The spine-brush complex occupies the same site as the first dorsal fin on other ratfish and contains a basal plate extending inside a usually posterior-pointing dorsal spine composed of trabecular dentine. The spines resemble those of modern sharks and rays but curiously lack any enamel-like surface tissue. The trabecular dentine contains patches of fibers suggesting attachments to the epaxial musculature. The way these muscles would have been positioned implies that the spine could have been moved in anterio-posterior direction. The so-called "brush" is not fibrous as was originally believed, but consists of a number of parallel, membranous tubules made of globular calcified cartilage. The brush base and basal plate are covered in a thin, acellular bone layer. Zangerl asserts that these tubules are similar to erectile tissues in humans, and thus the complex may have been inflatable. The complex itself is covered in up to nine rows of large denticles pointing anteriorly. The dorsal side of the head has its own collection of denticles which point posteriorly. The presence of these large denticles has led to theories that the spine-brush complex in combination with the denticles on the head was used to scare away predators by simulating the mouth of a larger fish. The complex has been affirmed only in males, and only in those males that have reached sexual maturity. Whether the complex was present in females of the species is still unknown. Another theory for the spine-brush complex is that it was involved either in attracting a mate or in the mating process itself.
A small amusement park for the little ones is conveniently located near the Phrom phong metro station. Adults there will definitely be fun, and of course children. Welcome!!!
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