Rating: 
Summary: A very impressive review of Mesozoic ocean reptiles
Review: This book has no real peer at the moment. Indeed, a comprehensive, detailed, but easily understandable book on marine reptilian predators of the Mesozoic has been long awaited, and overdue. These animals approached whales in size in some instances, and easily dwarfed their terrestrial counterparts. Indeed, a T Rex may have been only one eighth the size of the largest pliosaurs. Yet, most books on Mesozoic life have, until now, relegated these marvelous animals to one or two back chapters or sections at the most.Author Ellis, a renowned illustrator, writer, and researcher, has produced a masterpiece. His drawings of these seagoing reptiles are impeccable, if sometimes a bit speculative, and enable the reader to capably visualize these gigantic creatures.
Likewise, the text is enormously informative, not only about such FAQ's as size, weight, methods of reproduction, etc., but also on more arcane matters, such as how these huge beasts propelled themselves quickly and efficiently through the water. One glance at a long-necked, flippered plesiosaurus reveals that the answer to this problem is far from simple. After an excellent introduction, the author covers icthyosaurs, plesiosaurs, pliosaurs, and mosasaurs in turn. Ellis then concludes with what seems to be the mandatory conclusion to any Mesozoic book; i.e., what caused all of these fabulously efficient, dominant predators to disappear in one fell swoop. I found this book enormously enjoyable, and it was one of my best Christmas presents in years. I shall read it again and again. Anyone with a high school background will enjoy this book to the hilt, and my recommendation is extremely high. By the way, this is the sort of book one loans out only very carefully.
Rating:
Summary: A very impressive review of Mesozoic ocean reptiles
Review: This book has no real peer at the moment. Indeed, a comprehensive, detailed, but easily understandable book on marine reptilian predators of the Mesozoic has been long awaited, and overdue. These animals approached whales in size in some instances, and easily dwarfed their terrestrial counterparts. Indeed, a T Rex may have been only one eighth the size of the largest pliosaurs. Yet, most books on Mesozoic life have, until now, relegated these marvelous animals to one or two back chapters or sections at the most. Author Ellis, a renowned illustrator, writer, and researcher, has produced a masterpiece. His drawings of these seagoing reptiles are impeccable, if sometimes a bit speculative, and enable the reader to capably visualize these gigantic creatures.
Likewise, the text is enormously informative, not only about such FAQ's as size, weight, methods of reproduction, etc., but also on more arcane matters, such as how these huge beasts propelled themselves quickly and efficiently through the water. One glance at a long-necked, flippered plesiosaurus reveals that the answer to this problem is far from simple. After an excellent introduction, the author covers icthyosaurs, plesiosaurs, pliosaurs, and mosasaurs in turn. Ellis then concludes with what seems to be the mandatory conclusion to any Mesozoic book; i.e., what caused all of these fabulously efficient, dominant predators to disappear in one fell swoop. I found this book enormously enjoyable, and it was one of my best Christmas presents in years. I shall read it again and again. Anyone with a high school background will enjoy this book to the hilt, and my recommendation is extremely high. By the way, this is the sort of book one loans out only very carefully.
Rating:
Summary: very nice survey of mesozoic marine life - recommended !
Review: This is the first book I know that describes the whole variety of mesozoic marine life in a, for the averagely interested as well as experts, very clear and understandable manner. In four sections Ellis reflects the latest information on nearly all species of Ichthyosaurs, Plesiosaurs, Pliosaurs and Mosasaurs combined with a lot of outstanding life reconstructions (done by Ellis himself). The text is free of speculation but full of scientific background because Ellis frequently includes the latest inputs from the leading experts. What the book also makes very enjoyable is the fact, that the book is free of difficult technical jargon but gives a lot of references for people that are looking for these technical details. The style and print quality of the book is also very good.
In summary one can say confidently that this book is the best popularized book on mesozoic marine life available
Rating: 
Summary: Decent overview of Mesozoic marine reptiles.
Review: _Sea Dragons_ is a companion volume to author Richard Ellis' earlier work on the evolution of life in the sea, _Aquagenesis_. During the course of research for the earlier book, he uncovered so much material about Mesozoic marine reptiles that he made a decision to actually leave them out for the most part. He wrote that the material for _Sea Dragons_ came from the "scrap heap," a statement I find remarkable as they are among the most interesting - arguably the most "charismatic" - extinct marine organisms ever. I also think this book is better written, researched, and illustrated than _Aquagenesis_.
The first section of the book provided an introduction to Mesozoic marine reptiles in general, detailing the history of research into these animals and briefly detailing some extinct marine reptiles that are not explored in greater detail later, notably the mesosaurs (marine reptiles up to 3 feet long that lived in the Permian, about 300 million years ago), sea turtles (including extinct species), nothosaurs (Triassic animals that may be ancestral to plesiosaurs and possibly had a seal-like ecological niche), and placodonts (somewhat turtle like reptiles that fed on shellfish). The idea of endothermic marine reptiles is discussed, Ellis noting that not only marine mammals and birds are endothermic but also that several species of fast-swimming pelagic sharks and tuna as well as the leatherback turtle maintain temperatures higher than the waters in which they swim. Also whether or not marine reptiles were viviparous (meaning they bore live young rather than laid eggs) or not is discussed, a subject explored at greater length with each group in its respective chapter.
The first group of animals explored at length is the ichthyosaurs, a remarkable group who bear a great deal of resemblance in form to fast swimming shark, dolphin, and tuna species. They were a group of marine reptiles that were highly adapted to a marine existence, existing from the early Triassic (about 250 million years ago) and perishing well before the end of the Cretaceous (about 93 million years ago). Their ancestors a mystery, early ichthyosaurs were long and slim, somewhat eel-like in form, though later species were highly streamlined. The group is fairly well known, with one locale in Holzmaden, Germany, yielding about 35 ichthyosaurs a year and having produced all told over 3,000 specimens; from these and other fossil sites we know that they gave birth to live young and it is highly unlikely that they possessed echolocation but instead were highly dependent upon vision. Ellis reviewed many ichthyosaur species, notably _Shonisaurus_ (at 50 feet the largest described ichthyosaur to date though Ellis noted that an undescribed specimen from British Columbia is 75 feet long) and _Temnodontosaurs_ (a 30 foot long species with eyes 9 inches across, the largest eyes of any animal that ever lived).
Next Ellis examined the plesiosaurs, a group that is found from the uppermost Triassic to the very end of the Cretaceous (they were around for about 140 million years). Completely unlike ichthyosaurs in form, they possessed long necks with small heads (one species, _Elasmosaurus_, had a neck 47 feet long with 70 neck vertebrae). Much of his chapter on this group noted the many controversies that surround them. How they swam is subject to a great dealt of debate; did they paddle (the limbs moving in the vertical plane, like a human doing a crawl stroke or the movement of a waterwheel in a mill), row (moving in the horizontal plane, in a manner similar to how oars are used on a boat), or "fly" (the limbs moving roughly in a figure-eight pattern, much like modern sea turtles, sea lions, and penguins; and if they did fly did they have two "wings" in use or four)? Did they lay eggs or bear live young? How did they hunt; did they hunt from the surface or well beneath it and what sort of motions were their necks capable of?
The next group are the pliosaurs, a group that some feel is somewhat artificial, either believing the distinction between small-headed, long-necked plesiosaurs and large-headed, short-necked pliosaurs artificial to start with or noting that the pliosaur body plan may have arisen independently several times from ancestral plesiosaurs during the Mesozoic. This group possessed some of the largest predators ever, notably _Liopleurodon_ (most believing it 50 feet in length though Tim Haines, author of the book _Walking With Dinosaurs_ and producer of the BBC TV program of the same name was accused by others of being "irresponsible and sensationalistic" in claims that it was over 80 feet long). Ellis noted several remarkable specimens, such as a pliosaur (_Leptocleidus_) from Australia, "Eric," an almost complete skeleton comprised entirely of precious opal, and one dubbed by detractors "Plasterosaurus," a _Kronosaurus_ specimen that required massive amounts of reconstruction and liberal use of plaster.
The last group examined is the mosasaurs, a kind of marine lizard that appeared in the fossil record 90 million years ago. Not exactly small-sized animals (_Mosasaurus_ reached 58 feet in length), they were arguably the dominant marine predator for about 25 million years, existing after the extinction of the ichthyosaurs (some say there is a connection, though others think that faster, more evasive fish evolved, making ichthyosaur pursuit tactics to metabolically costly and that mosasaurs were ambush not pursuit predators) and during the decline of the pliosaurs. Like the ichthyosaurs, the mosasaurs are relatively well known with many fossils from locations as far apart as Africa, Belgium, Alabama, and Kansas (the Niobrara Chalk formation of Kansas has yielded 1,823 mosasaur specimens, many of which were collected by O.C. Marsh and E.D. Cope in a collecting and naming frenzy that produced such a taxonomic muddle that experts are still confused). I thought Ellis did a very good job in discussing mosasaur physiology and behavior as well as what evolutionary relationship they have (if any) with snakes and found this section particularly enlightening.
Not bad, some of the other reviews note the book's flaws better than I can.
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