Structural, functional, and physiological signals in ichthyosaur vertebral centrum microanatomy and histology

@article{Houssaye2018StructuralFA,
  title={Structural, functional, and physiological signals in ichthyosaur vertebral centrum microanatomy and histology},
  author={Alexandra Houssaye and Yasuhisa Nakajima and P. Martin Sander},
  journal={Geodiversitas},
  year={2018},
  volume={40},
  pages={161 - 170}
}
ABSTRACT The first tuna-shaped amniotes evolved among ichthyosaurs, but this group exhibits in fact a wide diversity of morphologies and swimming modes. The histology and microanatomical features of vertebral centra of a diversity of ichthyosaur taxa from most basal to highly derived illustrating this variability were analyzed. The occurrence of unusual parallel fibered bone with platings of true parallel-fibered bone confirms high growth rate in all these taxa. Ichthyosaur vertebrae, which are… 

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References

SHOWING 1-10 OF 34 REFERENCES

Vertebral microanatomy in squamates: structure, growth and ecological correlates

It is demonstrated that vertebrae in snakes are generally denser than those of lizards sensu stricto, this may drive the presence of a phylogenetic signal in the data, and preliminary analyses testing for associations between vertebral structure and habitat use suggest that vertebras of fossorial taxa are denserthan those of terrestrial taxa, those in aquatic taxa being of intermediate density.

A New Look at Ichthyosaur Long Bone Microanatomy and Histology: Implications for Their Adaptation to an Aquatic Life

The occurrence of two types of remodelling patterns along the diaphysis, characterized by bone mass decrease and increase respectively is described for the first time and raises questions about the definition of the osseous microanatomical specializations bone mass increase and osteoporosis, notably based on the processes involved.

What Vertebral Microanatomy Reveals About the Ecology of Juvenile Mosasaurs (Reptilia, Squamata)

This study tends to support recent views challenging the old hypothesis of sheltered nurseries and shows that, in mosasauroids, the functional requirements for buoyancy and body trim control are not correlated with individual size.

Rib and vertebral micro-anatomical characteristics of hydropelvic mosasauroids

Houssaye, A. & Bardet, N. 2011: Rib and vertebral micro-anatomical characteristics of hydropelvic mosasauroids. Lethaia, Vol. 45, pp. 200–209. Mosasauroids are squamates secondarily adapted to

Microanatomical and Histological Features in the Long Bones of Mosasaurine Mosasaurs (Reptilia, Squamata) – Implications for Aquatic Adaptation and Growth Rates

The more complete image of the various microanatomical trends observed in mosasaurine skeletal elements supports the evolutionary convergence between this lineage of secondarily aquatically adapted squamates and cetaceans in the ecological transition from a coastal to a pelagic lifestyle.

Bone Inner Structure Suggests Increasing Aquatic Adaptations in Desmostylia (Mammalia, Afrotheria)

This study suggests that all desmostylians had achieved an essentially, if not exclusively, aquatic lifestyle and are, with cetaceans, the second mammal group showing a shift from bone mass increase to a spongy inner organization of bones in their evolutionary history.

Specialization of bone structure in Pachyvaranus crassispondylus Arambourg, 1952, an aquatic squamate from the Late Cretaceous of the southern Tethyan margin

The histological organization of the vertebrae of the Maastrichtian squamate Pachyvaranus crassispondylus Arambourg, 1952, was compared to that of various extant squamates, in order to further

Eel-like swimming in the earliest ichthyosaurs

The most complete specimen of the oldest known ichthyosaur, Chensaurus, is reported, representing a transition between the two body plans, and seems to be an evolutionary intermediate between the shorter-bodied terrestrial stock from which the group evolved, and advanced thunniform ICHthyosaurs.

Adaptive Patterns in Aquatic Amniote Bone Microanatomy-More Complex than Previously Thought.

The analysis of the various microanatomical patterns observed in long bones, vertebrae, and ribs of a large sample of (semi-)aquatic extant and extinct amniotes reveals the wide diversity in microan atomical patterns and the variation in combination of these different patterns within a single skeleton.