Nicholas Fraser (1)
Auteur de Dawn of the Dinosaurs: Life in the Triassic
Pour les autres auteurs qui s'appellent Nicholas Fraser, voyez la page de désambigüisation.
Nicholas Fraser (1) a été combiné avec Nicholas C. Fraser.
Œuvres de Nicholas Fraser
Les œuvres ont été combinées en Nicholas C. Fraser.
Terrestrial Conservation Lagerstatten: Windows into the Evolution of Life on Land (2017) 2 exemplaires
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While readers are probably going to zero in on the "Dinosaurs" in the title, the author spends as much or more time considering the competitors to Dinosauria, and does so while considering what it meant to be living on a single super continent. Fraser is also to be complimented for keeping this book readable while not dumbing down the proper technical language. If nothing else one can enjoy the drawings and conceptual art of what these animals looked like in their environment.
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Auteurs associés
Statistiques
- Œuvres
- 2
- Membres
- 61
- Popularité
- #274,234
- Évaluation
- 3.9
- Critiques
- 2
- ISBN
- 34
- Langues
- 4
Fortunately, I’m fond of both pretty color pictures and vertebrate paleontology, so I rather liked it. Fraser starts off by setting the scene – laying out the position of Pangea on the globe and theorizing about paleoclimate, including the interesting speculation that the Triassic may have been a time of “megamonsoons”.
Following that, we get an introduction to tetrapod systematics. I had some trouble here, since Fraser is a staunch cladist. My vertebrate paleontology was years ago, and the definitive textbooks were by Alfred Sherman Romer. Romer had used the long-establish reptile classification scheme based on the number of openings (fenestrae) in the skull and their position: anapsid, euryapsid, synapsid, and diapsid. Fraser casually dismisses this by noting that that the anapsid skull is probably derived rather than ancestral and that the other characters aren’t very convincing either. Even the divisions “Amphibian”, “Reptile” and “Mammal” are dubious; for example, the modern definition of “amphibian” depends on knowing whether or not the animal laid amniote eggs – but there’s no way to tell that from a Triassic fossil. Thus Fraser sticks with cladistic taxonomy, which is all to the good, except that old guys like me with petrified brains have to keep going back to the cladograms to remind ourselves (for example) that when Fraser mentions proterochampsids, they’re archosauriformes and a sister group to the archosaurs. And so on.
Nevertheless, once we get into actual descriptions of fossils and reconstructions of the animals that made them, it’s fascinating. The Triassic, was a time when all sorts of things popped up, presumably moving into niches vacated by the Permotriassic extinction. (You may remember the “grotesque but strangely endearing” pareiosaurs from an earlier review). Tanystrophieds were little lizard-sized things with a neck three times the length of the rest of the body (including tail). One puzzled paleontologist once described them as “apparently specialized for cleaning out drains”. Fraser’s illustration dates from 1973 and show the neck as moderately flexible, but in the text he points out that more recent work using computer programs that analyze the capability of joint motion suggests that it was fairly rigid – which, of course, makes the animal’s possible life mode even stranger. Another interesting beastie is Sharovipteryx, known from only one (fortunately well preserved) specimen from Russia, a reptile which flew (or more probably glided) using a membrane that stretched from the hind legs to the front of the tail. (Aviation was fairly popular in the Triassic; pterosaurs were already around, Sharovipteryx was imitating an advanced fighter concept, Longisquama had some sort of pseudofeathered gliding apparatus, and the kuehneosaurs (once thought to be lizards but now of disputed taxonomic position) had the ribs greatly elongated to support a gliding membrane. No birds yet, unless Protoavis is one; it’s generally thought to be a chimera reconstructed from bones of more than one species but there are a couple of people that still hold out for it as an avian).
As the Triassic ended, the Atlantic Ocean began to form as a rift developed between North America and Europe. There are some interesting similarities to the modern African rift valley – a triple junction with a failed arm (Afar triangle in Africa, Connecticut river valley in NA) and a series of fresh water lakes. There’s even a similarity between the numerous but not identical cichlid fish species from Lake Victoria and equally numerous but not identical semionotid fossil fish species from the Newark Basin in New Jersey.
Even though I had to stretch sometimes to keep up with the jargon, I found the book very enjoyable. The illustrations proved to be less of a distraction than I originally expected, usually turning up just when I needed a break from complicated taxonomy. Although the list price is pretty steep, I was able to pick up the book from a remainder site and got a new copy for about half price. Recommended.… (plus d'informations)