How To Use placoid In A Sentence
- It is an axiom of this theory that hard-tissue units (odontodes in the sense of Orvig 1977) comparable in structure to placoid scales can be inferred to have developed in a directly comparable manner.
- These facts seem to point to stages in the fusion of placoid bases, and their withdrawal from the surface to become incorporated with the cranial apparatus as membrane bones, a process entirely completed in the mammalian type. Text Book of Biology, Part 1: Vertebrata
- Hertwig followed up this clue, and came to the conclusion not only that placoid scales and teeth were strictly homologous, but also that all membrane bones were derived phylogenetically from ossifications present in the skin or in the mucous membrane of the mouth, just as cartilage bones were derived from the cartilaginous skeletons of the primitive Vertebrates. Form and Function A Contribution to the History of Animal Morphology
- How placoid scales may have given rise to these structures will be understood by considering such a bone as the vomer of the frog. Text Book of Biology, Part 1: Vertebrata
- Finally, with respect to the ‘Vertebrata’, the same law holds good: certain types, such as those of the ganoid and placoid fishes, having persisted from the palaeozoic epoch to the present time without a greater amount of deviation from the normal standard than that which is seen within the limits of the group as it now exists. Essays
- Steenstrup -- had been struck with the resemblance existing between the placoid scales and the teeth of Elasmobranch fishes. Form and Function A Contribution to the History of Animal Morphology
- Similar attempts had been underway in the dermal skeleton, stemming from Williamson's use of placoid scales from extant sharks as conceptual units in comparative analysis.
- Finally, with respect to the ‘Vertebrata’, the same law holds good: certain types, such as those of the ganoid and placoid fishes, having persisted from the palaeozoic epoch to the present time without a greater amount of deviation from the normal standard than that which is seen within the limits of the group as it now exists. Essays
- The earliest attempts to unravel the nature of development and patterning of the vertebrate dermoskeleton and visceral skeleton place central importance upon the nature of the placoid scales in living sharks.
- Dogfish Shark Placoid Scales - The bodies of dogfishes, like all sharks, are externally lined with placoid scales, also known as dermal denticles. Undefined