This book evaluates the reputation of the coelacanth, presenting up-to-date accounts of the structure of fossil coelacanths, and suggests a family history to show that there have been subtle but significant changes in coelacanth history.
The purpose of this book is to give an account of the life and times of a single species of fish, Latimeria chalumnae- the coelacanth (or are there now two species?). Before the discovery of the modern Latimeria, relationships of the coelacanths were thought to lie with the rhipidistians, a group of fossil fishes that many think are tetrapod ancestors. Hence, by looking at the modern coelacanth and assuming conservatism we may be able to reconstruct the life of the 'missing link' between fishes and tetrapods. The coelacanth is the only living animal to retain some structuralcharacteristics that were certainly present in the tetrapod ancestors, such as the intracranial joint. Therefore it is of some interest to try and find out how this joint works and what it is there for. The gene pool of the coelacanth has been separated from that of all other living vertebrates for at least 360 million years. Therefore, it is of some interest to find out how much deviation from contemporaneous fishes there has been. Coelacanths have often been used as the classic example of a particular evolutionary pattern whereby evolution is very fast in the early years and then slows down to stability and finally stagnation. This needs to be evaluated in the light of what we now know of the history of the coelacanths as a genetic lineage.
Arranged logically to follow the most widely adopted course structure, this text will leave students with a full understanding of the unique structure, function, and living patterns of all vertebrates.
The book provides insight on the osteology, myology, phylogeny and evolution of Osteichthyes. It not only provides an extensive cladistic analysis of osteichthyan higher-level inter-relationships based on a phylogenetic comparison of 356 characters in 80 extant and fossil terminal taxa representing all major groups of Osteichthyes, but also analyses various terminal taxa and osteological characters. And also provides a general discussion on issues such as the comparative anatomy, homologies and evolution of osteichthyan cranial and pectoral muscles, the development of zebrafish cephalic muscles and the implications for evolutionary developmental studies, the origin homologies and evolution of one of the most peculiar and enigmatic structural complexes of osteichthyans, the Weberian apparatus, and the use of myological versus osteological characters in phylogenetic reconstructions.