The homologies and early evolution of the shoulder girdle in turtles

@article{Lee1996TheHA,
  title={The homologies and early evolution of the shoulder girdle in turtles},
  author={Michael S. Y. Lee},
  journal={Proceedings of the Royal Society of London. Series B: Biological Sciences},
  year={1996},
  volume={263},
  pages={111 - 117}
}
  • Michael S. Y. Lee
  • Published 22 January 1996
  • Biology
  • Proceedings of the Royal Society of London. Series B: Biological Sciences
The homologies of the highly distinctive shoulder girdle of turtles are reinterpreted in the light of recent phylogenetic studies. The acromion process is an extension of the scapula blade: it is not a modified anterior coracoid, contrary to recent suggestions. In modern turtles, the acromion process articulates with the plastron (the ventral portion of the turtle shell). However, recent phylogenetic analyses indicate that the acromion arose in the common ancestor of pareiasaurs and turtles… 

Figures from this paper

On the homology of the shoulder girdle in turtles.
TLDR
The history of the debate on the homology of the shoulder girdle in turtles is traced and based on the integrative aspects of developmental biology, comparative morphology, and paleontology, acromion and procoracoid identities for the two ventral processes are suggested.
Origin of the unique morphology of the shoulder girdle in turtles
TLDR
The shoulder girdle of turtles has been achieved through a transformation of the pattern in the late ontogenic period, implying that coracoids are not homologous between non‐mammals and mammals.
The girdles of the oldest fossil turtle, Proterochersis robusta, and the age of the turtle crown
TLDR
All current phylogenetic hypotheses support the basal placement of thisTaxon, imply that the sutured pelvis of this taxon developed independently from that of pleurodires, and conclude that the age of the turtle crown is Middle Jurassic.
Geometric morphometrics of the shoulder girdle in extant turtles (Chelonii)
TLDR
The results indicate that four shape patterns of the shoulder girdle can be distinguished and increasing size leads to allometrical shape changes that emphasize mechanical efficiency both in terrestrial and in aquatic turtles.
Development of the turtle plastron, the order-defining skeletal structure
TLDR
It is suggested that the early osteogenic fate adopted by the ventral mesenchyme prevents the chondrogenic sternal development in turtles and that this was a critical step in forming the ossification centers for this new type of vertebrate structure.
Homology of the reptilian coracoid and a reappraisal of the evolution and development of the amniote pectoral apparatus
TLDR
A comprehensive review of data from numerous sources, including the fossil record, experimental embryology, genetic manipulations and an analysis of morphology at the level cell condensations, supports the conclusion that the metacoracoid gives rise to the majority of the reptilian coracoid.
An Archosaur-Like Laterosphenoid in Early Turtles (Reptilia: Pantestudines)
TLDR
The presence in stem turtles of a laterosphenoid ossification identical to that in Archosauriformes is presented, which has been mistakenly dismissed as anatomically dissimilar in these two groups in the past.
The hooked element in the pes of turtles (Testudines): a global approach to exploring primary and secondary homology
TLDR
New myological and developmental observations on the hooked element of turtles are provided, and the term ‘ansulate bone’ is proposed to refer to hooked elements that result from the fusion of these two bones.
Pareiasaur phylogeny and the origin of turtles
TLDR
Many features thought to be restricted to turtles (and thus to have evolved simultaneously with the turtle shell) actually arose earlier, at various points along the pareiasaurian stem lineage.
Reptile phylogeny and the interrelationships of turtles
TLDR
The results refute earlier hypotheses that turtles are related to parareptiles, i.e. to procolophonids or pareiasaurs, and strongly supports a monophyletic Parareptilia, sister-group of a monphyletic Eureptilia.
...
1
2
3
...

References

SHOWING 1-10 OF 32 REFERENCES
The Origin of the Turtle Body Plan: Bridging a Famous Morphological Gap
TLDR
In pareiasaurs, the osteoderms represent the precursors of the chelonian shell and the morphology of the anterior region is consistent with the idea that the shoulder girdle in turtles has migrated posteriorly into the rib cage.
A structural and functional analysis of walking in the turtle, Chrysemys picta marginata
  • W. Walker
  • Biology, Medicine
    Journal of morphology
  • 1971
TLDR
Differences in the movements of comparable segments of front and hind limbs correlate with differences in the width of the girdles, a crus longer than the antebrachium, and different capacities for joint rotation.
The appendicular skeleton of the Early Permian genus Labidosaurus (Reptilia, Captorhinomorpha, Captorhinidae) and the hind limb musculature of captorhinid reptiles
TLDR
The pectoral girdle is heavily constructed, with a glenoid fossa that limited the humerus to an excursion arc of approximately 50 degrees, and indications of a system of cruciate ligaments are present in well preserved femora and ...
Pareiasaur phylogeny and the origin of turtles
TLDR
Many features thought to be restricted to turtles (and thus to have evolved simultaneously with the turtle shell) actually arose earlier, at various points along the pareiasaurian stem lineage.
Historical Burden In Systematics And The Interrelationships Of ‘Parareptiles’
TLDR
Turtles are the highly modified survivors of a radiation of poorly‐known reptiles commonly called ‘parareptiles’, and the procolophonoid hypotheses is supported by only one synapomorphy (the slender stapes).
Homologies in the fossil record: The middle ear as a test case
  • J. Clack
  • Biology, Medicine
    Acta biotheoretica
  • 1993
TLDR
Examining the middle ear of fossil living animals in terms of the homologies which have been drawn between its parts in different vertebrate groups finds that most of the conceptions have been overturned in recent years by new fossil discoveries and new ways of looking at old data.
Ancestors and homology
  • M. Coates
  • Biology, Medicine
    Acta biotheoretica
  • 1993
TLDR
The evolutionary origin of the tetrapod limb is examined in the light of its recent discussion in developmental genetics, and it is argued to be complex conjectural inferences dependant upon a pre-existing phylogenetic analysis and a theoretical model of the evolutionary development of ontogenetic information.
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).
The role of paleontological data in testing homology by congruence
With homology being defmed as shared similarity due to common ancestry, any initial perception of similarity (or relative invariance) among organisms may be treated as a conjecture of homology to be
Studies on skeleton formation in reptiles: Patterns of ossification in the skeleton of Chelydra serpentina (Reptilia, Testudines)
TLDR
Convergence of ontogenetic repatterning in the ossification of the axial skeleton in Chelydra and Squamata is discussed, as are problems of adaptive modification of oSSification patterns.
...
1
2
3
4
...