Tortoise Anatomical Changes From Early to Late Stages
|
 Show
Human Developed limbs, defined features in face, neck, ears, loss of tail, tiny fingers present Chicken Developed beak, tail shorter, wings and legs developed, head quite large Rabbit Tail gone, developed limbs, detailed features in ears and mouth Tortoise Shell developed, limbs have developed, tail is thinner, large belly, long tail, beak Salamander Has gills, tail and large underbelly Fish fins developed, gills, tail and scales
Review Body plan of turtles: an anatomical, developmental and evolutionary perspectiveHiroshi Nagashima et al. Anat Sci Int. 2012 Mar. AbstractThe evolution of the turtle shell has long been one of the central debates in comparative anatomy. The turtle shell consists of dorsal and ventral parts: the carapace and plastron, respectively. The basic structure of the carapace comprises vertebrae and ribs. The pectoral girdle of turtles sits inside the carapace or the rib cage, in striking contrast to the body plan of other tetrapods. Due to this topological change in the arrangement of skeletal elements, the carapace has been regarded as an example of evolutionary novelty that violates the ancestral body plan of tetrapods. Comparing the spatial relationships of anatomical structures in the embryos of turtles and other amniotes, we have shown that the topology of the musculoskeletal system is largely conserved even in turtles. The positional changes seen in the ribs and pectoral girdle can be ascribed to turtle-specific folding of the lateral body wall in the late developmental stages. Whereas the ribs of other amniotes grow from the axial domain to the lateral body wall, turtle ribs remain arrested axially. Marginal growth of the axial domain in turtle embryos brings the morphologically short ribs in to cover the scapula dorsocaudally. This concentric growth appears to be induced by the margin of the carapace, which involves an ancestral gene expression cascade in a new location. These comparative developmental data allow us to hypothesize the gradual evolution of turtles, which is consistent with the recent finding of a transitional fossil animal, Odontochelys, which did not have the carapace but already possessed the plastron. Similar articles
Cited by
Publication typesMeSH termsLinkOut - more resources
What are the 5 evidences of evolution?Evidence for evolution: anatomy, molecular biology, biogeography, fossils, & direct observation.
What about the internal structure of the cavefish and minnow suggest common ancestry?What about the internal structure of the cavefish and minnow suggest common ancestry? The arrangement of bones, muscles and other internal organs.
How are vestigial structures An example of evidence of evolution?Structures that have lost their use through evolution are called vestigial structures. They provide evidence for evolution because they suggest that an organism changed from using the structure to not using the structure, or using it for a different purpose.
|
