) from the Upper Permian Madumabisa Mudstone Formation (Luangwa Basin) of Zambia
TLDR
The new therocephalian therapsid Ichibengops munyamadziensis adds to a list of sister-group pairs of Wuchiapingian tetrapods in southern Gondwana and Laurasia, indicating that effective, though largely unknown, dispersal routes persisted in Pangea at least through early late Permian times. Expand
Bone histology of varanopids (Synapsida) from Richards Spur, Oklahoma, sheds light on growth patterns and lifestyle in early terrestrial colonizers
TLDR
It is shown that bone histology has the potential to explain how ballast was shed and the skeleton lightened for terrestrial mobility in ancestral synapsids and their basal amniote kin, as well as how adjustments in postnatal growth influenced the evolution of larger body sizes in the terrestrial frontier. Expand
...
1
2
3
...

References

SHOWING 1-10 OF 85 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
The Ancestry of Reptiles
TLDR
The ancestry of captorhinomorph reptiles from the gephyrostegid anthracosaurs can be firmly established and the nature of the amphibian-reptilian transition must be studied on the basis of relicts of earlier groups which are contemporary with true reptiles. Expand
DIAGNOSIS OF THE CLASSES REPTILIA AND MAMMALIA
TLDR
The editor has asked me to comment on two papers (Reed, 1960; Van Val en, 1960) that are published in this issue, and I have agreed to appear here as a representative of those who support the current arrangement of Mammalia. Expand
27th Du Toit Memorial LectureRe-uniting lost continents – Fossil reptiles from the ancient Karoo and their wanderlust
Fossil discoveries from South Africa have greatly expanded knowledge of the development of life on Earth. In particular, the enormous palaeontological wealth of the Karoo, covering a period of almostExpand
Synapsid Evolution and the Radiation of Non-Eutherian Mammals
TLDR
Of all the great transitions between major structural grades within vertebrates, the transition from basal amniotes to basal mammals is represented by the most complete and continuous fossil record, extending from the Middle Pennsylvanian to the Late Triassic and spanning some 75 to 100 million years. Expand
Phylogenetic evidence for and implications of a dual origin of propaliny in anomodont therapsids (Synapsida)
TLDR
The results of this investigation suggest that a dual origin of propaliny within anomodonts is not unlikely, but it depends largely on the interpretation of equivocal or poorly preserved features in some critical taxa, especially Otsheria. 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
Microanatomy of the radius and lifestyle in amniotes (Vertebrata, Tetrapoda)
TLDR
The discriminant function based on taxa of known lifestyle is used to infer the lifestyle of three extinct amniotes: the early nothosaur Pachypleurosaurus, therapsid Lystrosaurus and the synapsid Ophiacodon and these predictions are congruent with classical palaeoecological interpretations. Expand
The Osteology of the Reptiles
IN no domain of zoological science have the con tributions of American naturalists been more splendid than in that of vertebrate palaeontology, and in the list of pioneer workers in this domain anExpand
The oldest cynodont: new clues on the origin and early diversification of the Cynodontia
TLDR
One most parsimonious tree, from an analysis using implied weights, positions Charassognathus as the most basal cynodont, which implies that the Cynodontia initially diversified in Permian Gondwana, in what is now southern Africa. Expand
...
1
2
3
4
5
...