Flying Fish And Jerfish Analysis

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Over evolutionary time organisms have diversified beyond imaginable. The earth is full of life from the simplest, single celled organisms, to whales the size of school buses. Even though there is a sundry of species alive on the planet today, even more species have lived in the past. In comparing the flying fish and the jerboa, one can see the changes that organisms have made overtime to better their chance of survival in their environment. By studying comparative anatomy, one can see the way that life has changed over time and imfer the history of the earth that drove these changes.
The integument of species has changed a great deal over the course of evolutionary history. The flying fish integument is composed of an outer epidermal layer, and an inner dermal layer. Enamel is secreted from the bottom of the epidermis, and elasmodine is formed at the top of the dermal tissue. The enamel, and elasmodine come together to form the elasmoid scales. The dermis of fishes is layered in a checker pattern at a 45o angle to the body axis. This allows fish to stretch and move their body laterally, while maintaining a streamline structure. The
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However, they different slightly in design and jaw articulation. The flying fish has an amphstyly skull made up of sections of chondrocranium, splachnocranium, and dermatocranium. The jaw is supported by the hyomandibula and the upper jaw is attached to the chondrocranium and the dermatocranium. Fish have two sets of external nares, that both open to the outside. In the jerboa, a synapsid skull is found. Synapsid skulls have one fenestration that lies between the jugal, squamosal, and postorbital bones. The mammal skull is also formed by pieces of chondrocranium, and splachnocranium, covered in dermatocranium. The jerboa jaw has as secondary autostyly articulation; where the upper jaw is fully attached to the skull, and the jaw hinges anterior to the

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